Auto merge of #21744 - eddyb:rvalue-promotion, r=nikomatsakis

This includes everything necessary for promoting borrows of constant rvalues to `'static`.
That is, `&expr` will have the type `&'static T` if `const T: &'static T = &expr;` is valid.
There is a small exception, dereferences of raw pointers, as they misbehave.
They still "work" in constants as I didn't want to break legitimate uses (are there any?).

The qualification done here can be expanded to allow simple CTFE via `const fn`.

56 files changed, 1898 insertions, 1648 deletions

diff --git a/src/librand/reseeding.rs b/src/librand/reseeding.rs
index 06828911471..f4d3e975b75 100644
--- a/src/librand/reseeding.rs
+++ b/src/librand/reseeding.rs
@@ -134,7 +134,11 @@ pub trait Reseeder<R> {
 /// Reseed an RNG using a `Default` instance. This reseeds by
 /// replacing the RNG with the result of a `Default::default` call.
 #[derive(Copy)]
-pub struct ReseedWithDefault;
+pub struct ReseedWithDefault { __hack: [u8; 0] }
+// FIXME(#21721) used to be an unit struct but that can cause
+// certain LLVM versions to abort during optimizations.
+#[allow(non_upper_case_globals)]
+pub const ReseedWithDefault: ReseedWithDefault = ReseedWithDefault { __hack: [] };
 
 impl<R: Rng + Default> Reseeder<R> for ReseedWithDefault {
     fn reseed(&mut self, rng: &mut R) {
diff --git a/src/librustc/diagnostics.rs b/src/librustc/diagnostics.rs
index efcc3715d3e..133bef30e40 100644
--- a/src/librustc/diagnostics.rs
+++ b/src/librustc/diagnostics.rs
@@ -59,6 +59,7 @@ register_diagnostics! {
     E0010,
     E0011,
     E0012,
+    E0013,
     E0014,
     E0015,
     E0016,
diff --git a/src/librustc/lib.rs b/src/librustc/lib.rs
index f060d464e41..abf70813d36 100644
--- a/src/librustc/lib.rs
+++ b/src/librustc/lib.rs
@@ -90,7 +90,6 @@ pub mod middle {
     pub mod check_loop;
     pub mod check_match;
     pub mod check_rvalues;
-    pub mod check_static;
     pub mod const_eval;
     pub mod dataflow;
     pub mod dead;
diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index fe1d695ab7b..08db053d3f4 100644
--- a/src/librustc/lint/builtin.rs
+++ b/src/librustc/lint/builtin.rs
@@ -199,7 +199,7 @@ impl LintPass for TypeLimits {
                             if let ast::LitInt(shift, _) = lit.node { shift >= bits }
                             else { false }
                         } else {
-                            match eval_const_expr_partial(cx.tcx, &**r) {
+                            match eval_const_expr_partial(cx.tcx, &**r, Some(cx.tcx.types.uint)) {
                                 Ok(const_int(shift)) => { shift as u64 >= bits },
                                 Ok(const_uint(shift)) => { shift >= bits },
                                 _ => { false }
diff --git a/src/librustc/metadata/common.rs b/src/librustc/metadata/common.rs
index bf2f5bd22c4..4930eddb35a 100644
--- a/src/librustc/metadata/common.rs
+++ b/src/librustc/metadata/common.rs
@@ -12,7 +12,6 @@
 
 pub use self::astencode_tag::*;
 
-use std::mem;
 use back::svh::Svh;
 
 // EBML enum definitions and utils shared by the encoder and decoder
@@ -113,7 +112,7 @@ pub const tag_items_data_item_reexport_def_id: uint = 0x39;
 pub const tag_items_data_item_reexport_name: uint = 0x3a;
 
 // used to encode crate_ctxt side tables
-#[derive(Copy, PartialEq)]
+#[derive(Copy, PartialEq, FromPrimitive)]
 #[repr(uint)]
 pub enum astencode_tag { // Reserves 0x40 -- 0x5f
     tag_ast = 0x40,
@@ -144,17 +143,7 @@ pub enum astencode_tag { // Reserves 0x40 -- 0x5f
     tag_table_upvar_capture_map = 0x56,
     tag_table_capture_modes = 0x57,
     tag_table_object_cast_map = 0x58,
-}
-
-static first_astencode_tag: uint = tag_ast as uint;
-static last_astencode_tag: uint = tag_table_object_cast_map as uint;
-impl astencode_tag {
-    pub fn from_uint(value : uint) -> Option<astencode_tag> {
-        let is_a_tag = first_astencode_tag <= value && value <= last_astencode_tag;
-        if !is_a_tag { None } else {
-            Some(unsafe { mem::transmute::<uint, astencode_tag>(value) })
-        }
-    }
+    tag_table_const_qualif = 0x59,
 }
 
 pub const tag_item_trait_item_sort: uint = 0x60;
diff --git a/src/librustc/middle/astencode.rs b/src/librustc/middle/astencode.rs
index 423032d1287..c3302debdfa 100644
--- a/src/librustc/middle/astencode.rs
+++ b/src/librustc/middle/astencode.rs
@@ -23,6 +23,7 @@ use metadata::tydecode;
 use metadata::tydecode::{DefIdSource, NominalType, TypeWithId, TypeParameter};
 use metadata::tydecode::{RegionParameter, ClosureSource};
 use metadata::tyencode;
+use middle::check_const::ConstQualif;
 use middle::mem_categorization::Typer;
 use middle::subst;
 use middle::subst::VecPerParamSpace;
@@ -38,6 +39,7 @@ use syntax::ptr::P;
 use syntax;
 
 use std::old_io::Seek;
+use std::num::FromPrimitive;
 use std::rc::Rc;
 
 use rbml::io::SeekableMemWriter;
@@ -1305,6 +1307,15 @@ fn encode_side_tables_for_id(ecx: &e::EncodeContext,
             })
         })
     }
+
+    for &qualif in tcx.const_qualif_map.borrow().get(&id).iter() {
+        rbml_w.tag(c::tag_table_const_qualif, |rbml_w| {
+            rbml_w.id(id);
+            rbml_w.tag(c::tag_table_val, |rbml_w| {
+                qualif.encode(rbml_w).unwrap()
+            })
+        })
+    }
 }
 
 trait doc_decoder_helpers {
@@ -1836,8 +1847,8 @@ fn decode_side_tables(dcx: &DecodeContext,
         debug!(">> Side table document with tag 0x{:x} \
                 found for id {} (orig {})",
                tag, id, id0);
-
-        match c::astencode_tag::from_uint(tag) {
+        let decoded_tag: Option<c::astencode_tag> = FromPrimitive::from_uint(tag);
+        match decoded_tag {
             None => {
                 dcx.tcx.sess.bug(
                     &format!("unknown tag found in side tables: {:x}",
@@ -1919,6 +1930,10 @@ fn decode_side_tables(dcx: &DecodeContext,
                         dcx.tcx.closure_kinds.borrow_mut().insert(ast_util::local_def(id),
                                                                   closure_kind);
                     }
+                    c::tag_table_const_qualif => {
+                        let qualif: ConstQualif = Decodable::decode(val_dsr).unwrap();
+                        dcx.tcx.const_qualif_map.borrow_mut().insert(id, qualif);
+                    }
                     _ => {
                         dcx.tcx.sess.bug(
                             &format!("unknown tag found in side tables: {:x}",
diff --git a/src/librustc/middle/check_const.rs b/src/librustc/middle/check_const.rs
index b558f838a51..41d425cd2f6 100644
--- a/src/librustc/middle/check_const.rs
+++ b/src/librustc/middle/check_const.rs
@@ -1,4 +1,4 @@
-// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -8,91 +8,414 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// Verifies that the types and values of const and static items
+// are safe. The rules enforced by this module are:
+//
+// - For each *mutable* static item, it checks that its **type**:
+//     - doesn't have a destructor
+//     - doesn't own an owned pointer
+//
+// - For each *immutable* static item, it checks that its **value**:
+//       - doesn't own owned, managed pointers
+//       - doesn't contain a struct literal or a call to an enum variant / struct constructor where
+//           - the type of the struct/enum has a dtor
+//
+// Rules Enforced Elsewhere:
+// - It's not possible to take the address of a static item with unsafe interior. This is enforced
+// by borrowck::gather_loans
 
-use middle::def::*;
-use middle::ty;
+use middle::const_eval;
+use middle::def;
+use middle::expr_use_visitor as euv;
+use middle::infer;
+use middle::mem_categorization as mc;
+use middle::traits;
+use middle::ty::{self, Ty};
+use util::nodemap::NodeMap;
 use util::ppaux;
 
 use syntax::ast;
+use syntax::codemap::Span;
+use syntax::print::pprust;
 use syntax::visit::{self, Visitor};
 
+use std::collections::hash_map::Entry;
+
+// Const qualification, from partial to completely promotable.
+bitflags! {
+    #[derive(RustcEncodable, RustcDecodable)]
+    flags ConstQualif: u8 {
+        // Const rvalue which can be placed behind a reference.
+        const PURE_CONST          = 0b000000,
+        // Inner mutability (can not be placed behind a reference) or behind
+        // &mut in a non-global expression. Can be copied from static memory.
+        const MUTABLE_MEM         = 0b000001,
+        // Constant value with a type that implements Drop. Can be copied
+        // from static memory, similar to MUTABLE_MEM.
+        const NEEDS_DROP          = 0b000010,
+        // Even if the value can be placed in static memory, copying it from
+        // there is more expensive than in-place instantiation, and/or it may
+        // be too large. This applies to [T; N] and everything containing it.
+        // N.B.: references need to clear this flag to not end up on the stack.
+        const PREFER_IN_PLACE     = 0b000100,
+        // May use more than 0 bytes of memory, doesn't impact the constness
+        // directly, but is not allowed to be borrowed mutably in a constant.
+        const NON_ZERO_SIZED      = 0b001000,
+        // Actually borrowed, has to always be in static memory. Does not
+        // propagate, and requires the expression to behave like a 'static
+        // lvalue. The set of expressions with this flag is the minimum
+        // that have to be promoted.
+        const HAS_STATIC_BORROWS  = 0b010000,
+        // Invalid const for miscellaneous reasons (e.g. not implemented).
+        const NOT_CONST           = 0b100000,
+
+        // Borrowing the expression won't produce &'static T if any of these
+        // bits are set, though the value could be copied from static memory
+        // if `NOT_CONST` isn't set.
+        const NON_STATIC_BORROWS = MUTABLE_MEM.bits | NEEDS_DROP.bits | NOT_CONST.bits
+    }
+}
+
+#[derive(Copy, Eq, PartialEq)]
+enum Mode {
+    Const,
+    Static,
+    StaticMut,
+
+    // An expression that occurs outside of any constant context
+    // (i.e. `const`, `static`, array lengths, etc.). The value
+    // can be variable at runtime, but will be promotable to
+    // static memory if we can prove it is actually constant.
+    Var,
+}
+
 struct CheckCrateVisitor<'a, 'tcx: 'a> {
     tcx: &'a ty::ctxt<'tcx>,
-    in_const: bool
+    mode: Mode,
+    qualif: ConstQualif,
+    rvalue_borrows: NodeMap<ast::Mutability>
 }
 
 impl<'a, 'tcx> CheckCrateVisitor<'a, 'tcx> {
-    fn with_const<F>(&mut self, in_const: bool, f: F) where
-        F: FnOnce(&mut CheckCrateVisitor<'a, 'tcx>),
+    fn with_mode<F, R>(&mut self, mode: Mode, f: F) -> R where
+        F: FnOnce(&mut CheckCrateVisitor<'a, 'tcx>) -> R,
     {
-        let was_const = self.in_const;
-        self.in_const = in_const;
-        f(self);
-        self.in_const = was_const;
+        let (old_mode, old_qualif) = (self.mode, self.qualif);
+        self.mode = mode;
+        self.qualif = PURE_CONST;
+        let r = f(self);
+        self.mode = old_mode;
+        self.qualif = old_qualif;
+        r
     }
-    fn inside_const<F>(&mut self, f: F) where
-        F: FnOnce(&mut CheckCrateVisitor<'a, 'tcx>),
+
+    fn with_euv<'b, F, R>(&'b mut self, item_id: Option<ast::NodeId>, f: F) -> R where
+        F: for<'t> FnOnce(&mut euv::ExprUseVisitor<'b, 't, 'tcx,
+                                    ty::ParameterEnvironment<'a, 'tcx>>) -> R,
     {
-        self.with_const(true, f);
+        let param_env = match item_id {
+            Some(item_id) => ty::ParameterEnvironment::for_item(self.tcx, item_id),
+            None => ty::empty_parameter_environment(self.tcx)
+        };
+        f(&mut euv::ExprUseVisitor::new(self, &param_env))
+    }
+
+    fn global_expr(&mut self, mode: Mode, expr: &ast::Expr) -> ConstQualif {
+        assert!(mode != Mode::Var);
+        match self.tcx.const_qualif_map.borrow_mut().entry(expr.id) {
+            Entry::Occupied(entry) => return *entry.get(),
+            Entry::Vacant(entry) => {
+                // Prevent infinite recursion on re-entry.
+                entry.insert(PURE_CONST);
+            }
+        }
+        self.with_mode(mode, |this| {
+            this.with_euv(None, |euv| euv.consume_expr(expr));
+            this.visit_expr(expr);
+            this.qualif
+        })
+    }
+
+    fn add_qualif(&mut self, qualif: ConstQualif) {
+        self.qualif = self.qualif | qualif;
+    }
+
+    fn record_borrow(&mut self, id: ast::NodeId, mutbl: ast::Mutability) {
+        match self.rvalue_borrows.entry(id) {
+            Entry::Occupied(mut entry) => {
+                // Merge the two borrows, taking the most demanding
+                // one, mutability-wise.
+                if mutbl == ast::MutMutable {
+                    entry.insert(mutbl);
+                }
+            }
+            Entry::Vacant(entry) => {
+                entry.insert(mutbl);
+            }
+        }
+    }
+
+    fn msg(&self) -> &'static str {
+        match self.mode {
+            Mode::Const => "constant",
+            Mode::StaticMut | Mode::Static => "static",
+            Mode::Var => unreachable!(),
+        }
+    }
+
+    fn check_static_mut_type(&self, e: &ast::Expr) {
+        let node_ty = ty::node_id_to_type(self.tcx, e.id);
+        let tcontents = ty::type_contents(self.tcx, node_ty);
+
+        let suffix = if tcontents.has_dtor() {
+            "destructors"
+        } else if tcontents.owns_owned() {
+            "owned pointers"
+        } else {
+            return
+        };
+
+        self.tcx.sess.span_err(e.span, &format!("mutable statics are not allowed \
+                                                 to have {}", suffix)[]);
+    }
+
+    fn check_static_type(&self, e: &ast::Expr) {
+        let ty = ty::node_id_to_type(self.tcx, e.id);
+        let infcx = infer::new_infer_ctxt(self.tcx);
+        let mut fulfill_cx = traits::FulfillmentContext::new();
+        let cause = traits::ObligationCause::new(e.span, e.id, traits::SharedStatic);
+        fulfill_cx.register_builtin_bound(&infcx, ty, ty::BoundSync, cause);
+        let env = ty::empty_parameter_environment(self.tcx);
+        match fulfill_cx.select_all_or_error(&infcx, &env) {
+            Ok(()) => { },
+            Err(ref errors) => {
+                traits::report_fulfillment_errors(&infcx, errors);
+            }
+        }
     }
 }
 
 impl<'a, 'tcx, 'v> Visitor<'v> for CheckCrateVisitor<'a, 'tcx> {
     fn visit_item(&mut self, i: &ast::Item) {
+        debug!("visit_item(item={})", pprust::item_to_string(i));
         match i.node {
-            ast::ItemStatic(_, _, ref ex) |
-            ast::ItemConst(_, ref ex) => {
-                self.inside_const(|v| v.visit_expr(&**ex));
+            ast::ItemStatic(_, ast::MutImmutable, ref expr) => {
+                self.check_static_type(&**expr);
+                self.global_expr(Mode::Static, &**expr);
+            }
+            ast::ItemStatic(_, ast::MutMutable, ref expr) => {
+                self.check_static_mut_type(&**expr);
+                self.global_expr(Mode::StaticMut, &**expr);
+            }
+            ast::ItemConst(_, ref expr) => {
+                self.global_expr(Mode::Const, &**expr);
             }
             ast::ItemEnum(ref enum_definition, _) => {
-                self.inside_const(|v| {
-                    for var in &enum_definition.variants {
-                        if let Some(ref ex) = var.node.disr_expr {
-                            v.visit_expr(&**ex);
-                        }
+                for var in &enum_definition.variants {
+                    if let Some(ref ex) = var.node.disr_expr {
+                        self.global_expr(Mode::Const, &**ex);
                     }
-                });
+                }
+            }
+            _ => {
+                self.with_mode(Mode::Var, |v| visit::walk_item(v, i));
             }
-            _ => self.with_const(false, |v| visit::walk_item(v, i))
         }
     }
+
+    fn visit_fn(&mut self,
+                fk: visit::FnKind<'v>,
+                fd: &'v ast::FnDecl,
+                b: &'v ast::Block,
+                s: Span,
+                fn_id: ast::NodeId) {
+        assert!(self.mode == Mode::Var);
+        self.with_euv(Some(fn_id), |euv| euv.walk_fn(fd, b));
+        visit::walk_fn(self, fk, fd, b, s);
+    }
+
     fn visit_pat(&mut self, p: &ast::Pat) {
-        let is_const = match p.node {
-            ast::PatLit(_) | ast::PatRange(..) => true,
-            _ => false
-        };
-        self.with_const(is_const, |v| visit::walk_pat(v, p))
+        match p.node {
+            ast::PatLit(ref lit) => {
+                self.global_expr(Mode::Const, &**lit);
+            }
+            ast::PatRange(ref start, ref end) => {
+                self.global_expr(Mode::Const, &**start);
+                self.global_expr(Mode::Const, &**end);
+            }
+            _ => visit::walk_pat(self, p)
+        }
     }
+
     fn visit_expr(&mut self, ex: &ast::Expr) {
-        if self.in_const {
-            check_expr(self, ex);
+        let mut outer = self.qualif;
+        self.qualif = PURE_CONST;
+
+        let node_ty = ty::node_id_to_type(self.tcx, ex.id);
+        check_expr(self, ex, node_ty);
+
+        // Special-case some expressions to avoid certain flags bubbling up.
+        match ex.node {
+            ast::ExprCall(ref callee, ref args) => {
+                for arg in args.iter() {
+                    self.visit_expr(&**arg)
+                }
+
+                let inner = self.qualif;
+                self.visit_expr(&**callee);
+                // The callee's size doesn't count in the call.
+                let added = self.qualif - inner;
+                self.qualif = inner | (added - NON_ZERO_SIZED);
+            }
+            ast::ExprRepeat(ref element, _) => {
+                self.visit_expr(&**element);
+                // The count is checked elsewhere (typeck).
+                let count = match node_ty.sty {
+                    ty::ty_vec(_, Some(n)) => n,
+                    _ => unreachable!()
+                };
+                // [element; 0] is always zero-sized.
+                if count == 0 {
+                    self.qualif = self.qualif - (NON_ZERO_SIZED | PREFER_IN_PLACE);
+                }
+            }
+            ast::ExprMatch(ref discr, ref arms, _) => {
+                // Compute the most demanding borrow from all the arms'
+                // patterns and set that on the discriminator.
+                let mut borrow = None;
+                for pat in arms.iter().flat_map(|arm| arm.pats.iter()) {
+                    let pat_borrow = self.rvalue_borrows.remove(&pat.id);
+                    match (borrow, pat_borrow) {
+                        (None, _) | (_, Some(ast::MutMutable)) => {
+                            borrow = pat_borrow;
+                        }
+                        _ => {}
+                    }
+                }
+                if let Some(mutbl) = borrow {
+                    self.record_borrow(discr.id, mutbl);
+                }
+                visit::walk_expr(self, ex);
+            }
+            // Division by zero and overflow checking.
+            ast::ExprBinary(op, _, _) => {
+                visit::walk_expr(self, ex);
+                let div_or_rem = op.node == ast::BiDiv || op.node == ast::BiRem;
+                match node_ty.sty {
+                    ty::ty_uint(_) | ty::ty_int(_) if div_or_rem => {
+                        if !self.qualif.intersects(NOT_CONST) {
+                            match const_eval::eval_const_expr_partial(self.tcx, ex, None) {
+                                Ok(_) => {}
+                                Err(msg) => {
+                                    span_err!(self.tcx.sess, ex.span, E0020,
+                                              "{} in a constant expression", msg)
+                                }
+                            }
+                        }
+                    }
+                    _ => {}
+                }
+            }
+            _ => visit::walk_expr(self, ex)
+        }
+
+        // Handle borrows on (or inside the autorefs of) this expression.
+        match self.rvalue_borrows.remove(&ex.id) {
+            Some(ast::MutImmutable) => {
+                // Constants cannot be borrowed if they contain interior mutability as
+                // it means that our "silent insertion of statics" could change
+                // initializer values (very bad).
+                // If the type doesn't have interior mutability, then `MUTABLE_MEM` has
+                // propagated from another error, so erroring again would be just noise.
+                let tc = ty::type_contents(self.tcx, node_ty);
+                if self.qualif.intersects(MUTABLE_MEM) && tc.interior_unsafe() {
+                    outer = outer | NOT_CONST;
+                    if self.mode != Mode::Var {
+                        self.tcx.sess.span_err(ex.span,
+                            "cannot borrow a constant which contains \
+                             interior mutability, create a static instead");
+                    }
+                }
+                // If the reference has to be 'static, avoid in-place initialization
+                // as that will end up pointing to the stack instead.
+                if !self.qualif.intersects(NON_STATIC_BORROWS) {
+                    self.qualif = self.qualif - PREFER_IN_PLACE;
+                    self.add_qualif(HAS_STATIC_BORROWS);
+                }
+            }
+            Some(ast::MutMutable) => {
+                // `&mut expr` means expr could be mutated, unless it's zero-sized.
+                if self.qualif.intersects(NON_ZERO_SIZED) {
+                    if self.mode == Mode::Var {
+                        outer = outer | NOT_CONST;
+                        self.add_qualif(MUTABLE_MEM);
+                    } else {
+                        span_err!(self.tcx.sess, ex.span, E0017,
+                            "references in {}s may only refer \
+                             to immutable values", self.msg())
+                    }
+                }
+                if !self.qualif.intersects(NON_STATIC_BORROWS) {
+                    self.add_qualif(HAS_STATIC_BORROWS);
+                }
+            }
+            None => {}
         }
-        visit::walk_expr(self, ex);
+        self.tcx.const_qualif_map.borrow_mut().insert(ex.id, self.qualif);
+        // Don't propagate certain flags.
+        self.qualif = outer | (self.qualif - HAS_STATIC_BORROWS);
     }
 }
 
-pub fn check_crate(tcx: &ty::ctxt) {
-    visit::walk_crate(&mut CheckCrateVisitor { tcx: tcx, in_const: false },
-                      tcx.map.krate());
-    tcx.sess.abort_if_errors();
-}
+/// This function is used to enforce the constraints on
+/// const/static items. It walks through the *value*
+/// of the item walking down the expression and evaluating
+/// every nested expression. If the expression is not part
+/// of a const/static item, it is qualified for promotion
+/// instead of producing errors.
+fn check_expr<'a, 'tcx>(v: &mut CheckCrateVisitor<'a, 'tcx>,
+                        e: &ast::Expr, node_ty: Ty<'tcx>) {
+    match node_ty.sty {
+        ty::ty_struct(did, _) |
+        ty::ty_enum(did, _) if ty::has_dtor(v.tcx, did) => {
+            v.add_qualif(NEEDS_DROP);
+            if v.mode != Mode::Var {
+                v.tcx.sess.span_err(e.span,
+                                    &format!("{}s are not allowed to have destructors",
+                                             v.msg())[]);
+            }
+        }
+        _ => {}
+    }
 
-fn check_expr(v: &mut CheckCrateVisitor, e: &ast::Expr) {
+    let method_call = ty::MethodCall::expr(e.id);
     match e.node {
-        ast::ExprUnary(ast::UnDeref, _) => {}
+        ast::ExprUnary(..) |
+        ast::ExprBinary(..) |
+        ast::ExprIndex(..) if v.tcx.method_map.borrow().contains_key(&method_call) => {
+            v.add_qualif(NOT_CONST);
+            if v.mode != Mode::Var {
+                span_err!(v.tcx.sess, e.span, E0011,
+                            "user-defined operators are not allowed in {}s", v.msg());
+            }
+        }
+        ast::ExprBox(..) |
         ast::ExprUnary(ast::UnUniq, _) => {
-            span_err!(v.tcx.sess, e.span, E0010,
-                      "cannot do allocations in constant expressions");
+            v.add_qualif(NOT_CONST);
+            if v.mode != Mode::Var {
+                span_err!(v.tcx.sess, e.span, E0010,
+                          "allocations are not allowed in {}s", v.msg());
+            }
         }
-        ast::ExprBinary(..) | ast::ExprUnary(..) => {
-            let method_call = ty::MethodCall::expr(e.id);
-            if v.tcx.method_map.borrow().contains_key(&method_call) {
-                span_err!(v.tcx.sess, e.span, E0011,
-                          "user-defined operators are not allowed in constant \
-                           expressions");
+        ast::ExprUnary(ast::UnDeref, ref ptr) => {
+            match ty::node_id_to_type(v.tcx, ptr.id).sty {
+                ty::ty_ptr(_) => {
+                    // This shouldn't be allowed in constants at all.
+                    v.add_qualif(NOT_CONST);
+                }
+                _ => {}
             }
         }
-        ast::ExprLit(_) => {}
         ast::ExprCast(ref from, _) => {
             let toty = ty::expr_ty(v.tcx, e);
             let fromty = ty::expr_ty(v.tcx, &**from);
@@ -101,47 +424,110 @@ fn check_expr(v: &mut CheckCrateVisitor, e: &ast::Expr) {
                 ty::type_is_unsafe_ptr(toty) ||
                 (ty::type_is_bare_fn(toty) && ty::type_is_bare_fn_item(fromty));
             if !is_legal_cast {
-                span_err!(v.tcx.sess, e.span, E0012,
-                          "can not cast to `{}` in a constant expression",
-                          ppaux::ty_to_string(v.tcx, toty));
+                v.add_qualif(NOT_CONST);
+                if v.mode != Mode::Var {
+                    span_err!(v.tcx.sess, e.span, E0012,
+                              "can not cast to `{}` in {}s",
+                              ppaux::ty_to_string(v.tcx, toty), v.msg());
+                }
             }
             if ty::type_is_unsafe_ptr(fromty) && ty::type_is_numeric(toty) {
-                span_err!(v.tcx.sess, e.span, E0018,
-                          "can not cast a pointer to an integer in a constant \
-                           expression");
+                v.add_qualif(NOT_CONST);
+                if v.mode != Mode::Var {
+                    span_err!(v.tcx.sess, e.span, E0018,
+                              "can not cast a pointer to an integer in {}s", v.msg());
+                }
             }
         }
         ast::ExprPath(_) | ast::ExprQPath(_) => {
-            match v.tcx.def_map.borrow()[e.id] {
-                DefStatic(..) | DefConst(..) |
-                DefFn(..) | DefStaticMethod(..) | DefMethod(..) |
-                DefStruct(_) | DefVariant(_, _, _) => {}
-
+            let def = v.tcx.def_map.borrow().get(&e.id).cloned();
+            match def {
+                Some(def::DefVariant(_, _, _)) => {
+                    // Count the discriminator or function pointer.
+                    v.add_qualif(NON_ZERO_SIZED);
+                }
+                Some(def::DefStruct(_)) => {
+                    if let ty::ty_bare_fn(..) = node_ty.sty {
+                        // Count the function pointer.
+                        v.add_qualif(NON_ZERO_SIZED);
+                    }
+                }
+                Some(def::DefFn(..)) |
+                Some(def::DefStaticMethod(..)) | Some(def::DefMethod(..)) => {
+                    // Count the function pointer.
+                    v.add_qualif(NON_ZERO_SIZED);
+                }
+                Some(def::DefStatic(..)) => {
+                    match v.mode {
+                        Mode::Static | Mode::StaticMut => {}
+                        Mode::Const => {
+                            span_err!(v.tcx.sess, e.span, E0013,
+                                "constants cannot refer to other statics, \
+                                 insert an intermediate constant instead");
+                        }
+                        Mode::Var => v.add_qualif(NOT_CONST)
+                    }
+                }
+                Some(def::DefConst(did)) => {
+                    if let Some(expr) = const_eval::lookup_const_by_id(v.tcx, did) {
+                        let inner = v.global_expr(Mode::Const, expr);
+                        v.add_qualif(inner);
+                    } else {
+                        v.tcx.sess.span_bug(e.span, "DefConst doesn't point \
+                                                     to an ItemConst");
+                    }
+                }
                 def => {
-                    debug!("(checking const) found bad def: {:?}", def);
-                    span_err!(v.tcx.sess, e.span, E0014,
-                              "paths in constants may only refer to constants \
-                               or functions");
+                    v.add_qualif(NOT_CONST);
+                    if v.mode != Mode::Var {
+                        debug!("(checking const) found bad def: {:?}", def);
+                        span_err!(v.tcx.sess, e.span, E0014,
+                                  "paths in {}s may only refer to constants \
+                                   or functions", v.msg());
+                    }
                 }
             }
         }
         ast::ExprCall(ref callee, _) => {
-            match v.tcx.def_map.borrow()[callee.id] {
-                DefStruct(..) | DefVariant(..) => {}    // OK.
+            let mut callee = &**callee;
+            loop {
+                callee = match callee.node {
+                    ast::ExprParen(ref inner) => &**inner,
+                    ast::ExprBlock(ref block) => match block.expr {
+                        Some(ref tail) => &**tail,
+                        None => break
+                    },
+                    _ => break
+                };
+            }
+            let def = v.tcx.def_map.borrow().get(&callee.id).cloned();
+            match def {
+                Some(def::DefStruct(..)) => {}
+                Some(def::DefVariant(..)) => {
+                    // Count the discriminator.
+                    v.add_qualif(NON_ZERO_SIZED);
+                }
                 _ => {
-                    span_err!(v.tcx.sess, e.span, E0015,
-                              "function calls in constants are limited to \
-                               struct and enum constructors");
+                    v.add_qualif(NOT_CONST);
+                    if v.mode != Mode::Var {
+                        span_err!(v.tcx.sess, e.span, E0015,
+                                  "function calls in {}s are limited to \
+                                   struct and enum constructors", v.msg());
+                    }
                 }
             }
         }
         ast::ExprBlock(ref block) => {
             // Check all statements in the block
-            for stmt in &block.stmts {
-                let block_span_err = |span|
+            let mut block_span_err = |span| {
+                v.add_qualif(NOT_CONST);
+                if v.mode != Mode::Var {
                     span_err!(v.tcx.sess, span, E0016,
-                              "blocks in constants are limited to items and \
-                               tail expressions");
+                              "blocks in {}s are limited to items and \
+                               tail expressions", v.msg());
+                }
+            };
+            for stmt in &block.stmts {
                 match stmt.node {
                     ast::StmtDecl(ref decl, _) => {
                         match decl.node {
@@ -160,28 +546,184 @@ fn check_expr(v: &mut CheckCrateVisitor, e: &ast::Expr) {
                 }
             }
         }
-        ast::ExprVec(_) |
-        ast::ExprAddrOf(ast::MutImmutable, _) |
-        ast::ExprParen(..) |
+        ast::ExprStruct(..) => {
+            let did = v.tcx.def_map.borrow().get(&e.id).map(|def| def.def_id());
+            if did == v.tcx.lang_items.unsafe_cell_type() {
+                v.add_qualif(MUTABLE_MEM);
+            }
+        }
+
+        ast::ExprLit(_) |
+        ast::ExprAddrOf(..) => {
+            v.add_qualif(NON_ZERO_SIZED);
+        }
+
+        ast::ExprRepeat(..) => {
+            v.add_qualif(PREFER_IN_PLACE);
+        }
+
+        ast::ExprClosure(..) => {
+            // Paths in constant constexts cannot refer to local variables,
+            // as there are none, and thus closures can't have upvars there.
+            if ty::with_freevars(v.tcx, e.id, |fv| !fv.is_empty()) {
+                assert!(v.mode == Mode::Var,
+                        "global closures can't capture anything");
+                v.add_qualif(NOT_CONST);
+            }
+        }
+
+        ast::ExprUnary(..) |
+        ast::ExprBinary(..) |
+        ast::ExprIndex(..) |
         ast::ExprField(..) |
         ast::ExprTupField(..) |
-        ast::ExprIndex(..) |
-        ast::ExprTup(..) |
-        ast::ExprRepeat(..) |
-        ast::ExprStruct(..) => {}
+        ast::ExprVec(_) |
+        ast::ExprParen(..) |
+        ast::ExprTup(..) => {}
+
+        // Conditional control flow (possible to implement).
+        ast::ExprMatch(..) |
+        ast::ExprIf(..) |
+        ast::ExprIfLet(..) |
+
+        // Loops (not very meaningful in constants).
+        ast::ExprWhile(..) |
+        ast::ExprWhileLet(..) |
+        ast::ExprForLoop(..) |
+        ast::ExprLoop(..) |
+
+        // More control flow (also not very meaningful).
+        ast::ExprBreak(_) |
+        ast::ExprAgain(_) |
+        ast::ExprRet(_) |
+
+        // Miscellaneous expressions that could be implemented.
+        ast::ExprRange(..) |
+
+        // Various other expressions.
+        ast::ExprMethodCall(..) |
+        ast::ExprAssign(..) |
+        ast::ExprAssignOp(..) |
+        ast::ExprInlineAsm(_) |
+        ast::ExprMac(_) => {
+            v.add_qualif(NOT_CONST);
+            if v.mode != Mode::Var {
+                span_err!(v.tcx.sess, e.span, E0019,
+                          "{} contains unimplemented expression type", v.msg());
+            }
+        }
+    }
+}
+
+pub fn check_crate(tcx: &ty::ctxt) {
+    visit::walk_crate(&mut CheckCrateVisitor {
+        tcx: tcx,
+        mode: Mode::Var,
+        qualif: NOT_CONST,
+        rvalue_borrows: NodeMap()
+    }, tcx.map.krate());
 
-        ast::ExprAddrOf(_, ref inner) => {
-            match inner.node {
-                // Mutable slices are allowed.
-                ast::ExprVec(_) => {}
-                _ => span_err!(v.tcx.sess, e.span, E0017,
-                               "references in constants may only refer \
-                                to immutable values")
+    tcx.sess.abort_if_errors();
+}
+
+impl<'a, 'tcx> euv::Delegate<'tcx> for CheckCrateVisitor<'a, 'tcx> {
+    fn consume(&mut self,
+               _consume_id: ast::NodeId,
+               consume_span: Span,
+               cmt: mc::cmt,
+               _mode: euv::ConsumeMode) {
+        let mut cur = &cmt;
+        loop {
+            match cur.cat {
+                mc::cat_static_item => {
+                    if self.mode != Mode::Var {
+                        // statics cannot be consumed by value at any time, that would imply
+                        // that they're an initializer (what a const is for) or kept in sync
+                        // over time (not feasible), so deny it outright.
+                        self.tcx.sess.span_err(consume_span,
+                            "cannot refer to other statics by value, use the \
+                             address-of operator or a constant instead");
+                    }
+                    break;
+                }
+                mc::cat_deref(ref cmt, _, _) |
+                mc::cat_downcast(ref cmt, _) |
+                mc::cat_interior(ref cmt, _) => cur = cmt,
 
+                mc::cat_rvalue(..) |
+                mc::cat_upvar(..) |
+                mc::cat_local(..) => break
             }
         }
+    }
+    fn borrow(&mut self,
+              borrow_id: ast::NodeId,
+              borrow_span: Span,
+              cmt: mc::cmt<'tcx>,
+              _loan_region: ty::Region,
+              bk: ty::BorrowKind,
+              loan_cause: euv::LoanCause) {
+        let mut cur = &cmt;
+        let mut is_interior = false;
+        loop {
+            match cur.cat {
+                mc::cat_rvalue(..) => {
+                    if loan_cause == euv::MatchDiscriminant {
+                        // Ignore the dummy immutable borrow created by EUV.
+                        break;
+                    }
+                    let mutbl = bk.to_mutbl_lossy();
+                    if mutbl == ast::MutMutable && self.mode == Mode::StaticMut {
+                        // Mutable slices are the only `&mut` allowed in globals,
+                        // but only in `static mut`, nowhere else.
+                        match cmt.ty.sty {
+                            ty::ty_vec(_, _) => break,
+                            _ => {}
+                        }
+                    }
+                    self.record_borrow(borrow_id, mutbl);
+                    break;
+                }
+                mc::cat_static_item => {
+                    if is_interior && self.mode != Mode::Var {
+                        // Borrowed statics can specifically *only* have their address taken,
+                        // not any number of other borrows such as borrowing fields, reading
+                        // elements of an array, etc.
+                        self.tcx.sess.span_err(borrow_span,
+                            "cannot refer to the interior of another \
+                             static, use a constant instead");
+                    }
+                    break;
+                }
+                mc::cat_deref(ref cmt, _, _) |
+                mc::cat_downcast(ref cmt, _) |
+                mc::cat_interior(ref cmt, _) => {
+                    is_interior = true;
+                    cur = cmt;
+                }
 
-        _ => span_err!(v.tcx.sess, e.span, E0019,
-                       "constant contains unimplemented expression type")
+                mc::cat_upvar(..) |
+                mc::cat_local(..) => break
+            }
+        }
     }
+
+    fn decl_without_init(&mut self,
+                         _id: ast::NodeId,
+                         _span: Span) {}
+    fn mutate(&mut self,
+              _assignment_id: ast::NodeId,
+              _assignment_span: Span,
+              _assignee_cmt: mc::cmt,
+              _mode: euv::MutateMode) {}
+
+    fn matched_pat(&mut self,
+                   _: &ast::Pat,
+                   _: mc::cmt,
+                   _: euv::MatchMode) {}
+
+    fn consume_pat(&mut self,
+                   _consume_pat: &ast::Pat,
+                   _cmt: mc::cmt,
+                   _mode: euv::ConsumeMode) {}
 }
diff --git a/src/librustc/middle/check_match.rs b/src/librustc/middle/check_match.rs
index 7ac690f02e1..03456f85290 100644
--- a/src/librustc/middle/check_match.rs
+++ b/src/librustc/middle/check_match.rs
@@ -23,6 +23,7 @@ use middle::mem_categorization::cmt;
 use middle::pat_util::*;
 use middle::ty::*;
 use middle::ty;
+use std::cmp::Ordering;
 use std::fmt;
 use std::iter::{range_inclusive, AdditiveIterator, FromIterator, repeat};
 use std::num::Float;
@@ -821,7 +822,9 @@ fn range_covered_by_constructor(ctor: &Constructor,
     let cmp_from = compare_const_vals(c_from, from);
     let cmp_to = compare_const_vals(c_to, to);
     match (cmp_from, cmp_to) {
-        (Some(val1), Some(val2)) => Some(val1 >= 0 && val2 <= 0),
+        (Some(cmp_from), Some(cmp_to)) => {
+            Some(cmp_from != Ordering::Less && cmp_to != Ordering::Greater)
+        }
         _ => None
     }
 }
diff --git a/src/librustc/middle/check_static.rs b/src/librustc/middle/check_static.rs
deleted file mode 100644
index 9d3180864f2..00000000000
--- a/src/librustc/middle/check_static.rs
+++ /dev/null
@@ -1,341 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-// Verifies that the types and values of static items
-// are safe. The rules enforced by this module are:
-//
-// - For each *mutable* static item, it checks that its **type**:
-//     - doesn't have a destructor
-//     - doesn't own an owned pointer
-//
-// - For each *immutable* static item, it checks that its **value**:
-//       - doesn't own owned, managed pointers
-//       - doesn't contain a struct literal or a call to an enum variant / struct constructor where
-//           - the type of the struct/enum has a dtor
-//
-// Rules Enforced Elsewhere:
-// - It's not possible to take the address of a static item with unsafe interior. This is enforced
-// by borrowck::gather_loans
-use self::Mode::*;
-
-use middle::ty;
-use middle::def;
-use middle::infer;
-use middle::traits;
-use middle::mem_categorization as mc;
-use middle::expr_use_visitor as euv;
-use util::nodemap::NodeSet;
-
-use syntax::ast;
-use syntax::print::pprust;
-use syntax::visit::Visitor;
-use syntax::codemap::Span;
-use syntax::visit;
-
-#[derive(Copy, Eq, PartialEq)]
-enum Mode {
-    InConstant,
-    InStatic,
-    InStaticMut,
-    InNothing,
-}
-
-struct CheckStaticVisitor<'a, 'tcx: 'a> {
-    tcx: &'a ty::ctxt<'tcx>,
-    mode: Mode,
-    checker: &'a mut GlobalChecker,
-}
-
-struct GlobalVisitor<'a,'b,'tcx:'a+'b>(
-    euv::ExprUseVisitor<'a,'b,'tcx,ty::ParameterEnvironment<'b,'tcx>>);
-struct GlobalChecker {
-    static_consumptions: NodeSet,
-    const_borrows: NodeSet,
-    static_interior_borrows: NodeSet,
-    static_local_borrows: NodeSet,
-}
-
-pub fn check_crate(tcx: &ty::ctxt) {
-    let mut checker = GlobalChecker {
-        static_consumptions: NodeSet(),
-        const_borrows: NodeSet(),
-        static_interior_borrows: NodeSet(),
-        static_local_borrows: NodeSet(),
-    };
-    {
-        let param_env = ty::empty_parameter_environment(tcx);
-        let visitor = euv::ExprUseVisitor::new(&mut checker, &param_env);
-        visit::walk_crate(&mut GlobalVisitor(visitor), tcx.map.krate());
-    }
-    visit::walk_crate(&mut CheckStaticVisitor {
-        tcx: tcx,
-        mode: InNothing,
-        checker: &mut checker,
-    }, tcx.map.krate());
-}
-
-impl<'a, 'tcx> CheckStaticVisitor<'a, 'tcx> {
-    fn with_mode<F>(&mut self, mode: Mode, f: F) where
-        F: FnOnce(&mut CheckStaticVisitor<'a, 'tcx>),
-    {
-        let old = self.mode;
-        self.mode = mode;
-        f(self);
-        self.mode = old;
-    }
-
-    fn msg(&self) -> &'static str {
-        match self.mode {
-            InConstant => "constants",
-            InStaticMut | InStatic => "statics",
-            InNothing => unreachable!(),
-        }
-    }
-
-    fn check_static_mut_type(&self, e: &ast::Expr) {
-        let node_ty = ty::node_id_to_type(self.tcx, e.id);
-        let tcontents = ty::type_contents(self.tcx, node_ty);
-
-        let suffix = if tcontents.has_dtor() {
-            "destructors"
-        } else if tcontents.owns_owned() {
-            "owned pointers"
-        } else {
-            return
-        };
-
-        self.tcx.sess.span_err(e.span, &format!("mutable statics are not allowed \
-                                                to have {}", suffix)[]);
-    }
-
-    fn check_static_type(&self, e: &ast::Expr) {
-        let ty = ty::node_id_to_type(self.tcx, e.id);
-        let infcx = infer::new_infer_ctxt(self.tcx);
-        let mut fulfill_cx = traits::FulfillmentContext::new();
-        let cause = traits::ObligationCause::new(e.span, e.id, traits::SharedStatic);
-        fulfill_cx.register_builtin_bound(&infcx, ty, ty::BoundSync, cause);
-        let env = ty::empty_parameter_environment(self.tcx);
-        match fulfill_cx.select_all_or_error(&infcx, &env) {
-            Ok(()) => { },
-            Err(ref errors) => {
-                traits::report_fulfillment_errors(&infcx, errors);
-            }
-        }
-    }
-}
-
-impl<'a, 'tcx, 'v> Visitor<'v> for CheckStaticVisitor<'a, 'tcx> {
-    fn visit_item(&mut self, i: &ast::Item) {
-        debug!("visit_item(item={})", pprust::item_to_string(i));
-        match i.node {
-            ast::ItemStatic(_, ast::MutImmutable, ref expr) => {
-                self.check_static_type(&**expr);
-                self.with_mode(InStatic, |v| v.visit_expr(&**expr));
-            }
-            ast::ItemStatic(_, ast::MutMutable, ref expr) => {
-                self.check_static_mut_type(&**expr);
-                self.with_mode(InStaticMut, |v| v.visit_expr(&**expr));
-            }
-            ast::ItemConst(_, ref expr) => {
-                self.with_mode(InConstant, |v| v.visit_expr(&**expr));
-            }
-            _ => {
-                self.with_mode(InNothing, |v| visit::walk_item(v, i));
-            }
-        }
-    }
-
-    /// This method is used to enforce the constraints on
-    /// immutable static items. It walks through the *value*
-    /// of the item walking down the expression and evaluating
-    /// every nested expression. if the expression is not part
-    /// of a static item, this method does nothing but walking
-    /// down through it.
-    fn visit_expr(&mut self, e: &ast::Expr) {
-        if self.mode == InNothing {
-            return visit::walk_expr(self, e);
-        }
-
-        let node_ty = ty::node_id_to_type(self.tcx, e.id);
-
-        match node_ty.sty {
-            ty::ty_struct(did, _) |
-            ty::ty_enum(did, _) if ty::has_dtor(self.tcx, did) => {
-                self.tcx.sess.span_err(e.span,
-                                       &format!("{} are not allowed to have \
-                                                destructors", self.msg())[])
-            }
-            _ => {}
-        }
-
-        // statics cannot be consumed by value at any time, that would imply
-        // that they're an initializer (what a const is for) or kept in sync
-        // over time (not feasible), so deny it outright.
-        if self.checker.static_consumptions.remove(&e.id) {
-            self.tcx.sess.span_err(e.span, "cannot refer to other statics by \
-                                            value, use the address-of operator \
-                                            or a constant instead");
-        }
-
-        // Borrowed statics can specifically *only* have their address taken,
-        // not any number of other borrows such as borrowing fields, reading
-        // elements of an array, etc.
-        if self.checker.static_interior_borrows.remove(&e.id) {
-            self.tcx.sess.span_err(e.span, "cannot refer to the interior of \
-                                            another static, use a constant \
-                                            instead");
-        }
-
-        // constants cannot be borrowed if they contain interior mutability as
-        // it means that our "silent insertion of statics" could change
-        // initializer values (very bad).
-        if self.checker.const_borrows.remove(&e.id) {
-            let node_ty = ty::node_id_to_type(self.tcx, e.id);
-            let tcontents = ty::type_contents(self.tcx, node_ty);
-            if tcontents.interior_unsafe() {
-                self.tcx.sess.span_err(e.span, "cannot borrow a constant which \
-                                                contains interior mutability, \
-                                                create a static instead");
-            }
-        }
-
-        // local variables in a block expression in a static context (i.e. being
-        // assigned to a static variable) cannot be borrowed.
-        if self.checker.static_local_borrows.remove(&e.id) {
-            self.tcx.sess.span_err(e.span, "cannot borrow a local variable inside \
-                                            a static block, define a separate static \
-                                            instead");
-        }
-
-        match e.node {
-            ast::ExprAddrOf(ast::MutMutable, _) => {
-                if self.mode != InStaticMut {
-                    span_err!(self.tcx.sess, e.span, E0020,
-                              "{} are not allowed to have mutable references",
-                              self.msg());
-                }
-            },
-            ast::ExprBox(..) |
-            ast::ExprUnary(ast::UnUniq, _) => {
-                span_err!(self.tcx.sess, e.span, E0022,
-                          "{} are not allowed to have custom pointers",
-                          self.msg());
-            }
-            ast::ExprPath(_) | ast::ExprQPath(_) => {
-                match ty::resolve_expr(self.tcx, e) {
-                    def::DefStatic(..) if self.mode == InConstant => {
-                        let msg = "constants cannot refer to other statics, \
-                                   insert an intermediate constant \
-                                   instead";
-                        self.tcx.sess.span_err(e.span, &msg[]);
-                    }
-                    _ => {}
-                }
-            }
-            _ => {}
-        }
-        visit::walk_expr(self, e);
-    }
-}
-
-impl<'a,'b,'t,'v> Visitor<'v> for GlobalVisitor<'a,'b,'t> {
-    fn visit_item(&mut self, item: &ast::Item) {
-        match item.node {
-            ast::ItemConst(_, ref e) |
-            ast::ItemStatic(_, _, ref e) => {
-                let GlobalVisitor(ref mut v) = *self;
-                v.consume_expr(&**e);
-            }
-            _ => {}
-        }
-        visit::walk_item(self, item);
-    }
-}
-
-impl<'tcx> euv::Delegate<'tcx> for GlobalChecker {
-    fn consume(&mut self,
-               consume_id: ast::NodeId,
-               _consume_span: Span,
-               cmt: mc::cmt,
-               _mode: euv::ConsumeMode) {
-        let mut cur = &cmt;
-        loop {
-            match cur.cat {
-                mc::cat_static_item => {
-                    self.static_consumptions.insert(consume_id);
-                    break
-                }
-                mc::cat_deref(ref cmt, _, _) |
-                mc::cat_downcast(ref cmt, _) |
-                mc::cat_interior(ref cmt, _) => cur = cmt,
-
-                mc::cat_rvalue(..) |
-                mc::cat_upvar(..) |
-                mc::cat_local(..) => break,
-            }
-        }
-    }
-    fn borrow(&mut self,
-              borrow_id: ast::NodeId,
-              _borrow_span: Span,
-              cmt: mc::cmt,
-              _loan_region: ty::Region,
-              _bk: ty::BorrowKind,
-              _loan_cause: euv::LoanCause) {
-        let mut cur = &cmt;
-        let mut is_interior = false;
-        loop {
-            match cur.cat {
-                mc::cat_rvalue(..) => {
-                    self.const_borrows.insert(borrow_id);
-                    break
-                }
-                mc::cat_static_item => {
-                    if is_interior {
-                        self.static_interior_borrows.insert(borrow_id);
-                    }
-                    break
-                }
-                mc::cat_deref(ref cmt, _, _) |
-                mc::cat_interior(ref cmt, _) => {
-                    is_interior = true;
-                    cur = cmt;
-                }
-
-                mc::cat_downcast(..) |
-                mc::cat_upvar(..) => unreachable!(),
-
-                mc::cat_local(..) => {
-                    self.static_local_borrows.insert(borrow_id);
-                    break
-                }
-            }
-        }
-    }
-
-    fn decl_without_init(&mut self,
-                         _id: ast::NodeId,
-                         _span: Span) {}
-    fn mutate(&mut self,
-              _assignment_id: ast::NodeId,
-              _assignment_span: Span,
-              _assignee_cmt: mc::cmt,
-              _mode: euv::MutateMode) {}
-
-    fn matched_pat(&mut self,
-                   _: &ast::Pat,
-                   _: mc::cmt,
-                   _: euv::MatchMode) {}
-
-    fn consume_pat(&mut self,
-                   _consume_pat: &ast::Pat,
-                   _cmt: mc::cmt,
-                   _mode: euv::ConsumeMode) {}
-}
diff --git a/src/librustc/middle/const_eval.rs b/src/librustc/middle/const_eval.rs
index a6a647173fa..3d03cd946c4 100644
--- a/src/librustc/middle/const_eval.rs
+++ b/src/librustc/middle/const_eval.rs
@@ -12,80 +12,24 @@
 #![allow(unsigned_negation)]
 
 pub use self::const_val::*;
-pub use self::constness::*;
 
 use metadata::csearch;
 use middle::{astencode, def};
 use middle::pat_util::def_to_path;
-use middle::ty::{self};
+use middle::ty::{self, Ty};
 use middle::astconv_util::{ast_ty_to_prim_ty};
-use util::nodemap::DefIdMap;
 
 use syntax::ast::{self, Expr};
 use syntax::codemap::Span;
 use syntax::parse::token::InternedString;
 use syntax::ptr::P;
-use syntax::visit::{self, Visitor};
 use syntax::{ast_map, ast_util, codemap};
 
+use std::cmp::Ordering;
 use std::collections::hash_map::Entry::Vacant;
+use std::{i8, i16, i32, i64};
 use std::rc::Rc;
 
-//
-// This pass classifies expressions by their constant-ness.
-//
-// Constant-ness comes in 3 flavours:
-//
-//   - Integer-constants: can be evaluated by the frontend all the way down
-//     to their actual value. They are used in a few places (enum
-//     discriminants, switch arms) and are a subset of
-//     general-constants. They cover all the integer and integer-ish
-//     literals (nil, bool, int, uint, char, iNN, uNN) and all integer
-//     operators and copies applied to them.
-//
-//   - General-constants: can be evaluated by LLVM but not necessarily by
-//     the frontend; usually due to reliance on target-specific stuff such
-//     as "where in memory the value goes" or "what floating point mode the
-//     target uses". This _includes_ integer-constants, plus the following
-//     constructors:
-//
-//        fixed-size vectors and strings: [] and ""/_
-//        vector and string slices: &[] and &""
-//        tuples: (,)
-//        enums: foo(...)
-//        floating point literals and operators
-//        & and * pointers
-//        copies of general constants
-//
-//        (in theory, probably not at first: if/match on integer-const
-//         conditions / discriminants)
-//
-//   - Non-constants: everything else.
-//
-
-#[derive(Copy)]
-pub enum constness {
-    integral_const,
-    general_const,
-    non_const
-}
-
-type constness_cache = DefIdMap<constness>;
-
-pub fn join(a: constness, b: constness) -> constness {
-    match (a, b) {
-      (integral_const, integral_const) => integral_const,
-      (integral_const, general_const)
-      | (general_const, integral_const)
-      | (general_const, general_const) => general_const,
-      _ => non_const
-    }
-}
-
-pub fn join_all<It: Iterator<Item=constness>>(cs: It) -> constness {
-    cs.fold(integral_const, |a, b| join(a, b))
-}
-
 fn lookup_const<'a>(tcx: &'a ty::ctxt, e: &Expr) -> Option<&'a Expr> {
     let opt_def = tcx.def_map.borrow().get(&e.id).cloned();
     match opt_def {
@@ -186,113 +130,6 @@ pub fn lookup_const_by_id<'a>(tcx: &'a ty::ctxt, def_id: ast::DefId)
     }
 }
 
-struct ConstEvalVisitor<'a, 'tcx: 'a> {
-    tcx: &'a ty::ctxt<'tcx>,
-    ccache: constness_cache,
-}
-
-impl<'a, 'tcx> ConstEvalVisitor<'a, 'tcx> {
-    fn classify(&mut self, e: &Expr) -> constness {
-        let did = ast_util::local_def(e.id);
-        match self.ccache.get(&did) {
-            Some(&x) => return x,
-            None => {}
-        }
-        let cn = match e.node {
-            ast::ExprLit(ref lit) => {
-                match lit.node {
-                    ast::LitStr(..) | ast::LitFloat(..) => general_const,
-                    _ => integral_const
-                }
-            }
-
-            ast::ExprUnary(_, ref inner) | ast::ExprParen(ref inner) =>
-                self.classify(&**inner),
-
-            ast::ExprBinary(_, ref a, ref b) =>
-                join(self.classify(&**a), self.classify(&**b)),
-
-            ast::ExprTup(ref es) |
-            ast::ExprVec(ref es) =>
-                join_all(es.iter().map(|e| self.classify(&**e))),
-
-            ast::ExprStruct(_, ref fs, None) => {
-                let cs = fs.iter().map(|f| self.classify(&*f.expr));
-                join_all(cs)
-            }
-
-            ast::ExprCast(ref base, _) => {
-                let ty = ty::expr_ty(self.tcx, e);
-                let base = self.classify(&**base);
-                if ty::type_is_integral(ty) {
-                    join(integral_const, base)
-                } else if ty::type_is_fp(ty) {
-                    join(general_const, base)
-                } else {
-                    non_const
-                }
-            }
-
-            ast::ExprField(ref base, _) => self.classify(&**base),
-
-            ast::ExprTupField(ref base, _) => self.classify(&**base),
-
-            ast::ExprIndex(ref base, ref idx) =>
-                join(self.classify(&**base), self.classify(&**idx)),
-
-            ast::ExprAddrOf(ast::MutImmutable, ref base) =>
-                self.classify(&**base),
-
-            // FIXME: (#3728) we can probably do something CCI-ish
-            // surrounding nonlocal constants. But we don't yet.
-            ast::ExprPath(_) | ast::ExprQPath(_) => self.lookup_constness(e),
-
-            ast::ExprRepeat(..) => general_const,
-
-            ast::ExprBlock(ref block) => {
-                match block.expr {
-                    Some(ref e) => self.classify(&**e),
-                    None => integral_const
-                }
-            }
-
-            _ => non_const
-        };
-        self.ccache.insert(did, cn);
-        cn
-    }
-
-    fn lookup_constness(&self, e: &Expr) -> constness {
-        match lookup_const(self.tcx, e) {
-            Some(rhs) => {
-                let ty = ty::expr_ty(self.tcx, &*rhs);
-                if ty::type_is_integral(ty) {
-                    integral_const
-                } else {
-                    general_const
-                }
-            }
-            None => non_const
-        }
-    }
-
-}
-
-impl<'a, 'tcx, 'v> Visitor<'v> for ConstEvalVisitor<'a, 'tcx> {
-    fn visit_expr_post(&mut self, e: &Expr) {
-        self.classify(e);
-    }
-}
-
-pub fn process_crate(tcx: &ty::ctxt) {
-    visit::walk_crate(&mut ConstEvalVisitor {
-        tcx: tcx,
-        ccache: DefIdMap(),
-    }, tcx.map.krate());
-    tcx.sess.abort_if_errors();
-}
-
-
 // FIXME (#33): this doesn't handle big integer/float literals correctly
 // (nor does the rest of our literal handling).
 #[derive(Clone, PartialEq)]
@@ -370,17 +207,23 @@ pub fn const_expr_to_pat(tcx: &ty::ctxt, expr: &Expr, span: Span) -> P<ast::Pat>
 }
 
 pub fn eval_const_expr(tcx: &ty::ctxt, e: &Expr) -> const_val {
-    match eval_const_expr_partial(tcx, e) {
+    match eval_const_expr_partial(tcx, e, None) {
         Ok(r) => r,
         Err(s) => tcx.sess.span_fatal(e.span, &s[])
     }
 }
 
-pub fn eval_const_expr_partial(tcx: &ty::ctxt, e: &Expr) -> Result<const_val, String> {
+pub fn eval_const_expr_partial<'tcx>(tcx: &ty::ctxt<'tcx>,
+                                     e: &Expr,
+                                     ty_hint: Option<Ty<'tcx>>)
+                                     -> Result<const_val, String> {
     fn fromb(b: bool) -> Result<const_val, String> { Ok(const_int(b as i64)) }
+
+    let ety = ty_hint.or_else(|| ty::expr_ty_opt(tcx, e));
+
     match e.node {
       ast::ExprUnary(ast::UnNeg, ref inner) => {
-        match eval_const_expr_partial(tcx, &**inner) {
+        match eval_const_expr_partial(tcx, &**inner, ety) {
           Ok(const_float(f)) => Ok(const_float(-f)),
           Ok(const_int(i)) => Ok(const_int(-i)),
           Ok(const_uint(i)) => Ok(const_uint(-i)),
@@ -390,7 +233,7 @@ pub fn eval_const_expr_partial(tcx: &ty::ctxt, e: &Expr) -> Result<const_val, St
         }
       }
       ast::ExprUnary(ast::UnNot, ref inner) => {
-        match eval_const_expr_partial(tcx, &**inner) {
+        match eval_const_expr_partial(tcx, &**inner, ety) {
           Ok(const_int(i)) => Ok(const_int(!i)),
           Ok(const_uint(i)) => Ok(const_uint(!i)),
           Ok(const_bool(b)) => Ok(const_bool(!b)),
@@ -398,8 +241,12 @@ pub fn eval_const_expr_partial(tcx: &ty::ctxt, e: &Expr) -> Result<const_val, St
         }
       }
       ast::ExprBinary(op, ref a, ref b) => {
-        match (eval_const_expr_partial(tcx, &**a),
-               eval_const_expr_partial(tcx, &**b)) {
+        let b_ty = match op.node {
+            ast::BiShl | ast::BiShr => Some(tcx.types.uint),
+            _ => ety
+        };
+        match (eval_const_expr_partial(tcx, &**a, ety),
+               eval_const_expr_partial(tcx, &**b, b_ty)) {
           (Ok(const_float(a)), Ok(const_float(b))) => {
             match op.node {
               ast::BiAdd => Ok(const_float(a + b)),
@@ -417,19 +264,46 @@ pub fn eval_const_expr_partial(tcx: &ty::ctxt, e: &Expr) -> Result<const_val, St
             }
           }
           (Ok(const_int(a)), Ok(const_int(b))) => {
+            let is_a_min_value = |&:| {
+                let int_ty = match ty::expr_ty_opt(tcx, e).map(|ty| &ty.sty) {
+                    Some(&ty::ty_int(int_ty)) => int_ty,
+                    _ => return false
+                };
+                let int_ty = if let ast::TyIs(_) = int_ty {
+                    tcx.sess.target.int_type
+                } else {
+                    int_ty
+                };
+                match int_ty {
+                    ast::TyI8 => (a as i8) == i8::MIN,
+                    ast::TyI16 =>  (a as i16) == i16::MIN,
+                    ast::TyI32 =>  (a as i32) == i32::MIN,
+                    ast::TyI64 =>  (a as i64) == i64::MIN,
+                    ast::TyIs(_) => unreachable!()
+                }
+            };
             match op.node {
               ast::BiAdd => Ok(const_int(a + b)),
               ast::BiSub => Ok(const_int(a - b)),
               ast::BiMul => Ok(const_int(a * b)),
-              ast::BiDiv if b == 0 => {
-                  Err("attempted to divide by zero".to_string())
+              ast::BiDiv => {
+                  if b == 0 {
+                      Err("attempted to divide by zero".to_string())
+                  } else if b == -1 && is_a_min_value() {
+                      Err("attempted to divide with overflow".to_string())
+                  } else {
+                      Ok(const_int(a / b))
+                  }
               }
-              ast::BiDiv => Ok(const_int(a / b)),
-              ast::BiRem if b == 0 => {
-                  Err("attempted remainder with a divisor of \
-                       zero".to_string())
+              ast::BiRem => {
+                  if b == 0 {
+                      Err("attempted remainder with a divisor of zero".to_string())
+                  } else if b == -1 && is_a_min_value() {
+                      Err("attempted remainder with overflow".to_string())
+                  } else {
+                      Ok(const_int(a % b))
+                  }
               }
-              ast::BiRem => Ok(const_int(a % b)),
               ast::BiAnd | ast::BiBitAnd => Ok(const_int(a & b)),
               ast::BiOr | ast::BiBitOr => Ok(const_int(a | b)),
               ast::BiBitXor => Ok(const_int(a ^ b)),
@@ -504,63 +378,53 @@ pub fn eval_const_expr_partial(tcx: &ty::ctxt, e: &Expr) -> Result<const_val, St
         // This tends to get called w/o the type actually having been
         // populated in the ctxt, which was causing things to blow up
         // (#5900). Fall back to doing a limited lookup to get past it.
-        let ety = ty::expr_ty_opt(tcx, e)
-                .or_else(|| ast_ty_to_prim_ty(tcx, &**target_ty))
+        let ety = ety.or_else(|| ast_ty_to_prim_ty(tcx, &**target_ty))
                 .unwrap_or_else(|| {
                     tcx.sess.span_fatal(target_ty.span,
                                         "target type not found for const cast")
                 });
-
-        macro_rules! define_casts {
-            ($val:ident, {
-                $($ty_pat:pat => (
-                    $intermediate_ty:ty,
-                    $const_type:ident,
-                    $target_ty:ty
-                )),*
-            }) => (match ety.sty {
-                $($ty_pat => {
-                    match $val {
-                        const_bool(b) => Ok($const_type(b as $intermediate_ty as $target_ty)),
-                        const_uint(u) => Ok($const_type(u as $intermediate_ty as $target_ty)),
-                        const_int(i) => Ok($const_type(i as $intermediate_ty as $target_ty)),
-                        const_float(f) => Ok($const_type(f as $intermediate_ty as $target_ty)),
-                        _ => Err(concat!(
-                            "can't cast this type to ", stringify!($const_type)
-                        ).to_string())
-                    }
-                },)*
-                _ => Err("can't cast this type".to_string())
-            })
-        }
-
-        eval_const_expr_partial(tcx, &**base)
-            .and_then(|val| define_casts!(val, {
-                ty::ty_int(ast::TyIs(_)) => (int, const_int, i64),
-                ty::ty_int(ast::TyI8) => (i8, const_int, i64),
-                ty::ty_int(ast::TyI16) => (i16, const_int, i64),
-                ty::ty_int(ast::TyI32) => (i32, const_int, i64),
-                ty::ty_int(ast::TyI64) => (i64, const_int, i64),
-                ty::ty_uint(ast::TyUs(_)) => (uint, const_uint, u64),
-                ty::ty_uint(ast::TyU8) => (u8, const_uint, u64),
-                ty::ty_uint(ast::TyU16) => (u16, const_uint, u64),
-                ty::ty_uint(ast::TyU32) => (u32, const_uint, u64),
-                ty::ty_uint(ast::TyU64) => (u64, const_uint, u64),
-                ty::ty_float(ast::TyF32) => (f32, const_float, f64),
-                ty::ty_float(ast::TyF64) => (f64, const_float, f64)
-            }))
+        // Prefer known type to noop, but always have a type hint.
+        let base_hint = ty::expr_ty_opt(tcx, &**base).unwrap_or(ety);
+        let val = try!(eval_const_expr_partial(tcx, &**base, Some(base_hint)));
+        cast_const(val, ety)
       }
       ast::ExprPath(_) | ast::ExprQPath(_) => {
-          match lookup_const(tcx, e) {
-              Some(actual_e) => eval_const_expr_partial(tcx, &*actual_e),
-              None => Err("non-constant path in constant expr".to_string())
-          }
+          let opt_def = tcx.def_map.borrow().get(&e.id).cloned();
+          let (const_expr, const_ty) = match opt_def {
+              Some(def::DefConst(def_id)) => {
+                  if ast_util::is_local(def_id) {
+                      match tcx.map.find(def_id.node) {
+                          Some(ast_map::NodeItem(it)) => match it.node {
+                              ast::ItemConst(ref ty, ref expr) => {
+                                  (Some(&**expr), Some(&**ty))
+                              }
+                              _ => (None, None)
+                          },
+                          _ => (None, None)
+                      }
+                  } else {
+                      (lookup_const_by_id(tcx, def_id), None)
+                  }
+              }
+              Some(def::DefVariant(enum_def, variant_def, _)) => {
+                  (lookup_variant_by_id(tcx, enum_def, variant_def), None)
+              }
+              _ => (None, None)
+          };
+          let const_expr = match const_expr {
+              Some(actual_e) => actual_e,
+              None => return Err("non-constant path in constant expr".to_string())
+          };
+          let ety = ety.or_else(|| const_ty.and_then(|ty| ast_ty_to_prim_ty(tcx, ty)));
+          eval_const_expr_partial(tcx, const_expr, ety)
+      }
+      ast::ExprLit(ref lit) => {
+          Ok(lit_to_const(&**lit, ety))
       }
-      ast::ExprLit(ref lit) => Ok(lit_to_const(&**lit)),
-      ast::ExprParen(ref e)     => eval_const_expr_partial(tcx, &**e),
+      ast::ExprParen(ref e)     => eval_const_expr_partial(tcx, &**e, ety),
       ast::ExprBlock(ref block) => {
         match block.expr {
-            Some(ref expr) => eval_const_expr_partial(tcx, &**expr),
+            Some(ref expr) => eval_const_expr_partial(tcx, &**expr, ety),
             None => Ok(const_int(0i64))
         }
       }
@@ -569,7 +433,7 @@ pub fn eval_const_expr_partial(tcx: &ty::ctxt, e: &Expr) -> Result<const_val, St
         if let Some(&ast::ExprTup(ref fields)) = lookup_const(tcx, &**base).map(|s| &s.node) {
             // Check that the given index is within bounds and evaluate its value
             if fields.len() > index.node {
-                return eval_const_expr_partial(tcx, &*fields[index.node])
+                return eval_const_expr_partial(tcx, &*fields[index.node], None)
             } else {
                 return Err("tuple index out of bounds".to_string())
             }
@@ -584,7 +448,7 @@ pub fn eval_const_expr_partial(tcx: &ty::ctxt, e: &Expr) -> Result<const_val, St
             // Check that the given field exists and evaluate it
             if let Some(f) = fields.iter().find(|f|
                                            f.ident.node.as_str() == field_name.node.as_str()) {
-                return eval_const_expr_partial(tcx, &*f.expr)
+                return eval_const_expr_partial(tcx, &*f.expr, None)
             } else {
                 return Err("nonexistent struct field".to_string())
             }
@@ -596,7 +460,44 @@ pub fn eval_const_expr_partial(tcx: &ty::ctxt, e: &Expr) -> Result<const_val, St
     }
 }
 
-pub fn lit_to_const(lit: &ast::Lit) -> const_val {
+fn cast_const(val: const_val, ty: Ty) -> Result<const_val, String> {
+    macro_rules! define_casts {
+        ($($ty_pat:pat => (
+            $intermediate_ty:ty,
+            $const_type:ident,
+            $target_ty:ty
+        )),*) => (match ty.sty {
+            $($ty_pat => {
+                match val {
+                    const_bool(b) => Ok($const_type(b as $intermediate_ty as $target_ty)),
+                    const_uint(u) => Ok($const_type(u as $intermediate_ty as $target_ty)),
+                    const_int(i) => Ok($const_type(i as $intermediate_ty as $target_ty)),
+                    const_float(f) => Ok($const_type(f as $intermediate_ty as $target_ty)),
+                    _ => Err(concat!("can't cast this type to ",
+                                     stringify!($const_type)).to_string())
+                }
+            },)*
+            _ => Err("can't cast this type".to_string())
+        })
+    }
+
+    define_casts!{
+        ty::ty_int(ast::TyIs(_)) => (int, const_int, i64),
+        ty::ty_int(ast::TyI8) => (i8, const_int, i64),
+        ty::ty_int(ast::TyI16) => (i16, const_int, i64),
+        ty::ty_int(ast::TyI32) => (i32, const_int, i64),
+        ty::ty_int(ast::TyI64) => (i64, const_int, i64),
+        ty::ty_uint(ast::TyUs(_)) => (uint, const_uint, u64),
+        ty::ty_uint(ast::TyU8) => (u8, const_uint, u64),
+        ty::ty_uint(ast::TyU16) => (u16, const_uint, u64),
+        ty::ty_uint(ast::TyU32) => (u32, const_uint, u64),
+        ty::ty_uint(ast::TyU64) => (u64, const_uint, u64),
+        ty::ty_float(ast::TyF32) => (f32, const_float, f64),
+        ty::ty_float(ast::TyF64) => (f64, const_float, f64)
+    }
+}
+
+fn lit_to_const(lit: &ast::Lit, ty_hint: Option<Ty>) -> const_val {
     match lit.node {
         ast::LitStr(ref s, _) => const_str((*s).clone()),
         ast::LitBinary(ref data) => {
@@ -604,8 +505,13 @@ pub fn lit_to_const(lit: &ast::Lit) -> const_val {
         }
         ast::LitByte(n) => const_uint(n as u64),
         ast::LitChar(n) => const_uint(n as u64),
-        ast::LitInt(n, ast::SignedIntLit(_, ast::Plus)) |
-        ast::LitInt(n, ast::UnsuffixedIntLit(ast::Plus)) => const_int(n as i64),
+        ast::LitInt(n, ast::SignedIntLit(_, ast::Plus)) => const_int(n as i64),
+        ast::LitInt(n, ast::UnsuffixedIntLit(ast::Plus)) => {
+            match ty_hint.map(|ty| &ty.sty) {
+                Some(&ty::ty_uint(_)) => const_uint(n),
+                _ => const_int(n as i64)
+            }
+        }
         ast::LitInt(n, ast::SignedIntLit(_, ast::Minus)) |
         ast::LitInt(n, ast::UnsuffixedIntLit(ast::Minus)) => const_int(-(n as i64)),
         ast::LitInt(n, ast::UnsignedIntLit(_)) => const_uint(n),
@@ -617,21 +523,45 @@ pub fn lit_to_const(lit: &ast::Lit) -> const_val {
     }
 }
 
-fn compare_vals<T: PartialOrd>(a: T, b: T) -> Option<int> {
-    Some(if a == b { 0 } else if a < b { -1 } else { 1 })
-}
-pub fn compare_const_vals(a: &const_val, b: &const_val) -> Option<int> {
-    match (a, b) {
-        (&const_int(a), &const_int(b)) => compare_vals(a, b),
-        (&const_uint(a), &const_uint(b)) => compare_vals(a, b),
-        (&const_float(a), &const_float(b)) => compare_vals(a, b),
-        (&const_str(ref a), &const_str(ref b)) => compare_vals(a, b),
-        (&const_bool(a), &const_bool(b)) => compare_vals(a, b),
-        (&const_binary(ref a), &const_binary(ref b)) => compare_vals(a, b),
-        _ => None
-    }
+pub fn compare_const_vals(a: &const_val, b: &const_val) -> Option<Ordering> {
+    Some(match (a, b) {
+        (&const_int(a), &const_int(b)) => a.cmp(&b),
+        (&const_uint(a), &const_uint(b)) => a.cmp(&b),
+        (&const_float(a), &const_float(b)) => {
+            // This is pretty bad but it is the existing behavior.
+            if a == b {
+                Ordering::Equal
+            } else if a < b {
+                Ordering::Less
+            } else {
+                Ordering::Greater
+            }
+        }
+        (&const_str(ref a), &const_str(ref b)) => a.cmp(b),
+        (&const_bool(a), &const_bool(b)) => a.cmp(&b),
+        (&const_binary(ref a), &const_binary(ref b)) => a.cmp(b),
+        _ => return None
+    })
 }
 
-pub fn compare_lit_exprs(tcx: &ty::ctxt, a: &Expr, b: &Expr) -> Option<int> {
-    compare_const_vals(&eval_const_expr(tcx, a), &eval_const_expr(tcx, b))
+pub fn compare_lit_exprs<'tcx>(tcx: &ty::ctxt<'tcx>,
+                               a: &Expr,
+                               b: &Expr,
+                               ty_hint: Option<Ty<'tcx>>)
+                               -> Option<Ordering> {
+    let a = match eval_const_expr_partial(tcx, a, ty_hint) {
+        Ok(a) => a,
+        Err(s) => {
+            tcx.sess.span_err(a.span, &s[]);
+            return None;
+        }
+    };
+    let b = match eval_const_expr_partial(tcx, b, ty_hint) {
+        Ok(b) => b,
+        Err(s) => {
+            tcx.sess.span_err(b.span, &s[]);
+            return None;
+        }
+    };
+    compare_const_vals(&a, &b)
 }
diff --git a/src/librustc/middle/infer/error_reporting.rs b/src/librustc/middle/infer/error_reporting.rs
index 5d7a56ef0e6..72454046eb9 100644
--- a/src/librustc/middle/infer/error_reporting.rs
+++ b/src/librustc/middle/infer/error_reporting.rs
@@ -1435,7 +1435,6 @@ impl<'a, 'tcx> ErrorReportingHelpers<'tcx> for InferCtxt<'a, 'tcx> {
             infer::MiscVariable(_) => "".to_string(),
             infer::PatternRegion(_) => " for pattern".to_string(),
             infer::AddrOfRegion(_) => " for borrow expression".to_string(),
-            infer::AddrOfSlice(_) => " for slice expression".to_string(),
             infer::Autoref(_) => " for autoref".to_string(),
             infer::Coercion(_) => " for automatic coercion".to_string(),
             infer::LateBoundRegion(_, br, infer::FnCall) => {
diff --git a/src/librustc/middle/infer/mod.rs b/src/librustc/middle/infer/mod.rs
index 6c987bba389..00e377d65fe 100644
--- a/src/librustc/middle/infer/mod.rs
+++ b/src/librustc/middle/infer/mod.rs
@@ -247,9 +247,6 @@ pub enum RegionVariableOrigin<'tcx> {
     // Regions created by `&` operator
     AddrOfRegion(Span),
 
-    // Regions created by `&[...]` literal
-    AddrOfSlice(Span),
-
     // Regions created as part of an autoref of a method receiver
     Autoref(Span),
 
@@ -1273,7 +1270,6 @@ impl<'tcx> RegionVariableOrigin<'tcx> {
             MiscVariable(a) => a,
             PatternRegion(a) => a,
             AddrOfRegion(a) => a,
-            AddrOfSlice(a) => a,
             Autoref(a) => a,
             Coercion(ref a) => a.span(),
             EarlyBoundRegion(a, _) => a,
@@ -1296,7 +1292,6 @@ impl<'tcx> Repr<'tcx> for RegionVariableOrigin<'tcx> {
             AddrOfRegion(a) => {
                 format!("AddrOfRegion({})", a.repr(tcx))
             }
-            AddrOfSlice(a) => format!("AddrOfSlice({})", a.repr(tcx)),
             Autoref(a) => format!("Autoref({})", a.repr(tcx)),
             Coercion(ref a) => format!("Coercion({})", a.repr(tcx)),
             EarlyBoundRegion(a, b) => {
diff --git a/src/librustc/middle/mem_categorization.rs b/src/librustc/middle/mem_categorization.rs
index fed2f7d9245..6c295142c9f 100644
--- a/src/librustc/middle/mem_categorization.rs
+++ b/src/librustc/middle/mem_categorization.rs
@@ -71,6 +71,7 @@ pub use self::Note::*;
 pub use self::deref_kind::*;
 pub use self::categorization::*;
 
+use middle::check_const;
 use middle::def;
 use middle::region;
 use middle::ty::{self, Ty};
@@ -808,17 +809,29 @@ impl<'t,'tcx,TYPER:Typer<'tcx>> MemCategorizationContext<'t,TYPER> {
                            span: Span,
                            expr_ty: Ty<'tcx>)
                            -> cmt<'tcx> {
-        match self.typer.temporary_scope(id) {
-            Some(scope) => {
-                match expr_ty.sty {
-                    ty::ty_vec(_, Some(0)) => self.cat_rvalue(id, span, ty::ReStatic, expr_ty),
-                    _ => self.cat_rvalue(id, span, ty::ReScope(scope), expr_ty)
-                }
+        let qualif = self.tcx().const_qualif_map.borrow().get(&id).cloned()
+                               .unwrap_or(check_const::NOT_CONST);
+
+        // Only promote `[T; 0]` before an RFC for rvalue promotions
+        // is accepted.
+        let qualif = match expr_ty.sty {
+            ty::ty_vec(_, Some(0)) => qualif,
+            _ => check_const::NOT_CONST
+        };
+
+        let re = match qualif & check_const::NON_STATIC_BORROWS {
+            check_const::PURE_CONST => {
+                // Constant rvalues get promoted to 'static.
+                ty::ReStatic
             }
-            None => {
-                self.cat_rvalue(id, span, ty::ReStatic, expr_ty)
+            _ => {
+                match self.typer.temporary_scope(id) {
+                    Some(scope) => ty::ReScope(scope),
+                    None => ty::ReStatic
+                }
             }
-        }
+        };
+        self.cat_rvalue(id, span, re, expr_ty)
     }
 
     pub fn cat_rvalue(&self,
diff --git a/src/librustc/middle/ty.rs b/src/librustc/middle/ty.rs
index e276683236f..fe5c81bf2c0 100644
--- a/src/librustc/middle/ty.rs
+++ b/src/librustc/middle/ty.rs
@@ -44,6 +44,7 @@ use session::Session;
 use lint;
 use metadata::csearch;
 use middle;
+use middle::check_const;
 use middle::const_eval;
 use middle::def::{self, DefMap, ExportMap};
 use middle::dependency_format;
@@ -838,6 +839,9 @@ pub struct ctxt<'tcx> {
 
     /// Caches whether traits are object safe
     pub object_safety_cache: RefCell<DefIdMap<bool>>,
+
+    /// Maps Expr NodeId's to their constant qualification.
+    pub const_qualif_map: RefCell<NodeMap<check_const::ConstQualif>>,
 }
 
 // Flags that we track on types. These flags are propagated upwards
@@ -2472,6 +2476,7 @@ pub fn mk_ctxt<'tcx>(s: Session,
         type_impls_copy_cache: RefCell::new(HashMap::new()),
         type_impls_sized_cache: RefCell::new(HashMap::new()),
         object_safety_cache: RefCell::new(DefIdMap()),
+        const_qualif_map: RefCell::new(NodeMap()),
    }
 }
 
@@ -5350,26 +5355,25 @@ pub fn enum_variants<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
                                     None => INITIAL_DISCRIMINANT_VALUE
                                 };
 
-                                match variant.node.disr_expr {
-                                    Some(ref e) =>
-                                        match const_eval::eval_const_expr_partial(cx, &**e) {
-                                            Ok(const_eval::const_int(val)) => {
-                                                discriminant = val as Disr
-                                            }
-                                            Ok(const_eval::const_uint(val)) => {
-                                                discriminant = val as Disr
-                                            }
-                                            Ok(_) => {
-                                                span_err!(cx.sess, e.span, E0304,
-                                                            "expected signed integer constant");
-                                            }
-                                            Err(ref err) => {
-                                                span_err!(cx.sess, e.span, E0305,
-                                                            "expected constant: {}",
-                                                                    *err);
-                                            }
-                                        },
-                                    None => {}
+                                if let Some(ref e) = variant.node.disr_expr {
+                                    // Preserve all values, and prefer signed.
+                                    let ty = Some(cx.types.i64);
+                                    match const_eval::eval_const_expr_partial(cx, &**e, ty) {
+                                        Ok(const_eval::const_int(val)) => {
+                                            discriminant = val as Disr;
+                                        }
+                                        Ok(const_eval::const_uint(val)) => {
+                                            discriminant = val as Disr;
+                                        }
+                                        Ok(_) => {
+                                            span_err!(cx.sess, e.span, E0304,
+                                                      "expected signed integer constant");
+                                        }
+                                        Err(err) => {
+                                            span_err!(cx.sess, e.span, E0305,
+                                                      "expected constant: {}", err);
+                                        }
+                                    }
                                 };
 
                                 last_discriminant = Some(discriminant);
@@ -5822,7 +5826,7 @@ pub fn is_binopable<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>, op: ast::BinOp) -> bool
 
 // Returns the repeat count for a repeating vector expression.
 pub fn eval_repeat_count(tcx: &ctxt, count_expr: &ast::Expr) -> uint {
-    match const_eval::eval_const_expr_partial(tcx, count_expr) {
+    match const_eval::eval_const_expr_partial(tcx, count_expr, Some(tcx.types.uint)) {
         Ok(val) => {
             let found = match val {
                 const_eval::const_uint(count) => return count as uint,
diff --git a/src/librustc_driver/driver.rs b/src/librustc_driver/driver.rs
index 12f5041cad1..c3e205e050f 100644
--- a/src/librustc_driver/driver.rs
+++ b/src/librustc_driver/driver.rs
@@ -611,13 +611,6 @@ pub fn phase_3_run_analysis_passes<'tcx>(sess: Session,
     // passes are timed inside typeck
     typeck::check_crate(&ty_cx, trait_map);
 
-    time(time_passes, "check static items", (), |_|
-         middle::check_static::check_crate(&ty_cx));
-
-    // These next two const passes can probably be merged
-    time(time_passes, "const marking", (), |_|
-         middle::const_eval::process_crate(&ty_cx));
-
     time(time_passes, "const checking", (), |_|
          middle::check_const::check_crate(&ty_cx));
 
diff --git a/src/librustc_llvm/lib.rs b/src/librustc_llvm/lib.rs
index 878070e98e7..e73b626e6ef 100644
--- a/src/librustc_llvm/lib.rs
+++ b/src/librustc_llvm/lib.rs
@@ -881,6 +881,7 @@ extern {
 
 
     /* Operations on global variables */
+    pub fn LLVMIsAGlobalVariable(GlobalVar: ValueRef) -> ValueRef;
     pub fn LLVMAddGlobal(M: ModuleRef, Ty: TypeRef, Name: *const c_char)
                          -> ValueRef;
     pub fn LLVMAddGlobalInAddressSpace(M: ModuleRef,
diff --git a/src/librustc_trans/trans/_match.rs b/src/librustc_trans/trans/_match.rs
index 0f014800480..5ece5e59299 100644
--- a/src/librustc_trans/trans/_match.rs
+++ b/src/librustc_trans/trans/_match.rs
@@ -219,6 +219,7 @@ use util::nodemap::FnvHashMap;
 use util::ppaux::{Repr, vec_map_to_string};
 
 use std;
+use std::cmp::Ordering;
 use std::iter::AdditiveIterator;
 use std::rc::Rc;
 use syntax::ast;
@@ -232,10 +233,8 @@ struct ConstantExpr<'a>(&'a ast::Expr);
 
 impl<'a> ConstantExpr<'a> {
     fn eq(self, other: ConstantExpr<'a>, tcx: &ty::ctxt) -> bool {
-        let ConstantExpr(expr) = self;
-        let ConstantExpr(other_expr) = other;
-        match const_eval::compare_lit_exprs(tcx, expr, other_expr) {
-            Some(val1) => val1 == 0,
+        match const_eval::compare_lit_exprs(tcx, self.0, other.0, None) {
+            Some(result) => result == Ordering::Equal,
             None => panic!("compare_list_exprs: type mismatch"),
         }
     }
@@ -279,14 +278,14 @@ impl<'a, 'tcx> Opt<'a, 'tcx> {
         match *self {
             ConstantValue(ConstantExpr(lit_expr), _) => {
                 let lit_ty = ty::node_id_to_type(bcx.tcx(), lit_expr.id);
-                let (llval, _) = consts::const_expr(ccx, &*lit_expr);
+                let (llval, _) = consts::const_expr(ccx, &*lit_expr, bcx.fcx.param_substs);
                 let lit_datum = immediate_rvalue(llval, lit_ty);
                 let lit_datum = unpack_datum!(bcx, lit_datum.to_appropriate_datum(bcx));
                 SingleResult(Result::new(bcx, lit_datum.val))
             }
             ConstantRange(ConstantExpr(ref l1), ConstantExpr(ref l2), _) => {
-                let (l1, _) = consts::const_expr(ccx, &**l1);
-                let (l2, _) = consts::const_expr(ccx, &**l2);
+                let (l1, _) = consts::const_expr(ccx, &**l1, bcx.fcx.param_substs);
+                let (l2, _) = consts::const_expr(ccx, &**l2, bcx.fcx.param_substs);
                 RangeResult(Result::new(bcx, l1), Result::new(bcx, l2))
             }
             Variant(disr_val, ref repr, _, _) => {
@@ -833,8 +832,8 @@ fn compare_values<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
 
     let _icx = push_ctxt("compare_values");
     if ty::type_is_scalar(rhs_t) {
-        let rs = compare_scalar_types(cx, lhs, rhs, rhs_t, ast::BiEq, debug_loc);
-        return Result::new(rs.bcx, rs.val);
+        let cmp = compare_scalar_types(cx, lhs, rhs, rhs_t, ast::BiEq, debug_loc);
+        return Result::new(cx, cmp);
     }
 
     match rhs_t.sty {
@@ -1164,29 +1163,16 @@ fn compile_submatch_continue<'a, 'p, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
                             }
                             RangeResult(Result { val: vbegin, .. },
                                         Result { bcx, val: vend }) => {
-                                let Result { bcx, val: llge } =
-                                    compare_scalar_types(bcx,
-                                                         test_val,
-                                                         vbegin,
-                                                         t,
-                                                         ast::BiGe,
-                                                         debug_loc);
-                                let Result { bcx, val: llle } =
-                                    compare_scalar_types(bcx,
-                                                         test_val,
-                                                         vend,
-                                                         t,
-                                                         ast::BiLe,
-                                                         debug_loc);
-                                Result::new(bcx, And(bcx, llge, llle, debug_loc))
+                                let llge = compare_scalar_types(bcx, test_val, vbegin,
+                                                                t, ast::BiGe, debug_loc);
+                                let llle = compare_scalar_types(bcx, test_val, vend,
+                                                                t, ast::BiLe, debug_loc);
+                                Result::new(bcx, And(bcx, llge, llle, DebugLoc::None))
                             }
                             LowerBound(Result { bcx, val }) => {
-                                compare_scalar_types(bcx,
-                                                     test_val,
-                                                     val,
-                                                     t,
-                                                     ast::BiGe,
-                                                     debug_loc)
+                                Result::new(bcx, compare_scalar_types(bcx, test_val,
+                                                                      val, t, ast::BiGe,
+                                                                      debug_loc))
                             }
                         }
                     };
diff --git a/src/librustc_trans/trans/adt.rs b/src/librustc_trans/trans/adt.rs
index 8bb60eca8b1..ddd720f1e84 100644
--- a/src/librustc_trans/trans/adt.rs
+++ b/src/librustc_trans/trans/adt.rs
@@ -323,7 +323,7 @@ fn represent_type_uncached<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>,
                 mk_struct(cx, &ftys[], false, t)
             }).collect();
 
-            ensure_enum_fits_in_address_space(cx, ity, &fields[], t);
+            ensure_enum_fits_in_address_space(cx, &fields[], t);
 
             General(ity, fields, dtor)
         }
@@ -582,20 +582,14 @@ fn ensure_struct_fits_in_address_space<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
 
 fn union_size_and_align(sts: &[Struct]) -> (machine::llsize, machine::llalign) {
     let size = sts.iter().map(|st| st.size).max().unwrap();
-    let most_aligned = sts.iter().max_by(|st| st.align).unwrap();
-    (size, most_aligned.align)
+    let align = sts.iter().map(|st| st.align).max().unwrap();
+    (roundup(size, align), align)
 }
 
 fn ensure_enum_fits_in_address_space<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
-                                               discr: IntType,
                                                fields: &[Struct],
                                                scapegoat: Ty<'tcx>) {
-    let discr_size = machine::llsize_of_alloc(ccx, ll_inttype(ccx, discr));
-    let (field_size, field_align) = union_size_and_align(fields);
-
-    // field_align < 1<<32, discr_size <= 8, field_size < OBJ_SIZE_BOUND <= 1<<61
-    // so the sum is less than 1<<62 (and can't overflow).
-    let total_size = roundup(discr_size, field_align) + field_size;
+    let (total_size, _) = union_size_and_align(fields);
 
     if total_size >= ccx.obj_size_bound() {
         ccx.report_overbig_object(scapegoat);
@@ -667,9 +661,11 @@ fn generic_type_of<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>,
             // FIXME #10604: this breaks when vector types are present.
             let (size, align) = union_size_and_align(&sts[]);
             let align_s = align as u64;
+            assert_eq!(size % align_s, 0);
+            let align_units = size / align_s - 1;
+
             let discr_ty = ll_inttype(cx, ity);
             let discr_size = machine::llsize_of_alloc(cx, discr_ty);
-            let align_units = (size + align_s - 1) / align_s - 1;
             let fill_ty = match align_s {
                 1 => Type::array(&Type::i8(cx), align_units),
                 2 => Type::array(&Type::i16(cx), align_units),
@@ -1049,7 +1045,7 @@ pub fn trans_const<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, r: &Repr<'tcx>, discr
         }
         General(ity, ref cases, _) => {
             let case = &cases[discr as uint];
-            let max_sz = cases.iter().map(|x| x.size).max().unwrap();
+            let (max_sz, _) = union_size_and_align(&cases[]);
             let lldiscr = C_integral(ll_inttype(ccx, ity), discr as u64, true);
             let mut f = vec![lldiscr];
             f.push_all(vals);
diff --git a/src/librustc_trans/trans/base.rs b/src/librustc_trans/trans/base.rs
index 54c50b7a62b..7f7b5cd8006 100644
--- a/src/librustc_trans/trans/base.rs
+++ b/src/librustc_trans/trans/base.rs
@@ -26,7 +26,6 @@
 #![allow(non_camel_case_types)]
 
 pub use self::ValueOrigin::*;
-pub use self::scalar_type::*;
 
 use super::CrateTranslation;
 use super::ModuleTranslation;
@@ -40,7 +39,6 @@ use metadata::{csearch, encoder, loader};
 use middle::astencode;
 use middle::cfg;
 use middle::lang_items::{LangItem, ExchangeMallocFnLangItem, StartFnLangItem};
-use middle::subst;
 use middle::weak_lang_items;
 use middle::subst::{Subst, Substs};
 use middle::ty::{self, Ty, ClosureTyper};
@@ -498,7 +496,7 @@ pub fn get_res_dtor<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
                               did: ast::DefId,
                               t: Ty<'tcx>,
                               parent_id: ast::DefId,
-                              substs: &subst::Substs<'tcx>)
+                              substs: &Substs<'tcx>)
                               -> ValueRef {
     let _icx = push_ctxt("trans_res_dtor");
     let did = inline::maybe_instantiate_inline(ccx, did);
@@ -507,9 +505,9 @@ pub fn get_res_dtor<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
         assert_eq!(did.krate, ast::LOCAL_CRATE);
 
         // Since we're in trans we don't care for any region parameters
-        let substs = subst::Substs::erased(substs.types.clone());
+        let substs = ccx.tcx().mk_substs(Substs::erased(substs.types.clone()));
 
-        let (val, _, _) = monomorphize::monomorphic_fn(ccx, did, &substs, None);
+        let (val, _, _) = monomorphize::monomorphic_fn(ccx, did, substs, None);
 
         val
     } else if did.krate == ast::LOCAL_CRATE {
@@ -532,137 +530,100 @@ pub fn get_res_dtor<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
     }
 }
 
-// Used only for creating scalar comparison glue.
-#[derive(Copy)]
-pub enum scalar_type { nil_type, signed_int, unsigned_int, floating_point, }
+pub fn bin_op_to_icmp_predicate(ccx: &CrateContext, op: ast::BinOp_, signed: bool)
+                                -> llvm::IntPredicate {
+    match op {
+        ast::BiEq => llvm::IntEQ,
+        ast::BiNe => llvm::IntNE,
+        ast::BiLt => if signed { llvm::IntSLT } else { llvm::IntULT },
+        ast::BiLe => if signed { llvm::IntSLE } else { llvm::IntULE },
+        ast::BiGt => if signed { llvm::IntSGT } else { llvm::IntUGT },
+        ast::BiGe => if signed { llvm::IntSGE } else { llvm::IntUGE },
+        op => {
+            ccx.sess().bug(&format!("comparison_op_to_icmp_predicate: expected \
+                                     comparison operator, found {:?}", op)[]);
+        }
+    }
+}
+
+pub fn bin_op_to_fcmp_predicate(ccx: &CrateContext, op: ast::BinOp_)
+                                -> llvm::RealPredicate {
+    match op {
+        ast::BiEq => llvm::RealOEQ,
+        ast::BiNe => llvm::RealUNE,
+        ast::BiLt => llvm::RealOLT,
+        ast::BiLe => llvm::RealOLE,
+        ast::BiGt => llvm::RealOGT,
+        ast::BiGe => llvm::RealOGE,
+        op => {
+            ccx.sess().bug(&format!("comparison_op_to_fcmp_predicate: expected \
+                                     comparison operator, found {:?}", op)[]);
+        }
+    }
+}
 
-pub fn compare_scalar_types<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
+pub fn compare_scalar_types<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
                                         lhs: ValueRef,
                                         rhs: ValueRef,
                                         t: Ty<'tcx>,
                                         op: ast::BinOp_,
                                         debug_loc: DebugLoc)
-                                        -> Result<'blk, 'tcx> {
-    let f = |a| Result::new(cx, compare_scalar_values(cx, lhs, rhs, a, op, debug_loc));
-
+                                        -> ValueRef {
     match t.sty {
-        ty::ty_tup(ref tys) if tys.is_empty() => f(nil_type),
-        ty::ty_bool | ty::ty_uint(_) | ty::ty_char => f(unsigned_int),
-        ty::ty_ptr(mt) if common::type_is_sized(cx.tcx(), mt.ty) => f(unsigned_int),
-        ty::ty_int(_) => f(signed_int),
-        ty::ty_float(_) => f(floating_point),
-            // Should never get here, because t is scalar.
-        _ => cx.sess().bug("non-scalar type passed to compare_scalar_types")
-    }
-}
-
-
-// A helper function to do the actual comparison of scalar values.
-pub fn compare_scalar_values<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
-                                         lhs: ValueRef,
-                                         rhs: ValueRef,
-                                         nt: scalar_type,
-                                         op: ast::BinOp_,
-                                         debug_loc: DebugLoc)
-                                         -> ValueRef {
-    let _icx = push_ctxt("compare_scalar_values");
-    fn die(cx: Block) -> ! {
-        cx.sess().bug("compare_scalar_values: must be a comparison operator");
-    }
-    match nt {
-      nil_type => {
-        // We don't need to do actual comparisons for nil.
-        // () == () holds but () < () does not.
-        match op {
-          ast::BiEq | ast::BiLe | ast::BiGe => return C_bool(cx.ccx(), true),
-          ast::BiNe | ast::BiLt | ast::BiGt => return C_bool(cx.ccx(), false),
-          // refinements would be nice
-          _ => die(cx)
+        ty::ty_tup(ref tys) if tys.is_empty() => {
+            // We don't need to do actual comparisons for nil.
+            // () == () holds but () < () does not.
+            match op {
+                ast::BiEq | ast::BiLe | ast::BiGe => return C_bool(bcx.ccx(), true),
+                ast::BiNe | ast::BiLt | ast::BiGt => return C_bool(bcx.ccx(), false),
+                // refinements would be nice
+                _ => bcx.sess().bug("compare_scalar_types: must be a comparison operator")
+            }
         }
-      }
-      floating_point => {
-        let cmp = match op {
-          ast::BiEq => llvm::RealOEQ,
-          ast::BiNe => llvm::RealUNE,
-          ast::BiLt => llvm::RealOLT,
-          ast::BiLe => llvm::RealOLE,
-          ast::BiGt => llvm::RealOGT,
-          ast::BiGe => llvm::RealOGE,
-          _ => die(cx)
-        };
-        return FCmp(cx, cmp, lhs, rhs, debug_loc);
-      }
-      signed_int => {
-        let cmp = match op {
-          ast::BiEq => llvm::IntEQ,
-          ast::BiNe => llvm::IntNE,
-          ast::BiLt => llvm::IntSLT,
-          ast::BiLe => llvm::IntSLE,
-          ast::BiGt => llvm::IntSGT,
-          ast::BiGe => llvm::IntSGE,
-          _ => die(cx)
-        };
-        return ICmp(cx, cmp, lhs, rhs, debug_loc);
-      }
-      unsigned_int => {
-        let cmp = match op {
-          ast::BiEq => llvm::IntEQ,
-          ast::BiNe => llvm::IntNE,
-          ast::BiLt => llvm::IntULT,
-          ast::BiLe => llvm::IntULE,
-          ast::BiGt => llvm::IntUGT,
-          ast::BiGe => llvm::IntUGE,
-          _ => die(cx)
-        };
-        return ICmp(cx, cmp, lhs, rhs, debug_loc);
-      }
+        ty::ty_bool | ty::ty_uint(_) | ty::ty_char => {
+            ICmp(bcx, bin_op_to_icmp_predicate(bcx.ccx(), op, false), lhs, rhs, debug_loc)
+        }
+        ty::ty_ptr(mt) if common::type_is_sized(bcx.tcx(), mt.ty) => {
+            ICmp(bcx, bin_op_to_icmp_predicate(bcx.ccx(), op, false), lhs, rhs, debug_loc)
+        }
+        ty::ty_int(_) => {
+            ICmp(bcx, bin_op_to_icmp_predicate(bcx.ccx(), op, true), lhs, rhs, debug_loc)
+        }
+        ty::ty_float(_) => {
+            FCmp(bcx, bin_op_to_fcmp_predicate(bcx.ccx(), op), lhs, rhs, debug_loc)
+        }
+        // Should never get here, because t is scalar.
+        _ => bcx.sess().bug("non-scalar type passed to compare_scalar_types")
     }
 }
 
-pub fn compare_simd_types<'blk, 'tcx>(
-                    cx: Block<'blk, 'tcx>,
-                    lhs: ValueRef,
-                    rhs: ValueRef,
-                    t: Ty<'tcx>,
-                    size: uint,
-                    op: ast::BinOp_,
-                    debug_loc: DebugLoc)
-                    -> ValueRef {
-    let cmp = match t.sty {
+pub fn compare_simd_types<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
+                                      lhs: ValueRef,
+                                      rhs: ValueRef,
+                                      t: Ty<'tcx>,
+                                      op: ast::BinOp_,
+                                      debug_loc: DebugLoc)
+                                      -> ValueRef {
+    let signed = match t.sty {
         ty::ty_float(_) => {
             // The comparison operators for floating point vectors are challenging.
             // LLVM outputs a `< size x i1 >`, but if we perform a sign extension
             // then bitcast to a floating point vector, the result will be `-NaN`
             // for each truth value. Because of this they are unsupported.
-            cx.sess().bug("compare_simd_types: comparison operators \
-                           not supported for floating point SIMD types")
-        },
-        ty::ty_uint(_) => match op {
-            ast::BiEq => llvm::IntEQ,
-            ast::BiNe => llvm::IntNE,
-            ast::BiLt => llvm::IntULT,
-            ast::BiLe => llvm::IntULE,
-            ast::BiGt => llvm::IntUGT,
-            ast::BiGe => llvm::IntUGE,
-            _ => cx.sess().bug("compare_simd_types: must be a comparison operator"),
-        },
-        ty::ty_int(_) => match op {
-            ast::BiEq => llvm::IntEQ,
-            ast::BiNe => llvm::IntNE,
-            ast::BiLt => llvm::IntSLT,
-            ast::BiLe => llvm::IntSLE,
-            ast::BiGt => llvm::IntSGT,
-            ast::BiGe => llvm::IntSGE,
-            _ => cx.sess().bug("compare_simd_types: must be a comparison operator"),
+            bcx.sess().bug("compare_simd_types: comparison operators \
+                            not supported for floating point SIMD types")
         },
-        _ => cx.sess().bug("compare_simd_types: invalid SIMD type"),
+        ty::ty_uint(_) => false,
+        ty::ty_int(_) => true,
+        _ => bcx.sess().bug("compare_simd_types: invalid SIMD type"),
     };
-    let return_ty = Type::vector(&type_of(cx.ccx(), t), size as u64);
+
+    let cmp = bin_op_to_icmp_predicate(bcx.ccx(), op, signed);
     // LLVM outputs an `< size x i1 >`, so we need to perform a sign extension
     // to get the correctly sized type. This will compile to a single instruction
     // once the IR is converted to assembly if the SIMD instruction is supported
     // by the target architecture.
-    SExt(cx, ICmp(cx, cmp, lhs, rhs, debug_loc), return_ty)
+    SExt(bcx, ICmp(bcx, cmp, lhs, rhs, debug_loc), val_ty(lhs))
 }
 
 // Iterates through the elements of a structural type.
@@ -679,7 +640,7 @@ pub fn iter_structural_ty<'blk, 'tcx, F>(cx: Block<'blk, 'tcx>,
                                    repr: &adt::Repr<'tcx>,
                                    av: ValueRef,
                                    variant: &ty::VariantInfo<'tcx>,
-                                   substs: &subst::Substs<'tcx>,
+                                   substs: &Substs<'tcx>,
                                    f: &mut F)
                                    -> Block<'blk, 'tcx> where
         F: FnMut(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>,
@@ -1034,21 +995,39 @@ pub fn load_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
                            ptr: ValueRef, t: Ty<'tcx>) -> ValueRef {
     if type_is_zero_size(cx.ccx(), t) {
         C_undef(type_of::type_of(cx.ccx(), t))
-    } else if ty::type_is_bool(t) {
-        Trunc(cx, LoadRangeAssert(cx, ptr, 0, 2, llvm::False), Type::i1(cx.ccx()))
     } else if type_is_immediate(cx.ccx(), t) && type_of::type_of(cx.ccx(), t).is_aggregate() {
         // We want to pass small aggregates as immediate values, but using an aggregate LLVM type
         // for this leads to bad optimizations, so its arg type is an appropriately sized integer
         // and we have to convert it
         Load(cx, BitCast(cx, ptr, type_of::arg_type_of(cx.ccx(), t).ptr_to()))
-    } else if ty::type_is_region_ptr(t) || ty::type_is_unique(t) {
-        LoadNonNull(cx, ptr)
-    } else if ty::type_is_char(t) {
-        // a char is a Unicode codepoint, and so takes values from 0
-        // to 0x10FFFF inclusive only.
-        LoadRangeAssert(cx, ptr, 0, 0x10FFFF + 1, llvm::False)
     } else {
-        Load(cx, ptr)
+        unsafe {
+            let global = llvm::LLVMIsAGlobalVariable(ptr);
+            if !global.is_null() && llvm::LLVMIsGlobalConstant(global) == llvm::True {
+                let val = llvm::LLVMGetInitializer(global);
+                if !val.is_null() {
+                    // This could go into its own function, for DRY.
+                    // (something like "pre-store packing/post-load unpacking")
+                    if ty::type_is_bool(t) {
+                        return Trunc(cx, val, Type::i1(cx.ccx()));
+                    } else {
+                        return val;
+                    }
+                }
+            }
+        }
+        if ty::type_is_bool(t) {
+            Trunc(cx, LoadRangeAssert(cx, ptr, 0, 2, llvm::False), Type::i1(cx.ccx()))
+        } else if ty::type_is_char(t) {
+            // a char is a Unicode codepoint, and so takes values from 0
+            // to 0x10FFFF inclusive only.
+            LoadRangeAssert(cx, ptr, 0, 0x10FFFF + 1, llvm::False)
+        } else if (ty::type_is_region_ptr(t) || ty::type_is_unique(t))
+                  && !common::type_is_fat_ptr(cx.tcx(), t) {
+            LoadNonNull(cx, ptr)
+        } else {
+            Load(cx, ptr)
+        }
     }
 }
 
@@ -1064,7 +1043,7 @@ pub fn store_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>, v: ValueRef, dst: ValueRef, t
         Store(cx, v, BitCast(cx, dst, type_of::arg_type_of(cx.ccx(), t).ptr_to()));
     } else {
         Store(cx, v, dst);
-    };
+    }
 }
 
 pub fn init_local<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, local: &ast::Local)
@@ -1162,7 +1141,7 @@ pub fn memcpy_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
         let llalign = type_of::align_of(ccx, t);
         call_memcpy(bcx, dst, src, llsz, llalign as u32);
     } else {
-        store_ty(bcx, Load(bcx, src), dst, t);
+        store_ty(bcx, load_ty(bcx, src, t), dst, t);
     }
 }
 
@@ -1425,7 +1404,7 @@ pub fn new_fn_ctxt<'a, 'tcx>(ccx: &'a CrateContext<'a, 'tcx>,
                              id: ast::NodeId,
                              has_env: bool,
                              output_type: ty::FnOutput<'tcx>,
-                             param_substs: &'a Substs<'tcx>,
+                             param_substs: &'tcx Substs<'tcx>,
                              sp: Option<Span>,
                              block_arena: &'a TypedArena<common::BlockS<'a, 'tcx>>)
                              -> FunctionContext<'a, 'tcx> {
@@ -1793,7 +1772,7 @@ pub fn trans_closure<'a, 'b, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
                                    decl: &ast::FnDecl,
                                    body: &ast::Block,
                                    llfndecl: ValueRef,
-                                   param_substs: &Substs<'tcx>,
+                                   param_substs: &'tcx Substs<'tcx>,
                                    fn_ast_id: ast::NodeId,
                                    _attributes: &[ast::Attribute],
                                    output_type: ty::FnOutput<'tcx>,
@@ -1942,7 +1921,7 @@ pub fn trans_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
                           decl: &ast::FnDecl,
                           body: &ast::Block,
                           llfndecl: ValueRef,
-                          param_substs: &Substs<'tcx>,
+                          param_substs: &'tcx Substs<'tcx>,
                           id: ast::NodeId,
                           attrs: &[ast::Attribute]) {
     let _s = StatRecorder::new(ccx, ccx.tcx().map.path_to_string(id).to_string());
@@ -1968,7 +1947,7 @@ pub fn trans_enum_variant<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
                                     variant: &ast::Variant,
                                     _args: &[ast::VariantArg],
                                     disr: ty::Disr,
-                                    param_substs: &Substs<'tcx>,
+                                    param_substs: &'tcx Substs<'tcx>,
                                     llfndecl: ValueRef) {
     let _icx = push_ctxt("trans_enum_variant");
 
@@ -2049,7 +2028,7 @@ pub fn trans_named_tuple_constructor<'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
 pub fn trans_tuple_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
                                     _fields: &[ast::StructField],
                                     ctor_id: ast::NodeId,
-                                    param_substs: &Substs<'tcx>,
+                                    param_substs: &'tcx Substs<'tcx>,
                                     llfndecl: ValueRef) {
     let _icx = push_ctxt("trans_tuple_struct");
 
@@ -2064,7 +2043,7 @@ pub fn trans_tuple_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
 fn trans_enum_variant_or_tuple_like_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
                                                      ctor_id: ast::NodeId,
                                                      disr: ty::Disr,
-                                                     param_substs: &Substs<'tcx>,
+                                                     param_substs: &'tcx Substs<'tcx>,
                                                      llfndecl: ValueRef) {
     let ctor_ty = ty::node_id_to_type(ccx.tcx(), ctor_id);
     let ctor_ty = monomorphize::apply_param_substs(ccx.tcx(), param_substs, &ctor_ty);
@@ -2302,13 +2281,14 @@ pub fn trans_item(ccx: &CrateContext, item: &ast::Item) {
             // translated everywhere it's needed.
             for (ref ccx, is_origin) in ccx.maybe_iter(!from_external && trans_everywhere) {
                 let llfn = get_item_val(ccx, item.id);
+                let empty_substs = ccx.tcx().mk_substs(Substs::trans_empty());
                 if abi != Rust {
                     foreign::trans_rust_fn_with_foreign_abi(ccx,
                                                             &**decl,
                                                             &**body,
                                                             &item.attrs[],
                                                             llfn,
-                                                            &Substs::trans_empty(),
+                                                            empty_substs,
                                                             item.id,
                                                             None);
                 } else {
@@ -2316,7 +2296,7 @@ pub fn trans_item(ccx: &CrateContext, item: &ast::Item) {
                              &**decl,
                              &**body,
                              llfn,
-                             &Substs::trans_empty(),
+                             empty_substs,
                              item.id,
                              &item.attrs[]);
                 }
@@ -2792,7 +2772,8 @@ pub fn get_item_val(ccx: &CrateContext, id: ast::NodeId) -> ValueRef {
 
                     // We need the translated value here, because for enums the
                     // LLVM type is not fully determined by the Rust type.
-                    let (v, ty) = consts::const_expr(ccx, &**expr);
+                    let empty_substs = ccx.tcx().mk_substs(Substs::trans_empty());
+                    let (v, ty) = consts::const_expr(ccx, &**expr, empty_substs);
                     ccx.static_values().borrow_mut().insert(id, v);
                     unsafe {
                         // boolean SSA values are i1, but they have to be stored in i8 slots,
@@ -2820,12 +2801,6 @@ pub fn get_item_val(ccx: &CrateContext, id: ast::NodeId) -> ValueRef {
                     }
                 }
 
-                ast::ItemConst(_, ref expr) => {
-                    let (v, _) = consts::const_expr(ccx, &**expr);
-                    ccx.const_values().borrow_mut().insert(id, v);
-                    v
-                }
-
                 ast::ItemFn(_, _, abi, _, _) => {
                     let sym = sym();
                     let llfn = if abi == Rust {
diff --git a/src/librustc_trans/trans/callee.rs b/src/librustc_trans/trans/callee.rs
index e45918ce5a7..bda8b8938b7 100644
--- a/src/librustc_trans/trans/callee.rs
+++ b/src/librustc_trans/trans/callee.rs
@@ -226,7 +226,7 @@ fn trans<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, expr: &ast::Expr)
 pub fn trans_fn_ref<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
                               def_id: ast::DefId,
                               node: ExprOrMethodCall,
-                              param_substs: &subst::Substs<'tcx>)
+                              param_substs: &'tcx subst::Substs<'tcx>)
                               -> Datum<'tcx, Rvalue> {
     let _icx = push_ctxt("trans_fn_ref");
 
@@ -326,7 +326,7 @@ pub fn trans_fn_pointer_shim<'a, 'tcx>(
                               &function_name[]);
 
     //
-    let empty_substs = Substs::trans_empty();
+    let empty_substs = tcx.mk_substs(Substs::trans_empty());
     let (block_arena, fcx): (TypedArena<_>, FunctionContext);
     block_arena = TypedArena::new();
     fcx = new_fn_ctxt(ccx,
@@ -334,7 +334,7 @@ pub fn trans_fn_pointer_shim<'a, 'tcx>(
                       ast::DUMMY_NODE_ID,
                       false,
                       sig.output,
-                      &empty_substs,
+                      empty_substs,
                       None,
                       &block_arena);
     let mut bcx = init_function(&fcx, false, sig.output);
@@ -386,7 +386,7 @@ pub fn trans_fn_ref_with_substs<'a, 'tcx>(
     ccx: &CrateContext<'a, 'tcx>,
     def_id: ast::DefId,
     node: ExprOrMethodCall,
-    param_substs: &subst::Substs<'tcx>,
+    param_substs: &'tcx subst::Substs<'tcx>,
     substs: subst::Substs<'tcx>)
     -> Datum<'tcx, Rvalue>
 {
@@ -416,7 +416,9 @@ pub fn trans_fn_ref_with_substs<'a, 'tcx>(
     // We need to modify the def_id and our substs in order to monomorphize
     // the function.
     let (is_default, def_id, substs) = match ty::provided_source(tcx, def_id) {
-        None => (false, def_id, substs),
+        None => {
+            (false, def_id, tcx.mk_substs(substs))
+        }
         Some(source_id) => {
             // There are two relevant substitutions when compiling
             // default methods. First, there is the substitution for
@@ -444,7 +446,7 @@ pub fn trans_fn_ref_with_substs<'a, 'tcx>(
                         .erase_regions();
 
                     // And compose them
-                    let new_substs = first_subst.subst(tcx, &substs);
+                    let new_substs = tcx.mk_substs(first_subst.subst(tcx, &substs));
 
                     debug!("trans_fn_with_vtables - default method: \
                             substs = {}, trait_subst = {}, \
@@ -463,7 +465,7 @@ pub fn trans_fn_ref_with_substs<'a, 'tcx>(
     };
 
     // If this is a closure, redirect to it.
-    match closure::get_or_create_declaration_if_closure(ccx, def_id, &substs) {
+    match closure::get_or_create_declaration_if_closure(ccx, def_id, substs) {
         None => {}
         Some(llfn) => return llfn,
     }
@@ -505,7 +507,7 @@ pub fn trans_fn_ref_with_substs<'a, 'tcx>(
         };
 
         let (val, fn_ty, must_cast) =
-            monomorphize::monomorphic_fn(ccx, def_id, &substs, opt_ref_id);
+            monomorphize::monomorphic_fn(ccx, def_id, substs, opt_ref_id);
         if must_cast && node != ExprId(0) {
             // Monotype of the REFERENCE to the function (type params
             // are subst'd)
diff --git a/src/librustc_trans/trans/closure.rs b/src/librustc_trans/trans/closure.rs
index 8473ce1b797..f92df999e60 100644
--- a/src/librustc_trans/trans/closure.rs
+++ b/src/librustc_trans/trans/closure.rs
@@ -9,6 +9,7 @@
 // except according to those terms.
 
 use back::link::mangle_internal_name_by_path_and_seq;
+use llvm::ValueRef;
 use middle::mem_categorization::Typer;
 use trans::adt;
 use trans::base::*;
@@ -137,7 +138,7 @@ pub fn get_or_create_declaration_if_closure<'a, 'tcx>(ccx: &CrateContext<'a, 'tc
     // duplicate declarations
     let function_type = erase_regions(ccx.tcx(), &function_type);
     let params = match function_type.sty {
-        ty::ty_closure(_, _, ref substs) => substs.types.clone(),
+        ty::ty_closure(_, _, substs) => &substs.types,
         _ => unreachable!()
     };
     let mono_id = MonoId {
@@ -171,41 +172,51 @@ pub fn get_or_create_declaration_if_closure<'a, 'tcx>(ccx: &CrateContext<'a, 'tc
     Some(Datum::new(llfn, function_type, Rvalue::new(ByValue)))
 }
 
-pub fn trans_closure_expr<'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
-                                      decl: &ast::FnDecl,
-                                      body: &ast::Block,
-                                      id: ast::NodeId,
-                                      dest: expr::Dest)
-                                      -> Block<'blk, 'tcx>
+pub enum Dest<'a, 'tcx: 'a> {
+    SaveIn(Block<'a, 'tcx>, ValueRef),
+    Ignore(&'a CrateContext<'a, 'tcx>)
+}
+
+pub fn trans_closure_expr<'a, 'tcx>(dest: Dest<'a, 'tcx>,
+                                    decl: &ast::FnDecl,
+                                    body: &ast::Block,
+                                    id: ast::NodeId,
+                                    param_substs: &'tcx Substs<'tcx>)
+                                    -> Option<Block<'a, 'tcx>>
 {
+    let ccx = match dest {
+        Dest::SaveIn(bcx, _) => bcx.ccx(),
+        Dest::Ignore(ccx) => ccx
+    };
+    let tcx = ccx.tcx();
     let _icx = push_ctxt("closure::trans_closure");
 
     debug!("trans_closure()");
 
     let closure_id = ast_util::local_def(id);
     let llfn = get_or_create_declaration_if_closure(
-        bcx.ccx(),
+        ccx,
         closure_id,
-        bcx.fcx.param_substs).unwrap();
+        param_substs).unwrap();
 
     // Get the type of this closure. Use the current `param_substs` as
     // the closure substitutions. This makes sense because the closure
     // takes the same set of type arguments as the enclosing fn, and
     // this function (`trans_closure`) is invoked at the point
     // of the closure expression.
-    let typer = NormalizingClosureTyper::new(bcx.tcx());
-    let function_type = typer.closure_type(closure_id, bcx.fcx.param_substs);
+    let typer = NormalizingClosureTyper::new(tcx);
+    let function_type = typer.closure_type(closure_id, param_substs);
 
     let freevars: Vec<ty::Freevar> =
-        ty::with_freevars(bcx.tcx(), id, |fv| fv.iter().map(|&fv| fv).collect());
+        ty::with_freevars(tcx, id, |fv| fv.iter().map(|&fv| fv).collect());
 
-    let sig = ty::erase_late_bound_regions(bcx.tcx(), &function_type.sig);
+    let sig = ty::erase_late_bound_regions(tcx, &function_type.sig);
 
-    trans_closure(bcx.ccx(),
+    trans_closure(ccx,
                   decl,
                   body,
                   llfn.val,
-                  bcx.fcx.param_substs,
+                  param_substs,
                   id,
                   &[],
                   sig.output,
@@ -215,15 +226,15 @@ pub fn trans_closure_expr<'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
     // Don't hoist this to the top of the function. It's perfectly legitimate
     // to have a zero-size closure (in which case dest will be `Ignore`) and
     // we must still generate the closure body.
-    let dest_addr = match dest {
-        expr::SaveIn(p) => p,
-        expr::Ignore => {
+    let (mut bcx, dest_addr) = match dest {
+        Dest::SaveIn(bcx, p) => (bcx, p),
+        Dest::Ignore(_) => {
             debug!("trans_closure() ignoring result");
-            return bcx
+            return None;
         }
     };
 
-    let repr = adt::represent_type(bcx.ccx(), node_id_type(bcx, id));
+    let repr = adt::represent_type(ccx, node_id_type(bcx, id));
 
     // Create the closure.
     for (i, freevar) in freevars.iter().enumerate() {
@@ -235,8 +246,7 @@ pub fn trans_closure_expr<'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
                                                    i);
         let upvar_id = ty::UpvarId { var_id: freevar.def.local_node_id(),
                                      closure_expr_id: id };
-        let upvar_capture = bcx.tcx().upvar_capture(upvar_id).unwrap();
-        match upvar_capture {
+        match tcx.upvar_capture(upvar_id).unwrap() {
             ty::UpvarCapture::ByValue => {
                 bcx = datum.store_to(bcx, upvar_slot_dest);
             }
@@ -247,6 +257,6 @@ pub fn trans_closure_expr<'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
     }
     adt::trans_set_discr(bcx, &*repr, dest_addr, 0);
 
-    bcx
+    Some(bcx)
 }
 
diff --git a/src/librustc_trans/trans/common.rs b/src/librustc_trans/trans/common.rs
index 87b7f413fd1..d658003702d 100644
--- a/src/librustc_trans/trans/common.rs
+++ b/src/librustc_trans/trans/common.rs
@@ -410,7 +410,7 @@ pub struct FunctionContext<'a, 'tcx: 'a> {
 
     // If this function is being monomorphized, this contains the type
     // substitutions used.
-    pub param_substs: &'a Substs<'tcx>,
+    pub param_substs: &'tcx Substs<'tcx>,
 
     // The source span and nesting context where this function comes from, for
     // error reporting and symbol generation.
@@ -858,25 +858,6 @@ pub fn C_str_slice(cx: &CrateContext, s: InternedString) -> ValueRef {
     C_named_struct(cx.tn().find_type("str_slice").unwrap(), &[cs, C_uint(cx, len)])
 }
 
-pub fn C_binary_slice(cx: &CrateContext, data: &[u8]) -> ValueRef {
-    unsafe {
-        let len = data.len();
-        let lldata = C_bytes(cx, data);
-
-        let gsym = token::gensym("binary");
-        let name = format!("binary{}", gsym.usize());
-        let name = CString::from_vec(name.into_bytes());
-        let g = llvm::LLVMAddGlobal(cx.llmod(), val_ty(lldata).to_ref(),
-                                    name.as_ptr());
-        llvm::LLVMSetInitializer(g, lldata);
-        llvm::LLVMSetGlobalConstant(g, True);
-        llvm::SetLinkage(g, llvm::InternalLinkage);
-
-        let cs = consts::ptrcast(g, Type::i8p(cx));
-        C_struct(cx, &[cs, C_uint(cx, len)], false)
-    }
-}
-
 pub fn C_struct(cx: &CrateContext, elts: &[ValueRef], packed: bool) -> ValueRef {
     C_struct_in_context(cx.llcx(), elts, packed)
 }
@@ -901,6 +882,12 @@ pub fn C_array(ty: Type, elts: &[ValueRef]) -> ValueRef {
     }
 }
 
+pub fn C_vector(elts: &[ValueRef]) -> ValueRef {
+    unsafe {
+        return llvm::LLVMConstVector(elts.as_ptr(), elts.len() as c_uint);
+    }
+}
+
 pub fn C_bytes(cx: &CrateContext, bytes: &[u8]) -> ValueRef {
     C_bytes_in_context(cx.llcx(), bytes)
 }
diff --git a/src/librustc_trans/trans/consts.rs b/src/librustc_trans/trans/consts.rs
index 278323d186b..86f5589556a 100644
--- a/src/librustc_trans/trans/consts.rs
+++ b/src/librustc_trans/trans/consts.rs
@@ -11,13 +11,13 @@
 
 use back::abi;
 use llvm;
-use llvm::{ConstFCmp, ConstICmp, SetLinkage, PrivateLinkage, ValueRef, Bool, True, False};
-use llvm::{IntEQ, IntNE, IntUGT, IntUGE, IntULT, IntULE, IntSGT, IntSGE, IntSLT, IntSLE,
-           RealOEQ, RealOGT, RealOGE, RealOLT, RealOLE, RealONE};
-use middle::{const_eval, def};
-use trans::{adt, consts, debuginfo, expr, inline, machine};
+use llvm::{ConstFCmp, ConstICmp, SetLinkage, SetUnnamedAddr};
+use llvm::{InternalLinkage, ValueRef, Bool, True};
+use middle::{check_const, const_eval, def};
+use trans::{adt, closure, debuginfo, expr, inline, machine};
 use trans::base::{self, push_ctxt};
 use trans::common::*;
+use trans::monomorphize;
 use trans::type_::Type;
 use trans::type_of;
 use middle::subst::Substs;
@@ -74,7 +74,16 @@ pub fn const_lit(cx: &CrateContext, e: &ast::Expr, lit: &ast::Lit)
         }
         ast::LitBool(b) => C_bool(cx, b),
         ast::LitStr(ref s, _) => C_str_slice(cx, (*s).clone()),
-        ast::LitBinary(ref data) => C_binary_slice(cx, &data[]),
+        ast::LitBinary(ref data) => {
+            let g = addr_of(cx, C_bytes(cx, &data[]), "binary", e.id);
+            let base = ptrcast(g, Type::i8p(cx));
+            let prev_const = cx.const_unsized().borrow_mut()
+                               .insert(base, g);
+            assert!(prev_const.is_none() || prev_const == Some(g));
+            assert_eq!(abi::FAT_PTR_ADDR, 0);
+            assert_eq!(abi::FAT_PTR_EXTRA, 1);
+            C_struct(cx, &[base, C_uint(cx, data.len())], false)
+        }
     }
 }
 
@@ -84,36 +93,41 @@ pub fn ptrcast(val: ValueRef, ty: Type) -> ValueRef {
     }
 }
 
-fn const_vec(cx: &CrateContext, e: &ast::Expr,
-             es: &[P<ast::Expr>]) -> (ValueRef, Type) {
-    let vec_ty = ty::expr_ty(cx.tcx(), e);
-    let unit_ty = ty::sequence_element_type(cx.tcx(), vec_ty);
-    let llunitty = type_of::type_of(cx, unit_ty);
-    let vs = es.iter().map(|e| const_expr(cx, &**e).0)
-                      .collect::<Vec<_>>();
-    // If the vector contains enums, an LLVM array won't work.
-    let v = if vs.iter().any(|vi| val_ty(*vi) != llunitty) {
-        C_struct(cx, &vs[], false)
-    } else {
-        C_array(llunitty, &vs[])
-    };
-    (v, llunitty)
-}
-
-pub fn const_addr_of(cx: &CrateContext, cv: ValueRef, mutbl: ast::Mutability) -> ValueRef {
+fn addr_of_mut(ccx: &CrateContext,
+               cv: ValueRef,
+               kind: &str,
+               id: ast::NodeId)
+               -> ValueRef {
     unsafe {
-        let gv = llvm::LLVMAddGlobal(cx.llmod(), val_ty(cv).to_ref(),
-                                     "const\0".as_ptr() as *const _);
+        let name = format!("{}{}\0", kind, id);
+        let gv = llvm::LLVMAddGlobal(ccx.llmod(), val_ty(cv).to_ref(),
+                                     name.as_ptr() as *const _);
         llvm::LLVMSetInitializer(gv, cv);
-        llvm::LLVMSetGlobalConstant(gv,
-                                    if mutbl == ast::MutImmutable {True} else {False});
-        SetLinkage(gv, PrivateLinkage);
+        SetLinkage(gv, InternalLinkage);
+        SetUnnamedAddr(gv, true);
         gv
     }
 }
 
+pub fn addr_of(ccx: &CrateContext,
+               cv: ValueRef,
+               kind: &str,
+               id: ast::NodeId)
+               -> ValueRef {
+    match ccx.const_globals().borrow().get(&cv) {
+        Some(&gv) => return gv,
+        None => {}
+    }
+    let gv = addr_of_mut(ccx, cv, kind, id);
+    unsafe {
+        llvm::LLVMSetGlobalConstant(gv, True);
+    }
+    ccx.const_globals().borrow_mut().insert(cv, gv);
+    gv
+}
+
 fn const_deref_ptr(cx: &CrateContext, v: ValueRef) -> ValueRef {
-    let v = match cx.const_globals().borrow().get(&(v as int)) {
+    let v = match cx.const_unsized().borrow().get(&v) {
         Some(&v) => v,
         None => v
     };
@@ -122,155 +136,209 @@ fn const_deref_ptr(cx: &CrateContext, v: ValueRef) -> ValueRef {
     }
 }
 
-fn const_deref_newtype<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, v: ValueRef, t: Ty<'tcx>)
-    -> ValueRef {
-    let repr = adt::represent_type(cx, t);
-    adt::const_get_field(cx, &*repr, v, 0, 0)
-}
-
-fn const_deref<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, v: ValueRef,
-                         t: Ty<'tcx>, explicit: bool)
+fn const_deref<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>,
+                         v: ValueRef,
+                         ty: Ty<'tcx>)
                          -> (ValueRef, Ty<'tcx>) {
-    match ty::deref(t, explicit) {
-        Some(ref mt) => {
-            match t.sty {
-                ty::ty_ptr(mt) | ty::ty_rptr(_, mt) => {
-                    if type_is_sized(cx.tcx(), mt.ty) {
-                        (const_deref_ptr(cx, v), mt.ty)
-                    } else {
-                        // Derefing a fat pointer does not change the representation,
-                        // just the type to ty_open.
-                        (v, ty::mk_open(cx.tcx(), mt.ty))
-                    }
-                }
-                ty::ty_enum(..) | ty::ty_struct(..) => {
-                    assert!(mt.mutbl != ast::MutMutable);
-                    (const_deref_newtype(cx, v, t), mt.ty)
-                }
-                _ => {
-                    cx.sess().bug(&format!("unexpected dereferenceable type {}",
-                                          ty_to_string(cx.tcx(), t))[])
-                }
+    match ty::deref(ty, true) {
+        Some(mt) => {
+            if type_is_sized(cx.tcx(), mt.ty) {
+                (const_deref_ptr(cx, v), mt.ty)
+            } else {
+                // Derefing a fat pointer does not change the representation,
+                // just the type to ty_open.
+                (v, ty::mk_open(cx.tcx(), mt.ty))
             }
         }
         None => {
-            cx.sess().bug(&format!("cannot dereference const of type {}",
-                                  ty_to_string(cx.tcx(), t))[])
+            cx.sess().bug(&format!("unexpected dereferenceable type {}",
+                                   ty_to_string(cx.tcx(), ty))[])
         }
     }
 }
 
-pub fn get_const_val(cx: &CrateContext,
-                     mut def_id: ast::DefId) -> ValueRef {
-    let contains_key = cx.const_values().borrow().contains_key(&def_id.node);
-    if !ast_util::is_local(def_id) || !contains_key {
-        if !ast_util::is_local(def_id) {
-            def_id = inline::maybe_instantiate_inline(cx, def_id);
-        }
+pub fn get_const_expr<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
+                                def_id: ast::DefId,
+                                ref_expr: &ast::Expr)
+                                -> &'tcx ast::Expr {
+    let def_id = inline::maybe_instantiate_inline(ccx, def_id);
+
+    if def_id.krate != ast::LOCAL_CRATE {
+        ccx.sess().span_bug(ref_expr.span,
+                            "cross crate constant could not be inlined");
+    }
+
+    let item = ccx.tcx().map.expect_item(def_id.node);
+    if let ast::ItemConst(_, ref expr) = item.node {
+        &**expr
+    } else {
+        ccx.sess().span_bug(ref_expr.span,
+                            &format!("get_const_val given non-constant item {}",
+                                     item.repr(ccx.tcx()))[]);
+    }
+}
 
-        if let ast::ItemConst(..) = cx.tcx().map.expect_item(def_id.node).node {
-            base::get_item_val(cx, def_id.node);
+fn get_const_val(ccx: &CrateContext,
+                 def_id: ast::DefId,
+                 ref_expr: &ast::Expr) -> ValueRef {
+    let expr = get_const_expr(ccx, def_id, ref_expr);
+    let empty_substs = ccx.tcx().mk_substs(Substs::trans_empty());
+    get_const_expr_as_global(ccx, expr, check_const::PURE_CONST, empty_substs)
+}
+
+pub fn get_const_expr_as_global<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
+                                          expr: &ast::Expr,
+                                          qualif: check_const::ConstQualif,
+                                          param_substs: &'tcx Substs<'tcx>)
+                                          -> ValueRef {
+    // Special-case constants to cache a common global for all uses.
+    match expr.node {
+        ast::ExprPath(_) => {
+            let def = ccx.tcx().def_map.borrow()[expr.id];
+            match def {
+                def::DefConst(def_id) => {
+                    if !ccx.tcx().adjustments.borrow().contains_key(&expr.id) {
+                        return get_const_val(ccx, def_id, expr);
+                    }
+                }
+                _ => {}
+            }
         }
+        _ => {}
+    }
+
+    let key = (expr.id, param_substs);
+    match ccx.const_values().borrow().get(&key) {
+        Some(&val) => return val,
+        None => {}
     }
+    let val = if qualif.intersects(check_const::NON_STATIC_BORROWS) {
+        // Avoid autorefs as they would create global instead of stack
+        // references, even when only the latter are correct.
+        let ty = monomorphize::apply_param_substs(ccx.tcx(), param_substs,
+                                                  &ty::expr_ty(ccx.tcx(), expr));
+        const_expr_unadjusted(ccx, expr, ty, param_substs)
+    } else {
+        const_expr(ccx, expr, param_substs).0
+    };
 
-    cx.const_values().borrow()[def_id.node].clone()
+    // boolean SSA values are i1, but they have to be stored in i8 slots,
+    // otherwise some LLVM optimization passes don't work as expected
+    let val = unsafe {
+        if llvm::LLVMTypeOf(val) == Type::i1(ccx).to_ref() {
+            llvm::LLVMConstZExt(val, Type::i8(ccx).to_ref())
+        } else {
+            val
+        }
+    };
+
+    let lvalue = addr_of(ccx, val, "const", expr.id);
+    ccx.const_values().borrow_mut().insert(key, lvalue);
+    lvalue
 }
 
-pub fn const_expr<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, e: &ast::Expr)
+pub fn const_expr<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>,
+                            e: &ast::Expr,
+                            param_substs: &'tcx Substs<'tcx>)
                             -> (ValueRef, Ty<'tcx>) {
-    let llconst = const_expr_unadjusted(cx, e);
+    let ety = monomorphize::apply_param_substs(cx.tcx(), param_substs,
+                                               &ty::expr_ty(cx.tcx(), e));
+    let llconst = const_expr_unadjusted(cx, e, ety, param_substs);
     let mut llconst = llconst;
-    let ety = ty::expr_ty(cx.tcx(), e);
-    let mut ety_adjusted = ty::expr_ty_adjusted(cx.tcx(), e);
+    let mut ety_adjusted = monomorphize::apply_param_substs(cx.tcx(), param_substs,
+                                                            &ty::expr_ty_adjusted(cx.tcx(), e));
     let opt_adj = cx.tcx().adjustments.borrow().get(&e.id).cloned();
     match opt_adj {
-        None => { }
-        Some(adj) => {
-            match adj {
-               ty::AdjustReifyFnPointer(_def_id) => {
-                    // FIXME(#19925) once fn item types are
-                    // zero-sized, we'll need to do something here
+        Some(ty::AdjustReifyFnPointer(_def_id)) => {
+            // FIXME(#19925) once fn item types are
+            // zero-sized, we'll need to do something here
+        }
+        Some(ty::AdjustDerefRef(adj)) => {
+            let mut ty = ety;
+            // Save the last autoderef in case we can avoid it.
+            if adj.autoderefs > 0 {
+                for _ in 0..adj.autoderefs-1 {
+                    let (dv, dt) = const_deref(cx, llconst, ty);
+                    llconst = dv;
+                    ty = dt;
                 }
-                ty::AdjustDerefRef(ref adj) => {
-                    let mut ty = ety;
-                    // Save the last autoderef in case we can avoid it.
-                    if adj.autoderefs > 0 {
-                        for _ in 0..adj.autoderefs-1 {
-                            let (dv, dt) = const_deref(cx, llconst, ty, false);
-                            llconst = dv;
-                            ty = dt;
-                        }
-                    }
+            }
 
-                    match adj.autoref {
-                        None => {
-                            let (dv, dt) = const_deref(cx, llconst, ty, false);
-                            llconst = dv;
+            let second_autoref = match adj.autoref {
+                None => {
+                    let (dv, dt) = const_deref(cx, llconst, ty);
+                    llconst = dv;
 
-                            // If we derefed a fat pointer then we will have an
-                            // open type here. So we need to update the type with
-                            // the one returned from const_deref.
-                            ety_adjusted = dt;
-                        }
-                        Some(ref autoref) => {
-                            match *autoref {
-                                ty::AutoUnsafe(_, None) |
-                                ty::AutoPtr(ty::ReStatic, _, None) => {
-                                    // Don't copy data to do a deref+ref
-                                    // (i.e., skip the last auto-deref).
-                                    if adj.autoderefs == 0 {
-                                        llconst = const_addr_of(cx, llconst, ast::MutImmutable);
-                                    }
-                                }
-                                ty::AutoPtr(ty::ReStatic, _, Some(box ty::AutoUnsize(..))) => {
-                                    if adj.autoderefs > 0 {
-                                        // Seeing as we are deref'ing here and take a reference
-                                        // again to make the pointer part of the far pointer below,
-                                        // we just skip the whole thing. We still need the type
-                                        // though. This works even if we don't need to deref
-                                        // because of byref semantics. Note that this is not just
-                                        // an optimisation, it is necessary for mutable vectors to
-                                        // work properly.
-                                        let (_, dt) = const_deref(cx, llconst, ty, false);
-                                        ty = dt;
-                                    } else {
-                                        llconst = const_addr_of(cx, llconst, ast::MutImmutable)
-                                    }
-
-                                    match ty.sty {
-                                        ty::ty_vec(unit_ty, Some(len)) => {
-                                            let llunitty = type_of::type_of(cx, unit_ty);
-                                            let llptr = ptrcast(llconst, llunitty.ptr_to());
-                                            let prev_const = cx.const_globals().borrow_mut()
-                                                             .insert(llptr as int, llconst);
-                                            assert!(prev_const.is_none() ||
-                                                    prev_const == Some(llconst));
-                                            assert_eq!(abi::FAT_PTR_ADDR, 0);
-                                            assert_eq!(abi::FAT_PTR_EXTRA, 1);
-                                            llconst = C_struct(cx, &[
-                                                llptr,
-                                                C_uint(cx, len)
-                                            ], false);
-                                        }
-                                        _ => cx.sess().span_bug(e.span,
-                                            &format!("unimplemented type in const unsize: {}",
-                                                    ty_to_string(cx.tcx(), ty))[])
-                                    }
-                                }
-                                _ => {
-                                    cx.sess()
-                                      .span_bug(e.span,
-                                                &format!("unimplemented const \
-                                                         autoref {:?}",
-                                                        autoref)[])
+                    // If we derefed a fat pointer then we will have an
+                    // open type here. So we need to update the type with
+                    // the one returned from const_deref.
+                    ety_adjusted = dt;
+                    None
+                }
+                Some(ty::AutoUnsafe(_, opt_autoref)) |
+                Some(ty::AutoPtr(_, _, opt_autoref)) => {
+                    if adj.autoderefs == 0 {
+                        // Don't copy data to do a deref+ref
+                        // (i.e., skip the last auto-deref).
+                        llconst = addr_of(cx, llconst, "autoref", e.id);
+                    } else {
+                        // Seeing as we are deref'ing here and take a reference
+                        // again to make the pointer part of the far pointer below,
+                        // we just skip the whole thing. We still need the type
+                        // though. This works even if we don't need to deref
+                        // because of byref semantics. Note that this is not just
+                        // an optimisation, it is necessary for mutable vectors to
+                        // work properly.
+                        ty = match ty::deref(ty, true) {
+                            Some(mt) => {
+                                if type_is_sized(cx.tcx(), mt.ty) {
+                                    mt.ty
+                                } else {
+                                    // Derefing a fat pointer does not change the representation,
+                                    // just the type to ty_open.
+                                    ty::mk_open(cx.tcx(), mt.ty)
                                 }
                             }
+                            None => {
+                                cx.sess().bug(&format!("unexpected dereferenceable type {}",
+                                                       ty_to_string(cx.tcx(), ty))[])
+                            }
                         }
                     }
+                    opt_autoref
+                }
+                Some(autoref) => {
+                    cx.sess().span_bug(e.span,
+                        &format!("unimplemented const first autoref {:?}", autoref)[])
+                }
+            };
+            match second_autoref {
+                None => {}
+                Some(box ty::AutoUnsafe(_, None)) |
+                Some(box ty::AutoPtr(_, _, None)) => {
+                    llconst = addr_of(cx, llconst, "autoref", e.id);
+                }
+                Some(box ty::AutoUnsize(ref k)) => {
+                    let unsized_ty = ty::unsize_ty(cx.tcx(), ty, k, e.span);
+                    let info = expr::unsized_info(cx, k, e.id, ty, param_substs,
+                        |t| ty::mk_imm_rptr(cx.tcx(), cx.tcx().mk_region(ty::ReStatic), t));
+
+                    let base = ptrcast(llconst, type_of::type_of(cx, unsized_ty).ptr_to());
+                    let prev_const = cx.const_unsized().borrow_mut()
+                                       .insert(base, llconst);
+                    assert!(prev_const.is_none() || prev_const == Some(llconst));
+                    assert_eq!(abi::FAT_PTR_ADDR, 0);
+                    assert_eq!(abi::FAT_PTR_EXTRA, 1);
+                    llconst = C_struct(cx, &[base, info], false);
+                }
+                Some(autoref) => {
+                    cx.sess().span_bug(e.span,
+                        &format!("unimplemented const second autoref {:?}", autoref)[])
                 }
             }
         }
-    }
+        None => {}
+    };
 
     let llty = type_of::sizing_type_of(cx, ety_adjusted);
     let csize = machine::llsize_of_alloc(cx, val_ty(llconst));
@@ -282,36 +350,42 @@ pub fn const_expr<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, e: &ast::Expr)
             llvm::LLVMDumpValue(C_undef(llty));
         }
         cx.sess().bug(&format!("const {} of type {} has size {} instead of {}",
-                         e.repr(cx.tcx()), ty_to_string(cx.tcx(), ety),
+                         e.repr(cx.tcx()), ty_to_string(cx.tcx(), ety_adjusted),
                          csize, tsize)[]);
     }
     (llconst, ety_adjusted)
 }
 
-// the bool returned is whether this expression can be inlined into other crates
-// if it's assigned to a static.
-fn const_expr_unadjusted(cx: &CrateContext, e: &ast::Expr) -> ValueRef {
+fn const_expr_unadjusted<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>,
+                                   e: &ast::Expr,
+                                   ety: Ty<'tcx>,
+                                   param_substs: &'tcx Substs<'tcx>) -> ValueRef {
     let map_list = |exprs: &[P<ast::Expr>]| {
-        exprs.iter().map(|e| const_expr(cx, &**e).0)
+        exprs.iter().map(|e| const_expr(cx, &**e, param_substs).0)
              .fold(Vec::new(), |mut l, val| { l.push(val); l })
     };
     unsafe {
         let _icx = push_ctxt("const_expr");
         return match e.node {
           ast::ExprLit(ref lit) => {
-              consts::const_lit(cx, e, &**lit)
+              const_lit(cx, e, &**lit)
           }
           ast::ExprBinary(b, ref e1, ref e2) => {
-            let (te1, _) = const_expr(cx, &**e1);
-            let (te2, _) = const_expr(cx, &**e2);
+            /* Neither type is bottom, and we expect them to be unified
+             * already, so the following is safe. */
+            let (te1, ty) = const_expr(cx, &**e1, param_substs);
+            let is_simd = ty::type_is_simd(cx.tcx(), ty);
+            let intype = if is_simd {
+                ty::simd_type(cx.tcx(), ty)
+            } else {
+                ty
+            };
+            let is_float = ty::type_is_fp(intype);
+            let signed = ty::type_is_signed(intype);
 
+            let (te2, _) = const_expr(cx, &**e2, param_substs);
             let te2 = base::cast_shift_const_rhs(b, te1, te2);
 
-            /* Neither type is bottom, and we expect them to be unified
-             * already, so the following is safe. */
-            let ty = ty::expr_ty(cx.tcx(), &**e1);
-            let is_float = ty::type_is_fp(ty);
-            let signed = ty::type_is_signed(ty);
             return match b.node {
               ast::BiAdd   => {
                 if is_float { llvm::LLVMConstFAdd(te1, te2) }
@@ -345,52 +419,30 @@ fn const_expr_unadjusted(cx: &CrateContext, e: &ast::Expr) -> ValueRef {
                 if signed { llvm::LLVMConstAShr(te1, te2) }
                 else      { llvm::LLVMConstLShr(te1, te2) }
               }
-              ast::BiEq     => {
-                  if is_float { ConstFCmp(RealOEQ, te1, te2) }
-                  else        { ConstICmp(IntEQ, te1, te2)   }
-              },
-              ast::BiLt     => {
-                  if is_float { ConstFCmp(RealOLT, te1, te2) }
-                  else        {
-                      if signed { ConstICmp(IntSLT, te1, te2) }
-                      else      { ConstICmp(IntULT, te1, te2) }
-                  }
-              },
-              ast::BiLe     => {
-                  if is_float { ConstFCmp(RealOLE, te1, te2) }
-                  else        {
-                      if signed { ConstICmp(IntSLE, te1, te2) }
-                      else      { ConstICmp(IntULE, te1, te2) }
-                  }
-              },
-              ast::BiNe     => {
-                  if is_float { ConstFCmp(RealONE, te1, te2) }
-                  else        { ConstICmp(IntNE, te1, te2) }
-              },
-              ast::BiGe     => {
-                  if is_float { ConstFCmp(RealOGE, te1, te2) }
-                  else        {
-                      if signed { ConstICmp(IntSGE, te1, te2) }
-                      else      { ConstICmp(IntUGE, te1, te2) }
-                  }
-              },
-              ast::BiGt     => {
-                  if is_float { ConstFCmp(RealOGT, te1, te2) }
-                  else        {
-                      if signed { ConstICmp(IntSGT, te1, te2) }
-                      else      { ConstICmp(IntUGT, te1, te2) }
+              ast::BiEq | ast::BiNe | ast::BiLt | ast::BiLe | ast::BiGt | ast::BiGe => {
+                  if is_float {
+                      let cmp = base::bin_op_to_fcmp_predicate(cx, b.node);
+                      ConstFCmp(cmp, te1, te2)
+                  } else {
+                      let cmp = base::bin_op_to_icmp_predicate(cx, b.node, signed);
+                      let bool_val = ConstICmp(cmp, te1, te2);
+                      if is_simd {
+                          // LLVM outputs an `< size x i1 >`, so we need to perform
+                          // a sign extension to get the correctly sized type.
+                          llvm::LLVMConstIntCast(bool_val, val_ty(te1).to_ref(), True)
+                      } else {
+                          bool_val
+                      }
                   }
-              },
+              }
             }
           },
           ast::ExprUnary(u, ref e) => {
-            let (te, _) = const_expr(cx, &**e);
-            let ty = ty::expr_ty(cx.tcx(), &**e);
+            let (te, ty) = const_expr(cx, &**e, param_substs);
             let is_float = ty::type_is_fp(ty);
             return match u {
               ast::UnUniq | ast::UnDeref => {
-                let (dv, _dt) = const_deref(cx, te, ty, true);
-                dv
+                const_deref(cx, te, ty).0
               }
               ast::UnNot    => llvm::LLVMConstNot(te),
               ast::UnNeg    => {
@@ -400,7 +452,7 @@ fn const_expr_unadjusted(cx: &CrateContext, e: &ast::Expr) -> ValueRef {
             }
           }
           ast::ExprField(ref base, field) => {
-              let (bv, bt) = const_expr(cx, &**base);
+              let (bv, bt) = const_expr(cx, &**base, param_substs);
               let brepr = adt::represent_type(cx, bt);
               expr::with_field_tys(cx.tcx(), bt, None, |discr, field_tys| {
                   let ix = ty::field_idx_strict(cx.tcx(), field.node.name, field_tys);
@@ -408,7 +460,7 @@ fn const_expr_unadjusted(cx: &CrateContext, e: &ast::Expr) -> ValueRef {
               })
           }
           ast::ExprTupField(ref base, idx) => {
-              let (bv, bt) = const_expr(cx, &**base);
+              let (bv, bt) = const_expr(cx, &**base, param_substs);
               let brepr = adt::represent_type(cx, bt);
               expr::with_field_tys(cx.tcx(), bt, None, |discr, _| {
                   adt::const_get_field(cx, &*brepr, bv, discr, idx.node)
@@ -416,7 +468,7 @@ fn const_expr_unadjusted(cx: &CrateContext, e: &ast::Expr) -> ValueRef {
           }
 
           ast::ExprIndex(ref base, ref index) => {
-              let (bv, bt) = const_expr(cx, &**base);
+              let (bv, bt) = const_expr(cx, &**base, param_substs);
               let iv = match const_eval::eval_const_expr(cx.tcx(), &**index) {
                   const_eval::const_int(i) => i as u64,
                   const_eval::const_uint(u) => u,
@@ -470,9 +522,11 @@ fn const_expr_unadjusted(cx: &CrateContext, e: &ast::Expr) -> ValueRef {
               const_get_elt(cx, arr, &[iv as c_uint])
           }
           ast::ExprCast(ref base, _) => {
-            let ety = ty::expr_ty(cx.tcx(), e);
             let llty = type_of::type_of(cx, ety);
-            let (v, basety) = const_expr(cx, &**base);
+            let (v, basety) = const_expr(cx, &**base, param_substs);
+            if expr::cast_is_noop(basety, ety) {
+                return v;
+            }
             return match (expr::cast_type_kind(cx.tcx(), basety),
                            expr::cast_type_kind(cx.tcx(), ety)) {
 
@@ -523,7 +577,7 @@ fn const_expr_unadjusted(cx: &CrateContext, e: &ast::Expr) -> ValueRef {
               }
             }
           }
-          ast::ExprAddrOf(mutbl, ref sub) => {
+          ast::ExprAddrOf(ast::MutImmutable, ref sub) => {
               // If this is the address of some static, then we need to return
               // the actual address of the static itself (short circuit the rest
               // of const eval).
@@ -531,41 +585,48 @@ fn const_expr_unadjusted(cx: &CrateContext, e: &ast::Expr) -> ValueRef {
               loop {
                   match cur.node {
                       ast::ExprParen(ref sub) => cur = sub,
+                      ast::ExprBlock(ref blk) => {
+                        if let Some(ref sub) = blk.expr {
+                            cur = sub;
+                        } else {
+                            break;
+                        }
+                      }
                       _ => break,
                   }
               }
               let opt_def = cx.tcx().def_map.borrow().get(&cur.id).cloned();
               if let Some(def::DefStatic(def_id, _)) = opt_def {
-                  let ty = ty::expr_ty(cx.tcx(), e);
-                  return get_static_val(cx, def_id, ty);
+                  return get_static_val(cx, def_id, ety);
               }
 
               // If this isn't the address of a static, then keep going through
               // normal constant evaluation.
-              let (e, _) = const_expr(cx, &**sub);
-              const_addr_of(cx, e, mutbl)
+              let (v, _) = const_expr(cx, &**sub, param_substs);
+              addr_of(cx, v, "ref", e.id)
+          }
+          ast::ExprAddrOf(ast::MutMutable, ref sub) => {
+              let (v, _) = const_expr(cx, &**sub, param_substs);
+              addr_of_mut(cx, v, "ref_mut_slice", e.id)
           }
           ast::ExprTup(ref es) => {
-              let ety = ty::expr_ty(cx.tcx(), e);
               let repr = adt::represent_type(cx, ety);
               let vals = map_list(&es[]);
               adt::trans_const(cx, &*repr, 0, &vals[])
           }
           ast::ExprStruct(_, ref fs, ref base_opt) => {
-              let ety = ty::expr_ty(cx.tcx(), e);
               let repr = adt::represent_type(cx, ety);
-              let tcx = cx.tcx();
 
               let base_val = match *base_opt {
-                Some(ref base) => Some(const_expr(cx, &**base)),
+                Some(ref base) => Some(const_expr(cx, &**base, param_substs)),
                 None => None
               };
 
-              expr::with_field_tys(tcx, ety, Some(e.id), |discr, field_tys| {
+              expr::with_field_tys(cx.tcx(), ety, Some(e.id), |discr, field_tys| {
                   let cs = field_tys.iter().enumerate()
                                     .map(|(ix, &field_ty)| {
                       match fs.iter().find(|f| field_ty.name == f.ident.node.name) {
-                          Some(ref f) => const_expr(cx, &*f.expr).0,
+                          Some(ref f) => const_expr(cx, &*f.expr, param_substs).0,
                           None => {
                               match base_val {
                                   Some((bv, _)) => {
@@ -580,23 +641,36 @@ fn const_expr_unadjusted(cx: &CrateContext, e: &ast::Expr) -> ValueRef {
                           }
                       }
                   }).collect::<Vec<_>>();
-                  adt::trans_const(cx, &*repr, discr, &cs[])
+                  if ty::type_is_simd(cx.tcx(), ety) {
+                      C_vector(&cs[])
+                  } else {
+                      adt::trans_const(cx, &*repr, discr, &cs[])
+                  }
               })
           }
           ast::ExprVec(ref es) => {
-            const_vec(cx, e, es).0
+            let unit_ty = ty::sequence_element_type(cx.tcx(), ety);
+            let llunitty = type_of::type_of(cx, unit_ty);
+            let vs = es.iter().map(|e| const_expr(cx, &**e, param_substs).0)
+                              .collect::<Vec<_>>();
+            // If the vector contains enums, an LLVM array won't work.
+            if vs.iter().any(|vi| val_ty(*vi) != llunitty) {
+                C_struct(cx, &vs[], false)
+            } else {
+                C_array(llunitty, &vs[])
+            }
           }
           ast::ExprRepeat(ref elem, ref count) => {
-            let vec_ty = ty::expr_ty(cx.tcx(), e);
-            let unit_ty = ty::sequence_element_type(cx.tcx(), vec_ty);
+            let unit_ty = ty::sequence_element_type(cx.tcx(), ety);
             let llunitty = type_of::type_of(cx, unit_ty);
             let n = match const_eval::eval_const_expr(cx.tcx(), &**count) {
                 const_eval::const_int(i)  => i as uint,
                 const_eval::const_uint(i) => i as uint,
                 _ => cx.sess().span_bug(count.span, "count must be integral const expression.")
             };
-            let vs: Vec<_> = repeat(const_expr(cx, &**elem).0).take(n).collect();
-            if vs.iter().any(|vi| val_ty(*vi) != llunitty) {
+            let unit_val = const_expr(cx, &**elem, param_substs).0;
+            let vs: Vec<_> = repeat(unit_val).take(n).collect();
+            if val_ty(unit_val) != llunitty {
                 C_struct(cx, &vs[], false)
             } else {
                 C_array(llunitty, &vs[])
@@ -606,10 +680,10 @@ fn const_expr_unadjusted(cx: &CrateContext, e: &ast::Expr) -> ValueRef {
             let def = cx.tcx().def_map.borrow()[e.id];
             match def {
                 def::DefFn(..) | def::DefStaticMethod(..) | def::DefMethod(..) => {
-                    expr::trans_def_fn_unadjusted(cx, e, def, &Substs::trans_empty()).val
+                    expr::trans_def_fn_unadjusted(cx, e, def, param_substs).val
                 }
                 def::DefConst(def_id) => {
-                    get_const_val(cx, def_id)
+                    const_deref_ptr(cx, get_const_val(cx, def_id, e))
                 }
                 def::DefVariant(enum_did, variant_did, _) => {
                     let vinfo = ty::enum_variant_with_id(cx.tcx(),
@@ -617,19 +691,17 @@ fn const_expr_unadjusted(cx: &CrateContext, e: &ast::Expr) -> ValueRef {
                                                          variant_did);
                     if vinfo.args.len() > 0 {
                         // N-ary variant.
-                        expr::trans_def_fn_unadjusted(cx, e, def, &Substs::trans_empty()).val
+                        expr::trans_def_fn_unadjusted(cx, e, def, param_substs).val
                     } else {
                         // Nullary variant.
-                        let ety = ty::expr_ty(cx.tcx(), e);
                         let repr = adt::represent_type(cx, ety);
                         adt::trans_const(cx, &*repr, vinfo.disr_val, &[])
                     }
                 }
                 def::DefStruct(_) => {
-                    let ety = ty::expr_ty(cx.tcx(), e);
                     if let ty::ty_bare_fn(..) = ety.sty {
                         // Tuple struct.
-                        expr::trans_def_fn_unadjusted(cx, e, def, &Substs::trans_empty()).val
+                        expr::trans_def_fn_unadjusted(cx, e, def, param_substs).val
                     } else {
                         // Unit struct.
                         C_null(type_of::type_of(cx, ety))
@@ -643,20 +715,21 @@ fn const_expr_unadjusted(cx: &CrateContext, e: &ast::Expr) -> ValueRef {
           }
           ast::ExprCall(ref callee, ref args) => {
               let opt_def = cx.tcx().def_map.borrow().get(&callee.id).cloned();
+              let arg_vals = map_list(&args[]);
               match opt_def {
                   Some(def::DefStruct(_)) => {
-                      let ety = ty::expr_ty(cx.tcx(), e);
-                      let repr = adt::represent_type(cx, ety);
-                      let arg_vals = map_list(&args[]);
-                      adt::trans_const(cx, &*repr, 0, &arg_vals[])
+                      if ty::type_is_simd(cx.tcx(), ety) {
+                          C_vector(&arg_vals[])
+                      } else {
+                          let repr = adt::represent_type(cx, ety);
+                          adt::trans_const(cx, &*repr, 0, &arg_vals[])
+                      }
                   }
                   Some(def::DefVariant(enum_did, variant_did, _)) => {
-                      let ety = ty::expr_ty(cx.tcx(), e);
                       let repr = adt::represent_type(cx, ety);
                       let vinfo = ty::enum_variant_with_id(cx.tcx(),
                                                            enum_did,
                                                            variant_did);
-                      let arg_vals = map_list(&args[]);
                       adt::trans_const(cx,
                                        &*repr,
                                        vinfo.disr_val,
@@ -665,13 +738,19 @@ fn const_expr_unadjusted(cx: &CrateContext, e: &ast::Expr) -> ValueRef {
                   _ => cx.sess().span_bug(e.span, "expected a struct or variant def")
               }
           }
-          ast::ExprParen(ref e) => const_expr(cx, &**e).0,
+          ast::ExprParen(ref e) => const_expr(cx, &**e, param_substs).0,
           ast::ExprBlock(ref block) => {
             match block.expr {
-                Some(ref expr) => const_expr(cx, &**expr).0,
+                Some(ref expr) => const_expr(cx, &**expr, param_substs).0,
                 None => C_nil(cx)
             }
           }
+          ast::ExprClosure(_, ref decl, ref body) => {
+            closure::trans_closure_expr(closure::Dest::Ignore(cx),
+                                        &**decl, &**body, e.id,
+                                        param_substs);
+            C_null(type_of::type_of(cx, ety))
+          }
           _ => cx.sess().span_bug(e.span,
                   "bad constant expression type in consts::const_expr")
         };
diff --git a/src/librustc_trans/trans/context.rs b/src/librustc_trans/trans/context.rs
index 27dba9c4809..96506291b5a 100644
--- a/src/librustc_trans/trans/context.rs
+++ b/src/librustc_trans/trans/context.rs
@@ -22,6 +22,7 @@ use trans::common::{ExternMap,tydesc_info,BuilderRef_res};
 use trans::debuginfo;
 use trans::monomorphize::MonoId;
 use trans::type_::{Type, TypeNames};
+use middle::subst::Substs;
 use middle::ty::{self, Ty};
 use session::config::NoDebugInfo;
 use session::Session;
@@ -105,17 +106,20 @@ pub struct LocalCrateContext<'tcx> {
     const_cstr_cache: RefCell<FnvHashMap<InternedString, ValueRef>>,
 
     /// Reverse-direction for const ptrs cast from globals.
-    /// Key is an int, cast from a ValueRef holding a *T,
+    /// Key is a ValueRef holding a *T,
     /// Val is a ValueRef holding a *[T].
     ///
     /// Needed because LLVM loses pointer->pointee association
     /// when we ptrcast, and we have to ptrcast during translation
-    /// of a [T] const because we form a slice, a [*T,int] pair, not
-    /// a pointer to an LLVM array type.
-    const_globals: RefCell<FnvHashMap<int, ValueRef>>,
+    /// of a [T] const because we form a slice, a (*T,usize) pair, not
+    /// a pointer to an LLVM array type. Similar for trait objects.
+    const_unsized: RefCell<FnvHashMap<ValueRef, ValueRef>>,
+
+    /// Cache of emitted const globals (value -> global)
+    const_globals: RefCell<FnvHashMap<ValueRef, ValueRef>>,
 
     /// Cache of emitted const values
-    const_values: RefCell<NodeMap<ValueRef>>,
+    const_values: RefCell<FnvHashMap<(ast::NodeId, &'tcx Substs<'tcx>), ValueRef>>,
 
     /// Cache of emitted static values
     static_values: RefCell<NodeMap<ValueRef>>,
@@ -400,8 +404,9 @@ impl<'tcx> LocalCrateContext<'tcx> {
                 monomorphizing: RefCell::new(DefIdMap()),
                 vtables: RefCell::new(FnvHashMap()),
                 const_cstr_cache: RefCell::new(FnvHashMap()),
+                const_unsized: RefCell::new(FnvHashMap()),
                 const_globals: RefCell::new(FnvHashMap()),
-                const_values: RefCell::new(NodeMap()),
+                const_values: RefCell::new(FnvHashMap()),
                 static_values: RefCell::new(NodeMap()),
                 extern_const_values: RefCell::new(DefIdMap()),
                 impl_method_cache: RefCell::new(FnvHashMap()),
@@ -615,11 +620,16 @@ impl<'b, 'tcx> CrateContext<'b, 'tcx> {
         &self.local.const_cstr_cache
     }
 
-    pub fn const_globals<'a>(&'a self) -> &'a RefCell<FnvHashMap<int, ValueRef>> {
+    pub fn const_unsized<'a>(&'a self) -> &'a RefCell<FnvHashMap<ValueRef, ValueRef>> {
+        &self.local.const_unsized
+    }
+
+    pub fn const_globals<'a>(&'a self) -> &'a RefCell<FnvHashMap<ValueRef, ValueRef>> {
         &self.local.const_globals
     }
 
-    pub fn const_values<'a>(&'a self) -> &'a RefCell<NodeMap<ValueRef>> {
+    pub fn const_values<'a>(&'a self) -> &'a RefCell<FnvHashMap<(ast::NodeId, &'tcx Substs<'tcx>),
+                                                                ValueRef>> {
         &self.local.const_values
     }
 
diff --git a/src/librustc_trans/trans/controlflow.rs b/src/librustc_trans/trans/controlflow.rs
index 8004726d25e..ea5eef48257 100644
--- a/src/librustc_trans/trans/controlflow.rs
+++ b/src/librustc_trans/trans/controlflow.rs
@@ -372,7 +372,8 @@ pub fn trans_fail<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
     let filename = C_str_slice(ccx, filename);
     let line = C_uint(ccx, loc.line);
     let expr_file_line_const = C_struct(ccx, &[v_str, filename, line], false);
-    let expr_file_line = consts::const_addr_of(ccx, expr_file_line_const, ast::MutImmutable);
+    let expr_file_line = consts::addr_of(ccx, expr_file_line_const,
+                                         "panic_loc", call_info.id);
     let args = vec!(expr_file_line);
     let did = langcall(bcx, Some(call_info.span), "", PanicFnLangItem);
     let bcx = callee::trans_lang_call(bcx,
@@ -400,7 +401,8 @@ pub fn trans_fail_bounds_check<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
     let filename = C_str_slice(ccx,  filename);
     let line = C_uint(ccx, loc.line);
     let file_line_const = C_struct(ccx, &[filename, line], false);
-    let file_line = consts::const_addr_of(ccx, file_line_const, ast::MutImmutable);
+    let file_line = consts::addr_of(ccx, file_line_const,
+                                    "panic_bounds_check_loc", call_info.id);
     let args = vec!(file_line, index, len);
     let did = langcall(bcx, Some(call_info.span), "", PanicBoundsCheckFnLangItem);
     let bcx = callee::trans_lang_call(bcx,
diff --git a/src/librustc_trans/trans/expr.rs b/src/librustc_trans/trans/expr.rs
index 44d8457c316..480679f43cb 100644
--- a/src/librustc_trans/trans/expr.rs
+++ b/src/librustc_trans/trans/expr.rs
@@ -54,6 +54,7 @@ use self::lazy_binop_ty::*;
 
 use back::abi;
 use llvm::{self, ValueRef};
+use middle::check_const;
 use middle::def;
 use middle::mem_categorization::Typer;
 use middle::subst::{self, Substs};
@@ -68,7 +69,6 @@ use trans::glue;
 use trans::machine;
 use trans::meth;
 use trans::monomorphize;
-use trans::inline;
 use trans::tvec;
 use trans::type_of;
 use middle::ty::{struct_fields, tup_fields};
@@ -84,8 +84,9 @@ use trans::type_::Type;
 use syntax::{ast, ast_util, codemap};
 use syntax::ptr::P;
 use syntax::parse::token;
-use std::rc::Rc;
 use std::iter::repeat;
+use std::mem;
+use std::rc::Rc;
 
 // Destinations
 
@@ -115,11 +116,56 @@ pub fn trans_into<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
                               -> Block<'blk, 'tcx> {
     let mut bcx = bcx;
 
+    debuginfo::set_source_location(bcx.fcx, expr.id, expr.span);
+
     if bcx.tcx().adjustments.borrow().contains_key(&expr.id) {
         // use trans, which may be less efficient but
         // which will perform the adjustments:
         let datum = unpack_datum!(bcx, trans(bcx, expr));
-        return datum.store_to_dest(bcx, dest, expr.id)
+        return datum.store_to_dest(bcx, dest, expr.id);
+    }
+
+    let qualif = bcx.tcx().const_qualif_map.borrow()[expr.id];
+    if !qualif.intersects(check_const::NOT_CONST | check_const::NEEDS_DROP) {
+        if !qualif.intersects(check_const::PREFER_IN_PLACE) {
+            if let SaveIn(lldest) = dest {
+                let global = consts::get_const_expr_as_global(bcx.ccx(), expr, qualif,
+                                                            bcx.fcx.param_substs);
+                // Cast pointer to destination, because constants
+                // have different types.
+                let lldest = PointerCast(bcx, lldest, val_ty(global));
+                memcpy_ty(bcx, lldest, global, expr_ty_adjusted(bcx, expr));
+            }
+            // Don't do anything in the Ignore case, consts don't need drop.
+            return bcx;
+        } else {
+            // The only way we're going to see a `const` at this point is if
+            // it prefers in-place instantiation, likely because it contains
+            // `[x; N]` somewhere within.
+            match expr.node {
+                ast::ExprPath(_) | ast::ExprQPath(_) => {
+                    match bcx.def(expr.id) {
+                        def::DefConst(did) => {
+                            let expr = consts::get_const_expr(bcx.ccx(), did, expr);
+                            // Temporarily get cleanup scopes out of the way,
+                            // as they require sub-expressions to be contained
+                            // inside the current AST scope.
+                            // These should record no cleanups anyways, `const`
+                            // can't have destructors.
+                            let scopes = mem::replace(&mut *bcx.fcx.scopes.borrow_mut(),
+                                                      vec![]);
+                            bcx = trans_into(bcx, expr, dest);
+                            let scopes = mem::replace(&mut *bcx.fcx.scopes.borrow_mut(),
+                                                      scopes);
+                            assert!(scopes.is_empty());
+                            return bcx;
+                        }
+                        _ => {}
+                    }
+                }
+                _ => {}
+            }
+        }
     }
 
     debug!("trans_into() expr={}", expr.repr(bcx.tcx()));
@@ -130,7 +176,6 @@ pub fn trans_into<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
                                                                           false);
     bcx.fcx.push_ast_cleanup_scope(cleanup_debug_loc);
 
-    debuginfo::set_source_location(bcx.fcx, expr.id, expr.span);
     let kind = ty::expr_kind(bcx.tcx(), expr);
     bcx = match kind {
         ty::LvalueExpr | ty::RvalueDatumExpr => {
@@ -157,14 +202,70 @@ pub fn trans<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
 
     let mut bcx = bcx;
     let fcx = bcx.fcx;
+    let qualif = bcx.tcx().const_qualif_map.borrow()[expr.id];
+    let adjusted_global = !qualif.intersects(check_const::NON_STATIC_BORROWS);
+    let global = if !qualif.intersects(check_const::NOT_CONST | check_const::NEEDS_DROP) {
+        let global = consts::get_const_expr_as_global(bcx.ccx(), expr, qualif,
+                                                      bcx.fcx.param_substs);
+
+        if qualif.intersects(check_const::HAS_STATIC_BORROWS) {
+            // Is borrowed as 'static, must return lvalue.
+
+            // Cast pointer to global, because constants have different types.
+            let const_ty = expr_ty_adjusted(bcx, expr);
+            let llty = type_of::type_of(bcx.ccx(), const_ty);
+            let global = PointerCast(bcx, global, llty.ptr_to());
+            let datum = Datum::new(global, const_ty, Lvalue);
+            return DatumBlock::new(bcx, datum.to_expr_datum());
+        }
+
+        // Otherwise, keep around and perform adjustments, if needed.
+        let const_ty = if adjusted_global {
+            expr_ty_adjusted(bcx, expr)
+        } else {
+            expr_ty(bcx, expr)
+        };
+
+        // This could use a better heuristic.
+        Some(if type_is_immediate(bcx.ccx(), const_ty) {
+            // Cast pointer to global, because constants have different types.
+            let llty = type_of::type_of(bcx.ccx(), const_ty);
+            let global = PointerCast(bcx, global, llty.ptr_to());
+            // Maybe just get the value directly, instead of loading it?
+            immediate_rvalue(load_ty(bcx, global, const_ty), const_ty)
+        } else {
+            let llty = type_of::type_of(bcx.ccx(), const_ty);
+            // HACK(eddyb) get around issues with lifetime intrinsics.
+            let scratch = alloca_no_lifetime(bcx, llty, "const");
+            let lldest = if !ty::type_is_structural(const_ty) {
+                // Cast pointer to slot, because constants have different types.
+                PointerCast(bcx, scratch, val_ty(global))
+            } else {
+                // In this case, memcpy_ty calls llvm.memcpy after casting both
+                // source and destination to i8*, so we don't need any casts.
+                scratch
+            };
+            memcpy_ty(bcx, lldest, global, const_ty);
+            Datum::new(scratch, const_ty, Rvalue::new(ByRef))
+        })
+    } else {
+        None
+    };
 
     let cleanup_debug_loc = debuginfo::get_cleanup_debug_loc_for_ast_node(bcx.ccx(),
                                                                           expr.id,
                                                                           expr.span,
                                                                           false);
     fcx.push_ast_cleanup_scope(cleanup_debug_loc);
-    let datum = unpack_datum!(bcx, trans_unadjusted(bcx, expr));
-    let datum = unpack_datum!(bcx, apply_adjustments(bcx, expr, datum));
+    let datum = match global {
+        Some(rvalue) => rvalue.to_expr_datum(),
+        None => unpack_datum!(bcx, trans_unadjusted(bcx, expr))
+    };
+    let datum = if adjusted_global {
+        datum // trans::consts already performed adjustments.
+    } else {
+        unpack_datum!(bcx, apply_adjustments(bcx, expr, datum))
+    };
     bcx = fcx.pop_and_trans_ast_cleanup_scope(bcx, expr.id);
     return DatumBlock::new(bcx, datum);
 }
@@ -177,6 +278,54 @@ pub fn get_dataptr(bcx: Block, fat_ptr: ValueRef) -> ValueRef {
     GEPi(bcx, fat_ptr, &[0, abi::FAT_PTR_ADDR])
 }
 
+// Retrieve the information we are losing (making dynamic) in an unsizing
+// adjustment.
+// When making a dtor, we need to do different things depending on the
+// ownership of the object.. mk_ty is a function for turning `unadjusted_ty`
+// into a type to be destructed. If we want to end up with a Box pointer,
+// then mk_ty should make a Box pointer (T -> Box<T>), if we want a
+// borrowed reference then it should be T -> &T.
+pub fn unsized_info<'a, 'tcx, F>(ccx: &CrateContext<'a, 'tcx>,
+                                 kind: &ty::UnsizeKind<'tcx>,
+                                 id: ast::NodeId,
+                                 unadjusted_ty: Ty<'tcx>,
+                                 param_substs: &'tcx subst::Substs<'tcx>,
+                                 mk_ty: F) -> ValueRef where
+    F: FnOnce(Ty<'tcx>) -> Ty<'tcx>,
+{
+    // FIXME(#19596) workaround: `|t| t` causes monomorphization recursion
+    fn identity<T>(t: T) -> T { t }
+
+    debug!("unsized_info(kind={:?}, id={}, unadjusted_ty={})",
+           kind, id, unadjusted_ty.repr(ccx.tcx()));
+    match kind {
+        &ty::UnsizeLength(len) => C_uint(ccx, len),
+        &ty::UnsizeStruct(box ref k, tp_index) => match unadjusted_ty.sty {
+            ty::ty_struct(_, ref substs) => {
+                let ty_substs = substs.types.get_slice(subst::TypeSpace);
+                // The dtor for a field treats it like a value, so mk_ty
+                // should just be the identity function.
+                unsized_info(ccx, k, id, ty_substs[tp_index], param_substs, identity)
+            }
+            _ => ccx.sess().bug(&format!("UnsizeStruct with bad sty: {}",
+                                         unadjusted_ty.repr(ccx.tcx()))[])
+        },
+        &ty::UnsizeVtable(ty::TyTrait { ref principal, .. }, _) => {
+            // Note that we preserve binding levels here:
+            let substs = principal.0.substs.with_self_ty(unadjusted_ty).erase_regions();
+            let substs = ccx.tcx().mk_substs(substs);
+            let trait_ref = ty::Binder(Rc::new(ty::TraitRef { def_id: principal.def_id(),
+                                                             substs: substs }));
+            let trait_ref = monomorphize::apply_param_substs(ccx.tcx(),
+                                                             param_substs,
+                                                             &trait_ref);
+            let box_ty = mk_ty(unadjusted_ty);
+            consts::ptrcast(meth::get_vtable(ccx, box_ty, trait_ref, param_substs),
+                            Type::vtable_ptr(ccx))
+        }
+    }
+}
+
 /// Helper for trans that apply adjustments from `expr` to `datum`, which should be the unadjusted
 /// translation of `expr`.
 fn apply_adjustments<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
@@ -262,13 +411,17 @@ fn apply_adjustments<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
         let datum = match autoref {
             &AutoPtr(_, _, ref a) | &AutoUnsafe(_, ref a) => {
                 debug!("  AutoPtr");
-                match a {
-                    &Some(box ref a) => {
-                        datum = unpack_datum!(bcx, apply_autoref(a, bcx, expr, datum));
-                    }
-                    &None => {}
+                if let &Some(box ref a) = a {
+                    datum = unpack_datum!(bcx, apply_autoref(a, bcx, expr, datum));
+                }
+                if !type_is_sized(bcx.tcx(), datum.ty) {
+                    // Arrange cleanup
+                    let lval = unpack_datum!(bcx,
+                        datum.to_lvalue_datum(bcx, "ref_fat_ptr", expr.id));
+                    unpack_datum!(bcx, ref_fat_ptr(bcx, lval))
+                } else {
+                    unpack_datum!(bcx, auto_ref(bcx, datum, expr))
                 }
-                unpack_datum!(bcx, ref_ptr(bcx, expr, datum))
             }
             &ty::AutoUnsize(ref k) => {
                 debug!("  AutoUnsize");
@@ -288,139 +441,35 @@ fn apply_adjustments<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
         DatumBlock::new(bcx, datum)
     }
 
-    fn ref_ptr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
-                           expr: &ast::Expr,
-                           datum: Datum<'tcx, Expr>)
-                           -> DatumBlock<'blk, 'tcx, Expr> {
-        debug!("ref_ptr(expr={}, datum={})",
-               expr.repr(bcx.tcx()),
-               datum.to_string(bcx.ccx()));
-
-        if !type_is_sized(bcx.tcx(), datum.ty) {
-            debug!("Taking address of unsized type {}",
-                   bcx.ty_to_string(datum.ty));
-            ref_fat_ptr(bcx, expr, datum)
-        } else {
-            debug!("Taking address of sized type {}",
-                   bcx.ty_to_string(datum.ty));
-            auto_ref(bcx, datum, expr)
-        }
-    }
-
-    // Retrieve the information we are losing (making dynamic) in an unsizing
-    // adjustment.
-    // When making a dtor, we need to do different things depending on the
-    // ownership of the object.. mk_ty is a function for turning `unadjusted_ty`
-    // into a type to be destructed. If we want to end up with a Box pointer,
-    // then mk_ty should make a Box pointer (T -> Box<T>), if we want a
-    // borrowed reference then it should be T -> &T.
-    fn unsized_info<'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>,
-                                   kind: &ty::UnsizeKind<'tcx>,
-                                   id: ast::NodeId,
-                                   unadjusted_ty: Ty<'tcx>,
-                                   mk_ty: F) -> ValueRef where
-        F: FnOnce(Ty<'tcx>) -> Ty<'tcx>,
-    {
-        // FIXME(#19596) workaround: `|t| t` causes monomorphization recursion
-        fn identity<T>(t: T) -> T { t }
-
-        debug!("unsized_info(kind={:?}, id={}, unadjusted_ty={})",
-               kind, id, unadjusted_ty.repr(bcx.tcx()));
-        match kind {
-            &ty::UnsizeLength(len) => C_uint(bcx.ccx(), len),
-            &ty::UnsizeStruct(box ref k, tp_index) => match unadjusted_ty.sty {
-                ty::ty_struct(_, ref substs) => {
-                    let ty_substs = substs.types.get_slice(subst::TypeSpace);
-                    // The dtor for a field treats it like a value, so mk_ty
-                    // should just be the identity function.
-                    unsized_info(bcx, k, id, ty_substs[tp_index], identity)
-                }
-                _ => bcx.sess().bug(&format!("UnsizeStruct with bad sty: {}",
-                                          bcx.ty_to_string(unadjusted_ty))[])
-            },
-            &ty::UnsizeVtable(ty::TyTrait { ref principal, .. }, _) => {
-                // Note that we preserve binding levels here:
-                let substs = principal.0.substs.with_self_ty(unadjusted_ty).erase_regions();
-                let substs = bcx.tcx().mk_substs(substs);
-                let trait_ref =
-                    ty::Binder(Rc::new(ty::TraitRef { def_id: principal.def_id(),
-                                                      substs: substs }));
-                let trait_ref = bcx.monomorphize(&trait_ref);
-                let box_ty = mk_ty(unadjusted_ty);
-                PointerCast(bcx,
-                            meth::get_vtable(bcx, box_ty, trait_ref),
-                            Type::vtable_ptr(bcx.ccx()))
-            }
-        }
-    }
-
     fn unsize_expr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
                                expr: &ast::Expr,
                                datum: Datum<'tcx, Expr>,
                                k: &ty::UnsizeKind<'tcx>)
                                -> DatumBlock<'blk, 'tcx, Expr> {
+        let mut bcx = bcx;
         let tcx = bcx.tcx();
         let datum_ty = datum.ty;
         let unsized_ty = ty::unsize_ty(tcx, datum_ty, k, expr.span);
         debug!("unsized_ty={}", unsized_ty.repr(bcx.tcx()));
         let dest_ty = ty::mk_open(tcx, unsized_ty);
         debug!("dest_ty={}", unsized_ty.repr(bcx.tcx()));
-        // Closures for extracting and manipulating the data and payload parts of
-        // the fat pointer.
-        let info = |bcx, _val| unsized_info(bcx,
-                                              k,
-                                              expr.id,
-                                              datum_ty,
-                                              |t| ty::mk_rptr(tcx,
-                                                              tcx.mk_region(ty::ReStatic),
-                                                              ty::mt{
-                                                                  ty: t,
-                                                                  mutbl: ast::MutImmutable
-                                                              }));
-        match *k {
-            ty::UnsizeStruct(..) =>
-                into_fat_ptr(bcx, expr, datum, dest_ty, |bcx, val| {
-                    PointerCast(bcx, val, type_of::type_of(bcx.ccx(), unsized_ty).ptr_to())
-                }, info),
-            ty::UnsizeLength(..) =>
-                into_fat_ptr(bcx, expr, datum, dest_ty, |bcx, val| {
-                    GEPi(bcx, val, &[0, 0])
-                }, info),
-            ty::UnsizeVtable(..) =>
-                into_fat_ptr(bcx, expr, datum, dest_ty, |_bcx, val| {
-                    PointerCast(bcx, val, Type::i8p(bcx.ccx()))
-                }, info),
-        }
-    }
 
-    fn ref_fat_ptr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
-                               expr: &ast::Expr,
-                               datum: Datum<'tcx, Expr>)
-                               -> DatumBlock<'blk, 'tcx, Expr> {
-        let tcx = bcx.tcx();
-        let dest_ty = ty::close_type(tcx, datum.ty);
-        let base = |bcx, val| Load(bcx, get_dataptr(bcx, val));
-        let len = |bcx, val| Load(bcx, get_len(bcx, val));
-        into_fat_ptr(bcx, expr, datum, dest_ty, base, len)
-    }
-
-    fn into_fat_ptr<'blk, 'tcx, F, G>(bcx: Block<'blk, 'tcx>,
-                                      expr: &ast::Expr,
-                                      datum: Datum<'tcx, Expr>,
-                                      dest_ty: Ty<'tcx>,
-                                      base: F,
-                                      info: G)
-                                      -> DatumBlock<'blk, 'tcx, Expr> where
-        F: FnOnce(Block<'blk, 'tcx>, ValueRef) -> ValueRef,
-        G: FnOnce(Block<'blk, 'tcx>, ValueRef) -> ValueRef,
-    {
-        let mut bcx = bcx;
+        let info = unsized_info(bcx.ccx(), k, expr.id, datum_ty, bcx.fcx.param_substs,
+                                |t| ty::mk_imm_rptr(tcx, tcx.mk_region(ty::ReStatic), t));
 
         // Arrange cleanup
         let lval = unpack_datum!(bcx,
                                  datum.to_lvalue_datum(bcx, "into_fat_ptr", expr.id));
-        let base = base(bcx, lval.val);
-        let info = info(bcx, lval.val);
+        // Compute the base pointer. This doesn't change the pointer value,
+        // but merely its type.
+        let base = match *k {
+            ty::UnsizeStruct(..) | ty::UnsizeVtable(..) => {
+                PointerCast(bcx, lval.val, type_of::type_of(bcx.ccx(), unsized_ty).ptr_to())
+            }
+            ty::UnsizeLength(..) => {
+                GEPi(bcx, lval.val, &[0u, 0u])
+            }
+        };
 
         let scratch = rvalue_scratch_datum(bcx, dest_ty, "__fat_ptr");
         Store(bcx, base, get_dataptr(bcx, scratch.val));
@@ -490,7 +539,8 @@ fn apply_adjustments<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
         let base = PointerCast(bcx, get_dataptr(bcx, scratch.val), llbox_ty.ptr_to());
         bcx = datum.store_to(bcx, base);
 
-        let info = unsized_info(bcx, k, expr.id, unboxed_ty, |t| ty::mk_uniq(tcx, t));
+        let info = unsized_info(bcx.ccx(), k, expr.id, unboxed_ty, bcx.fcx.param_substs,
+                                |t| ty::mk_uniq(tcx, t));
         Store(bcx, info, get_len(bcx, scratch.val));
 
         DatumBlock::new(bcx, scratch.to_expr_datum())
@@ -847,53 +897,25 @@ fn trans_def<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
             //     pointer to that.
             let const_ty = expr_ty(bcx, ref_expr);
 
-            fn get_val<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, did: ast::DefId,
-                                   const_ty: Ty<'tcx>) -> ValueRef {
-                // For external constants, we don't inline.
-                if did.krate == ast::LOCAL_CRATE {
-                    // Case 1.
-
-                    // The LLVM global has the type of its initializer,
-                    // which may not be equal to the enum's type for
-                    // non-C-like enums.
-                    let val = base::get_item_val(bcx.ccx(), did.node);
-                    let pty = type_of::type_of(bcx.ccx(), const_ty).ptr_to();
-                    PointerCast(bcx, val, pty)
-                } else {
-                    // Case 2.
-                    base::get_extern_const(bcx.ccx(), did, const_ty)
-                }
-            }
-            let val = get_val(bcx, did, const_ty);
+            // For external constants, we don't inline.
+            let val = if did.krate == ast::LOCAL_CRATE {
+                // Case 1.
+
+                // The LLVM global has the type of its initializer,
+                // which may not be equal to the enum's type for
+                // non-C-like enums.
+                let val = base::get_item_val(bcx.ccx(), did.node);
+                let pty = type_of::type_of(bcx.ccx(), const_ty).ptr_to();
+                PointerCast(bcx, val, pty)
+            } else {
+                // Case 2.
+                base::get_extern_const(bcx.ccx(), did, const_ty)
+            };
             DatumBlock::new(bcx, Datum::new(val, const_ty, LvalueExpr))
         }
-        def::DefConst(did) => {
-            // First, inline any external constants into the local crate so we
-            // can be sure to get the LLVM value corresponding to it.
-            let did = inline::maybe_instantiate_inline(bcx.ccx(), did);
-            if did.krate != ast::LOCAL_CRATE {
-                bcx.tcx().sess.span_bug(ref_expr.span,
-                                        "cross crate constant could not \
-                                         be inlined");
-            }
-            let val = base::get_item_val(bcx.ccx(), did.node);
-
-            // Next, we need to crate a ByRef rvalue datum to return. We can't
-            // use the normal .to_ref_datum() function because the type of
-            // `val` is not actually the same as `const_ty`.
-            //
-            // To get around this, we make a custom alloca slot with the
-            // appropriate type (const_ty), and then we cast it to a pointer of
-            // typeof(val), store the value, and then hand this slot over to
-            // the datum infrastructure.
-            let const_ty = expr_ty(bcx, ref_expr);
-            let llty = type_of::type_of(bcx.ccx(), const_ty);
-            let slot = alloca(bcx, llty, "const");
-            let pty = Type::from_ref(unsafe { llvm::LLVMTypeOf(val) }).ptr_to();
-            Store(bcx, val, PointerCast(bcx, slot, pty));
-
-            let datum = Datum::new(slot, const_ty, Rvalue::new(ByRef));
-            DatumBlock::new(bcx, datum.to_expr_datum())
+        def::DefConst(_) => {
+            bcx.sess().span_bug(ref_expr.span,
+                "constant expression should not reach expr::trans_def")
         }
         _ => {
             DatumBlock::new(bcx, trans_local_var(bcx, def).to_expr_datum())
@@ -1119,7 +1141,12 @@ fn trans_rvalue_dps_unadjusted<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
             tvec::trans_fixed_vstore(bcx, expr, dest)
         }
         ast::ExprClosure(_, ref decl, ref body) => {
-            closure::trans_closure_expr(bcx, &**decl, &**body, expr.id, dest)
+            let dest = match dest {
+                SaveIn(lldest) => closure::Dest::SaveIn(bcx, lldest),
+                Ignore => closure::Dest::Ignore(bcx.ccx())
+            };
+            closure::trans_closure_expr(dest, &**decl, &**body, expr.id, bcx.fcx.param_substs)
+                .unwrap_or(bcx)
         }
         ast::ExprCall(ref f, ref args) => {
             if bcx.tcx().is_method_call(expr.id) {
@@ -1247,7 +1274,7 @@ fn trans_def_dps_unadjusted<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
 pub fn trans_def_fn_unadjusted<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
                                          ref_expr: &ast::Expr,
                                          def: def::Def,
-                                         param_substs: &subst::Substs<'tcx>)
+                                         param_substs: &'tcx subst::Substs<'tcx>)
                                          -> Datum<'tcx, Rvalue> {
     let _icx = push_ctxt("trans_def_datum_unadjusted");
 
@@ -1641,6 +1668,16 @@ fn trans_uniq_expr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
     immediate_rvalue_bcx(bcx, val, box_ty).to_expr_datumblock()
 }
 
+fn ref_fat_ptr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
+                           lval: Datum<'tcx, Lvalue>)
+                           -> DatumBlock<'blk, 'tcx, Expr> {
+    let dest_ty = ty::close_type(bcx.tcx(), lval.ty);
+    let scratch = rvalue_scratch_datum(bcx, dest_ty, "__fat_ptr");
+    memcpy_ty(bcx, scratch.val, lval.val, scratch.ty);
+
+    DatumBlock::new(bcx, scratch.to_expr_datum())
+}
+
 fn trans_addr_of<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
                              expr: &ast::Expr,
                              subexpr: &ast::Expr)
@@ -1651,18 +1688,7 @@ fn trans_addr_of<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
     match sub_datum.ty.sty {
         ty::ty_open(_) => {
             // Opened DST value, close to a fat pointer
-            debug!("Closing fat pointer {}", bcx.ty_to_string(sub_datum.ty));
-
-            let scratch = rvalue_scratch_datum(bcx,
-                                               ty::close_type(bcx.tcx(), sub_datum.ty),
-                                               "fat_addr_of");
-            let base = Load(bcx, get_dataptr(bcx, sub_datum.val));
-            Store(bcx, base, get_dataptr(bcx, scratch.val));
-
-            let len = Load(bcx, get_len(bcx, sub_datum.val));
-            Store(bcx, len, get_len(bcx, scratch.val));
-
-            DatumBlock::new(bcx, scratch.to_expr_datum())
+            ref_fat_ptr(bcx, sub_datum)
         }
         _ => {
             // Sized value, ref to a thin pointer
@@ -1687,9 +1713,10 @@ fn trans_eager_binop<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
 
     let tcx = bcx.tcx();
     let is_simd = ty::type_is_simd(tcx, lhs_t);
-    let intype = {
-        if is_simd { ty::simd_type(tcx, lhs_t) }
-        else { lhs_t }
+    let intype = if is_simd {
+        ty::simd_type(tcx, lhs_t)
+    } else {
+        lhs_t
     };
     let is_float = ty::type_is_fp(intype);
     let is_signed = ty::type_is_signed(intype);
@@ -1766,24 +1793,10 @@ fn trans_eager_binop<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
         }
       }
       ast::BiEq | ast::BiNe | ast::BiLt | ast::BiGe | ast::BiLe | ast::BiGt => {
-        if ty::type_is_scalar(rhs_t) {
-            unpack_result!(bcx,
-                           base::compare_scalar_types(bcx,
-                                                      lhs,
-                                                      rhs,
-                                                      rhs_t,
-                                                      op.node,
-                                                      binop_debug_loc))
-        } else if is_simd {
-            base::compare_simd_types(bcx,
-                                     lhs,
-                                     rhs,
-                                     intype,
-                                     ty::simd_size(tcx, lhs_t),
-                                     op.node,
-                                     binop_debug_loc)
+        if is_simd {
+            base::compare_simd_types(bcx, lhs, rhs, intype, op.node, binop_debug_loc)
         } else {
-            bcx.tcx().sess.span_bug(binop_expr.span, "comparison operator unsupported for type")
+            base::compare_scalar_types(bcx, lhs, rhs, intype, op.node, binop_debug_loc)
         }
       }
       _ => {
@@ -1997,7 +2010,7 @@ pub fn cast_type_kind<'tcx>(tcx: &ty::ctxt<'tcx>, t: Ty<'tcx>) -> cast_kind {
     }
 }
 
-fn cast_is_noop<'tcx>(t_in: Ty<'tcx>, t_out: Ty<'tcx>) -> bool {
+pub fn cast_is_noop<'tcx>(t_in: Ty<'tcx>, t_out: Ty<'tcx>) -> bool {
     match (ty::deref(t_in, true), ty::deref(t_out, true)) {
         (Some(ty::mt{ ty: t_in, .. }), Some(ty::mt{ ty: t_out, .. })) => {
             t_in == t_out
diff --git a/src/librustc_trans/trans/foreign.rs b/src/librustc_trans/trans/foreign.rs
index 96bd028aa9d..8f0e4e647b5 100644
--- a/src/librustc_trans/trans/foreign.rs
+++ b/src/librustc_trans/trans/foreign.rs
@@ -557,7 +557,7 @@ pub fn trans_rust_fn_with_foreign_abi<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
                                                 body: &ast::Block,
                                                 attrs: &[ast::Attribute],
                                                 llwrapfn: ValueRef,
-                                                param_substs: &Substs<'tcx>,
+                                                param_substs: &'tcx Substs<'tcx>,
                                                 id: ast::NodeId,
                                                 hash: Option<&str>) {
     let _icx = push_ctxt("foreign::build_foreign_fn");
@@ -577,7 +577,7 @@ pub fn trans_rust_fn_with_foreign_abi<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
     fn build_rust_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
                                decl: &ast::FnDecl,
                                body: &ast::Block,
-                               param_substs: &Substs<'tcx>,
+                               param_substs: &'tcx Substs<'tcx>,
                                attrs: &[ast::Attribute],
                                id: ast::NodeId,
                                hash: Option<&str>)
diff --git a/src/librustc_trans/trans/glue.rs b/src/librustc_trans/trans/glue.rs
index 8cf9a51b3bf..af90e1ec5c5 100644
--- a/src/librustc_trans/trans/glue.rs
+++ b/src/librustc_trans/trans/glue.rs
@@ -558,12 +558,12 @@ fn make_generic_glue<'a, 'tcx, F>(ccx: &CrateContext<'a, 'tcx>,
     let glue_name = format!("glue {} {}", name, ty_to_short_str(ccx.tcx(), t));
     let _s = StatRecorder::new(ccx, glue_name);
 
-    let empty_param_substs = Substs::trans_empty();
+    let empty_substs = ccx.tcx().mk_substs(Substs::trans_empty());
     let (arena, fcx): (TypedArena<_>, FunctionContext);
     arena = TypedArena::new();
     fcx = new_fn_ctxt(ccx, llfn, ast::DUMMY_NODE_ID, false,
                       ty::FnConverging(ty::mk_nil(ccx.tcx())),
-                      &empty_param_substs, None, &arena);
+                      empty_substs, None, &arena);
 
     let bcx = init_function(&fcx, false, ty::FnConverging(ty::mk_nil(ccx.tcx())));
 
diff --git a/src/librustc_trans/trans/inline.rs b/src/librustc_trans/trans/inline.rs
index ea6d9b88e11..56fda20e0e8 100644
--- a/src/librustc_trans/trans/inline.rs
+++ b/src/librustc_trans/trans/inline.rs
@@ -159,13 +159,14 @@ fn instantiate_inline(ccx: &CrateContext, fn_id: ast::DefId)
                     let unparameterized = impl_tpt.generics.types.is_empty() &&
                             mth.pe_generics().ty_params.is_empty();
 
+                    let empty_substs = ccx.tcx().mk_substs(Substs::trans_empty());
                     if unparameterized {
                         let llfn = get_item_val(ccx, mth.id);
                         trans_fn(ccx,
                                  &*mth.pe_fn_decl(),
                                  &*mth.pe_body(),
                                  llfn,
-                                 &Substs::trans_empty(),
+                                 empty_substs,
                                  mth.id,
                                  &[]);
                         // Use InternalLinkage so LLVM can optimize more
diff --git a/src/librustc_trans/trans/meth.rs b/src/librustc_trans/trans/meth.rs
index 5161382a927..1d5d24a6403 100644
--- a/src/librustc_trans/trans/meth.rs
+++ b/src/librustc_trans/trans/meth.rs
@@ -11,7 +11,7 @@
 use arena::TypedArena;
 use back::abi;
 use back::link;
-use llvm::{self, ValueRef, get_param};
+use llvm::{ValueRef, get_param};
 use metadata::csearch;
 use middle::subst::Substs;
 use middle::subst::VecPerParamSpace;
@@ -23,6 +23,7 @@ use trans::callee::*;
 use trans::callee;
 use trans::cleanup;
 use trans::common::*;
+use trans::consts;
 use trans::datum::*;
 use trans::debuginfo::DebugLoc;
 use trans::expr::{SaveIn, Ignore};
@@ -36,7 +37,6 @@ use middle::ty::{self, Ty};
 use middle::ty::MethodCall;
 use util::ppaux::Repr;
 
-use std::ffi::CString;
 use std::rc::Rc;
 use syntax::abi::{Rust, RustCall};
 use syntax::parse::token;
@@ -82,11 +82,12 @@ pub fn trans_impl(ccx: &CrateContext,
                     let trans_everywhere = attr::requests_inline(&method.attrs[]);
                     for (ref ccx, is_origin) in ccx.maybe_iter(trans_everywhere) {
                         let llfn = get_item_val(ccx, method.id);
+                        let empty_substs = tcx.mk_substs(Substs::trans_empty());
                         trans_fn(ccx,
                                  method.pe_fn_decl(),
                                  method.pe_body(),
                                  llfn,
-                                 &Substs::trans_empty(),
+                                 empty_substs,
                                  method.id,
                                  &[]);
                         update_linkage(ccx,
@@ -174,7 +175,7 @@ pub fn trans_static_method_callee<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
                                             method_id: ast::DefId,
                                             trait_id: ast::DefId,
                                             expr_id: ast::NodeId,
-                                            param_substs: &subst::Substs<'tcx>)
+                                            param_substs: &'tcx subst::Substs<'tcx>)
                                             -> Datum<'tcx, Rvalue>
 {
     let _icx = push_ctxt("meth::trans_static_method_callee");
@@ -599,7 +600,7 @@ pub fn trans_object_shim<'a, 'tcx>(
 
     let sig = ty::erase_late_bound_regions(ccx.tcx(), &fty.sig);
 
-    let empty_substs = Substs::trans_empty();
+    let empty_substs = tcx.mk_substs(Substs::trans_empty());
     let (block_arena, fcx): (TypedArena<_>, FunctionContext);
     block_arena = TypedArena::new();
     fcx = new_fn_ctxt(ccx,
@@ -607,7 +608,7 @@ pub fn trans_object_shim<'a, 'tcx>(
                       ast::DUMMY_NODE_ID,
                       false,
                       sig.output,
-                      &empty_substs,
+                      empty_substs,
                       None,
                       &block_arena);
     let mut bcx = init_function(&fcx, false, sig.output);
@@ -689,19 +690,19 @@ pub fn trans_object_shim<'a, 'tcx>(
 /// `trait_ref` would map `T:Trait`, but `box_ty` would be
 /// `Foo<T>`. This `box_ty` is primarily used to encode the destructor.
 /// This will hopefully change now that DST is underway.
-pub fn get_vtable<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
-                              box_ty: Ty<'tcx>,
-                              trait_ref: ty::PolyTraitRef<'tcx>)
-                              -> ValueRef
+pub fn get_vtable<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
+                            box_ty: Ty<'tcx>,
+                            trait_ref: ty::PolyTraitRef<'tcx>,
+                            param_substs: &'tcx subst::Substs<'tcx>)
+                            -> ValueRef
 {
-    debug!("get_vtable(box_ty={}, trait_ref={})",
-           box_ty.repr(bcx.tcx()),
-           trait_ref.repr(bcx.tcx()));
-
-    let tcx = bcx.tcx();
-    let ccx = bcx.ccx();
+    let tcx = ccx.tcx();
     let _icx = push_ctxt("meth::get_vtable");
 
+    debug!("get_vtable(box_ty={}, trait_ref={})",
+           box_ty.repr(tcx),
+           trait_ref.repr(tcx));
+
     // Check the cache.
     let cache_key = (box_ty, trait_ref.clone());
     match ccx.vtables().borrow().get(&cache_key) {
@@ -711,9 +712,7 @@ pub fn get_vtable<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
 
     // Not in the cache. Build it.
     let methods = traits::supertraits(tcx, trait_ref.clone()).flat_map(|trait_ref| {
-        let vtable = fulfill_obligation(bcx.ccx(),
-                                        DUMMY_SP,
-                                        trait_ref.clone());
+        let vtable = fulfill_obligation(ccx, DUMMY_SP, trait_ref.clone());
         match vtable {
             traits::VtableBuiltin(_) => {
                 Vec::new().into_iter()
@@ -723,83 +722,61 @@ pub fn get_vtable<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
                     impl_def_id: id,
                     substs,
                     nested: _ }) => {
-                emit_vtable_methods(bcx, id, substs).into_iter()
+                emit_vtable_methods(ccx, id, substs, param_substs).into_iter()
             }
             traits::VtableClosure(closure_def_id, substs) => {
                 let llfn = trans_fn_ref_with_substs(
-                    bcx.ccx(),
+                    ccx,
                     closure_def_id,
                     ExprId(0),
-                    bcx.fcx.param_substs,
-                    substs.clone()).val;
+                    param_substs,
+                    substs).val;
 
-                (vec!(llfn)).into_iter()
+                vec![llfn].into_iter()
             }
             traits::VtableFnPointer(bare_fn_ty) => {
-                let llfn = vec![trans_fn_pointer_shim(bcx.ccx(), bare_fn_ty)];
-                llfn.into_iter()
+                vec![trans_fn_pointer_shim(ccx, bare_fn_ty)].into_iter()
             }
             traits::VtableObject(ref data) => {
                 // this would imply that the Self type being erased is
                 // an object type; this cannot happen because we
                 // cannot cast an unsized type into a trait object
-                bcx.sess().bug(
+                tcx.sess.bug(
                     &format!("cannot get vtable for an object type: {}",
-                             data.repr(bcx.tcx())));
+                            data.repr(tcx)));
             }
             traits::VtableParam(..) => {
-                bcx.sess().bug(
+                tcx.sess.bug(
                     &format!("resolved vtable for {} to bad vtable {} in trans",
-                            trait_ref.repr(bcx.tcx()),
-                            vtable.repr(bcx.tcx()))[]);
+                            trait_ref.repr(tcx),
+                            vtable.repr(tcx))[]);
             }
         }
     });
 
     let size_ty = sizing_type_of(ccx, trait_ref.self_ty());
     let size = machine::llsize_of_alloc(ccx, size_ty);
-    let ll_size = C_uint(ccx, size);
     let align = align_of(ccx, trait_ref.self_ty());
-    let ll_align = C_uint(ccx, align);
 
-    // Generate a destructor for the vtable.
-    let drop_glue = glue::get_drop_glue(ccx, box_ty);
-    let vtable = make_vtable(ccx, drop_glue, ll_size, ll_align, methods);
+    let components: Vec<_> = vec![
+        // Generate a destructor for the vtable.
+        glue::get_drop_glue(ccx, box_ty),
+        C_uint(ccx, size),
+        C_uint(ccx, align)
+    ].into_iter().chain(methods).collect();
+
+    let vtable = consts::addr_of(ccx, C_struct(ccx, &components, false),
+                                 "vtable", trait_ref.def_id().node);
 
     ccx.vtables().borrow_mut().insert(cache_key, vtable);
     vtable
 }
 
-/// Helper function to declare and initialize the vtable.
-pub fn make_vtable<I: Iterator<Item=ValueRef>>(ccx: &CrateContext,
-                                          drop_glue: ValueRef,
-                                          size: ValueRef,
-                                          align: ValueRef,
-                                          ptrs: I)
-                                          -> ValueRef {
-    let _icx = push_ctxt("meth::make_vtable");
-
-    let head = vec![drop_glue, size, align];
-    let components: Vec<_> = head.into_iter().chain(ptrs).collect();
-
-    unsafe {
-        let tbl = C_struct(ccx, &components[], false);
-        let sym = token::gensym("vtable");
-        let buf = CString::from_vec(format!("vtable{}", sym.usize()).into_bytes());
-        let vt_gvar = llvm::LLVMAddGlobal(ccx.llmod(), val_ty(tbl).to_ref(),
-                                          buf.as_ptr());
-        llvm::LLVMSetInitializer(vt_gvar, tbl);
-        llvm::LLVMSetGlobalConstant(vt_gvar, llvm::True);
-        llvm::SetLinkage(vt_gvar, llvm::InternalLinkage);
-        vt_gvar
-    }
-}
-
-fn emit_vtable_methods<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
-                                   impl_id: ast::DefId,
-                                   substs: subst::Substs<'tcx>)
-                                   -> Vec<ValueRef> {
-    let ccx = bcx.ccx();
+fn emit_vtable_methods<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
+                                 impl_id: ast::DefId,
+                                 substs: subst::Substs<'tcx>,
+                                 param_substs: &'tcx subst::Substs<'tcx>)
+                                 -> Vec<ValueRef> {
     let tcx = ccx.tcx();
 
     let trt_id = match ty::impl_trait_ref(tcx, impl_id) {
@@ -808,7 +785,7 @@ fn emit_vtable_methods<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
                                       make a vtable for a type impl!")
     };
 
-    ty::populate_implementations_for_trait_if_necessary(bcx.tcx(), trt_id);
+    ty::populate_implementations_for_trait_if_necessary(tcx, trt_id);
 
     let trait_item_def_ids = ty::trait_item_def_ids(tcx, trt_id);
     trait_item_def_ids.iter().flat_map(|method_def_id| {
@@ -835,7 +812,7 @@ fn emit_vtable_methods<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
                         ccx,
                         m_id,
                         ExprId(0),
-                        bcx.fcx.param_substs,
+                        param_substs,
                         substs.clone()).val;
 
                     // currently, at least, by-value self is not object safe
@@ -882,7 +859,7 @@ pub fn trans_trait_cast<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
     bcx = datum.store_to(bcx, llboxdest);
 
     // Store the vtable into the second half of pair.
-    let vtable = get_vtable(bcx, datum_ty, trait_ref);
+    let vtable = get_vtable(bcx.ccx(), datum_ty, trait_ref, bcx.fcx.param_substs);
     let llvtabledest = GEPi(bcx, lldest, &[0, abi::FAT_PTR_EXTRA]);
     let llvtabledest = PointerCast(bcx, llvtabledest, val_ty(vtable).ptr_to());
     Store(bcx, vtable, llvtabledest);
diff --git a/src/librustc_trans/trans/monomorphize.rs b/src/librustc_trans/trans/monomorphize.rs
index 5796e72a610..30797344da8 100644
--- a/src/librustc_trans/trans/monomorphize.rs
+++ b/src/librustc_trans/trans/monomorphize.rs
@@ -36,7 +36,7 @@ use std::hash::{Hasher, Hash, SipHasher};
 
 pub fn monomorphic_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
                                 fn_id: ast::DefId,
-                                psubsts: &subst::Substs<'tcx>,
+                                psubsts: &'tcx subst::Substs<'tcx>,
                                 ref_id: Option<ast::NodeId>)
     -> (ValueRef, Ty<'tcx>, bool) {
     debug!("monomorphic_fn(\
@@ -55,7 +55,7 @@ pub fn monomorphic_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
 
     let hash_id = MonoId {
         def: fn_id,
-        params: psubsts.types.clone()
+        params: &psubsts.types
     };
 
     let item_ty = ty::lookup_item_type(ccx.tcx(), fn_id).ty;
@@ -289,7 +289,7 @@ pub fn monomorphic_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
 #[derive(PartialEq, Eq, Hash, Debug)]
 pub struct MonoId<'tcx> {
     pub def: ast::DefId,
-    pub params: subst::VecPerParamSpace<Ty<'tcx>>
+    pub params: &'tcx subst::VecPerParamSpace<Ty<'tcx>>
 }
 
 /// Monomorphizes a type from the AST by first applying the in-scope
diff --git a/src/librustc_trans/trans/tvec.rs b/src/librustc_trans/trans/tvec.rs
index edd4da4711f..8f10865ae32 100644
--- a/src/librustc_trans/trans/tvec.rs
+++ b/src/librustc_trans/trans/tvec.rs
@@ -309,8 +309,6 @@ pub fn write_content<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
                                                     |set_bcx, lleltptr, _| {
                                                         elem.shallow_copy(set_bcx, lleltptr)
                                                     });
-
-                            elem.add_clean_if_rvalue(bcx, element.id);
                             bcx
                         }
                     }
diff --git a/src/librustc_typeck/astconv.rs b/src/librustc_typeck/astconv.rs
index 1951d9946bc..68054c79f27 100644
--- a/src/librustc_typeck/astconv.rs
+++ b/src/librustc_typeck/astconv.rs
@@ -1183,7 +1183,7 @@ pub fn ast_ty_to_ty<'tcx>(
                 qpath_to_ty(this, rscope, ast_ty, &**qpath)
             }
             ast::TyFixedLengthVec(ref ty, ref e) => {
-                match const_eval::eval_const_expr_partial(tcx, &**e) {
+                match const_eval::eval_const_expr_partial(tcx, &**e, Some(tcx.types.uint)) {
                     Ok(ref r) => {
                         match *r {
                             const_eval::const_int(i) =>
diff --git a/src/librustc_typeck/check/_match.rs b/src/librustc_typeck/check/_match.rs
index 3ea2743c63e..81868f3695c 100644
--- a/src/librustc_typeck/check/_match.rs
+++ b/src/librustc_typeck/check/_match.rs
@@ -8,6 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use middle::const_eval;
 use middle::def;
 use middle::infer;
 use middle::pat_util::{PatIdMap, pat_id_map, pat_is_binding, pat_is_const};
@@ -15,12 +16,12 @@ use middle::subst::{Substs};
 use middle::ty::{self, Ty};
 use check::{check_expr, check_expr_has_type, check_expr_with_expectation};
 use check::{check_expr_coercable_to_type, demand, FnCtxt, Expectation};
-use check::{instantiate_path, structurally_resolved_type, valid_range_bounds};
+use check::{instantiate_path, structurally_resolved_type};
 use require_same_types;
 use util::nodemap::FnvHashMap;
 use util::ppaux::Repr;
 
-use std::cmp;
+use std::cmp::{self, Ordering};
 use std::collections::hash_map::Entry::{Occupied, Vacant};
 use syntax::ast;
 use syntax::ast_util;
@@ -79,16 +80,17 @@ pub fn check_pat<'a, 'tcx>(pcx: &pat_ctxt<'a, 'tcx>,
                 lhs_eq_rhs && (ty::type_is_numeric(lhs_ty) || ty::type_is_char(lhs_ty));
 
             if numeric_or_char {
-                match valid_range_bounds(fcx.ccx, &**begin, &**end) {
-                    Some(false) => {
+                match const_eval::compare_lit_exprs(tcx, &**begin, &**end, Some(lhs_ty)) {
+                    Some(Ordering::Less) |
+                    Some(Ordering::Equal) => {}
+                    Some(Ordering::Greater) => {
                         span_err!(tcx.sess, begin.span, E0030,
                             "lower range bound must be less than upper");
-                    },
+                    }
                     None => {
                         span_err!(tcx.sess, begin.span, E0031,
                             "mismatched types in range");
-                    },
-                    Some(true) => {}
+                    }
                 }
             } else {
                 span_err!(tcx.sess, begin.span, E0029,
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index d12b23187b8..1c15e295ad9 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -2499,16 +2499,6 @@ fn check_lit<'a, 'tcx>(fcx: &FnCtxt<'a, 'tcx>,
     }
 }
 
-pub fn valid_range_bounds(ccx: &CrateCtxt,
-                          from: &ast::Expr,
-                          to: &ast::Expr)
-                       -> Option<bool> {
-    match const_eval::compare_lit_exprs(ccx.tcx, from, to) {
-        Some(val) => Some(val <= 0),
-        None => None
-    }
-}
-
 pub fn check_expr_has_type<'a, 'tcx>(fcx: &FnCtxt<'a, 'tcx>,
                                      expr: &'tcx ast::Expr,
                                      expected: Ty<'tcx>) {
@@ -3596,24 +3586,8 @@ fn check_expr_with_unifier<'a, 'tcx, F>(fcx: &FnCtxt<'a, 'tcx>,
             // Finally, borrowck is charged with guaranteeing that the
             // value whose address was taken can actually be made to live
             // as long as it needs to live.
-            match oprnd.node {
-                // String literals are already, implicitly converted to slices.
-                //ast::ExprLit(lit) if ast_util::lit_is_str(lit) => fcx.expr_ty(oprnd),
-                // Empty slices live in static memory.
-                ast::ExprVec(ref elements) if elements.len() == 0 => {
-                    // Note: we do not assign a lifetime of
-                    // static. This is because the resulting type
-                    // `&'static [T]` would require that T outlives
-                    // `'static`!
-                    let region = fcx.infcx().next_region_var(
-                        infer::AddrOfSlice(expr.span));
-                    ty::mk_rptr(tcx, tcx.mk_region(region), tm)
-                }
-                _ => {
-                    let region = fcx.infcx().next_region_var(infer::AddrOfRegion(expr.span));
-                    ty::mk_rptr(tcx, tcx.mk_region(region), tm)
-                }
-            }
+            let region = fcx.infcx().next_region_var(infer::AddrOfRegion(expr.span));
+            ty::mk_rptr(tcx, tcx.mk_region(region), tm)
         };
         fcx.write_ty(id, oprnd_t);
       }
@@ -4550,7 +4524,7 @@ pub fn check_enum_variants<'a,'tcx>(ccx: &CrateCtxt<'a,'tcx>,
                     // that the expression is in a form that eval_const_expr can
                     // handle, so we may still get an internal compiler error
 
-                    match const_eval::eval_const_expr_partial(ccx.tcx, &**e) {
+                    match const_eval::eval_const_expr_partial(ccx.tcx, &**e, Some(declty)) {
                         Ok(const_eval::const_int(val)) => current_disr_val = val as Disr,
                         Ok(const_eval::const_uint(val)) => current_disr_val = val as Disr,
                         Ok(_) => {
diff --git a/src/test/bench/task-perf-alloc-unwind.rs b/src/test/bench/task-perf-alloc-unwind.rs
index f09e64cb9c5..c45efe5f54b 100644
--- a/src/test/bench/task-perf-alloc-unwind.rs
+++ b/src/test/bench/task-perf-alloc-unwind.rs
@@ -40,7 +40,9 @@ fn run(repeat: int, depth: int) {
     }
 }
 
-type nillist = List<()>;
+// FIXME(#21721) used to be `List<()>` but that can cause
+// certain LLVM versions to abort during optimizations.
+type nillist = List<[u8; 0]>;
 
 // Filled with things that have to be unwound
 
@@ -81,11 +83,11 @@ fn recurse_or_panic(depth: int, st: Option<State>) {
             }
             Some(st) => {
                 let mut v = st.vec.clone();
-                v.push_all(&[box List::Cons((), st.vec.last().unwrap().clone())]);
+                v.push_all(&[box List::Cons([], st.vec.last().unwrap().clone())]);
                 State {
-                    unique: box List::Cons((), box *st.unique),
+                    unique: box List::Cons([], box *st.unique),
                     vec: v,
-                    res: r(box List::Cons((), st.res._l.clone())),
+                    res: r(box List::Cons([], st.res._l.clone())),
                 }
             }
         };
diff --git a/src/test/compile-fail/check-static-immutable-mut-slices.rs b/src/test/compile-fail/check-static-immutable-mut-slices.rs
index d1e3fe25253..1804b9e04c2 100644
--- a/src/test/compile-fail/check-static-immutable-mut-slices.rs
+++ b/src/test/compile-fail/check-static-immutable-mut-slices.rs
@@ -11,6 +11,6 @@
 // Checks that immutable static items can't have mutable slices
 
 static TEST: &'static mut [isize] = &mut [];
-//~^ ERROR statics are not allowed to have mutable references
+//~^ ERROR references in statics may only refer to immutable values
 
 pub fn main() { }
diff --git a/src/test/compile-fail/check-static-values-constraints.rs b/src/test/compile-fail/check-static-values-constraints.rs
index 7c4f9ada2d3..0180bccbca4 100644
--- a/src/test/compile-fail/check-static-values-constraints.rs
+++ b/src/test/compile-fail/check-static-values-constraints.rs
@@ -99,7 +99,7 @@ static STATIC10: UnsafeStruct = UnsafeStruct;
 struct MyOwned;
 
 static STATIC11: Box<MyOwned> = box MyOwned;
-//~^ ERROR statics are not allowed to have custom pointers
+//~^ ERROR allocations are not allowed in statics
 
 // The following examples test that mutable structs are just forbidden
 // to have types with destructors
@@ -117,16 +117,17 @@ static mut STATIC14: SafeStruct = SafeStruct {
 //~^ ERROR mutable statics are not allowed to have destructors
     field1: SafeEnum::Variant1,
     field2: SafeEnum::Variant4("str".to_string())
+//~^ ERROR static contains unimplemented expression type
 };
 
 static STATIC15: &'static [Box<MyOwned>] = &[
-    box MyOwned, //~ ERROR statics are not allowed to have custom pointers
-    box MyOwned, //~ ERROR statics are not allowed to have custom pointers
+    box MyOwned, //~ ERROR allocations are not allowed in statics
+    box MyOwned, //~ ERROR allocations are not allowed in statics
 ];
 
 static STATIC16: (&'static Box<MyOwned>, &'static Box<MyOwned>) = (
-    &box MyOwned, //~ ERROR statics are not allowed to have custom pointers
-    &box MyOwned, //~ ERROR statics are not allowed to have custom pointers
+    &box MyOwned, //~ ERROR allocations are not allowed in statics
+    &box MyOwned, //~ ERROR allocations are not allowed in statics
 );
 
 static mut STATIC17: SafeEnum = SafeEnum::Variant1;
@@ -134,9 +135,9 @@ static mut STATIC17: SafeEnum = SafeEnum::Variant1;
 
 static STATIC19: Box<isize> =
     box 3;
-//~^ ERROR statics are not allowed to have custom pointers
+//~^ ERROR allocations are not allowed in statics
 
 pub fn main() {
     let y = { static x: Box<isize> = box 3; x };
-    //~^ ERROR statics are not allowed to have custom pointers
+    //~^ ERROR allocations are not allowed in statics
 }
diff --git a/src/test/compile-fail/const-block-non-item-statement.rs b/src/test/compile-fail/const-block-non-item-statement.rs
index 62e8fccbda0..f66c68541b1 100644
--- a/src/test/compile-fail/const-block-non-item-statement.rs
+++ b/src/test/compile-fail/const-block-non-item-statement.rs
@@ -8,18 +8,18 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-static A: usize = { 1us; 2 };
+const A: usize = { 1us; 2 };
 //~^ ERROR: blocks in constants are limited to items and tail expressions
 
-static B: usize = { { } 2 };
+const B: usize = { { } 2 };
 //~^ ERROR: blocks in constants are limited to items and tail expressions
 
 macro_rules! foo {
     () => (()) //~ ERROR: blocks in constants are limited to items and tail expressions
 }
-static C: usize = { foo!(); 2 };
+const C: usize = { foo!(); 2 };
 
-static D: usize = { let x = 4us; 2 };
+const D: usize = { let x = 4us; 2 };
 //~^ ERROR: blocks in constants are limited to items and tail expressions
 
 pub fn main() {
diff --git a/src/test/compile-fail/issue-16538.rs b/src/test/compile-fail/issue-16538.rs
index a6b73dcc19c..6d2cfcab04e 100644
--- a/src/test/compile-fail/issue-16538.rs
+++ b/src/test/compile-fail/issue-16538.rs
@@ -20,6 +20,7 @@ mod Y {
 
 static foo: *const Y::X = Y::foo(Y::x as *const Y::X);
 //~^ ERROR cannot refer to other statics by value
-//~| ERROR: the trait `core::marker::Sync` is not implemented for the type
+//~| ERROR the trait `core::marker::Sync` is not implemented for the type
+//~| ERROR function calls in statics are limited to struct and enum constructors
 
 fn main() {}
diff --git a/src/test/compile-fail/issue-17458.rs b/src/test/compile-fail/issue-17458.rs
index d9fd67f9197..d6f70ae1e57 100644
--- a/src/test/compile-fail/issue-17458.rs
+++ b/src/test/compile-fail/issue-17458.rs
@@ -9,7 +9,7 @@
 // except according to those terms.
 
 static X: usize = 0 as *const usize as usize;
-//~^ ERROR: can not cast a pointer to an integer in a constant expression
+//~^ ERROR: can not cast a pointer to an integer in statics
 
 fn main() {
     assert_eq!(X, 0);
diff --git a/src/test/compile-fail/issue-17718-const-bad-values.rs b/src/test/compile-fail/issue-17718-const-bad-values.rs
index daa250d12f5..2347d3f3d5c 100644
--- a/src/test/compile-fail/issue-17718-const-bad-values.rs
+++ b/src/test/compile-fail/issue-17718-const-bad-values.rs
@@ -9,12 +9,12 @@
 // except according to those terms.
 
 const C1: &'static mut [usize] = &mut [];
-//~^ ERROR: constants are not allowed to have mutable references
+//~^ ERROR: references in constants may only refer to immutable values
 
 static mut S: usize = 3;
 const C2: &'static mut usize = &mut S;
 //~^ ERROR: constants cannot refer to other statics
-//~^^ ERROR: are not allowed to have mutable references
+//~^^ ERROR: references in constants may only refer to immutable values
 
 fn main() {}
 
diff --git a/src/test/compile-fail/issue-18118.rs b/src/test/compile-fail/issue-18118.rs
index 129f28f1d89..c5370879cc2 100644
--- a/src/test/compile-fail/issue-18118.rs
+++ b/src/test/compile-fail/issue-18118.rs
@@ -9,9 +9,10 @@
 // except according to those terms.
 
 pub fn main() {
-    static z: &'static isize = {
+    const z: &'static isize = {
         let p = 3;
+        //~^ ERROR blocks in constants are limited to items and tail expressions
         &p
-//~^ ERROR cannot borrow a local variable inside a static block, define a separate static instead
+        //~^ ERROR paths in constants may only refer to constants or functions
     };
 }
diff --git a/src/test/compile-fail/issue-6977.rs b/src/test/compile-fail/issue-6977.rs
deleted file mode 100644
index c2bd810abad..00000000000
--- a/src/test/compile-fail/issue-6977.rs
+++ /dev/null
@@ -1,15 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-// Trying to create a fixed-length vector with a negative size
-
-fn main() {
-      let _x = [0; -1]; //~ ERROR found negative integer
-}
diff --git a/src/test/compile-fail/issue-7364.rs b/src/test/compile-fail/issue-7364.rs
index 465a38111ba..6a36b2f84bf 100644
--- a/src/test/compile-fail/issue-7364.rs
+++ b/src/test/compile-fail/issue-7364.rs
@@ -14,8 +14,9 @@ use std::cell::RefCell;
 
 // Regression test for issue 7364
 static boxed: Box<RefCell<isize>> = box RefCell::new(0);
-//~^ ERROR statics are not allowed to have custom pointers
-//~| ERROR: the trait `core::marker::Sync` is not implemented for the type
-//~| ERROR: the trait `core::marker::Sync` is not implemented for the type
+//~^ ERROR allocations are not allowed in statics
+//~| ERROR the trait `core::marker::Sync` is not implemented for the type
+//~| ERROR the trait `core::marker::Sync` is not implemented for the type
+//~| ERROR function calls in statics are limited to struct and enum constructors
 
 fn main() { }
diff --git a/src/test/compile-fail/issue-8460-const.rs b/src/test/compile-fail/issue-8460-const.rs
new file mode 100644
index 00000000000..01bed69fb1d
--- /dev/null
+++ b/src/test/compile-fail/issue-8460-const.rs
@@ -0,0 +1,55 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::{int, i8, i16, i32, i64};
+use std::thread::Thread;
+
+fn main() {
+    assert!(Thread::scoped(move|| int::MIN / -1).join().is_err());
+    //~^ ERROR attempted to divide with overflow in a constant expression
+    assert!(Thread::scoped(move|| i8::MIN / -1).join().is_err());
+    //~^ ERROR attempted to divide with overflow in a constant expression
+    assert!(Thread::scoped(move|| i16::MIN / -1).join().is_err());
+    //~^ ERROR attempted to divide with overflow in a constant expression
+    assert!(Thread::scoped(move|| i32::MIN / -1).join().is_err());
+    //~^ ERROR attempted to divide with overflow in a constant expression
+    assert!(Thread::scoped(move|| i64::MIN / -1).join().is_err());
+    //~^ ERROR attempted to divide with overflow in a constant expression
+    assert!(Thread::scoped(move|| 1is / 0).join().is_err());
+    //~^ ERROR attempted to divide by zero in a constant expression
+    assert!(Thread::scoped(move|| 1i8 / 0).join().is_err());
+    //~^ ERROR attempted to divide by zero in a constant expression
+    assert!(Thread::scoped(move|| 1i16 / 0).join().is_err());
+    //~^ ERROR attempted to divide by zero in a constant expression
+    assert!(Thread::scoped(move|| 1i32 / 0).join().is_err());
+    //~^ ERROR attempted to divide by zero in a constant expression
+    assert!(Thread::scoped(move|| 1i64 / 0).join().is_err());
+    //~^ ERROR attempted to divide by zero in a constant expression
+    assert!(Thread::scoped(move|| int::MIN % -1).join().is_err());
+    //~^ ERROR attempted remainder with overflow in a constant expression
+    assert!(Thread::scoped(move|| i8::MIN % -1).join().is_err());
+    //~^ ERROR attempted remainder with overflow in a constant expression
+    assert!(Thread::scoped(move|| i16::MIN % -1).join().is_err());
+    //~^ ERROR attempted remainder with overflow in a constant expression
+    assert!(Thread::scoped(move|| i32::MIN % -1).join().is_err());
+    //~^ ERROR attempted remainder with overflow in a constant expression
+    assert!(Thread::scoped(move|| i64::MIN % -1).join().is_err());
+    //~^ ERROR attempted remainder with overflow in a constant expression
+    assert!(Thread::scoped(move|| 1is % 0).join().is_err());
+    //~^ ERROR attempted remainder with a divisor of zero in a constant expression
+    assert!(Thread::scoped(move|| 1i8 % 0).join().is_err());
+    //~^ ERROR attempted remainder with a divisor of zero in a constant expression
+    assert!(Thread::scoped(move|| 1i16 % 0).join().is_err());
+    //~^ ERROR attempted remainder with a divisor of zero in a constant expression
+    assert!(Thread::scoped(move|| 1i32 % 0).join().is_err());
+    //~^ ERROR attempted remainder with a divisor of zero in a constant expression
+    assert!(Thread::scoped(move|| 1i64 % 0).join().is_err());
+    //~^ ERROR attempted remainder with a divisor of zero in a constant expression
+}
diff --git a/src/test/compile-fail/repeat_count.rs b/src/test/compile-fail/repeat_count.rs
index df69e13bf1e..d730add00b7 100644
--- a/src/test/compile-fail/repeat_count.rs
+++ b/src/test/compile-fail/repeat_count.rs
@@ -41,8 +41,18 @@ fn main() {
     //~| expected usize
     //~| found &-ptr
     //~| ERROR expected positive integer for repeat count, found string
-    let f = [0; -4];
-    //~^ ERROR expected positive integer for repeat count, found negative integer
-    let f = [0us; -1];
-    //~^ ERROR expected positive integer for repeat count, found negative integer
+    let f = [0; -4is];
+    //~^ ERROR mismatched types
+    //~| expected `usize`
+    //~| found `isize`
+    //~| expected usize
+    //~| found isize
+    //~| ERROR expected positive integer for repeat count, found negative integer
+    let f = [0us; -1is];
+    //~^ ERROR mismatched types
+    //~| expected `usize`
+    //~| found `isize`
+    //~| expected usize
+    //~| found isize
+    //~| ERROR expected positive integer for repeat count, found negative integer
 }
diff --git a/src/test/compile-fail/static-mut-not-constant.rs b/src/test/compile-fail/static-mut-not-constant.rs
index 7c228ce413f..08148328edc 100644
--- a/src/test/compile-fail/static-mut-not-constant.rs
+++ b/src/test/compile-fail/static-mut-not-constant.rs
@@ -11,7 +11,7 @@
 #![feature(box_syntax)]
 
 static mut a: Box<isize> = box 3;
-//~^ ERROR statics are not allowed to have custom pointers
+//~^ ERROR allocations are not allowed in statics
 //~^^ ERROR mutable statics are not allowed to have owned pointers
 
 fn main() {}
diff --git a/src/test/compile-fail/static-vec-repeat-not-constant.rs b/src/test/compile-fail/static-vec-repeat-not-constant.rs
index 7cb7615526a..7a957564587 100644
--- a/src/test/compile-fail/static-vec-repeat-not-constant.rs
+++ b/src/test/compile-fail/static-vec-repeat-not-constant.rs
@@ -11,6 +11,6 @@
 fn foo() -> isize { 23 }
 
 static a: [isize; 2] = [foo(); 2];
-//~^ ERROR: function calls in constants are limited to struct and enum constructors
+//~^ ERROR: function calls in statics are limited to struct and enum constructors
 
 fn main() {}
diff --git a/src/test/debuginfo/basic-types-globals-metadata.rs b/src/test/debuginfo/basic-types-globals-metadata.rs
index e9f801c5f05..91e78c820e6 100644
--- a/src/test/debuginfo/basic-types-globals-metadata.rs
+++ b/src/test/debuginfo/basic-types-globals-metadata.rs
@@ -47,26 +47,26 @@
 #![allow(dead_code)]
 #![omit_gdb_pretty_printer_section]
 
-
-static B: bool = false;
-static I: int = -1;
-static C: char = 'a';
-static I8: i8 = 68;
-static I16: i16 = -16;
-static I32: i32 = -32;
-static I64: i64 = -64;
-static U: uint = 1;
-static U8: u8 = 100;
-static U16: u16 = 16;
-static U32: u32 = 32;
-static U64: u64 = 64;
-static F32: f32 = 2.5;
-static F64: f64 = 3.5;
+// N.B. These are `mut` only so they don't constant fold away.
+static mut B: bool = false;
+static mut I: int = -1;
+static mut C: char = 'a';
+static mut I8: i8 = 68;
+static mut I16: i16 = -16;
+static mut I32: i32 = -32;
+static mut I64: i64 = -64;
+static mut U: uint = 1;
+static mut U8: u8 = 100;
+static mut U16: u16 = 16;
+static mut U32: u32 = 32;
+static mut U64: u64 = 64;
+static mut F32: f32 = 2.5;
+static mut F64: f64 = 3.5;
 
 fn main() {
     _zzz(); // #break
 
-    let a = (B, I, C, I8, I16, I32, I64, U, U8, U16, U32, U64, F32, F64);
+    let a = unsafe { (B, I, C, I8, I16, I32, I64, U, U8, U16, U32, U64, F32, F64) };
 }
 
 fn _zzz() {()}
diff --git a/src/test/debuginfo/basic-types-globals.rs b/src/test/debuginfo/basic-types-globals.rs
index a4d4ddfea53..d37b0f60d3d 100644
--- a/src/test/debuginfo/basic-types-globals.rs
+++ b/src/test/debuginfo/basic-types-globals.rs
@@ -52,25 +52,26 @@
 #![allow(unused_variables)]
 #![omit_gdb_pretty_printer_section]
 
-static B: bool = false;
-static I: int = -1;
-static C: char = 'a';
-static I8: i8 = 68;
-static I16: i16 = -16;
-static I32: i32 = -32;
-static I64: i64 = -64;
-static U: uint = 1;
-static U8: u8 = 100;
-static U16: u16 = 16;
-static U32: u32 = 32;
-static U64: u64 = 64;
-static F32: f32 = 2.5;
-static F64: f64 = 3.5;
+// N.B. These are `mut` only so they don't constant fold away.
+static mut B: bool = false;
+static mut I: int = -1;
+static mut C: char = 'a';
+static mut I8: i8 = 68;
+static mut I16: i16 = -16;
+static mut I32: i32 = -32;
+static mut I64: i64 = -64;
+static mut U: uint = 1;
+static mut U8: u8 = 100;
+static mut U16: u16 = 16;
+static mut U32: u32 = 32;
+static mut U64: u64 = 64;
+static mut F32: f32 = 2.5;
+static mut F64: f64 = 3.5;
 
 fn main() {
     _zzz(); // #break
 
-    let a = (B, I, C, I8, I16, I32, I64, U, U8, U16, U32, U64, F32, F64);
+    let a = unsafe { (B, I, C, I8, I16, I32, I64, U, U8, U16, U32, U64, F32, F64) };
 }
 
 fn _zzz() {()}
diff --git a/src/test/run-make/issue-7349/Makefile b/src/test/run-make/issue-7349/Makefile
index f24933cac01..50dc63b1deb 100644
--- a/src/test/run-make/issue-7349/Makefile
+++ b/src/test/run-make/issue-7349/Makefile
@@ -7,5 +7,5 @@
 
 all:
 	$(RUSTC) foo.rs --emit=llvm-ir
-	[ "$$(grep -c 8675309 "$(TMPDIR)/foo.ll")" -eq "1" ]
-	[ "$$(grep -c 11235813 "$(TMPDIR)/foo.ll")" -eq "1" ]
+	[ "$$(grep -c 'ret i32 8675309' "$(TMPDIR)/foo.ll")" -eq "1" ]
+	[ "$$(grep -c 'ret i32 11235813' "$(TMPDIR)/foo.ll")" -eq "1" ]
diff --git a/src/test/run-make/issue-7349/foo.rs b/src/test/run-make/issue-7349/foo.rs
index 870d1749278..3a2ced80ef4 100644
--- a/src/test/run-make/issue-7349/foo.rs
+++ b/src/test/run-make/issue-7349/foo.rs
@@ -10,14 +10,14 @@
 
 fn outer<T>() {
     #[allow(dead_code)]
-    fn inner() -> uint {
+    fn inner() -> u32 {
         8675309
     }
 }
 
 extern "C" fn outer_foreign<T>() {
     #[allow(dead_code)]
-    fn inner() -> uint {
+    fn inner() -> u32 {
         11235813
     }
 }
diff --git a/src/test/run-pass/const-adt-align-mismatch.rs b/src/test/run-pass/const-adt-align-mismatch.rs
new file mode 100644
index 00000000000..5377d9a62b9
--- /dev/null
+++ b/src/test/run-pass/const-adt-align-mismatch.rs
@@ -0,0 +1,28 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::mem;
+
+#[derive(PartialEq, Show)]
+enum Foo {
+    A(u32),
+    Bar([u16; 4]),
+    C
+}
+
+// NOTE(eddyb) Don't make this a const, needs to be a static
+// so it is always instantiated as a LLVM constant value.
+static FOO: Foo = Foo::C;
+
+fn main() {
+    assert_eq!(FOO, Foo::C);
+    assert_eq!(mem::size_of::<Foo>(), 12);
+    assert_eq!(mem::min_align_of::<Foo>(), 4);
+}
diff --git a/src/test/run-pass/issue-17216.rs b/src/test/run-pass/issue-17216.rs
index e48d7b0756c..ce5a0aa96e3 100644
--- a/src/test/run-pass/issue-17216.rs
+++ b/src/test/run-pass/issue-17216.rs
@@ -25,7 +25,9 @@ fn main() {
     let mut dropped = false;
     {
         let leak = Leak { dropped: &mut dropped };
-        for ((), leaked) in Some(((),leak)).into_iter() {}
+        // FIXME(#21721) "hack" used to be () but that can cause
+        // certain LLVM versions to abort during optimizations.
+        for (_, leaked) in Some(("hack", leak)).into_iter() {}
     }
 
     assert!(dropped);
diff --git a/src/test/run-pass/issue-8460.rs b/src/test/run-pass/issue-8460.rs
index 3944895460f..4b9ed44c7cd 100644
--- a/src/test/run-pass/issue-8460.rs
+++ b/src/test/run-pass/issue-8460.rs
@@ -8,28 +8,32 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use std::{int, i8, i16, i32, i64};
+use std::num::Int;
 use std::thread::Thread;
 
+// Avoid using constants, which would trigger compile-time errors.
+fn min_val<T: Int>() -> T { Int::min_value() }
+fn zero<T: Int>() -> T { Int::zero() }
+
 fn main() {
-    assert!(Thread::scoped(move|| int::MIN / -1).join().is_err());
-    assert!(Thread::scoped(move|| i8::MIN / -1).join().is_err());
-    assert!(Thread::scoped(move|| i16::MIN / -1).join().is_err());
-    assert!(Thread::scoped(move|| i32::MIN / -1).join().is_err());
-    assert!(Thread::scoped(move|| i64::MIN / -1).join().is_err());
-    assert!(Thread::scoped(move|| 1 / 0).join().is_err());
-    assert!(Thread::scoped(move|| 1i8 / 0).join().is_err());
-    assert!(Thread::scoped(move|| 1i16 / 0).join().is_err());
-    assert!(Thread::scoped(move|| 1i32 / 0).join().is_err());
-    assert!(Thread::scoped(move|| 1i64 / 0).join().is_err());
-    assert!(Thread::scoped(move|| int::MIN % -1).join().is_err());
-    assert!(Thread::scoped(move|| i8::MIN % -1).join().is_err());
-    assert!(Thread::scoped(move|| i16::MIN % -1).join().is_err());
-    assert!(Thread::scoped(move|| i32::MIN % -1).join().is_err());
-    assert!(Thread::scoped(move|| i64::MIN % -1).join().is_err());
-    assert!(Thread::scoped(move|| 1 % 0).join().is_err());
-    assert!(Thread::scoped(move|| 1i8 % 0).join().is_err());
-    assert!(Thread::scoped(move|| 1i16 % 0).join().is_err());
-    assert!(Thread::scoped(move|| 1i32 % 0).join().is_err());
-    assert!(Thread::scoped(move|| 1i64 % 0).join().is_err());
+    assert!(Thread::scoped(move|| min_val::<isize>() / -1).join().is_err());
+    assert!(Thread::scoped(move|| min_val::<i8>() / -1).join().is_err());
+    assert!(Thread::scoped(move|| min_val::<i16>() / -1).join().is_err());
+    assert!(Thread::scoped(move|| min_val::<i32>() / -1).join().is_err());
+    assert!(Thread::scoped(move|| min_val::<i64>() / -1).join().is_err());
+    assert!(Thread::scoped(move|| 1is / zero()).join().is_err());
+    assert!(Thread::scoped(move|| 1i8 / zero()).join().is_err());
+    assert!(Thread::scoped(move|| 1i16 / zero()).join().is_err());
+    assert!(Thread::scoped(move|| 1i32 / zero()).join().is_err());
+    assert!(Thread::scoped(move|| 1i64 / zero()).join().is_err());
+    assert!(Thread::scoped(move|| min_val::<isize>() % -1).join().is_err());
+    assert!(Thread::scoped(move|| min_val::<i8>() % -1).join().is_err());
+    assert!(Thread::scoped(move|| min_val::<i16>() % -1).join().is_err());
+    assert!(Thread::scoped(move|| min_val::<i32>() % -1).join().is_err());
+    assert!(Thread::scoped(move|| min_val::<i64>() % -1).join().is_err());
+    assert!(Thread::scoped(move|| 1is % zero()).join().is_err());
+    assert!(Thread::scoped(move|| 1i8 % zero()).join().is_err());
+    assert!(Thread::scoped(move|| 1i16 % zero()).join().is_err());
+    assert!(Thread::scoped(move|| 1i32 % zero()).join().is_err());
+    assert!(Thread::scoped(move|| 1i64 % zero()).join().is_err());
 }