Great separation of librustc_codegen_llvm: librustc_codegen_ssa compiles

41 files changed, 1634 insertions, 1470 deletions

diff --git a/src/librustc_codegen_llvm/base.rs b/src/librustc_codegen_llvm/base.rs
index 4e69bf8e8b3..bd396e89e07 100644
--- a/src/librustc_codegen_llvm/base.rs
+++ b/src/librustc_codegen_llvm/base.rs
@@ -38,7 +38,7 @@ use rustc::middle::weak_lang_items;
 use rustc::mir::mono::{Linkage, Visibility, Stats, CodegenUnitNameBuilder};
 use rustc::middle::cstore::{EncodedMetadata};
 use rustc::ty::{self, Ty, TyCtxt};
-use rustc::ty::layout::{self, Align, TyLayout, LayoutOf, VariantIdx, HasTyCtxt};
+use rustc::ty::layout::{self, Align, TyLayout, LayoutOf, HasTyCtxt};
 use rustc::ty::query::Providers;
 use rustc::middle::cstore::{self, LinkagePreference};
 use rustc::middle::exported_symbols;
@@ -66,7 +66,6 @@ use rustc::util::nodemap::FxHashMap;
 use CrateInfo;
 use rustc_data_structures::small_c_str::SmallCStr;
 use rustc_data_structures::sync::Lrc;
-use rustc_data_structures::indexed_vec::Idx;
 
 use interfaces::*;
 
@@ -88,500 +87,6 @@ use mir::operand::OperandValue;
 
 use rustc_codegen_utils::check_for_rustc_errors_attr;
 
-pub struct StatRecorder<'a, 'tcx, Cx: 'a + CodegenMethods<'tcx>> {
-    cx: &'a Cx,
-    name: Option<String>,
-    istart: usize,
-    _marker: marker::PhantomData<&'tcx ()>,
-}
-
-impl<'a, 'tcx, Cx: CodegenMethods<'tcx>> StatRecorder<'a, 'tcx, Cx> {
-    pub fn new(cx: &'a Cx, name: String) -> Self {
-        let istart = cx.stats().borrow().n_llvm_insns;
-        StatRecorder {
-            cx,
-            name: Some(name),
-            istart,
-            _marker: marker::PhantomData,
-        }
-    }
-}
-
-impl<'a, 'tcx, Cx: CodegenMethods<'tcx>> Drop for StatRecorder<'a, 'tcx, Cx> {
-    fn drop(&mut self) {
-        if self.cx.sess().codegen_stats() {
-            let mut stats = self.cx.stats().borrow_mut();
-            let iend = stats.n_llvm_insns;
-            stats.fn_stats.push((self.name.take().unwrap(), iend - self.istart));
-            stats.n_fns += 1;
-            // Reset LLVM insn count to avoid compound costs.
-            stats.n_llvm_insns = self.istart;
-        }
-    }
-}
-
-pub fn bin_op_to_icmp_predicate(op: hir::BinOpKind,
-                                signed: bool)
-                                -> IntPredicate {
-    match op {
-        hir::BinOpKind::Eq => IntPredicate::IntEQ,
-        hir::BinOpKind::Ne => IntPredicate::IntNE,
-        hir::BinOpKind::Lt => if signed { IntPredicate::IntSLT } else { IntPredicate::IntULT },
-        hir::BinOpKind::Le => if signed { IntPredicate::IntSLE } else { IntPredicate::IntULE },
-        hir::BinOpKind::Gt => if signed { IntPredicate::IntSGT } else { IntPredicate::IntUGT },
-        hir::BinOpKind::Ge => if signed { IntPredicate::IntSGE } else { IntPredicate::IntUGE },
-        op => {
-            bug!("comparison_op_to_icmp_predicate: expected comparison operator, \
-                  found {:?}",
-                 op)
-        }
-    }
-}
-
-pub fn bin_op_to_fcmp_predicate(op: hir::BinOpKind) -> RealPredicate {
-    match op {
-        hir::BinOpKind::Eq => RealPredicate::RealOEQ,
-        hir::BinOpKind::Ne => RealPredicate::RealUNE,
-        hir::BinOpKind::Lt => RealPredicate::RealOLT,
-        hir::BinOpKind::Le => RealPredicate::RealOLE,
-        hir::BinOpKind::Gt => RealPredicate::RealOGT,
-        hir::BinOpKind::Ge => RealPredicate::RealOGE,
-        op => {
-            bug!("comparison_op_to_fcmp_predicate: expected comparison operator, \
-                  found {:?}",
-                 op);
-        }
-    }
-}
-
-pub fn compare_simd_types<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
-    bx: &Bx,
-    lhs: Bx::Value,
-    rhs: Bx::Value,
-    t: Ty<'tcx>,
-    ret_ty: Bx::Type,
-    op: hir::BinOpKind
-) -> Bx::Value {
-    let signed = match t.sty {
-        ty::Float(_) => {
-            let cmp = bin_op_to_fcmp_predicate(op);
-            return bx.sext(bx.fcmp(cmp, lhs, rhs), ret_ty);
-        },
-        ty::Uint(_) => false,
-        ty::Int(_) => true,
-        _ => bug!("compare_simd_types: invalid SIMD type"),
-    };
-
-    let cmp = bin_op_to_icmp_predicate(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.
-    bx.sext(bx.icmp(cmp, lhs, rhs), ret_ty)
-}
-
-/// Retrieve the information we are losing (making dynamic) in an unsizing
-/// adjustment.
-///
-/// The `old_info` argument is a bit funny. It is intended for use
-/// in an upcast, where the new vtable for an object will be derived
-/// from the old one.
-pub fn unsized_info<'tcx, Cx: CodegenMethods<'tcx>>(
-    cx: &Cx,
-    source: Ty<'tcx>,
-    target: Ty<'tcx>,
-    old_info: Option<Cx::Value>,
-) -> Cx::Value {
-    let (source, target) = cx.tcx().struct_lockstep_tails(source, target);
-    match (&source.sty, &target.sty) {
-        (&ty::Array(_, len), &ty::Slice(_)) => {
-            cx.const_usize(len.unwrap_usize(cx.tcx()))
-        }
-        (&ty::Dynamic(..), &ty::Dynamic(..)) => {
-            // For now, upcasts are limited to changes in marker
-            // traits, and hence never actually require an actual
-            // change to the vtable.
-            old_info.expect("unsized_info: missing old info for trait upcast")
-        }
-        (_, &ty::Dynamic(ref data, ..)) => {
-            let vtable_ptr = cx.layout_of(cx.tcx().mk_mut_ptr(target))
-                .field(cx, abi::FAT_PTR_EXTRA);
-            cx.static_ptrcast(meth::get_vtable(cx, source, data.principal()),
-                            cx.backend_type(vtable_ptr))
-        }
-        _ => bug!("unsized_info: invalid unsizing {:?} -> {:?}",
-                  source,
-                  target),
-    }
-}
-
-/// Coerce `src` to `dst_ty`. `src_ty` must be a thin pointer.
-pub fn unsize_thin_ptr<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
-    bx: &Bx,
-    src: Bx::Value,
-    src_ty: Ty<'tcx>,
-    dst_ty: Ty<'tcx>
-) -> (Bx::Value, Bx::Value) {
-    debug!("unsize_thin_ptr: {:?} => {:?}", src_ty, dst_ty);
-    match (&src_ty.sty, &dst_ty.sty) {
-        (&ty::Ref(_, a, _),
-         &ty::Ref(_, b, _)) |
-        (&ty::Ref(_, a, _),
-         &ty::RawPtr(ty::TypeAndMut { ty: b, .. })) |
-        (&ty::RawPtr(ty::TypeAndMut { ty: a, .. }),
-         &ty::RawPtr(ty::TypeAndMut { ty: b, .. })) => {
-            assert!(bx.cx().type_is_sized(a));
-            let ptr_ty = bx.cx().type_ptr_to(bx.cx().backend_type(bx.cx().layout_of(b)));
-            (bx.pointercast(src, ptr_ty), unsized_info(bx.cx(), a, b, None))
-        }
-        (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) if def_a.is_box() && def_b.is_box() => {
-            let (a, b) = (src_ty.boxed_ty(), dst_ty.boxed_ty());
-            assert!(bx.cx().type_is_sized(a));
-            let ptr_ty = bx.cx().type_ptr_to(bx.cx().backend_type(bx.cx().layout_of(b)));
-            (bx.pointercast(src, ptr_ty), unsized_info(bx.cx(), a, b, None))
-        }
-        (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) => {
-            assert_eq!(def_a, def_b);
-
-            let src_layout = bx.cx().layout_of(src_ty);
-            let dst_layout = bx.cx().layout_of(dst_ty);
-            let mut result = None;
-            for i in 0..src_layout.fields.count() {
-                let src_f = src_layout.field(bx.cx(), i);
-                assert_eq!(src_layout.fields.offset(i).bytes(), 0);
-                assert_eq!(dst_layout.fields.offset(i).bytes(), 0);
-                if src_f.is_zst() {
-                    continue;
-                }
-                assert_eq!(src_layout.size, src_f.size);
-
-                let dst_f = dst_layout.field(bx.cx(), i);
-                assert_ne!(src_f.ty, dst_f.ty);
-                assert_eq!(result, None);
-                result = Some(unsize_thin_ptr(bx, src, src_f.ty, dst_f.ty));
-            }
-            let (lldata, llextra) = result.unwrap();
-            // HACK(eddyb) have to bitcast pointers until LLVM removes pointee types.
-            (bx.bitcast(lldata, bx.cx().scalar_pair_element_backend_type(dst_layout, 0, true)),
-             bx.bitcast(llextra, bx.cx().scalar_pair_element_backend_type(dst_layout, 1, true)))
-        }
-        _ => bug!("unsize_thin_ptr: called on bad types"),
-    }
-}
-
-/// Coerce `src`, which is a reference to a value of type `src_ty`,
-/// to a value of type `dst_ty` and store the result in `dst`
-pub fn coerce_unsized_into<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
-    bx: &Bx,
-    src: PlaceRef<'tcx, Bx::Value>,
-    dst: PlaceRef<'tcx, Bx::Value>
-)  {
-    let src_ty = src.layout.ty;
-    let dst_ty = dst.layout.ty;
-    let coerce_ptr = || {
-        let (base, info) = match bx.load_operand(src).val {
-            OperandValue::Pair(base, info) => {
-                // fat-ptr to fat-ptr unsize preserves the vtable
-                // i.e. &'a fmt::Debug+Send => &'a fmt::Debug
-                // So we need to pointercast the base to ensure
-                // the types match up.
-                let thin_ptr = dst.layout.field(bx.cx(), abi::FAT_PTR_ADDR);
-                (bx.pointercast(base, bx.cx().backend_type(thin_ptr)), info)
-            }
-            OperandValue::Immediate(base) => {
-                unsize_thin_ptr(bx, base, src_ty, dst_ty)
-            }
-            OperandValue::Ref(..) => bug!()
-        };
-        OperandValue::Pair(base, info).store(bx, dst);
-    };
-    match (&src_ty.sty, &dst_ty.sty) {
-        (&ty::Ref(..), &ty::Ref(..)) |
-        (&ty::Ref(..), &ty::RawPtr(..)) |
-        (&ty::RawPtr(..), &ty::RawPtr(..)) => {
-            coerce_ptr()
-        }
-        (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) if def_a.is_box() && def_b.is_box() => {
-            coerce_ptr()
-        }
-
-        (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) => {
-            assert_eq!(def_a, def_b);
-
-            for i in 0..def_a.variants[VariantIdx::new(0)].fields.len() {
-                let src_f = src.project_field(bx, i);
-                let dst_f = dst.project_field(bx, i);
-
-                if dst_f.layout.is_zst() {
-                    continue;
-                }
-
-                if src_f.layout.ty == dst_f.layout.ty {
-                    memcpy_ty(bx, dst_f.llval, dst_f.align, src_f.llval, src_f.align,
-                              src_f.layout, MemFlags::empty());
-                } else {
-                    coerce_unsized_into(bx, src_f, dst_f);
-                }
-            }
-        }
-        _ => bug!("coerce_unsized_into: invalid coercion {:?} -> {:?}",
-                  src_ty,
-                  dst_ty),
-    }
-}
-
-pub fn cast_shift_expr_rhs<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
-    bx: &Bx,
-    op: hir::BinOpKind,
-    lhs: Bx::Value,
-    rhs: Bx::Value
-) -> Bx::Value {
-    cast_shift_rhs(bx, op, lhs, rhs, |a, b| bx.trunc(a, b), |a, b| bx.zext(a, b))
-}
-
-fn cast_shift_rhs<'a, 'tcx: 'a, F, G, Bx: BuilderMethods<'a, 'tcx>>(
-    bx: &Bx,
-    op: hir::BinOpKind,
-    lhs: Bx::Value,
-    rhs: Bx::Value,
-    trunc: F,
-    zext: G
-) -> Bx::Value
-    where F: FnOnce(
-        Bx::Value,
-        Bx::Type
-    ) -> Bx::Value,
-    G: FnOnce(
-        Bx::Value,
-        Bx::Type
-    ) -> Bx::Value
-{
-    // Shifts may have any size int on the rhs
-    if op.is_shift() {
-        let mut rhs_llty = bx.cx().val_ty(rhs);
-        let mut lhs_llty = bx.cx().val_ty(lhs);
-        if bx.cx().type_kind(rhs_llty) == TypeKind::Vector {
-            rhs_llty = bx.cx().element_type(rhs_llty)
-        }
-        if bx.cx().type_kind(lhs_llty) == TypeKind::Vector {
-            lhs_llty = bx.cx().element_type(lhs_llty)
-        }
-        let rhs_sz = bx.cx().int_width(rhs_llty);
-        let lhs_sz = bx.cx().int_width(lhs_llty);
-        if lhs_sz < rhs_sz {
-            trunc(rhs, lhs_llty)
-        } else if lhs_sz > rhs_sz {
-            // FIXME (#1877: If in the future shifting by negative
-            // values is no longer undefined then this is wrong.
-            zext(rhs, lhs_llty)
-        } else {
-            rhs
-        }
-    } else {
-        rhs
-    }
-}
-
-/// Returns whether this session's target will use SEH-based unwinding.
-///
-/// This is only true for MSVC targets, and even then the 64-bit MSVC target
-/// currently uses SEH-ish unwinding with DWARF info tables to the side (same as
-/// 64-bit MinGW) instead of "full SEH".
-pub fn wants_msvc_seh(sess: &Session) -> bool {
-    sess.target.target.options.is_like_msvc
-}
-
-pub fn call_assume<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
-    bx: &Bx,
-    val: Bx::Value
-) {
-    let assume_intrinsic = bx.cx().get_intrinsic("llvm.assume");
-    bx.call(assume_intrinsic, &[val], None);
-}
-
-pub fn from_immediate<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
-    bx: &Bx,
-    val: Bx::Value
-) -> Bx::Value {
-    if bx.cx().val_ty(val) == bx.cx().type_i1() {
-        bx.zext(val, bx.cx().type_i8())
-    } else {
-        val
-    }
-}
-
-pub fn to_immediate<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
-    bx: &Bx,
-    val: Bx::Value,
-    layout: layout::TyLayout,
-) -> Bx::Value {
-    if let layout::Abi::Scalar(ref scalar) = layout.abi {
-        return to_immediate_scalar(bx, val, scalar);
-    }
-    val
-}
-
-pub fn to_immediate_scalar<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
-    bx: &Bx,
-    val: Bx::Value,
-    scalar: &layout::Scalar,
-) -> Bx::Value {
-    if scalar.is_bool() {
-        return bx.trunc(val, bx.cx().type_i1());
-    }
-    val
-}
-
-pub fn memcpy_ty<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
-    bx: &Bx,
-    dst: Bx::Value,
-    dst_align: Align,
-    src: Bx::Value,
-    src_align: Align,
-    layout: TyLayout<'tcx>,
-    flags: MemFlags,
-) {
-    let size = layout.size.bytes();
-    if size == 0 {
-        return;
-    }
-
-    bx.memcpy(dst, dst_align, src, src_align, bx.cx().const_usize(size), flags);
-}
-
-pub fn codegen_instance<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
-    cx: &'a Bx::CodegenCx,
-    instance: Instance<'tcx>,
-) {
-    let _s = if cx.sess().codegen_stats() {
-        let mut instance_name = String::new();
-        DefPathBasedNames::new(cx.tcx(), true, true)
-            .push_def_path(instance.def_id(), &mut instance_name);
-        Some(StatRecorder::new(cx, instance_name))
-    } else {
-        None
-    };
-
-    // this is an info! to allow collecting monomorphization statistics
-    // and to allow finding the last function before LLVM aborts from
-    // release builds.
-    info!("codegen_instance({})", instance);
-
-    let sig = instance.fn_sig(cx.tcx());
-    let sig = cx.tcx().normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), &sig);
-
-    let lldecl = cx.instances().borrow().get(&instance).cloned().unwrap_or_else(||
-        bug!("Instance `{:?}` not already declared", instance));
-
-    cx.stats().borrow_mut().n_closures += 1;
-
-    let mir = cx.tcx().instance_mir(instance.def);
-    mir::codegen_mir::<Bx>(cx, lldecl, &mir, instance, sig);
-}
-
-pub fn set_link_section(llval: &Value, attrs: &CodegenFnAttrs) {
-    let sect = match attrs.link_section {
-        Some(name) => name,
-        None => return,
-    };
-    unsafe {
-        let buf = SmallCStr::new(&sect.as_str());
-        llvm::LLVMSetSection(llval, buf.as_ptr());
-    }
-}
-
-/// Create the `main` function which will initialize the rust runtime and call
-/// users main function.
-fn maybe_create_entry_wrapper<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
-    cx: &'a Bx::CodegenCx
-) {
-    let (main_def_id, span) = match *cx.sess().entry_fn.borrow() {
-        Some((id, span, _)) => {
-            (cx.tcx().hir.local_def_id(id), span)
-        }
-        None => return,
-    };
-
-    let instance = Instance::mono(cx.tcx(), main_def_id);
-
-    if !cx.codegen_unit().contains_item(&MonoItem::Fn(instance)) {
-        // We want to create the wrapper in the same codegen unit as Rust's main
-        // function.
-        return;
-    }
-
-    let main_llfn = cx.get_fn(instance);
-
-    let et = cx.sess().entry_fn.get().map(|e| e.2);
-    match et {
-        Some(EntryFnType::Main) => create_entry_fn::<Bx>(cx, span, main_llfn, main_def_id, true),
-        Some(EntryFnType::Start) => create_entry_fn::<Bx>(cx, span, main_llfn, main_def_id, false),
-        None => {}    // Do nothing.
-    }
-
-    fn create_entry_fn<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
-        cx: &'a Bx::CodegenCx,
-        sp: Span,
-        rust_main: Bx::Value,
-        rust_main_def_id: DefId,
-        use_start_lang_item: bool,
-    ) {
-        let llfty =
-            cx.type_func(&[cx.type_int(), cx.type_ptr_to(cx.type_i8p())], cx.type_int());
-
-        let main_ret_ty = cx.tcx().fn_sig(rust_main_def_id).output();
-        // Given that `main()` has no arguments,
-        // then its return type cannot have
-        // late-bound regions, since late-bound
-        // regions must appear in the argument
-        // listing.
-        let main_ret_ty = cx.tcx().erase_regions(
-            &main_ret_ty.no_bound_vars().unwrap(),
-        );
-
-        if cx.get_defined_value("main").is_some() {
-            // FIXME: We should be smart and show a better diagnostic here.
-            cx.sess().struct_span_err(sp, "entry symbol `main` defined multiple times")
-                     .help("did you use #[no_mangle] on `fn main`? Use #[start] instead")
-                     .emit();
-            cx.sess().abort_if_errors();
-            bug!();
-        }
-        let llfn = cx.declare_cfn("main", llfty);
-
-        // `main` should respect same config for frame pointer elimination as rest of code
-        cx.set_frame_pointer_elimination(llfn);
-        cx.apply_target_cpu_attr(llfn);
-
-        let bx = Bx::new_block(&cx, llfn, "top");
-
-        bx.insert_reference_to_gdb_debug_scripts_section_global();
-
-        // Params from native main() used as args for rust start function
-        let param_argc = cx.get_param(llfn, 0);
-        let param_argv = cx.get_param(llfn, 1);
-        let arg_argc = bx.intcast(param_argc, cx.type_isize(), true);
-        let arg_argv = param_argv;
-
-        let (start_fn, args) = if use_start_lang_item {
-            let start_def_id = cx.tcx().require_lang_item(StartFnLangItem);
-            let start_fn = callee::resolve_and_get_fn(
-                cx,
-                start_def_id,
-                cx.tcx().intern_substs(&[main_ret_ty.into()]),
-            );
-            (start_fn, vec![bx.pointercast(rust_main, cx.type_ptr_to(cx.type_i8p())),
-                            arg_argc, arg_argv])
-        } else {
-            debug!("using user-defined start fn");
-            (rust_main, vec![arg_argc, arg_argv])
-        };
-
-        let result = bx.call(start_fn, &args, None);
-        bx.ret(bx.intcast(result, cx.type_int(), true));
-    }
-}
-
 pub(crate) fn write_metadata<'a, 'gcx>(
     tcx: TyCtxt<'a, 'gcx, 'gcx>,
     llvm_module: &ModuleLlvm
@@ -675,397 +180,6 @@ pub fn iter_globals(llmod: &'ll llvm::Module) -> ValueIter<'ll> {
     }
 }
 
-fn determine_cgu_reuse<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                                 cgu: &CodegenUnit<'tcx>)
-                                 -> CguReuse {
-    if !tcx.dep_graph.is_fully_enabled() {
-        return CguReuse::No
-    }
-
-    let work_product_id = &cgu.work_product_id();
-    if tcx.dep_graph.previous_work_product(work_product_id).is_none() {
-        // We don't have anything cached for this CGU. This can happen
-        // if the CGU did not exist in the previous session.
-        return CguReuse::No
-    }
-
-    // Try to mark the CGU as green. If it we can do so, it means that nothing
-    // affecting the LLVM module has changed and we can re-use a cached version.
-    // If we compile with any kind of LTO, this means we can re-use the bitcode
-    // of the Pre-LTO stage (possibly also the Post-LTO version but we'll only
-    // know that later). If we are not doing LTO, there is only one optimized
-    // version of each module, so we re-use that.
-    let dep_node = cgu.codegen_dep_node(tcx);
-    assert!(!tcx.dep_graph.dep_node_exists(&dep_node),
-        "CompileCodegenUnit dep-node for CGU `{}` already exists before marking.",
-        cgu.name());
-
-    if tcx.dep_graph.try_mark_green(tcx, &dep_node).is_some() {
-        // We can re-use either the pre- or the post-thinlto state
-        if tcx.sess.lto() != Lto::No {
-            CguReuse::PreLto
-        } else {
-            CguReuse::PostLto
-        }
-    } else {
-        CguReuse::No
-    }
-}
-
-pub fn codegen_crate<B: BackendMethods>(
-    backend: B,
-    tcx: TyCtxt<'a, 'tcx, 'tcx>,
-    rx: mpsc::Receiver<Box<dyn Any + Send>>
-) -> B::OngoingCodegen {
-
-    check_for_rustc_errors_attr(tcx);
-
-    let cgu_name_builder = &mut CodegenUnitNameBuilder::new(tcx);
-
-    // Codegen the metadata.
-    tcx.sess.profiler(|p| p.start_activity(ProfileCategory::Codegen));
-
-    let metadata_cgu_name = cgu_name_builder.build_cgu_name(LOCAL_CRATE,
-                                                            &["crate"],
-                                                            Some("metadata")).as_str()
-                                                                             .to_string();
-    let metadata_llvm_module = backend.new_metadata(tcx.sess, &metadata_cgu_name);
-    let metadata = time(tcx.sess, "write metadata", || {
-        backend.write_metadata(tcx, &metadata_llvm_module)
-    });
-    tcx.sess.profiler(|p| p.end_activity(ProfileCategory::Codegen));
-
-    let metadata_module = ModuleCodegen {
-        name: metadata_cgu_name,
-        module_llvm: metadata_llvm_module,
-        kind: ModuleKind::Metadata,
-    };
-
-    let time_graph = if tcx.sess.opts.debugging_opts.codegen_time_graph {
-        Some(time_graph::TimeGraph::new())
-    } else {
-        None
-    };
-
-    // Skip crate items and just output metadata in -Z no-codegen mode.
-    if tcx.sess.opts.debugging_opts.no_codegen ||
-       !tcx.sess.opts.output_types.should_codegen() {
-        let ongoing_codegen = backend.start_async_codegen(
-            tcx,
-            time_graph,
-            metadata,
-            rx,
-            1);
-
-        backend.submit_pre_codegened_module_to_llvm(&ongoing_codegen, tcx, metadata_module);
-        backend.codegen_finished(&ongoing_codegen, tcx);
-
-        assert_and_save_dep_graph(tcx);
-
-        backend.check_for_errors(&ongoing_codegen, tcx.sess);
-
-        return ongoing_codegen;
-    }
-
-    // Run the monomorphization collector and partition the collected items into
-    // codegen units.
-    let codegen_units = tcx.collect_and_partition_mono_items(LOCAL_CRATE).1;
-    let codegen_units = (*codegen_units).clone();
-
-    // Force all codegen_unit queries so they are already either red or green
-    // when compile_codegen_unit accesses them. We are not able to re-execute
-    // the codegen_unit query from just the DepNode, so an unknown color would
-    // lead to having to re-execute compile_codegen_unit, possibly
-    // unnecessarily.
-    if tcx.dep_graph.is_fully_enabled() {
-        for cgu in &codegen_units {
-            tcx.codegen_unit(cgu.name().clone());
-        }
-    }
-
-    let ongoing_codegen = backend.start_async_codegen(
-        tcx,
-        time_graph.clone(),
-        metadata,
-        rx,
-        codegen_units.len());
-    let ongoing_codegen = AbortCodegenOnDrop::<B>(Some(ongoing_codegen));
-
-    // Codegen an allocator shim, if necessary.
-    //
-    // If the crate doesn't have an `allocator_kind` set then there's definitely
-    // no shim to generate. Otherwise we also check our dependency graph for all
-    // our output crate types. If anything there looks like its a `Dynamic`
-    // linkage, then it's already got an allocator shim and we'll be using that
-    // one instead. If nothing exists then it's our job to generate the
-    // allocator!
-    let any_dynamic_crate = tcx.sess.dependency_formats.borrow()
-        .iter()
-        .any(|(_, list)| {
-            use rustc::middle::dependency_format::Linkage;
-            list.iter().any(|&linkage| linkage == Linkage::Dynamic)
-        });
-    let allocator_module = if any_dynamic_crate {
-        None
-    } else if let Some(kind) = *tcx.sess.allocator_kind.get() {
-        let llmod_id = cgu_name_builder.build_cgu_name(LOCAL_CRATE,
-                                                       &["crate"],
-                                                       Some("allocator")).as_str()
-                                                                         .to_string();
-        let modules = backend.new_metadata(tcx.sess, &llmod_id);
-        time(tcx.sess, "write allocator module", || {
-            backend.codegen_allocator(tcx, &modules, kind)
-        });
-
-        Some(ModuleCodegen {
-            name: llmod_id,
-            module_llvm: modules,
-            kind: ModuleKind::Allocator,
-        })
-    } else {
-        None
-    };
-
-    if let Some(allocator_module) = allocator_module {
-        backend.submit_pre_codegened_module_to_llvm(&ongoing_codegen, tcx, allocator_module);
-    }
-
-    backend.submit_pre_codegened_module_to_llvm(&ongoing_codegen, tcx, metadata_module);
-
-    // We sort the codegen units by size. This way we can schedule work for LLVM
-    // a bit more efficiently.
-    let codegen_units = {
-        let mut codegen_units = codegen_units;
-        codegen_units.sort_by_cached_key(|cgu| cmp::Reverse(cgu.size_estimate()));
-        codegen_units
-    };
-
-    let mut total_codegen_time = Duration::new(0, 0);
-    let mut all_stats = Stats::default();
-
-    for cgu in codegen_units.into_iter() {
-        backend.wait_for_signal_to_codegen_item(&ongoing_codegen);
-        backend.check_for_errors(&ongoing_codegen, tcx.sess);
-
-        let cgu_reuse = determine_cgu_reuse(tcx, &cgu);
-        tcx.sess.cgu_reuse_tracker.set_actual_reuse(&cgu.name().as_str(), cgu_reuse);
-
-        match cgu_reuse {
-            CguReuse::No => {
-                let _timing_guard = time_graph.as_ref().map(|time_graph| {
-                    time_graph.start(write::CODEGEN_WORKER_TIMELINE,
-                                     write::CODEGEN_WORK_PACKAGE_KIND,
-                                     &format!("codegen {}", cgu.name()))
-                });
-                let start_time = Instant::now();
-                let stats = backend.compile_codegen_unit(tcx, *cgu.name());
-                all_stats.extend(stats);
-                total_codegen_time += start_time.elapsed();
-                false
-            }
-            CguReuse::PreLto => {
-                write::submit_pre_lto_module_to_llvm(tcx, CachedModuleCodegen {
-                    name: cgu.name().to_string(),
-                    source: cgu.work_product(tcx),
-                });
-                true
-            }
-            CguReuse::PostLto => {
-                write::submit_post_lto_module_to_llvm(tcx, CachedModuleCodegen {
-                    name: cgu.name().to_string(),
-                    source: cgu.work_product(tcx),
-                });
-                true
-            }
-        };
-    }
-
-    backend.codegen_finished(&ongoing_codegen, tcx);
-
-    // Since the main thread is sometimes blocked during codegen, we keep track
-    // -Ztime-passes output manually.
-    print_time_passes_entry(tcx.sess.time_passes(),
-                            "codegen to LLVM IR",
-                            total_codegen_time);
-
-    rustc_incremental::assert_module_sources::assert_module_sources(tcx);
-
-    symbol_names_test::report_symbol_names(tcx);
-
-    if tcx.sess.codegen_stats() {
-        println!("--- codegen stats ---");
-        println!("n_glues_created: {}", all_stats.n_glues_created);
-        println!("n_null_glues: {}", all_stats.n_null_glues);
-        println!("n_real_glues: {}", all_stats.n_real_glues);
-
-        println!("n_fns: {}", all_stats.n_fns);
-        println!("n_inlines: {}", all_stats.n_inlines);
-        println!("n_closures: {}", all_stats.n_closures);
-        println!("fn stats:");
-        all_stats.fn_stats.sort_by_key(|&(_, insns)| insns);
-        for &(ref name, insns) in all_stats.fn_stats.iter() {
-            println!("{} insns, {}", insns, *name);
-        }
-    }
-
-    if tcx.sess.count_llvm_insns() {
-        for (k, v) in all_stats.llvm_insns.iter() {
-            println!("{:7} {}", *v, *k);
-        }
-    }
-
-    backend.check_for_errors(&ongoing_codegen, tcx.sess);
-
-    assert_and_save_dep_graph(tcx);
-    ongoing_codegen.into_inner()
-}
-
-/// A curious wrapper structure whose only purpose is to call `codegen_aborted`
-/// when it's dropped abnormally.
-///
-/// In the process of working on rust-lang/rust#55238 a mysterious segfault was
-/// stumbled upon. The segfault was never reproduced locally, but it was
-/// suspected to be related to the fact that codegen worker threads were
-/// sticking around by the time the main thread was exiting, causing issues.
-///
-/// This structure is an attempt to fix that issue where the `codegen_aborted`
-/// message will block until all workers have finished. This should ensure that
-/// even if the main codegen thread panics we'll wait for pending work to
-/// complete before returning from the main thread, hopefully avoiding
-/// segfaults.
-///
-/// If you see this comment in the code, then it means that this workaround
-/// worked! We may yet one day track down the mysterious cause of that
-/// segfault...
-struct AbortCodegenOnDrop<B: BackendMethods>(Option<B::OngoingCodegen>);
-
-impl<B: BackendMethods> AbortCodegenOnDrop<B> {
-    fn into_inner(mut self) -> B::OngoingCodegen {
-        self.0.take().unwrap()
-    }
-}
-
-impl<B: BackendMethods> Deref for AbortCodegenOnDrop<B> {
-    type Target = B::OngoingCodegen;
-
-    fn deref(&self) -> &B::OngoingCodegen {
-        self.0.as_ref().unwrap()
-    }
-}
-
-impl<B: BackendMethods> DerefMut for AbortCodegenOnDrop<B> {
-    fn deref_mut(&mut self) -> &mut B::OngoingCodegen {
-        self.0.as_mut().unwrap()
-    }
-}
-
-impl<B: BackendMethods> Drop for AbortCodegenOnDrop<B> {
-    fn drop(&mut self) {
-        if let Some(codegen) = self.0.take() {
-            B::codegen_aborted(codegen);
-        }
-    }
-}
-
-fn assert_and_save_dep_graph<'ll, 'tcx>(tcx: TyCtxt<'ll, 'tcx, 'tcx>) {
-    time(tcx.sess,
-         "assert dep graph",
-         || rustc_incremental::assert_dep_graph(tcx));
-
-    time(tcx.sess,
-         "serialize dep graph",
-         || rustc_incremental::save_dep_graph(tcx));
-}
-
-impl CrateInfo {
-    pub fn new(tcx: TyCtxt) -> CrateInfo {
-        let mut info = CrateInfo {
-            panic_runtime: None,
-            compiler_builtins: None,
-            profiler_runtime: None,
-            sanitizer_runtime: None,
-            is_no_builtins: Default::default(),
-            native_libraries: Default::default(),
-            used_libraries: tcx.native_libraries(LOCAL_CRATE),
-            link_args: tcx.link_args(LOCAL_CRATE),
-            crate_name: Default::default(),
-            used_crates_dynamic: cstore::used_crates(tcx, LinkagePreference::RequireDynamic),
-            used_crates_static: cstore::used_crates(tcx, LinkagePreference::RequireStatic),
-            used_crate_source: Default::default(),
-            wasm_imports: Default::default(),
-            lang_item_to_crate: Default::default(),
-            missing_lang_items: Default::default(),
-        };
-        let lang_items = tcx.lang_items();
-
-        let load_wasm_items = tcx.sess.crate_types.borrow()
-            .iter()
-            .any(|c| *c != config::CrateType::Rlib) &&
-            tcx.sess.opts.target_triple.triple() == "wasm32-unknown-unknown";
-
-        if load_wasm_items {
-            info.load_wasm_imports(tcx, LOCAL_CRATE);
-        }
-
-        let crates = tcx.crates();
-
-        let n_crates = crates.len();
-        info.native_libraries.reserve(n_crates);
-        info.crate_name.reserve(n_crates);
-        info.used_crate_source.reserve(n_crates);
-        info.missing_lang_items.reserve(n_crates);
-
-        for &cnum in crates.iter() {
-            info.native_libraries.insert(cnum, tcx.native_libraries(cnum));
-            info.crate_name.insert(cnum, tcx.crate_name(cnum).to_string());
-            info.used_crate_source.insert(cnum, tcx.used_crate_source(cnum));
-            if tcx.is_panic_runtime(cnum) {
-                info.panic_runtime = Some(cnum);
-            }
-            if tcx.is_compiler_builtins(cnum) {
-                info.compiler_builtins = Some(cnum);
-            }
-            if tcx.is_profiler_runtime(cnum) {
-                info.profiler_runtime = Some(cnum);
-            }
-            if tcx.is_sanitizer_runtime(cnum) {
-                info.sanitizer_runtime = Some(cnum);
-            }
-            if tcx.is_no_builtins(cnum) {
-                info.is_no_builtins.insert(cnum);
-            }
-            if load_wasm_items {
-                info.load_wasm_imports(tcx, cnum);
-            }
-            let missing = tcx.missing_lang_items(cnum);
-            for &item in missing.iter() {
-                if let Ok(id) = lang_items.require(item) {
-                    info.lang_item_to_crate.insert(item, id.krate);
-                }
-            }
-
-            // No need to look for lang items that are whitelisted and don't
-            // actually need to exist.
-            let missing = missing.iter()
-                .cloned()
-                .filter(|&l| !weak_lang_items::whitelisted(tcx, l))
-                .collect();
-            info.missing_lang_items.insert(cnum, missing);
-        }
-
-        return info
-    }
-
-    fn load_wasm_imports(&mut self, tcx: TyCtxt, cnum: CrateNum) {
-        self.wasm_imports.extend(tcx.wasm_import_module_map(cnum).iter().map(|(&id, module)| {
-            let instance = Instance::mono(tcx, id);
-            let import_name = tcx.symbol_name(instance);
-
-            (import_name.to_string(), module.clone())
-        }));
-    }
-}
-
 pub fn compile_codegen_unit<'ll, 'tcx>(tcx: TyCtxt<'ll, 'tcx, 'tcx>,
                                   cgu_name: InternedString)
                                   -> Stats {
@@ -1141,35 +255,15 @@ pub fn compile_codegen_unit<'ll, 'tcx>(tcx: TyCtxt<'ll, 'tcx, 'tcx>,
     }
 }
 
-pub fn provide_both(providers: &mut Providers) {
-    providers.dllimport_foreign_items = |tcx, krate| {
-        let module_map = tcx.foreign_modules(krate);
-        let module_map = module_map.iter()
-            .map(|lib| (lib.def_id, lib))
-            .collect::<FxHashMap<_, _>>();
-
-        let dllimports = tcx.native_libraries(krate)
-            .iter()
-            .filter(|lib| {
-                if lib.kind != cstore::NativeLibraryKind::NativeUnknown {
-                    return false
-                }
-                let cfg = match lib.cfg {
-                    Some(ref cfg) => cfg,
-                    None => return true,
-                };
-                attr::cfg_matches(cfg, &tcx.sess.parse_sess, None)
-            })
-            .filter_map(|lib| lib.foreign_module)
-            .map(|id| &module_map[&id])
-            .flat_map(|module| module.foreign_items.iter().cloned())
-            .collect();
-        Lrc::new(dllimports)
-    };
-
-    providers.is_dllimport_foreign_item = |tcx, def_id| {
-        tcx.dllimport_foreign_items(def_id.krate).contains(&def_id)
+pub fn set_link_section(llval: &Value, attrs: &CodegenFnAttrs) {
+    let sect = match attrs.link_section {
+        Some(name) => name,
+        None => return,
     };
+    unsafe {
+        let buf = SmallCStr::new(&sect.as_str());
+        llvm::LLVMSetSection(llval, buf.as_ptr());
+    }
 }
 
 pub fn linkage_to_llvm(linkage: Linkage) -> llvm::Linkage {
diff --git a/src/librustc_codegen_llvm/builder.rs b/src/librustc_codegen_llvm/builder.rs
index efd2e146f35..40fddef8be3 100644
--- a/src/librustc_codegen_llvm/builder.rs
+++ b/src/librustc_codegen_llvm/builder.rs
@@ -53,14 +53,6 @@ fn noname() -> *const c_char {
     &CNULL
 }
 
-bitflags! {
-    pub struct MemFlags: u8 {
-        const VOLATILE = 1 << 0;
-        const NONTEMPORAL = 1 << 1;
-        const UNALIGNED = 1 << 2;
-    }
-}
-
 impl BackendTypes for Builder<'_, 'll, 'tcx> {
     type Value = <CodegenCx<'ll, 'tcx> as BackendTypes>::Value;
     type BasicBlock = <CodegenCx<'ll, 'tcx> as BackendTypes>::BasicBlock;
diff --git a/src/librustc_codegen_llvm/callee.rs b/src/librustc_codegen_llvm/callee.rs
index e049a43fd6a..d5b398d8a33 100644
--- a/src/librustc_codegen_llvm/callee.rs
+++ b/src/librustc_codegen_llvm/callee.rs
@@ -202,35 +202,3 @@ pub fn get_fn(
 
     llfn
 }
-
-pub fn resolve_and_get_fn<'tcx, Cx: CodegenMethods<'tcx>>(
-    cx: &Cx,
-    def_id: DefId,
-    substs: &'tcx Substs<'tcx>,
-) -> Cx::Value {
-    cx.get_fn(
-        ty::Instance::resolve(
-            cx.tcx(),
-            ty::ParamEnv::reveal_all(),
-            def_id,
-            substs
-        ).unwrap()
-    )
-}
-
-pub fn resolve_and_get_fn_for_vtable<'tcx,
-    Cx: Backend<'tcx> + MiscMethods<'tcx> + TypeMethods<'tcx>
->(
-    cx: &Cx,
-    def_id: DefId,
-    substs: &'tcx Substs<'tcx>,
-) -> Cx::Value {
-    cx.get_fn(
-        ty::Instance::resolve_for_vtable(
-            cx.tcx(),
-            ty::ParamEnv::reveal_all(),
-            def_id,
-            substs
-        ).unwrap()
-    )
-}
diff --git a/src/librustc_codegen_llvm/common.rs b/src/librustc_codegen_llvm/common.rs
index 7dc4b00f794..2211ec5247f 100644
--- a/src/librustc_codegen_llvm/common.rs
+++ b/src/librustc_codegen_llvm/common.rs
@@ -405,88 +405,3 @@ pub fn struct_in_context(
 fn hi_lo_to_u128(lo: u64, hi: u64) -> u128 {
     ((hi as u128) << 64) | (lo as u128)
 }
-
-pub fn langcall(tcx: TyCtxt,
-                span: Option<Span>,
-                msg: &str,
-                li: LangItem)
-                -> DefId {
-    tcx.lang_items().require(li).unwrap_or_else(|s| {
-        let msg = format!("{} {}", msg, s);
-        match span {
-            Some(span) => tcx.sess.span_fatal(span, &msg[..]),
-            None => tcx.sess.fatal(&msg[..]),
-        }
-    })
-}
-
-// To avoid UB from LLVM, these two functions mask RHS with an
-// appropriate mask unconditionally (i.e. the fallback behavior for
-// all shifts). For 32- and 64-bit types, this matches the semantics
-// of Java. (See related discussion on #1877 and #10183.)
-
-pub fn build_unchecked_lshift<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
-    bx: &Bx,
-    lhs: Bx::Value,
-    rhs: Bx::Value
-) -> Bx::Value {
-    let rhs = base::cast_shift_expr_rhs(bx, hir::BinOpKind::Shl, lhs, rhs);
-    // #1877, #10183: Ensure that input is always valid
-    let rhs = shift_mask_rhs(bx, rhs);
-    bx.shl(lhs, rhs)
-}
-
-pub fn build_unchecked_rshift<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
-    bx: &Bx,
-    lhs_t: Ty<'tcx>,
-    lhs: Bx::Value,
-    rhs: Bx::Value
-) -> Bx::Value {
-    let rhs = base::cast_shift_expr_rhs(bx, hir::BinOpKind::Shr, lhs, rhs);
-    // #1877, #10183: Ensure that input is always valid
-    let rhs = shift_mask_rhs(bx, rhs);
-    let is_signed = lhs_t.is_signed();
-    if is_signed {
-        bx.ashr(lhs, rhs)
-    } else {
-        bx.lshr(lhs, rhs)
-    }
-}
-
-fn shift_mask_rhs<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
-    bx: &Bx,
-    rhs: Bx::Value
-) -> Bx::Value {
-    let rhs_llty = bx.cx().val_ty(rhs);
-    bx.and(rhs, shift_mask_val(bx, rhs_llty, rhs_llty, false))
-}
-
-pub fn shift_mask_val<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
-    bx: &Bx,
-    llty: Bx::Type,
-    mask_llty: Bx::Type,
-    invert: bool
-) -> Bx::Value {
-    let kind = bx.cx().type_kind(llty);
-    match kind {
-        TypeKind::Integer => {
-            // i8/u8 can shift by at most 7, i16/u16 by at most 15, etc.
-            let val = bx.cx().int_width(llty) - 1;
-            if invert {
-                bx.cx().const_int(mask_llty, !val as i64)
-            } else {
-                bx.cx().const_uint(mask_llty, val)
-            }
-        },
-        TypeKind::Vector => {
-            let mask = shift_mask_val(
-                bx,
-                bx.cx().element_type(llty),
-                bx.cx().element_type(mask_llty),
-                invert
-            );
-            bx.vector_splat(bx.cx().vector_length(mask_llty), mask)
-        },
-        _ => bug!("shift_mask_val: expected Integer or Vector, found {:?}", kind),
-    }
-}
diff --git a/src/librustc_codegen_llvm/consts.rs b/src/librustc_codegen_llvm/consts.rs
index cbbda28994b..8a5a817f574 100644
--- a/src/librustc_codegen_llvm/consts.rs
+++ b/src/librustc_codegen_llvm/consts.rs
@@ -31,6 +31,58 @@ use rustc::hir::{self, CodegenFnAttrs, CodegenFnAttrFlags};
 
 use std::ffi::{CStr, CString};
 
+pub fn const_alloc_to_llvm(cx: &CodegenCx<'ll, '_>, alloc: &Allocation) -> &'ll Value {
+    let mut llvals = Vec::with_capacity(alloc.relocations.len() + 1);
+    let dl = cx.data_layout();
+    let pointer_size = dl.pointer_size.bytes() as usize;
+
+    let mut next_offset = 0;
+    for &(offset, ((), alloc_id)) in alloc.relocations.iter() {
+        let offset = offset.bytes();
+        assert_eq!(offset as usize as u64, offset);
+        let offset = offset as usize;
+        if offset > next_offset {
+            llvals.push(cx.const_bytes(&alloc.bytes[next_offset..offset]));
+        }
+        let ptr_offset = read_target_uint(
+            dl.endian,
+            &alloc.bytes[offset..(offset + pointer_size)],
+        ).expect("const_alloc_to_llvm: could not read relocation pointer") as u64;
+        llvals.push(cx.scalar_to_backend(
+            Pointer::new(alloc_id, Size::from_bytes(ptr_offset)).into(),
+            &layout::Scalar {
+                value: layout::Primitive::Pointer,
+                valid_range: 0..=!0
+            },
+            cx.type_i8p()
+        ));
+        next_offset = offset + pointer_size;
+    }
+    if alloc.bytes.len() >= next_offset {
+        llvals.push(cx.const_bytes(&alloc.bytes[next_offset ..]));
+    }
+
+    cx.const_struct(&llvals, true)
+}
+
+pub fn codegen_static_initializer(
+    cx: &CodegenCx<'ll, 'tcx>,
+    def_id: DefId,
+) -> Result<(&'ll Value, &'tcx Allocation), ErrorHandled> {
+    let instance = ty::Instance::mono(cx.tcx, def_id);
+    let cid = GlobalId {
+        instance,
+        promoted: None,
+    };
+    let param_env = ty::ParamEnv::reveal_all();
+    let static_ = cx.tcx.const_eval(param_env.and(cid))?;
+
+    let alloc = match static_.val {
+        ConstValue::ByRef(_, alloc, n) if n.bytes() == 0 => alloc,
+        _ => bug!("static const eval returned {:#?}", static_),
+    };
+    Ok((const_alloc_to_llvm(cx, alloc), alloc))
+}
 
 fn set_global_alignment(cx: &CodegenCx<'ll, '_>,
                         gv: &'ll Value,
diff --git a/src/librustc_codegen_llvm/context.rs b/src/librustc_codegen_llvm/context.rs
index b0d153f8efc..3eb9728e90c 100644
--- a/src/librustc_codegen_llvm/context.rs
+++ b/src/librustc_codegen_llvm/context.rs
@@ -10,6 +10,7 @@
 
 use attributes;
 use llvm;
+use llvm_util;
 use rustc::dep_graph::DepGraphSafe;
 use rustc::hir;
 use debuginfo;
@@ -445,6 +446,9 @@ impl MiscMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         attributes::apply_target_cpu_attr(self, llfn)
     }
 
+    fn closure_env_needs_indirect_debuginfo(&self) {
+        llvm_util::get_major_version() < 6
+    }
 
     fn create_used_variable(&self) {
         let name = const_cstr!("llvm.used");
diff --git a/src/librustc_codegen_llvm/debuginfo/create_scope_map.rs b/src/librustc_codegen_llvm/debuginfo/create_scope_map.rs
index 0fd5f7fb8cd..8eb266f8069 100644
--- a/src/librustc_codegen_llvm/debuginfo/create_scope_map.rs
+++ b/src/librustc_codegen_llvm/debuginfo/create_scope_map.rs
@@ -26,21 +26,6 @@ use rustc_data_structures::indexed_vec::{Idx, IndexVec};
 
 use syntax_pos::BytePos;
 
-#[derive(Clone, Copy, Debug)]
-pub struct MirDebugScope<D> {
-    pub scope_metadata: Option<D>,
-    // Start and end offsets of the file to which this DIScope belongs.
-    // These are used to quickly determine whether some span refers to the same file.
-    pub file_start_pos: BytePos,
-    pub file_end_pos: BytePos,
-}
-
-impl<D> MirDebugScope<D> {
-    pub fn is_valid(&self) -> bool {
-        self.scope_metadata.is_some()
-    }
-}
-
 /// Produce DIScope DIEs for each MIR Scope which has variables defined in it.
 /// If debuginfo is disabled, the returned vector is empty.
 pub fn create_mir_scopes(
diff --git a/src/librustc_codegen_llvm/debuginfo/mod.rs b/src/librustc_codegen_llvm/debuginfo/mod.rs
index 8ef7350747d..ddd346e99d5 100644
--- a/src/librustc_codegen_llvm/debuginfo/mod.rs
+++ b/src/librustc_codegen_llvm/debuginfo/mod.rs
@@ -111,54 +111,6 @@ impl<'a, 'tcx> CrateDebugContext<'a, 'tcx> {
     }
 }
 
-pub enum FunctionDebugContext<D> {
-    RegularContext(FunctionDebugContextData<D>),
-    DebugInfoDisabled,
-    FunctionWithoutDebugInfo,
-}
-
-impl<D> FunctionDebugContext<D> {
-    pub fn get_ref<'a>(&'a self, span: Span) -> &'a FunctionDebugContextData<D> {
-        match *self {
-            FunctionDebugContext::RegularContext(ref data) => data,
-            FunctionDebugContext::DebugInfoDisabled => {
-                span_bug!(span, "{}", Self::debuginfo_disabled_message());
-            }
-            FunctionDebugContext::FunctionWithoutDebugInfo => {
-                span_bug!(span, "{}", Self::should_be_ignored_message());
-            }
-        }
-    }
-
-    fn debuginfo_disabled_message() -> &'static str {
-        "debuginfo: Error trying to access FunctionDebugContext although debug info is disabled!"
-    }
-
-    fn should_be_ignored_message() -> &'static str {
-        "debuginfo: Error trying to access FunctionDebugContext for function that should be \
-         ignored by debug info!"
-    }
-}
-
-pub struct FunctionDebugContextData<D> {
-    fn_metadata: D,
-    source_locations_enabled: Cell<bool>,
-    pub defining_crate: CrateNum,
-}
-
-pub enum VariableAccess<'a, V> {
-    // The llptr given is an alloca containing the variable's value
-    DirectVariable { alloca: V },
-    // The llptr given is an alloca containing the start of some pointer chain
-    // leading to the variable's content.
-    IndirectVariable { alloca: V, address_operations: &'a [i64] }
-}
-
-pub enum VariableKind {
-    ArgumentVariable(usize /*index*/),
-    LocalVariable,
-}
-
 /// Create any deferred debug metadata nodes
 pub fn finalize(cx: &CodegenCx) {
     if cx.dbg_cx.is_none() {
@@ -578,15 +530,24 @@ impl DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
     }
 
     fn extend_scope_to_file(
-        &self,
-        scope_metadata: &'ll DIScope,
-        file: &syntax_pos::SourceFile,
-        defining_crate: CrateNum,
-    ) -> &'ll DILexicalBlock {
-        metadata::extend_scope_to_file(&self, scope_metadata, file, defining_crate)
-    }
+         &self,
+         scope_metadata: &'ll DIScope,
+         file: &syntax_pos::SourceFile,
+         defining_crate: CrateNum,
+     ) -> &'ll DILexicalBlock {
+         metadata::extend_scope_to_file(&self, scope_metadata, file, defining_crate)
+     }
 
     fn debuginfo_finalize(&self) {
         finalize(self)
     }
+
+    fn debuginfo_upvar_decls_ops_sequence(&self, byte_offset_of_var_in_env: u64) -> &[i64] {
+        unsafe {
+            [llvm::LLVMRustDIBuilderCreateOpDeref(),
+             llvm::LLVMRustDIBuilderCreateOpPlusUconst(),
+             byte_offset_of_var_in_env as i64,
+             llvm::LLVMRustDIBuilderCreateOpDeref()]
+        };
+    }
 }
diff --git a/src/librustc_codegen_llvm/debuginfo/source_loc.rs b/src/librustc_codegen_llvm/debuginfo/source_loc.rs
index 514649290e2..a4fe912d1d7 100644
--- a/src/librustc_codegen_llvm/debuginfo/source_loc.rs
+++ b/src/librustc_codegen_llvm/debuginfo/source_loc.rs
@@ -50,18 +50,6 @@ pub fn set_source_location<D>(
     set_debug_location(bx, dbg_loc);
 }
 
-/// Enables emitting source locations for the given functions.
-///
-/// Since we don't want source locations to be emitted for the function prelude,
-/// they are disabled when beginning to codegen a new function. This functions
-/// switches source location emitting on and must therefore be called before the
-/// first real statement/expression of the function is codegened.
-pub fn start_emitting_source_locations<D>(dbg_context: &FunctionDebugContext<D>) {
-    if let FunctionDebugContext::RegularContext(ref data) = *dbg_context {
-        data.source_locations_enabled.set(true);
-    }
-}
-
 
 #[derive(Copy, Clone, PartialEq)]
 pub enum InternalDebugLocation<'ll> {
diff --git a/src/librustc_codegen_llvm/diagnostics.rs b/src/librustc_codegen_llvm/diagnostics.rs
index 5721938c9c0..94776f17c79 100644
--- a/src/librustc_codegen_llvm/diagnostics.rs
+++ b/src/librustc_codegen_llvm/diagnostics.rs
@@ -47,37 +47,4 @@ unsafe { simd_add(i32x2(0, 0), i32x2(1, 2)); } // ok!
 ```
 "##,
 
-E0668: r##"
-Malformed inline assembly rejected by LLVM.
-
-LLVM checks the validity of the constraints and the assembly string passed to
-it. This error implies that LLVM seems something wrong with the inline
-assembly call.
-
-In particular, it can happen if you forgot the closing bracket of a register
-constraint (see issue #51430):
-```ignore (error-emitted-at-codegen-which-cannot-be-handled-by-compile_fail)
-#![feature(asm)]
-
-fn main() {
-    let rax: u64;
-    unsafe {
-        asm!("" :"={rax"(rax));
-        println!("Accumulator is: {}", rax);
-    }
-}
-```
-"##,
-
-E0669: r##"
-Cannot convert inline assembly operand to a single LLVM value.
-
-This error usually happens when trying to pass in a value to an input inline
-assembly operand that is actually a pair of values. In particular, this can
-happen when trying to pass in a slice, for instance a `&str`. In Rust, these
-values are represented internally as a pair of values, the pointer and its
-length. When passed as an input operand, this pair of values can not be
-coerced into a register and thus we must fail with an error.
-"##,
-
 }
diff --git a/src/librustc_codegen_llvm/interfaces/mod.rs b/src/librustc_codegen_llvm/interfaces/mod.rs
deleted file mode 100644
index 5fff0567585..00000000000
--- a/src/librustc_codegen_llvm/interfaces/mod.rs
+++ /dev/null
@@ -1,72 +0,0 @@
-// Copyright 2018 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.
-
-mod abi;
-mod asm;
-mod builder;
-mod consts;
-mod debuginfo;
-mod intrinsic;
-mod type_;
-
-pub use self::abi::{AbiBuilderMethods, AbiMethods};
-pub use self::asm::{AsmBuilderMethods, AsmMethods};
-pub use self::builder::BuilderMethods;
-pub use self::consts::ConstMethods;
-pub use self::debuginfo::{DebugInfoBuilderMethods, DebugInfoMethods};
-pub use self::intrinsic::{IntrinsicCallMethods, IntrinsicDeclarationMethods};
-pub use self::type_::{
-    ArgTypeMethods, BaseTypeMethods, DerivedTypeMethods, LayoutTypeMethods, TypeMethods,
-};
-pub use rustc_codegen_ssa::interfaces::{
-    Backend, BackendMethods, BackendTypes, CodegenObject, DeclareMethods, MiscMethods,
-    PreDefineMethods, StaticMethods,
-};
-
-pub trait CodegenMethods<'tcx>:
-    Backend<'tcx>
-    + TypeMethods<'tcx>
-    + MiscMethods<'tcx>
-    + ConstMethods<'tcx>
-    + StaticMethods<'tcx>
-    + DebugInfoMethods<'tcx>
-    + AbiMethods<'tcx>
-    + IntrinsicDeclarationMethods<'tcx>
-    + DeclareMethods<'tcx>
-    + AsmMethods<'tcx>
-    + PreDefineMethods<'tcx>
-{
-}
-
-impl<'tcx, T> CodegenMethods<'tcx> for T where
-    Self: Backend<'tcx>
-        + TypeMethods<'tcx>
-        + MiscMethods<'tcx>
-        + ConstMethods<'tcx>
-        + StaticMethods<'tcx>
-        + DebugInfoMethods<'tcx>
-        + AbiMethods<'tcx>
-        + IntrinsicDeclarationMethods<'tcx>
-        + DeclareMethods<'tcx>
-        + AsmMethods<'tcx>
-        + PreDefineMethods<'tcx>
-{}
-
-pub trait HasCodegen<'tcx>: Backend<'tcx> {
-    type CodegenCx: CodegenMethods<'tcx>
-        + BackendTypes<
-            Value = Self::Value,
-            BasicBlock = Self::BasicBlock,
-            Type = Self::Type,
-            Context = Self::Context,
-            Funclet = Self::Funclet,
-            DIScope = Self::DIScope,
-        >;
-}
diff --git a/src/librustc_codegen_llvm/lib.rs b/src/librustc_codegen_llvm/lib.rs
index 8d5214ce376..41796d24d9e 100644
--- a/src/librustc_codegen_llvm/lib.rs
+++ b/src/librustc_codegen_llvm/lib.rs
@@ -39,7 +39,6 @@
 use back::write::create_target_machine;
 use syntax_pos::symbol::Symbol;
 
-#[macro_use] extern crate bitflags;
 extern crate flate2;
 extern crate libc;
 #[macro_use] extern crate rustc;
@@ -92,7 +91,7 @@ use rustc::util::time_graph;
 use rustc::util::nodemap::{FxHashSet, FxHashMap};
 use rustc::util::profiling::ProfileCategory;
 use rustc_mir::monomorphize;
-use rustc_codegen_ssa::{ModuleCodegen, CompiledModule};
+use rustc_codegen_ssa::{interfaces, ModuleCodegen, CompiledModule};
 use rustc_codegen_utils::codegen_backend::CodegenBackend;
 use rustc_data_structures::svh::Svh;
 
@@ -108,8 +107,6 @@ mod back {
     pub mod wasm;
 }
 
-mod interfaces;
-
 mod abi;
 mod allocator;
 mod asm;
@@ -122,7 +119,6 @@ mod consts;
 mod context;
 mod debuginfo;
 mod declare;
-mod glue;
 mod intrinsic;
 
 // The following is a work around that replaces `pub mod llvm;` and that fixes issue 53912.
@@ -130,8 +126,6 @@ mod intrinsic;
 
 mod llvm_util;
 mod metadata;
-mod meth;
-mod mir;
 mod mono_item;
 mod type_;
 mod type_of;
@@ -171,6 +165,12 @@ impl BackendMethods for LlvmCodegenBackend {
     ) {
         codegen.submit_pre_codegened_module_to_llvm(tcx, module)
     }
+    fn submit_pre_lto_module_to_llvm(&self, tcx: TyCtxt, module: CachedModuleCodegen) {
+        write::submit_pre_lto_module_to_llvm(tcx, module)
+    }
+    fn submit_post_lto_module_to_llvm(&self, tcx: TyCtxt, module: CachedModuleCodegen) {
+        write::submit_post_lto_module_to_llvm(tcx, module)
+    }
     fn codegen_aborted(codegen: OngoingCodegen) {
         codegen.codegen_aborted();
     }
@@ -378,24 +378,4 @@ struct CodegenResults {
     linker_info: rustc_codegen_utils::linker::LinkerInfo,
     crate_info: CrateInfo,
 }
-
-/// Misc info we load from metadata to persist beyond the tcx
-struct CrateInfo {
-    panic_runtime: Option<CrateNum>,
-    compiler_builtins: Option<CrateNum>,
-    profiler_runtime: Option<CrateNum>,
-    sanitizer_runtime: Option<CrateNum>,
-    is_no_builtins: FxHashSet<CrateNum>,
-    native_libraries: FxHashMap<CrateNum, Lrc<Vec<NativeLibrary>>>,
-    crate_name: FxHashMap<CrateNum, String>,
-    used_libraries: Lrc<Vec<NativeLibrary>>,
-    link_args: Lrc<Vec<String>>,
-    used_crate_source: FxHashMap<CrateNum, Lrc<CrateSource>>,
-    used_crates_static: Vec<(CrateNum, LibSource)>,
-    used_crates_dynamic: Vec<(CrateNum, LibSource)>,
-    wasm_imports: FxHashMap<String, String>,
-    lang_item_to_crate: FxHashMap<LangItem, CrateNum>,
-    missing_lang_items: FxHashMap<CrateNum, Vec<LangItem>>,
-}
-
 __build_diagnostic_array! { librustc_codegen_llvm, DIAGNOSTICS }
diff --git a/src/librustc_codegen_llvm/mono_item.rs b/src/librustc_codegen_llvm/mono_item.rs
index 1defb2c16f8..750e2ab0741 100644
--- a/src/librustc_codegen_llvm/mono_item.rs
+++ b/src/librustc_codegen_llvm/mono_item.rs
@@ -8,12 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-//! Walks the crate looking for items/impl-items/trait-items that have
-//! either a `rustc_symbol_name` or `rustc_item_path` attribute and
-//! generates an error giving, respectively, the symbol name or
-//! item-path. This is used for unit testing the code that generates
-//! paths etc in all kinds of annoying scenarios.
-
 use attributes;
 use base;
 use context::CodegenCx;
@@ -31,98 +25,6 @@ use interfaces::*;
 
 pub use rustc::mir::mono::MonoItem;
 
-pub use rustc_mir::monomorphize::item::MonoItemExt as BaseMonoItemExt;
-
-pub trait MonoItemExt<'a, 'tcx: 'a>: fmt::Debug + BaseMonoItemExt<'a, 'tcx> {
-    fn define<Bx: BuilderMethods<'a, 'tcx>>(&self, cx: &'a Bx::CodegenCx) {
-        debug!("BEGIN IMPLEMENTING '{} ({})' in cgu {}",
-               self.to_string(cx.tcx()),
-               self.to_raw_string(),
-               cx.codegen_unit().name());
-
-        match *self.as_mono_item() {
-            MonoItem::Static(def_id) => {
-                let tcx = cx.tcx();
-                let is_mutable = match tcx.describe_def(def_id) {
-                    Some(Def::Static(_, is_mutable)) => is_mutable,
-                    Some(other) => {
-                        bug!("Expected Def::Static, found {:?}", other)
-                    }
-                    None => {
-                        bug!("Expected Def::Static for {:?}, found nothing", def_id)
-                    }
-                };
-                cx.codegen_static(def_id, is_mutable);
-            }
-            MonoItem::GlobalAsm(node_id) => {
-                let item = cx.tcx().hir.expect_item(node_id);
-                if let hir::ItemKind::GlobalAsm(ref ga) = item.node {
-                    cx.codegen_global_asm(ga);
-                } else {
-                    span_bug!(item.span, "Mismatch between hir::Item type and MonoItem type")
-                }
-            }
-            MonoItem::Fn(instance) => {
-                base::codegen_instance::<Bx>(&cx, instance);
-            }
-        }
-
-        debug!("END IMPLEMENTING '{} ({})' in cgu {}",
-               self.to_string(cx.tcx()),
-               self.to_raw_string(),
-               cx.codegen_unit().name());
-    }
-
-    fn predefine<Bx: BuilderMethods<'a, 'tcx>>(
-        &self,
-        cx: &'a Bx::CodegenCx,
-        linkage: Linkage,
-        visibility: Visibility
-    ) {
-        debug!("BEGIN PREDEFINING '{} ({})' in cgu {}",
-               self.to_string(cx.tcx()),
-               self.to_raw_string(),
-               cx.codegen_unit().name());
-
-        let symbol_name = self.symbol_name(cx.tcx()).as_str();
-
-        debug!("symbol {}", &symbol_name);
-
-        match *self.as_mono_item() {
-            MonoItem::Static(def_id) => {
-                cx.predefine_static(def_id, linkage, visibility, &symbol_name);
-            }
-            MonoItem::Fn(instance) => {
-                cx.predefine_fn(instance, linkage, visibility, &symbol_name);
-            }
-            MonoItem::GlobalAsm(..) => {}
-        }
-
-        debug!("END PREDEFINING '{} ({})' in cgu {}",
-               self.to_string(cx.tcx()),
-               self.to_raw_string(),
-               cx.codegen_unit().name());
-    }
-
-    fn to_raw_string(&self) -> String {
-        match *self.as_mono_item() {
-            MonoItem::Fn(instance) => {
-                format!("Fn({:?}, {})",
-                        instance.def,
-                        instance.substs.as_ptr() as usize)
-            }
-            MonoItem::Static(id) => {
-                format!("Static({:?})", id)
-            }
-            MonoItem::GlobalAsm(id) => {
-                format!("GlobalAsm({:?})", id)
-            }
-        }
-    }
-}
-
-impl<'a, 'tcx: 'a> MonoItemExt<'a, 'tcx> for MonoItem<'tcx> {}
-
 impl PreDefineMethods<'tcx> for CodegenCx<'ll, 'tcx> {
     fn predefine_static(&self,
                                   def_id: DefId,
diff --git a/src/librustc_codegen_llvm/type_.rs b/src/librustc_codegen_llvm/type_.rs
index 00dd3be8c9f..d21542a50fb 100644
--- a/src/librustc_codegen_llvm/type_.rs
+++ b/src/librustc_codegen_llvm/type_.rs
@@ -400,6 +400,12 @@ impl LayoutTypeMethods<'tcx> for CodegenCx<'ll, 'tcx> {
     fn is_backend_immediate(&self, layout: TyLayout<'tcx>) -> bool {
         layout.is_llvm_immediate()
     }
+    fn is_backend_scalar_pair(&self, ty: &TyLayout<'tcx>) -> bool {
+        ty.is_llvm_scalar_pair()
+    }
+    fn backend_field_index(&self, ty: &TyLayout<'tcx>, index: usize) -> u64 {
+        ty.llvm_field_index()
+    }
     fn scalar_pair_element_backend_type<'a>(
         &self,
         layout: TyLayout<'tcx>,
diff --git a/src/librustc_codegen_ssa/base.rs b/src/librustc_codegen_ssa/base.rs
new file mode 100644
index 00000000000..de85bb54397
--- /dev/null
+++ b/src/librustc_codegen_ssa/base.rs
@@ -0,0 +1,989 @@
+// Copyright 2012-2015 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.
+
+//! Codegen the completed AST to the LLVM IR.
+//!
+//! Some functions here, such as codegen_block and codegen_expr, return a value --
+//! the result of the codegen to LLVM -- while others, such as codegen_fn
+//! and mono_item, are called only for the side effect of adding a
+//! particular definition to the LLVM IR output we're producing.
+//!
+//! Hopefully useful general knowledge about codegen:
+//!
+//!   * There's no way to find out the Ty type of a Value.  Doing so
+//!     would be "trying to get the eggs out of an omelette" (credit:
+//!     pcwalton).  You can, instead, find out its llvm::Type by calling val_ty,
+//!     but one llvm::Type corresponds to many `Ty`s; for instance, tup(int, int,
+//!     int) and rec(x=int, y=int, z=int) will have the same llvm::Type.
+
+use {ModuleCodegen, ModuleKind, CachedModuleCodegen};
+
+use rustc::dep_graph::cgu_reuse_tracker::CguReuse;
+use rustc::hir::def_id::{CrateNum, DefId, LOCAL_CRATE};
+use rustc::middle::lang_items::StartFnLangItem;
+use rustc::middle::weak_lang_items;
+use rustc::mir::mono::{Stats, CodegenUnitNameBuilder};
+use rustc::ty::{self, Ty, TyCtxt};
+use rustc::ty::layout::{self, Align, TyLayout, LayoutOf, VariantIdx, HasTyCtxt};
+use rustc::ty::query::Providers;
+use rustc::middle::cstore::{self, LinkagePreference};
+use rustc::util::common::{time, print_time_passes_entry};
+use rustc::util::profiling::ProfileCategory;
+use rustc::session::config::{self, EntryFnType, Lto};
+use rustc::session::Session;
+use mir::place::PlaceRef;
+use {MemFlags, CrateInfo};
+use callee;
+use rustc_mir::monomorphize::item::DefPathBasedNames;
+use common::{RealPredicate, TypeKind, IntPredicate};
+use meth;
+use mir;
+use rustc::util::time_graph;
+use rustc_mir::monomorphize::Instance;
+use rustc_mir::monomorphize::partitioning::{CodegenUnit, CodegenUnitExt};
+use mono_item::MonoItem;
+use rustc::util::nodemap::FxHashMap;
+use rustc_data_structures::indexed_vec::Idx;
+use rustc_data_structures::sync::Lrc;
+use rustc_codegen_utils::{symbol_names_test, check_for_rustc_errors_attr};
+use rustc::ty::layout::{FAT_PTR_ADDR, FAT_PTR_EXTRA};
+
+use interfaces::*;
+
+use std::any::Any;
+use std::cmp;
+use std::ops::{Deref, DerefMut};
+use std::time::{Instant, Duration};
+use std::sync::mpsc;
+use syntax_pos::Span;
+use syntax::attr;
+use rustc::hir;
+
+use mir::operand::OperandValue;
+
+use std::marker::PhantomData;
+
+pub struct StatRecorder<'a, 'tcx, Cx: 'a + CodegenMethods<'tcx>> {
+    cx: &'a Cx,
+    name: Option<String>,
+    istart: usize,
+    _marker: PhantomData<&'tcx ()>,
+}
+
+impl<'a, 'tcx, Cx: CodegenMethods<'tcx>> StatRecorder<'a, 'tcx, Cx> {
+    pub fn new(cx: &'a Cx, name: String) -> Self {
+        let istart = cx.stats().borrow().n_llvm_insns;
+        StatRecorder {
+            cx,
+            name: Some(name),
+            istart,
+            _marker: PhantomData,
+        }
+    }
+}
+
+impl<'a, 'tcx, Cx: CodegenMethods<'tcx>> Drop for StatRecorder<'a, 'tcx, Cx> {
+    fn drop(&mut self) {
+        if self.cx.sess().codegen_stats() {
+            let mut stats = self.cx.stats().borrow_mut();
+            let iend = stats.n_llvm_insns;
+            stats.fn_stats.push((self.name.take().unwrap(), iend - self.istart));
+            stats.n_fns += 1;
+            // Reset LLVM insn count to avoid compound costs.
+            stats.n_llvm_insns = self.istart;
+        }
+    }
+}
+
+pub fn bin_op_to_icmp_predicate(op: hir::BinOpKind,
+                                signed: bool)
+                                -> IntPredicate {
+    match op {
+        hir::BinOpKind::Eq => IntPredicate::IntEQ,
+        hir::BinOpKind::Ne => IntPredicate::IntNE,
+        hir::BinOpKind::Lt => if signed { IntPredicate::IntSLT } else { IntPredicate::IntULT },
+        hir::BinOpKind::Le => if signed { IntPredicate::IntSLE } else { IntPredicate::IntULE },
+        hir::BinOpKind::Gt => if signed { IntPredicate::IntSGT } else { IntPredicate::IntUGT },
+        hir::BinOpKind::Ge => if signed { IntPredicate::IntSGE } else { IntPredicate::IntUGE },
+        op => {
+            bug!("comparison_op_to_icmp_predicate: expected comparison operator, \
+                  found {:?}",
+                 op)
+        }
+    }
+}
+
+pub fn bin_op_to_fcmp_predicate(op: hir::BinOpKind) -> RealPredicate {
+    match op {
+        hir::BinOpKind::Eq => RealPredicate::RealOEQ,
+        hir::BinOpKind::Ne => RealPredicate::RealUNE,
+        hir::BinOpKind::Lt => RealPredicate::RealOLT,
+        hir::BinOpKind::Le => RealPredicate::RealOLE,
+        hir::BinOpKind::Gt => RealPredicate::RealOGT,
+        hir::BinOpKind::Ge => RealPredicate::RealOGE,
+        op => {
+            bug!("comparison_op_to_fcmp_predicate: expected comparison operator, \
+                  found {:?}",
+                 op);
+        }
+    }
+}
+
+pub fn compare_simd_types<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
+    bx: &Bx,
+    lhs: Bx::Value,
+    rhs: Bx::Value,
+    t: Ty<'tcx>,
+    ret_ty: Bx::Type,
+    op: hir::BinOpKind
+) -> Bx::Value {
+    let signed = match t.sty {
+        ty::Float(_) => {
+            let cmp = bin_op_to_fcmp_predicate(op);
+            return bx.sext(bx.fcmp(cmp, lhs, rhs), ret_ty);
+        },
+        ty::Uint(_) => false,
+        ty::Int(_) => true,
+        _ => bug!("compare_simd_types: invalid SIMD type"),
+    };
+
+    let cmp = bin_op_to_icmp_predicate(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.
+    bx.sext(bx.icmp(cmp, lhs, rhs), ret_ty)
+}
+
+/// Retrieve the information we are losing (making dynamic) in an unsizing
+/// adjustment.
+///
+/// The `old_info` argument is a bit funny. It is intended for use
+/// in an upcast, where the new vtable for an object will be derived
+/// from the old one.
+pub fn unsized_info<'tcx, Cx: CodegenMethods<'tcx>>(
+    cx: &Cx,
+    source: Ty<'tcx>,
+    target: Ty<'tcx>,
+    old_info: Option<Cx::Value>,
+) -> Cx::Value {
+    let (source, target) = cx.tcx().struct_lockstep_tails(source, target);
+    match (&source.sty, &target.sty) {
+        (&ty::Array(_, len), &ty::Slice(_)) => {
+            cx.const_usize(len.unwrap_usize(cx.tcx()))
+        }
+        (&ty::Dynamic(..), &ty::Dynamic(..)) => {
+            // For now, upcasts are limited to changes in marker
+            // traits, and hence never actually require an actual
+            // change to the vtable.
+            old_info.expect("unsized_info: missing old info for trait upcast")
+        }
+        (_, &ty::Dynamic(ref data, ..)) => {
+            let vtable_ptr = cx.layout_of(cx.tcx().mk_mut_ptr(target))
+                .field(cx, FAT_PTR_EXTRA);
+            cx.static_ptrcast(meth::get_vtable(cx, source, data.principal()),
+                            cx.backend_type(vtable_ptr))
+        }
+        _ => bug!("unsized_info: invalid unsizing {:?} -> {:?}",
+                  source,
+                  target),
+    }
+}
+
+/// Coerce `src` to `dst_ty`. `src_ty` must be a thin pointer.
+pub fn unsize_thin_ptr<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
+    bx: &Bx,
+    src: Bx::Value,
+    src_ty: Ty<'tcx>,
+    dst_ty: Ty<'tcx>
+) -> (Bx::Value, Bx::Value) {
+    debug!("unsize_thin_ptr: {:?} => {:?}", src_ty, dst_ty);
+    match (&src_ty.sty, &dst_ty.sty) {
+        (&ty::Ref(_, a, _),
+         &ty::Ref(_, b, _)) |
+        (&ty::Ref(_, a, _),
+         &ty::RawPtr(ty::TypeAndMut { ty: b, .. })) |
+        (&ty::RawPtr(ty::TypeAndMut { ty: a, .. }),
+         &ty::RawPtr(ty::TypeAndMut { ty: b, .. })) => {
+            assert!(bx.cx().type_is_sized(a));
+            let ptr_ty = bx.cx().type_ptr_to(bx.cx().backend_type(bx.cx().layout_of(b)));
+            (bx.pointercast(src, ptr_ty), unsized_info(bx.cx(), a, b, None))
+        }
+        (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) if def_a.is_box() && def_b.is_box() => {
+            let (a, b) = (src_ty.boxed_ty(), dst_ty.boxed_ty());
+            assert!(bx.cx().type_is_sized(a));
+            let ptr_ty = bx.cx().type_ptr_to(bx.cx().backend_type(bx.cx().layout_of(b)));
+            (bx.pointercast(src, ptr_ty), unsized_info(bx.cx(), a, b, None))
+        }
+        (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) => {
+            assert_eq!(def_a, def_b);
+
+            let src_layout = bx.cx().layout_of(src_ty);
+            let dst_layout = bx.cx().layout_of(dst_ty);
+            let mut result = None;
+            for i in 0..src_layout.fields.count() {
+                let src_f = src_layout.field(bx.cx(), i);
+                assert_eq!(src_layout.fields.offset(i).bytes(), 0);
+                assert_eq!(dst_layout.fields.offset(i).bytes(), 0);
+                if src_f.is_zst() {
+                    continue;
+                }
+                assert_eq!(src_layout.size, src_f.size);
+
+                let dst_f = dst_layout.field(bx.cx(), i);
+                assert_ne!(src_f.ty, dst_f.ty);
+                assert_eq!(result, None);
+                result = Some(unsize_thin_ptr(bx, src, src_f.ty, dst_f.ty));
+            }
+            let (lldata, llextra) = result.unwrap();
+            // HACK(eddyb) have to bitcast pointers until LLVM removes pointee types.
+            (bx.bitcast(lldata, bx.cx().scalar_pair_element_backend_type(dst_layout, 0, true)),
+             bx.bitcast(llextra, bx.cx().scalar_pair_element_backend_type(dst_layout, 1, true)))
+        }
+        _ => bug!("unsize_thin_ptr: called on bad types"),
+    }
+}
+
+/// Coerce `src`, which is a reference to a value of type `src_ty`,
+/// to a value of type `dst_ty` and store the result in `dst`
+pub fn coerce_unsized_into<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
+    bx: &Bx,
+    src: PlaceRef<'tcx, Bx::Value>,
+    dst: PlaceRef<'tcx, Bx::Value>
+)  {
+    let src_ty = src.layout.ty;
+    let dst_ty = dst.layout.ty;
+    let coerce_ptr = || {
+        let (base, info) = match bx.load_operand(src).val {
+            OperandValue::Pair(base, info) => {
+                // fat-ptr to fat-ptr unsize preserves the vtable
+                // i.e. &'a fmt::Debug+Send => &'a fmt::Debug
+                // So we need to pointercast the base to ensure
+                // the types match up.
+                let thin_ptr = dst.layout.field(bx.cx(), FAT_PTR_ADDR);
+                (bx.pointercast(base, bx.cx().backend_type(thin_ptr)), info)
+            }
+            OperandValue::Immediate(base) => {
+                unsize_thin_ptr(bx, base, src_ty, dst_ty)
+            }
+            OperandValue::Ref(..) => bug!()
+        };
+        OperandValue::Pair(base, info).store(bx, dst);
+    };
+    match (&src_ty.sty, &dst_ty.sty) {
+        (&ty::Ref(..), &ty::Ref(..)) |
+        (&ty::Ref(..), &ty::RawPtr(..)) |
+        (&ty::RawPtr(..), &ty::RawPtr(..)) => {
+            coerce_ptr()
+        }
+        (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) if def_a.is_box() && def_b.is_box() => {
+            coerce_ptr()
+        }
+
+        (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) => {
+            assert_eq!(def_a, def_b);
+
+            for i in 0..def_a.variants[VariantIdx::new(0)].fields.len() {
+                let src_f = src.project_field(bx, i);
+                let dst_f = dst.project_field(bx, i);
+
+                if dst_f.layout.is_zst() {
+                    continue;
+                }
+
+                if src_f.layout.ty == dst_f.layout.ty {
+                    memcpy_ty(bx, dst_f.llval, dst_f.align, src_f.llval, src_f.align,
+                              src_f.layout, MemFlags::empty());
+                } else {
+                    coerce_unsized_into(bx, src_f, dst_f);
+                }
+            }
+        }
+        _ => bug!("coerce_unsized_into: invalid coercion {:?} -> {:?}",
+                  src_ty,
+                  dst_ty),
+    }
+}
+
+pub fn cast_shift_expr_rhs<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
+    bx: &Bx,
+    op: hir::BinOpKind,
+    lhs: Bx::Value,
+    rhs: Bx::Value
+) -> Bx::Value {
+    cast_shift_rhs(bx, op, lhs, rhs, |a, b| bx.trunc(a, b), |a, b| bx.zext(a, b))
+}
+
+fn cast_shift_rhs<'a, 'tcx: 'a, F, G, Bx: BuilderMethods<'a, 'tcx>>(
+    bx: &Bx,
+    op: hir::BinOpKind,
+    lhs: Bx::Value,
+    rhs: Bx::Value,
+    trunc: F,
+    zext: G
+) -> Bx::Value
+    where F: FnOnce(
+        Bx::Value,
+        Bx::Type
+    ) -> Bx::Value,
+    G: FnOnce(
+        Bx::Value,
+        Bx::Type
+    ) -> Bx::Value
+{
+    // Shifts may have any size int on the rhs
+    if op.is_shift() {
+        let mut rhs_llty = bx.cx().val_ty(rhs);
+        let mut lhs_llty = bx.cx().val_ty(lhs);
+        if bx.cx().type_kind(rhs_llty) == TypeKind::Vector {
+            rhs_llty = bx.cx().element_type(rhs_llty)
+        }
+        if bx.cx().type_kind(lhs_llty) == TypeKind::Vector {
+            lhs_llty = bx.cx().element_type(lhs_llty)
+        }
+        let rhs_sz = bx.cx().int_width(rhs_llty);
+        let lhs_sz = bx.cx().int_width(lhs_llty);
+        if lhs_sz < rhs_sz {
+            trunc(rhs, lhs_llty)
+        } else if lhs_sz > rhs_sz {
+            // FIXME (#1877: If in the future shifting by negative
+            // values is no longer undefined then this is wrong.
+            zext(rhs, lhs_llty)
+        } else {
+            rhs
+        }
+    } else {
+        rhs
+    }
+}
+
+/// Returns whether this session's target will use SEH-based unwinding.
+///
+/// This is only true for MSVC targets, and even then the 64-bit MSVC target
+/// currently uses SEH-ish unwinding with DWARF info tables to the side (same as
+/// 64-bit MinGW) instead of "full SEH".
+pub fn wants_msvc_seh(sess: &Session) -> bool {
+    sess.target.target.options.is_like_msvc
+}
+
+pub fn call_assume<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
+    bx: &Bx,
+    val: Bx::Value
+) {
+    let assume_intrinsic = bx.cx().get_intrinsic("llvm.assume");
+    bx.call(assume_intrinsic, &[val], None);
+}
+
+pub fn from_immediate<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
+    bx: &Bx,
+    val: Bx::Value
+) -> Bx::Value {
+    if bx.cx().val_ty(val) == bx.cx().type_i1() {
+        bx.zext(val, bx.cx().type_i8())
+    } else {
+        val
+    }
+}
+
+pub fn to_immediate<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
+    bx: &Bx,
+    val: Bx::Value,
+    layout: layout::TyLayout,
+) -> Bx::Value {
+    if let layout::Abi::Scalar(ref scalar) = layout.abi {
+        return to_immediate_scalar(bx, val, scalar);
+    }
+    val
+}
+
+pub fn to_immediate_scalar<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
+    bx: &Bx,
+    val: Bx::Value,
+    scalar: &layout::Scalar,
+) -> Bx::Value {
+    if scalar.is_bool() {
+        return bx.trunc(val, bx.cx().type_i1());
+    }
+    val
+}
+
+pub fn memcpy_ty<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
+    bx: &Bx,
+    dst: Bx::Value,
+    dst_align: Align,
+    src: Bx::Value,
+    src_align: Align,
+    layout: TyLayout<'tcx>,
+    flags: MemFlags,
+) {
+    let size = layout.size.bytes();
+    if size == 0 {
+        return;
+    }
+
+    bx.memcpy(dst, dst_align, src, src_align, bx.cx().const_usize(size), flags);
+}
+
+pub fn codegen_instance<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
+    cx: &'a Bx::CodegenCx,
+    instance: Instance<'tcx>,
+) {
+    let _s = if cx.sess().codegen_stats() {
+        let mut instance_name = String::new();
+        DefPathBasedNames::new(cx.tcx(), true, true)
+            .push_def_path(instance.def_id(), &mut instance_name);
+        Some(StatRecorder::new(cx, instance_name))
+    } else {
+        None
+    };
+
+    // this is an info! to allow collecting monomorphization statistics
+    // and to allow finding the last function before LLVM aborts from
+    // release builds.
+    info!("codegen_instance({})", instance);
+
+    let sig = instance.fn_sig(cx.tcx());
+    let sig = cx.tcx().normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), &sig);
+
+    let lldecl = cx.instances().borrow().get(&instance).cloned().unwrap_or_else(||
+        bug!("Instance `{:?}` not already declared", instance));
+
+    cx.stats().borrow_mut().n_closures += 1;
+
+    let mir = cx.tcx().instance_mir(instance.def);
+    mir::codegen_mir::<Bx>(cx, lldecl, &mir, instance, sig);
+}
+
+/// Create the `main` function which will initialize the rust runtime and call
+/// users main function.
+fn maybe_create_entry_wrapper<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
+    cx: &'a Bx::CodegenCx
+) {
+    let (main_def_id, span) = match *cx.sess().entry_fn.borrow() {
+        Some((id, span, _)) => {
+            (cx.tcx().hir.local_def_id(id), span)
+        }
+        None => return,
+    };
+
+    let instance = Instance::mono(cx.tcx(), main_def_id);
+
+    if !cx.codegen_unit().contains_item(&MonoItem::Fn(instance)) {
+        // We want to create the wrapper in the same codegen unit as Rust's main
+        // function.
+        return;
+    }
+
+    let main_llfn = cx.get_fn(instance);
+
+    let et = cx.sess().entry_fn.get().map(|e| e.2);
+    match et {
+        Some(EntryFnType::Main) => create_entry_fn::<Bx>(cx, span, main_llfn, main_def_id, true),
+        Some(EntryFnType::Start) => create_entry_fn::<Bx>(cx, span, main_llfn, main_def_id, false),
+        None => {}    // Do nothing.
+    }
+
+    fn create_entry_fn<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
+        cx: &'a Bx::CodegenCx,
+        sp: Span,
+        rust_main: Bx::Value,
+        rust_main_def_id: DefId,
+        use_start_lang_item: bool,
+    ) {
+        let llfty =
+            cx.type_func(&[cx.type_int(), cx.type_ptr_to(cx.type_i8p())], cx.type_int());
+
+        let main_ret_ty = cx.tcx().fn_sig(rust_main_def_id).output();
+        // Given that `main()` has no arguments,
+        // then its return type cannot have
+        // late-bound regions, since late-bound
+        // regions must appear in the argument
+        // listing.
+        let main_ret_ty = cx.tcx().erase_regions(
+            &main_ret_ty.no_bound_vars().unwrap(),
+        );
+
+        if cx.get_defined_value("main").is_some() {
+            // FIXME: We should be smart and show a better diagnostic here.
+            cx.sess().struct_span_err(sp, "entry symbol `main` defined multiple times")
+                     .help("did you use #[no_mangle] on `fn main`? Use #[start] instead")
+                     .emit();
+            cx.sess().abort_if_errors();
+            bug!();
+        }
+        let llfn = cx.declare_cfn("main", llfty);
+
+        // `main` should respect same config for frame pointer elimination as rest of code
+        cx.set_frame_pointer_elimination(llfn);
+        cx.apply_target_cpu_attr(llfn);
+
+        let bx = Bx::new_block(&cx, llfn, "top");
+
+        bx.insert_reference_to_gdb_debug_scripts_section_global();
+
+        // Params from native main() used as args for rust start function
+        let param_argc = cx.get_param(llfn, 0);
+        let param_argv = cx.get_param(llfn, 1);
+        let arg_argc = bx.intcast(param_argc, cx.type_isize(), true);
+        let arg_argv = param_argv;
+
+        let (start_fn, args) = if use_start_lang_item {
+            let start_def_id = cx.tcx().require_lang_item(StartFnLangItem);
+            let start_fn = callee::resolve_and_get_fn(
+                cx,
+                start_def_id,
+                cx.tcx().intern_substs(&[main_ret_ty.into()]),
+            );
+            (start_fn, vec![bx.pointercast(rust_main, cx.type_ptr_to(cx.type_i8p())),
+                            arg_argc, arg_argv])
+        } else {
+            debug!("using user-defined start fn");
+            (rust_main, vec![arg_argc, arg_argv])
+        };
+
+        let result = bx.call(start_fn, &args, None);
+        bx.ret(bx.intcast(result, cx.type_int(), true));
+    }
+}
+
+pub const CODEGEN_WORKER_ID: usize = ::std::usize::MAX;
+pub const CODEGEN_WORKER_TIMELINE: time_graph::TimelineId =
+    time_graph::TimelineId(CODEGEN_WORKER_ID);
+pub const CODEGEN_WORK_PACKAGE_KIND: time_graph::WorkPackageKind =
+    time_graph::WorkPackageKind(&["#DE9597", "#FED1D3", "#FDC5C7", "#B46668", "#88494B"]);
+
+
+pub fn codegen_crate<B: BackendMethods>(
+    backend: B,
+    tcx: TyCtxt<'a, 'tcx, 'tcx>,
+    rx: mpsc::Receiver<Box<dyn Any + Send>>
+) -> B::OngoingCodegen {
+
+    check_for_rustc_errors_attr(tcx);
+
+    let cgu_name_builder = &mut CodegenUnitNameBuilder::new(tcx);
+
+    // Codegen the metadata.
+    tcx.sess.profiler(|p| p.start_activity(ProfileCategory::Codegen));
+
+    let metadata_cgu_name = cgu_name_builder.build_cgu_name(LOCAL_CRATE,
+                                                            &["crate"],
+                                                            Some("metadata")).as_str()
+                                                                             .to_string();
+    let metadata_llvm_module = backend.new_metadata(tcx.sess, &metadata_cgu_name);
+    let metadata = time(tcx.sess, "write metadata", || {
+        backend.write_metadata(tcx, &metadata_llvm_module)
+    });
+    tcx.sess.profiler(|p| p.end_activity(ProfileCategory::Codegen));
+
+    let metadata_module = ModuleCodegen {
+        name: metadata_cgu_name,
+        module_llvm: metadata_llvm_module,
+        kind: ModuleKind::Metadata,
+    };
+
+    let time_graph = if tcx.sess.opts.debugging_opts.codegen_time_graph {
+        Some(time_graph::TimeGraph::new())
+    } else {
+        None
+    };
+
+    // Skip crate items and just output metadata in -Z no-codegen mode.
+    if tcx.sess.opts.debugging_opts.no_codegen ||
+       !tcx.sess.opts.output_types.should_codegen() {
+        let ongoing_codegen = backend.start_async_codegen(
+            tcx,
+            time_graph,
+            metadata,
+            rx,
+            1);
+
+        backend.submit_pre_codegened_module_to_backend(&ongoing_codegen, tcx, metadata_module);
+        backend.codegen_finished(&ongoing_codegen, tcx);
+
+        assert_and_save_dep_graph(tcx);
+
+        backend.check_for_errors(&ongoing_codegen, tcx.sess);
+
+        return ongoing_codegen;
+    }
+
+    // Run the monomorphization collector and partition the collected items into
+    // codegen units.
+    let codegen_units = tcx.collect_and_partition_mono_items(LOCAL_CRATE).1;
+    let codegen_units = (*codegen_units).clone();
+
+    // Force all codegen_unit queries so they are already either red or green
+    // when compile_codegen_unit accesses them. We are not able to re-execute
+    // the codegen_unit query from just the DepNode, so an unknown color would
+    // lead to having to re-execute compile_codegen_unit, possibly
+    // unnecessarily.
+    if tcx.dep_graph.is_fully_enabled() {
+        for cgu in &codegen_units {
+            tcx.codegen_unit(cgu.name().clone());
+        }
+    }
+
+    let ongoing_codegen = backend.start_async_codegen(
+        tcx,
+        time_graph.clone(),
+        metadata,
+        rx,
+        codegen_units.len());
+    let ongoing_codegen = AbortCodegenOnDrop::<B>(Some(ongoing_codegen));
+
+    // Codegen an allocator shim, if necessary.
+    //
+    // If the crate doesn't have an `allocator_kind` set then there's definitely
+    // no shim to generate. Otherwise we also check our dependency graph for all
+    // our output crate types. If anything there looks like its a `Dynamic`
+    // linkage, then it's already got an allocator shim and we'll be using that
+    // one instead. If nothing exists then it's our job to generate the
+    // allocator!
+    let any_dynamic_crate = tcx.sess.dependency_formats.borrow()
+        .iter()
+        .any(|(_, list)| {
+            use rustc::middle::dependency_format::Linkage;
+            list.iter().any(|&linkage| linkage == Linkage::Dynamic)
+        });
+    let allocator_module = if any_dynamic_crate {
+        None
+    } else if let Some(kind) = *tcx.sess.allocator_kind.get() {
+        let llmod_id = cgu_name_builder.build_cgu_name(LOCAL_CRATE,
+                                                       &["crate"],
+                                                       Some("allocator")).as_str()
+                                                                         .to_string();
+        let modules = backend.new_metadata(tcx.sess, &llmod_id);
+        time(tcx.sess, "write allocator module", || {
+            backend.codegen_allocator(tcx, &modules, kind)
+        });
+
+        Some(ModuleCodegen {
+            name: llmod_id,
+            module_llvm: modules,
+            kind: ModuleKind::Allocator,
+        })
+    } else {
+        None
+    };
+
+    if let Some(allocator_module) = allocator_module {
+        backend.submit_pre_codegened_module_to_backend(&ongoing_codegen, tcx, allocator_module);
+    }
+
+    backend.submit_pre_codegened_module_to_backend(&ongoing_codegen, tcx, metadata_module);
+
+    // We sort the codegen units by size. This way we can schedule work for LLVM
+    // a bit more efficiently.
+    let codegen_units = {
+        let mut codegen_units = codegen_units;
+        codegen_units.sort_by_cached_key(|cgu| cmp::Reverse(cgu.size_estimate()));
+        codegen_units
+    };
+
+    let mut total_codegen_time = Duration::new(0, 0);
+    let mut all_stats = Stats::default();
+
+    for cgu in codegen_units.into_iter() {
+        backend.wait_for_signal_to_codegen_item(&ongoing_codegen);
+        backend.check_for_errors(&ongoing_codegen, tcx.sess);
+
+        let cgu_reuse = determine_cgu_reuse(tcx, &cgu);
+        tcx.sess.cgu_reuse_tracker.set_actual_reuse(&cgu.name().as_str(), cgu_reuse);
+
+        match cgu_reuse {
+            CguReuse::No => {
+                let _timing_guard = time_graph.as_ref().map(|time_graph| {
+                    time_graph.start(CODEGEN_WORKER_TIMELINE,
+                                     CODEGEN_WORK_PACKAGE_KIND,
+                                     &format!("codegen {}", cgu.name()))
+                });
+                let start_time = Instant::now();
+                let stats = backend.compile_codegen_unit(tcx, *cgu.name());
+                all_stats.extend(stats);
+                total_codegen_time += start_time.elapsed();
+                false
+            }
+            CguReuse::PreLto => {
+                backend.submit_pre_lto_module_to_backend(tcx, CachedModuleCodegen {
+                    name: cgu.name().to_string(),
+                    source: cgu.work_product(tcx),
+                });
+                true
+            }
+            CguReuse::PostLto => {
+                backend.submit_post_lto_module_to_backend(tcx, CachedModuleCodegen {
+                    name: cgu.name().to_string(),
+                    source: cgu.work_product(tcx),
+                });
+                true
+            }
+        };
+    }
+
+    backend.codegen_finished(&ongoing_codegen, tcx);
+
+    // Since the main thread is sometimes blocked during codegen, we keep track
+    // -Ztime-passes output manually.
+    print_time_passes_entry(tcx.sess.time_passes(),
+                            "codegen to LLVM IR",
+                            total_codegen_time);
+
+    ::rustc_incremental::assert_module_sources::assert_module_sources(tcx);
+
+    symbol_names_test::report_symbol_names(tcx);
+
+    if tcx.sess.codegen_stats() {
+        println!("--- codegen stats ---");
+        println!("n_glues_created: {}", all_stats.n_glues_created);
+        println!("n_null_glues: {}", all_stats.n_null_glues);
+        println!("n_real_glues: {}", all_stats.n_real_glues);
+
+        println!("n_fns: {}", all_stats.n_fns);
+        println!("n_inlines: {}", all_stats.n_inlines);
+        println!("n_closures: {}", all_stats.n_closures);
+        println!("fn stats:");
+        all_stats.fn_stats.sort_by_key(|&(_, insns)| insns);
+        for &(ref name, insns) in all_stats.fn_stats.iter() {
+            println!("{} insns, {}", insns, *name);
+        }
+    }
+
+    if tcx.sess.count_llvm_insns() {
+        for (k, v) in all_stats.llvm_insns.iter() {
+            println!("{:7} {}", *v, *k);
+        }
+    }
+
+    backend.check_for_errors(&ongoing_codegen, tcx.sess);
+
+    assert_and_save_dep_graph(tcx);
+    ongoing_codegen.into_inner()
+}
+
+/// A curious wrapper structure whose only purpose is to call `codegen_aborted`
+/// when it's dropped abnormally.
+///
+/// In the process of working on rust-lang/rust#55238 a mysterious segfault was
+/// stumbled upon. The segfault was never reproduced locally, but it was
+/// suspected to be related to the fact that codegen worker threads were
+/// sticking around by the time the main thread was exiting, causing issues.
+///
+/// This structure is an attempt to fix that issue where the `codegen_aborted`
+/// message will block until all workers have finished. This should ensure that
+/// even if the main codegen thread panics we'll wait for pending work to
+/// complete before returning from the main thread, hopefully avoiding
+/// segfaults.
+///
+/// If you see this comment in the code, then it means that this workaround
+/// worked! We may yet one day track down the mysterious cause of that
+/// segfault...
+struct AbortCodegenOnDrop<B: BackendMethods>(Option<B::OngoingCodegen>);
+
+impl<B: BackendMethods> AbortCodegenOnDrop<B> {
+    fn into_inner(mut self) -> B::OngoingCodegen {
+        self.0.take().unwrap()
+    }
+}
+
+impl<B: BackendMethods> Deref for AbortCodegenOnDrop<B> {
+    type Target = B::OngoingCodegen;
+
+    fn deref(&self) -> &B::OngoingCodegen {
+        self.0.as_ref().unwrap()
+    }
+}
+
+impl<B: BackendMethods> DerefMut for AbortCodegenOnDrop<B> {
+    fn deref_mut(&mut self) -> &mut B::OngoingCodegen {
+        self.0.as_mut().unwrap()
+    }
+}
+
+impl<B: BackendMethods> Drop for AbortCodegenOnDrop<B> {
+    fn drop(&mut self) {
+        if let Some(codegen) = self.0.take() {
+            B::codegen_aborted(codegen);
+        }
+    }
+}
+
+fn assert_and_save_dep_graph<'ll, 'tcx>(tcx: TyCtxt<'ll, 'tcx, 'tcx>) {
+    time(tcx.sess,
+         "assert dep graph",
+         || ::rustc_incremental::assert_dep_graph(tcx));
+
+    time(tcx.sess,
+         "serialize dep graph",
+         || ::rustc_incremental::save_dep_graph(tcx));
+}
+
+impl CrateInfo {
+    pub fn new(tcx: TyCtxt) -> CrateInfo {
+        let mut info = CrateInfo {
+            panic_runtime: None,
+            compiler_builtins: None,
+            profiler_runtime: None,
+            sanitizer_runtime: None,
+            is_no_builtins: Default::default(),
+            native_libraries: Default::default(),
+            used_libraries: tcx.native_libraries(LOCAL_CRATE),
+            link_args: tcx.link_args(LOCAL_CRATE),
+            crate_name: Default::default(),
+            used_crates_dynamic: cstore::used_crates(tcx, LinkagePreference::RequireDynamic),
+            used_crates_static: cstore::used_crates(tcx, LinkagePreference::RequireStatic),
+            used_crate_source: Default::default(),
+            wasm_imports: Default::default(),
+            lang_item_to_crate: Default::default(),
+            missing_lang_items: Default::default(),
+        };
+        let lang_items = tcx.lang_items();
+
+        let load_wasm_items = tcx.sess.crate_types.borrow()
+            .iter()
+            .any(|c| *c != config::CrateType::Rlib) &&
+            tcx.sess.opts.target_triple.triple() == "wasm32-unknown-unknown";
+
+        if load_wasm_items {
+            info.load_wasm_imports(tcx, LOCAL_CRATE);
+        }
+
+        let crates = tcx.crates();
+
+        let n_crates = crates.len();
+        info.native_libraries.reserve(n_crates);
+        info.crate_name.reserve(n_crates);
+        info.used_crate_source.reserve(n_crates);
+        info.missing_lang_items.reserve(n_crates);
+
+        for &cnum in crates.iter() {
+            info.native_libraries.insert(cnum, tcx.native_libraries(cnum));
+            info.crate_name.insert(cnum, tcx.crate_name(cnum).to_string());
+            info.used_crate_source.insert(cnum, tcx.used_crate_source(cnum));
+            if tcx.is_panic_runtime(cnum) {
+                info.panic_runtime = Some(cnum);
+            }
+            if tcx.is_compiler_builtins(cnum) {
+                info.compiler_builtins = Some(cnum);
+            }
+            if tcx.is_profiler_runtime(cnum) {
+                info.profiler_runtime = Some(cnum);
+            }
+            if tcx.is_sanitizer_runtime(cnum) {
+                info.sanitizer_runtime = Some(cnum);
+            }
+            if tcx.is_no_builtins(cnum) {
+                info.is_no_builtins.insert(cnum);
+            }
+            if load_wasm_items {
+                info.load_wasm_imports(tcx, cnum);
+            }
+            let missing = tcx.missing_lang_items(cnum);
+            for &item in missing.iter() {
+                if let Ok(id) = lang_items.require(item) {
+                    info.lang_item_to_crate.insert(item, id.krate);
+                }
+            }
+
+            // No need to look for lang items that are whitelisted and don't
+            // actually need to exist.
+            let missing = missing.iter()
+                .cloned()
+                .filter(|&l| !weak_lang_items::whitelisted(tcx, l))
+                .collect();
+            info.missing_lang_items.insert(cnum, missing);
+        }
+
+        return info
+    }
+
+    fn load_wasm_imports(&mut self, tcx: TyCtxt, cnum: CrateNum) {
+        self.wasm_imports.extend(tcx.wasm_import_module_map(cnum).iter().map(|(&id, module)| {
+            let instance = Instance::mono(tcx, id);
+            let import_name = tcx.symbol_name(instance);
+
+            (import_name.to_string(), module.clone())
+        }));
+    }
+}
+
+fn is_codegened_item(tcx: TyCtxt, id: DefId) -> bool {
+    let (all_mono_items, _) =
+        tcx.collect_and_partition_mono_items(LOCAL_CRATE);
+    all_mono_items.contains(&id)
+}
+
+pub fn provide_both(providers: &mut Providers) {
+    providers.dllimport_foreign_items = |tcx, krate| {
+        let module_map = tcx.foreign_modules(krate);
+        let module_map = module_map.iter()
+            .map(|lib| (lib.def_id, lib))
+            .collect::<FxHashMap<_, _>>();
+
+        let dllimports = tcx.native_libraries(krate)
+            .iter()
+            .filter(|lib| {
+                if lib.kind != cstore::NativeLibraryKind::NativeUnknown {
+                    return false
+                }
+                let cfg = match lib.cfg {
+                    Some(ref cfg) => cfg,
+                    None => return true,
+                };
+                attr::cfg_matches(cfg, &tcx.sess.parse_sess, None)
+            })
+            .filter_map(|lib| lib.foreign_module)
+            .map(|id| &module_map[&id])
+            .flat_map(|module| module.foreign_items.iter().cloned())
+            .collect();
+        Lrc::new(dllimports)
+    };
+
+    providers.is_dllimport_foreign_item = |tcx, def_id| {
+        tcx.dllimport_foreign_items(def_id.krate).contains(&def_id)
+    };
+}
+
+fn determine_cgu_reuse<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                                 cgu: &CodegenUnit<'tcx>)
+                                 -> CguReuse {
+    if !tcx.dep_graph.is_fully_enabled() {
+        return CguReuse::No
+    }
+
+    let work_product_id = &cgu.work_product_id();
+    if tcx.dep_graph.previous_work_product(work_product_id).is_none() {
+        // We don't have anything cached for this CGU. This can happen
+        // if the CGU did not exist in the previous session.
+        return CguReuse::No
+    }
+
+    // Try to mark the CGU as green. If it we can do so, it means that nothing
+    // affecting the LLVM module has changed and we can re-use a cached version.
+    // If we compile with any kind of LTO, this means we can re-use the bitcode
+    // of the Pre-LTO stage (possibly also the Post-LTO version but we'll only
+    // know that later). If we are not doing LTO, there is only one optimized
+    // version of each module, so we re-use that.
+    let dep_node = cgu.codegen_dep_node(tcx);
+    assert!(!tcx.dep_graph.dep_node_exists(&dep_node),
+        "CompileCodegenUnit dep-node for CGU `{}` already exists before marking.",
+        cgu.name());
+
+    if tcx.dep_graph.try_mark_green(tcx, &dep_node).is_some() {
+        // We can re-use either the pre- or the post-thinlto state
+        if tcx.sess.lto() != Lto::No {
+            CguReuse::PreLto
+        } else {
+            CguReuse::PostLto
+        }
+    } else {
+        CguReuse::No
+    }
+}
diff --git a/src/librustc_codegen_ssa/callee.rs b/src/librustc_codegen_ssa/callee.rs
new file mode 100644
index 00000000000..3d8f96573db
--- /dev/null
+++ b/src/librustc_codegen_ssa/callee.rs
@@ -0,0 +1,46 @@
+// Copyright 2018 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 interfaces::*;
+use rustc::ty;
+use rustc::ty::subst::Substs;
+use rustc::hir::def_id::DefId;
+
+pub fn resolve_and_get_fn<'tcx, Cx: CodegenMethods<'tcx>>(
+    cx: &Cx,
+    def_id: DefId,
+    substs: &'tcx Substs<'tcx>,
+) -> Cx::Value {
+    cx.get_fn(
+        ty::Instance::resolve(
+            cx.tcx(),
+            ty::ParamEnv::reveal_all(),
+            def_id,
+            substs
+        ).unwrap()
+    )
+}
+
+pub fn resolve_and_get_fn_for_vtable<'tcx,
+    Cx: Backend<'tcx> + MiscMethods<'tcx> + TypeMethods<'tcx>
+>(
+    cx: &Cx,
+    def_id: DefId,
+    substs: &'tcx Substs<'tcx>,
+) -> Cx::Value {
+    cx.get_fn(
+        ty::Instance::resolve_for_vtable(
+            cx.tcx(),
+            ty::ParamEnv::reveal_all(),
+            def_id,
+            substs
+        ).unwrap()
+    )
+}
diff --git a/src/librustc_codegen_ssa/common.rs b/src/librustc_codegen_ssa/common.rs
index 3f4389913ae..619fd078fb7 100644
--- a/src/librustc_codegen_ssa/common.rs
+++ b/src/librustc_codegen_ssa/common.rs
@@ -10,8 +10,15 @@
 #![allow(non_camel_case_types, non_snake_case)]
 
 use rustc::ty::{self, Ty, TyCtxt};
-use syntax_pos::DUMMY_SP;
+use syntax_pos::{DUMMY_SP, Span};
 
+use rustc::hir::def_id::DefId;
+use rustc::middle::lang_items::LangItem;
+use base;
+use interfaces::*;
+
+use rustc::hir;
+use interfaces::BuilderMethods;
 
 pub fn type_needs_drop<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, ty: Ty<'tcx>) -> bool {
     ty.needs_drop(tcx, ty::ParamEnv::reveal_all())
@@ -135,3 +142,88 @@ mod temp_stable_hash_impls {
         }
     }
 }
+
+pub fn langcall(tcx: TyCtxt,
+                span: Option<Span>,
+                msg: &str,
+                li: LangItem)
+                -> DefId {
+    tcx.lang_items().require(li).unwrap_or_else(|s| {
+        let msg = format!("{} {}", msg, s);
+        match span {
+            Some(span) => tcx.sess.span_fatal(span, &msg[..]),
+            None => tcx.sess.fatal(&msg[..]),
+        }
+    })
+}
+
+// To avoid UB from LLVM, these two functions mask RHS with an
+// appropriate mask unconditionally (i.e. the fallback behavior for
+// all shifts). For 32- and 64-bit types, this matches the semantics
+// of Java. (See related discussion on #1877 and #10183.)
+
+pub fn build_unchecked_lshift<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
+    bx: &Bx,
+    lhs: Bx::Value,
+    rhs: Bx::Value
+) -> Bx::Value {
+    let rhs = base::cast_shift_expr_rhs(bx, hir::BinOpKind::Shl, lhs, rhs);
+    // #1877, #10183: Ensure that input is always valid
+    let rhs = shift_mask_rhs(bx, rhs);
+    bx.shl(lhs, rhs)
+}
+
+pub fn build_unchecked_rshift<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
+    bx: &Bx,
+    lhs_t: Ty<'tcx>,
+    lhs: Bx::Value,
+    rhs: Bx::Value
+) -> Bx::Value {
+    let rhs = base::cast_shift_expr_rhs(bx, hir::BinOpKind::Shr, lhs, rhs);
+    // #1877, #10183: Ensure that input is always valid
+    let rhs = shift_mask_rhs(bx, rhs);
+    let is_signed = lhs_t.is_signed();
+    if is_signed {
+        bx.ashr(lhs, rhs)
+    } else {
+        bx.lshr(lhs, rhs)
+    }
+}
+
+fn shift_mask_rhs<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
+    bx: &Bx,
+    rhs: Bx::Value
+) -> Bx::Value {
+    let rhs_llty = bx.cx().val_ty(rhs);
+    bx.and(rhs, shift_mask_val(bx, rhs_llty, rhs_llty, false))
+}
+
+pub fn shift_mask_val<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
+    bx: &Bx,
+    llty: Bx::Type,
+    mask_llty: Bx::Type,
+    invert: bool
+) -> Bx::Value {
+    let kind = bx.cx().type_kind(llty);
+    match kind {
+        TypeKind::Integer => {
+            // i8/u8 can shift by at most 7, i16/u16 by at most 15, etc.
+            let val = bx.cx().int_width(llty) - 1;
+            if invert {
+                bx.cx().const_int(mask_llty, !val as i64)
+            } else {
+                bx.cx().const_uint(mask_llty, val)
+            }
+        },
+        TypeKind::Vector => {
+            let mask = shift_mask_val(
+                bx,
+                bx.cx().element_type(llty),
+                bx.cx().element_type(mask_llty),
+                invert
+            );
+            bx.vector_splat(bx.cx().vector_length(mask_llty), mask)
+        },
+        _ => bug!("shift_mask_val: expected Integer or Vector, found {:?}", kind),
+    }
+}
diff --git a/src/librustc_codegen_ssa/debuginfo.rs b/src/librustc_codegen_ssa/debuginfo.rs
new file mode 100644
index 00000000000..2891b1c22fe
--- /dev/null
+++ b/src/librustc_codegen_ssa/debuginfo.rs
@@ -0,0 +1,92 @@
+// Copyright 2018 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 syntax_pos::{BytePos, Span};
+use rustc::hir::def_id::CrateNum;
+use std::cell::Cell;
+
+pub enum FunctionDebugContext<D> {
+    RegularContext(FunctionDebugContextData<D>),
+    DebugInfoDisabled,
+    FunctionWithoutDebugInfo,
+}
+
+impl<D> FunctionDebugContext<D> {
+    pub fn get_ref<'a>(&'a self, span: Span) -> &'a FunctionDebugContextData<D> {
+        match *self {
+            FunctionDebugContext::RegularContext(ref data) => data,
+            FunctionDebugContext::DebugInfoDisabled => {
+                span_bug!(span, "{}", FunctionDebugContext::<D>::debuginfo_disabled_message());
+            }
+            FunctionDebugContext::FunctionWithoutDebugInfo => {
+                span_bug!(span, "{}", FunctionDebugContext::<D>::should_be_ignored_message());
+            }
+        }
+    }
+
+    fn debuginfo_disabled_message() -> &'static str {
+        "debuginfo: Error trying to access FunctionDebugContext although debug info is disabled!"
+    }
+
+    fn should_be_ignored_message() -> &'static str {
+        "debuginfo: Error trying to access FunctionDebugContext for function that should be \
+         ignored by debug info!"
+    }
+}
+
+/// Enables emitting source locations for the given functions.
+///
+/// Since we don't want source locations to be emitted for the function prelude,
+/// they are disabled when beginning to codegen a new function. This functions
+/// switches source location emitting on and must therefore be called before the
+/// first real statement/expression of the function is codegened.
+pub fn start_emitting_source_locations<D>(dbg_context: &FunctionDebugContext<D>) {
+    match *dbg_context {
+        FunctionDebugContext::RegularContext(ref data) => {
+            data.source_locations_enabled.set(true)
+        },
+        _ => { /* safe to ignore */ }
+    }
+}
+
+pub struct FunctionDebugContextData<D> {
+    fn_metadata: D,
+    source_locations_enabled: Cell<bool>,
+    pub defining_crate: CrateNum,
+}
+
+pub enum VariableAccess<'a, V> {
+    // The llptr given is an alloca containing the variable's value
+    DirectVariable { alloca: V },
+    // The llptr given is an alloca containing the start of some pointer chain
+    // leading to the variable's content.
+    IndirectVariable { alloca: V, address_operations: &'a [i64] }
+}
+
+pub enum VariableKind {
+    ArgumentVariable(usize /*index*/),
+    LocalVariable,
+}
+
+
+#[derive(Clone, Copy, Debug)]
+pub struct MirDebugScope<D> {
+    pub scope_metadata: Option<D>,
+    // Start and end offsets of the file to which this DIScope belongs.
+    // These are used to quickly determine whether some span refers to the same file.
+    pub file_start_pos: BytePos,
+    pub file_end_pos: BytePos,
+}
+
+impl<D> MirDebugScope<D> {
+    pub fn is_valid(&self) -> bool {
+        !self.scope_metadata.is_none()
+    }
+}
diff --git a/src/librustc_codegen_ssa/diagnostics.rs b/src/librustc_codegen_ssa/diagnostics.rs
new file mode 100644
index 00000000000..abe19068889
--- /dev/null
+++ b/src/librustc_codegen_ssa/diagnostics.rs
@@ -0,0 +1,48 @@
+// 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.
+
+#![allow(non_snake_case)]
+
+register_long_diagnostics! {
+
+E0668: r##"
+Malformed inline assembly rejected by LLVM.
+
+LLVM checks the validity of the constraints and the assembly string passed to
+it. This error implies that LLVM seems something wrong with the inline
+assembly call.
+
+In particular, it can happen if you forgot the closing bracket of a register
+constraint (see issue #51430):
+```ignore (error-emitted-at-codegen-which-cannot-be-handled-by-compile_fail)
+#![feature(asm)]
+
+fn main() {
+    let rax: u64;
+    unsafe {
+        asm!("" :"={rax"(rax));
+        println!("Accumulator is: {}", rax);
+    }
+}
+```
+"##,
+
+E0669: r##"
+Cannot convert inline assembly operand to a single LLVM value.
+
+This error usually happens when trying to pass in a value to an input inline
+assembly operand that is actually a pair of values. In particular, this can
+happen when trying to pass in a slice, for instance a `&str`. In Rust, these
+values are represented internally as a pair of values, the pointer and its
+length. When passed as an input operand, this pair of values can not be
+coerced into a register and thus we must fail with an error.
+"##,
+
+}
diff --git a/src/librustc_codegen_llvm/glue.rs b/src/librustc_codegen_ssa/glue.rs
index 5e1a03031dd..cfb2ceb5a1a 100644
--- a/src/librustc_codegen_llvm/glue.rs
+++ b/src/librustc_codegen_ssa/glue.rs
@@ -14,7 +14,7 @@
 
 use std;
 
-use rustc_codegen_ssa::common::IntPredicate;
+use common::IntPredicate;
 use meth;
 use rustc::ty::layout::LayoutOf;
 use rustc::ty::{self, Ty};
diff --git a/src/librustc_codegen_llvm/interfaces/abi.rs b/src/librustc_codegen_ssa/interfaces/abi.rs
index 528599e9690..eda6d92dabe 100644
--- a/src/librustc_codegen_llvm/interfaces/abi.rs
+++ b/src/librustc_codegen_ssa/interfaces/abi.rs
@@ -9,8 +9,8 @@
 // except according to those terms.
 
 use super::HasCodegen;
-use abi::FnType;
 use rustc::ty::{FnSig, Instance, Ty};
+use rustc_target::abi::call::FnType;
 
 pub trait AbiMethods<'tcx> {
     fn new_fn_type(&self, sig: FnSig<'tcx>, extra_args: &[Ty<'tcx>]) -> FnType<'tcx, Ty<'tcx>>;
diff --git a/src/librustc_codegen_llvm/interfaces/asm.rs b/src/librustc_codegen_ssa/interfaces/asm.rs
index ffe9679fcd6..ffe9679fcd6 100644
--- a/src/librustc_codegen_llvm/interfaces/asm.rs
+++ b/src/librustc_codegen_ssa/interfaces/asm.rs
diff --git a/src/librustc_codegen_ssa/interfaces/backend.rs b/src/librustc_codegen_ssa/interfaces/backend.rs
index 3cdb1c6a0dd..6cc7d66a207 100644
--- a/src/librustc_codegen_ssa/interfaces/backend.rs
+++ b/src/librustc_codegen_ssa/interfaces/backend.rs
@@ -21,7 +21,7 @@ use rustc::util::time_graph::TimeGraph;
 use std::any::Any;
 use std::sync::mpsc::Receiver;
 use syntax_pos::symbol::InternedString;
-use ModuleCodegen;
+use {CachedModuleCodegen, ModuleCodegen};
 
 pub trait BackendTypes {
     type Value: CodegenObject;
@@ -62,12 +62,14 @@ pub trait BackendMethods {
         coordinator_receive: Receiver<Box<dyn Any + Send>>,
         total_cgus: usize,
     ) -> Self::OngoingCodegen;
-    fn submit_pre_codegened_module_to_llvm(
+    fn submit_pre_codegened_module_to_backend(
         &self,
         codegen: &Self::OngoingCodegen,
         tcx: TyCtxt,
         module: ModuleCodegen<Self::Module>,
     );
+    fn submit_pre_lto_module_to_backend(&self, tcx: TyCtxt, module: CachedModuleCodegen);
+    fn submit_post_lto_module_to_backend(&self, tcx: TyCtxt, module: CachedModuleCodegen);
     fn codegen_aborted(codegen: Self::OngoingCodegen);
     fn codegen_finished(&self, codegen: &Self::OngoingCodegen, tcx: TyCtxt);
     fn check_for_errors(&self, codegen: &Self::OngoingCodegen, sess: &Session);
diff --git a/src/librustc_codegen_llvm/interfaces/builder.rs b/src/librustc_codegen_ssa/interfaces/builder.rs
index 2e1abb12e16..953152534d3 100644
--- a/src/librustc_codegen_llvm/interfaces/builder.rs
+++ b/src/librustc_codegen_ssa/interfaces/builder.rs
@@ -14,14 +14,12 @@ use super::debuginfo::DebugInfoBuilderMethods;
 use super::intrinsic::IntrinsicCallMethods;
 use super::type_::ArgTypeMethods;
 use super::HasCodegen;
-use builder::MemFlags;
+use common::{AtomicOrdering, AtomicRmwBinOp, IntPredicate, RealPredicate, SynchronizationScope};
 use libc::c_char;
 use mir::operand::OperandRef;
 use mir::place::PlaceRef;
 use rustc::ty::layout::{Align, Size};
-use rustc_codegen_ssa::common::{
-    AtomicOrdering, AtomicRmwBinOp, IntPredicate, RealPredicate, SynchronizationScope,
-};
+use MemFlags;
 
 use std::borrow::Cow;
 use std::ops::Range;
diff --git a/src/librustc_codegen_llvm/interfaces/consts.rs b/src/librustc_codegen_ssa/interfaces/consts.rs
index c0a54452195..c0a54452195 100644
--- a/src/librustc_codegen_llvm/interfaces/consts.rs
+++ b/src/librustc_codegen_ssa/interfaces/consts.rs
diff --git a/src/librustc_codegen_llvm/interfaces/debuginfo.rs b/src/librustc_codegen_ssa/interfaces/debuginfo.rs
index 24f6cb85c7b..784d69e93bf 100644
--- a/src/librustc_codegen_llvm/interfaces/debuginfo.rs
+++ b/src/librustc_codegen_ssa/interfaces/debuginfo.rs
@@ -11,11 +11,11 @@
 use super::Backend;
 use super::HasCodegen;
 use debuginfo::{FunctionDebugContext, MirDebugScope, VariableAccess, VariableKind};
-use monomorphize::Instance;
 use rustc::hir::def_id::CrateNum;
 use rustc::mir;
 use rustc::ty::{self, Ty};
 use rustc_data_structures::indexed_vec::IndexVec;
+use rustc_mir::monomorphize::Instance;
 use syntax::ast::Name;
 use syntax_pos::{SourceFile, Span};
 
@@ -48,6 +48,7 @@ pub trait DebugInfoMethods<'tcx>: Backend<'tcx> {
         defining_crate: CrateNum,
     ) -> Self::DIScope;
     fn debuginfo_finalize(&self);
+    fn debuginfo_upvar_decls_ops_sequence(&self, byte_offset_of_var_in_env: u64) -> &[i64];
 }
 
 pub trait DebugInfoBuilderMethods<'tcx>: HasCodegen<'tcx> {
diff --git a/src/librustc_codegen_llvm/interfaces/intrinsic.rs b/src/librustc_codegen_ssa/interfaces/intrinsic.rs
index 1ea377b5a1d..84a7c47ac62 100644
--- a/src/librustc_codegen_llvm/interfaces/intrinsic.rs
+++ b/src/librustc_codegen_ssa/interfaces/intrinsic.rs
@@ -10,9 +10,9 @@
 
 use super::Backend;
 use super::HasCodegen;
-use abi::FnType;
 use mir::operand::OperandRef;
 use rustc::ty::Ty;
+use rustc_target::abi::call::FnType;
 use syntax_pos::Span;
 
 pub trait IntrinsicCallMethods<'tcx>: HasCodegen<'tcx> {
diff --git a/src/librustc_codegen_ssa/interfaces/misc.rs b/src/librustc_codegen_ssa/interfaces/misc.rs
index 462061f1493..0425b8e8e23 100644
--- a/src/librustc_codegen_ssa/interfaces/misc.rs
+++ b/src/librustc_codegen_ssa/interfaces/misc.rs
@@ -33,6 +33,7 @@ pub trait MiscMethods<'tcx>: Backend<'tcx> {
     fn consume_stats(self) -> RefCell<Stats>;
     fn codegen_unit(&self) -> &Arc<CodegenUnit<'tcx>>;
     fn statics_to_rauw(&self) -> &RefCell<Vec<(Self::Value, Self::Value)>>;
+    fn closure_env_needs_indirect_debuginfo(&self) -> bool;
     fn used_statics(&self) -> &RefCell<Vec<Self::Value>>;
     fn set_frame_pointer_elimination(&self, llfn: Self::Value);
     fn apply_target_cpu_attr(&self, llfn: Self::Value);
diff --git a/src/librustc_codegen_ssa/interfaces/mod.rs b/src/librustc_codegen_ssa/interfaces/mod.rs
index aa8355e7dfd..0b2617072a3 100644
--- a/src/librustc_codegen_ssa/interfaces/mod.rs
+++ b/src/librustc_codegen_ssa/interfaces/mod.rs
@@ -8,17 +8,74 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+mod abi;
+mod asm;
 mod backend;
+mod builder;
+mod consts;
+mod debuginfo;
 mod declare;
+mod intrinsic;
 mod misc;
 mod statics;
+mod type_;
 
+pub use self::abi::{AbiBuilderMethods, AbiMethods};
+pub use self::asm::{AsmBuilderMethods, AsmMethods};
 pub use self::backend::{Backend, BackendMethods, BackendTypes};
+pub use self::builder::BuilderMethods;
+pub use self::consts::ConstMethods;
+pub use self::debuginfo::{DebugInfoBuilderMethods, DebugInfoMethods};
 pub use self::declare::{DeclareMethods, PreDefineMethods};
+pub use self::intrinsic::{IntrinsicCallMethods, IntrinsicDeclarationMethods};
 pub use self::misc::MiscMethods;
 pub use self::statics::StaticMethods;
+pub use self::type_::{
+    ArgTypeMethods, BaseTypeMethods, DerivedTypeMethods, LayoutTypeMethods, TypeMethods,
+};
 
 use std::fmt;
 
 pub trait CodegenObject: Copy + PartialEq + fmt::Debug {}
 impl<T: Copy + PartialEq + fmt::Debug> CodegenObject for T {}
+
+pub trait CodegenMethods<'tcx>:
+    Backend<'tcx>
+    + TypeMethods<'tcx>
+    + MiscMethods<'tcx>
+    + ConstMethods<'tcx>
+    + StaticMethods<'tcx>
+    + DebugInfoMethods<'tcx>
+    + AbiMethods<'tcx>
+    + IntrinsicDeclarationMethods<'tcx>
+    + DeclareMethods<'tcx>
+    + AsmMethods<'tcx>
+    + PreDefineMethods<'tcx>
+{
+}
+
+impl<'tcx, T> CodegenMethods<'tcx> for T where
+    Self: Backend<'tcx>
+        + TypeMethods<'tcx>
+        + MiscMethods<'tcx>
+        + ConstMethods<'tcx>
+        + StaticMethods<'tcx>
+        + DebugInfoMethods<'tcx>
+        + AbiMethods<'tcx>
+        + IntrinsicDeclarationMethods<'tcx>
+        + DeclareMethods<'tcx>
+        + AsmMethods<'tcx>
+        + PreDefineMethods<'tcx>
+{}
+
+pub trait HasCodegen<'tcx>: Backend<'tcx> {
+    type CodegenCx: CodegenMethods<'tcx>
+        + BackendTypes<
+            Value = Self::Value,
+            BasicBlock = Self::BasicBlock,
+            Type = Self::Type,
+            Context = Self::Context,
+            Funclet = Self::Funclet,
+            DIScope = Self::DIScope,
+        >;
+}
diff --git a/src/librustc_codegen_llvm/interfaces/type_.rs b/src/librustc_codegen_ssa/interfaces/type_.rs
index fe4b7a0b852..52c06618faa 100644
--- a/src/librustc_codegen_llvm/interfaces/type_.rs
+++ b/src/librustc_codegen_ssa/interfaces/type_.rs
@@ -10,13 +10,13 @@
 
 use super::Backend;
 use super::HasCodegen;
+use common::TypeKind;
 use mir::place::PlaceRef;
 use rustc::ty::layout::TyLayout;
 use rustc::ty::layout::{self, Align, Size};
 use rustc::ty::Ty;
 use rustc::util::nodemap::FxHashMap;
-use rustc_codegen_ssa::common::TypeKind;
-use rustc_target::abi::call::{ArgType, CastTarget, FnType, Reg};
+    use rustc_target::abi::call::{ArgType, CastTarget, FnType, Reg};
 use std::cell::RefCell;
 use syntax::ast;
 
@@ -93,6 +93,8 @@ pub trait LayoutTypeMethods<'tcx>: Backend<'tcx> {
     fn reg_backend_type(&self, ty: &Reg) -> Self::Type;
     fn immediate_backend_type(&self, layout: TyLayout<'tcx>) -> Self::Type;
     fn is_backend_immediate(&self, layout: TyLayout<'tcx>) -> bool;
+    fn is_backend_scalar_pair(&self, layout: TyLayout<'tcx>) -> bool;
+    fn backend_field_index(&self, layout: TyLayout<'tcx>, index: usize) -> u64;
     fn scalar_pair_element_backend_type<'a>(
         &self,
         layout: TyLayout<'tcx>,
diff --git a/src/librustc_codegen_ssa/lib.rs b/src/librustc_codegen_ssa/lib.rs
index 7c062781fc0..9c4dfb0825a 100644
--- a/src/librustc_codegen_ssa/lib.rs
+++ b/src/librustc_codegen_ssa/lib.rs
@@ -20,28 +20,49 @@
 #![feature(box_syntax)]
 #![feature(custom_attribute)]
 #![feature(libc)]
+#![feature(rustc_diagnostic_macros)]
+#![feature(in_band_lifetimes)]
+#![feature(slice_sort_by_cached_key)]
 #![feature(nll)]
 #![allow(unused_attributes)]
 #![allow(dead_code)]
 #![feature(quote)]
-#![feature(rustc_diagnostic_macros)]
 
-#![recursion_limit="256"]
-
-extern crate rustc;
+#[macro_use] extern crate bitflags;
+#[macro_use] extern crate log;
+extern crate rustc_apfloat;
+#[macro_use]  extern crate rustc;
 extern crate rustc_target;
 extern crate rustc_mir;
-extern crate syntax;
+#[macro_use] extern crate syntax;
 extern crate syntax_pos;
+extern crate rustc_incremental;
+extern crate rustc_codegen_utils;
 extern crate rustc_data_structures;
 extern crate libc;
 
 use std::path::PathBuf;
 use rustc::dep_graph::WorkProduct;
 use rustc::session::config::{OutputFilenames, OutputType};
+use rustc::middle::lang_items::LangItem;
+use rustc::hir::def_id::CrateNum;
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_data_structures::sync::Lrc;
+use rustc::middle::cstore::{LibSource, CrateSource, NativeLibrary};
+
+// NB: This module needs to be declared first so diagnostics are
+// registered before they are used.
+mod diagnostics;
 
 pub mod common;
 pub mod interfaces;
+pub mod mir;
+pub mod debuginfo;
+pub mod base;
+pub mod callee;
+pub mod glue;
+pub mod meth;
+pub mod mono_item;
 
 pub struct ModuleCodegen<M> {
     /// The name of the module. When the crate may be saved between
@@ -111,5 +132,31 @@ pub enum ModuleKind {
     Allocator,
 }
 
+bitflags! {
+    pub struct MemFlags: u8 {
+        const VOLATILE = 1 << 0;
+        const NONTEMPORAL = 1 << 1;
+        const UNALIGNED = 1 << 2;
+    }
+}
+
+/// Misc info we load from metadata to persist beyond the tcx
+struct CrateInfo {
+    panic_runtime: Option<CrateNum>,
+    compiler_builtins: Option<CrateNum>,
+    profiler_runtime: Option<CrateNum>,
+    sanitizer_runtime: Option<CrateNum>,
+    is_no_builtins: FxHashSet<CrateNum>,
+    native_libraries: FxHashMap<CrateNum, Lrc<Vec<NativeLibrary>>>,
+    crate_name: FxHashMap<CrateNum, String>,
+    used_libraries: Lrc<Vec<NativeLibrary>>,
+    link_args: Lrc<Vec<String>>,
+    used_crate_source: FxHashMap<CrateNum, Lrc<CrateSource>>,
+    used_crates_static: Vec<(CrateNum, LibSource)>,
+    used_crates_dynamic: Vec<(CrateNum, LibSource)>,
+    wasm_imports: FxHashMap<String, String>,
+    lang_item_to_crate: FxHashMap<LangItem, CrateNum>,
+    missing_lang_items: FxHashMap<CrateNum, Vec<LangItem>>,
+}
 
 __build_diagnostic_array! { librustc_codegen_ssa, DIAGNOSTICS }
diff --git a/src/librustc_codegen_llvm/meth.rs b/src/librustc_codegen_ssa/meth.rs
index 2be1c288440..4584adfff65 100644
--- a/src/librustc_codegen_llvm/meth.rs
+++ b/src/librustc_codegen_ssa/meth.rs
@@ -8,9 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use abi::FnType;
+use rustc_target::abi::call::FnType;
 use callee;
-use monomorphize;
+use rustc_mir::monomorphize;
 
 use interfaces::*;
 
diff --git a/src/librustc_codegen_llvm/mir/analyze.rs b/src/librustc_codegen_ssa/mir/analyze.rs
index 9e54330b4ef..2dc6ae3a049 100644
--- a/src/librustc_codegen_llvm/mir/analyze.rs
+++ b/src/librustc_codegen_ssa/mir/analyze.rs
@@ -19,7 +19,6 @@ use rustc::mir::visit::{Visitor, PlaceContext, MutatingUseContext, NonMutatingUs
 use rustc::mir::traversal;
 use rustc::ty;
 use rustc::ty::layout::{LayoutOf, HasTyCtxt};
-use type_of::LayoutLlvmExt;
 use super::FunctionCx;
 use interfaces::*;
 
@@ -35,10 +34,10 @@ pub fn non_ssa_locals<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
         let ty = fx.monomorphize(&ty);
         debug!("local {} has type {:?}", index, ty);
         let layout = fx.cx.layout_of(ty);
-        if layout.is_llvm_immediate() {
+        if fx.cx.is_backend_immediate(layout) {
             // These sorts of types are immediates that we can store
             // in an Value without an alloca.
-        } else if layout.is_llvm_scalar_pair() {
+        } else if fx.cx.is_backend_scalar_pair(layout) {
             // We allow pairs and uses of any of their 2 fields.
         } else {
             // These sorts of types require an alloca. Note that
@@ -191,7 +190,7 @@ impl<'mir, 'a: 'mir, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> Visitor<'tcx>
 
                 if let mir::ProjectionElem::Field(..) = proj.elem {
                     let layout = cx.layout_of(base_ty.to_ty(cx.tcx()));
-                    if layout.is_llvm_immediate() || layout.is_llvm_scalar_pair() {
+                    if cx.is_backend_immediate(layout) || cx.is_backend_scalar_pair(layout) {
                         // Recurse with the same context, instead of `Projection`,
                         // potentially stopping at non-operand projections,
                         // which would trigger `not_ssa` on locals.
diff --git a/src/librustc_codegen_llvm/mir/block.rs b/src/librustc_codegen_ssa/mir/block.rs
index d72fdb2fb23..46665193ab5 100644
--- a/src/librustc_codegen_llvm/mir/block.rs
+++ b/src/librustc_codegen_ssa/mir/block.rs
@@ -13,14 +13,13 @@ use rustc::ty::{self, Ty, TypeFoldable};
 use rustc::ty::layout::{self, LayoutOf, HasTyCtxt};
 use rustc::mir;
 use rustc::mir::interpret::EvalErrorKind;
-use abi::{Abi, FnType, PassMode};
-use rustc_target::abi::call::ArgType;
+use rustc_target::abi::call::{ArgType, FnType, PassMode};
+use rustc_target::spec::abi::Abi;
 use base;
-use builder::MemFlags;
-use common;
-use rustc_codegen_ssa::common::IntPredicate;
+use MemFlags;
+use common::{self, IntPredicate};
 use meth;
-use monomorphize;
+use rustc_mir::monomorphize;
 
 use interfaces::*;
 
diff --git a/src/librustc_codegen_llvm/mir/constant.rs b/src/librustc_codegen_ssa/mir/constant.rs
index a052473beec..b71a0bc54b1 100644
--- a/src/librustc_codegen_llvm/mir/constant.rs
+++ b/src/librustc_codegen_ssa/mir/constant.rs
@@ -8,74 +8,18 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use rustc::mir::interpret::{ErrorHandled, read_target_uint};
+use rustc::mir::interpret::ErrorHandled;
 use rustc_mir::const_eval::const_field;
-use rustc::hir::def_id::DefId;
 use rustc::mir;
 use rustc_data_structures::indexed_vec::Idx;
-use rustc::mir::interpret::{GlobalId, Pointer, Allocation, ConstValue};
+use rustc::mir::interpret::{GlobalId, ConstValue};
 use rustc::ty::{self, Ty};
-use rustc::ty::layout::{self, HasDataLayout, LayoutOf, Size};
-use common::CodegenCx;
+use rustc::ty::layout::{self, LayoutOf};
 use syntax::source_map::Span;
-use value::Value;
 use interfaces::*;
 
 use super::FunctionCx;
 
-pub fn const_alloc_to_llvm(cx: &CodegenCx<'ll, '_>, alloc: &Allocation) -> &'ll Value {
-    let mut llvals = Vec::with_capacity(alloc.relocations.len() + 1);
-    let dl = cx.data_layout();
-    let pointer_size = dl.pointer_size.bytes() as usize;
-
-    let mut next_offset = 0;
-    for &(offset, ((), alloc_id)) in alloc.relocations.iter() {
-        let offset = offset.bytes();
-        assert_eq!(offset as usize as u64, offset);
-        let offset = offset as usize;
-        if offset > next_offset {
-            llvals.push(cx.const_bytes(&alloc.bytes[next_offset..offset]));
-        }
-        let ptr_offset = read_target_uint(
-            dl.endian,
-            &alloc.bytes[offset..(offset + pointer_size)],
-        ).expect("const_alloc_to_llvm: could not read relocation pointer") as u64;
-        llvals.push(cx.scalar_to_backend(
-            Pointer::new(alloc_id, Size::from_bytes(ptr_offset)).into(),
-            &layout::Scalar {
-                value: layout::Primitive::Pointer,
-                valid_range: 0..=!0
-            },
-            cx.type_i8p()
-        ));
-        next_offset = offset + pointer_size;
-    }
-    if alloc.bytes.len() >= next_offset {
-        llvals.push(cx.const_bytes(&alloc.bytes[next_offset ..]));
-    }
-
-    cx.const_struct(&llvals, true)
-}
-
-pub fn codegen_static_initializer(
-    cx: &CodegenCx<'ll, 'tcx>,
-    def_id: DefId,
-) -> Result<(&'ll Value, &'tcx Allocation), ErrorHandled> {
-    let instance = ty::Instance::mono(cx.tcx, def_id);
-    let cid = GlobalId {
-        instance,
-        promoted: None,
-    };
-    let param_env = ty::ParamEnv::reveal_all();
-    let static_ = cx.tcx.const_eval(param_env.and(cid))?;
-
-    let alloc = match static_.val {
-        ConstValue::ByRef(_, alloc, n) if n.bytes() == 0 => alloc,
-        _ => bug!("static const eval returned {:#?}", static_),
-    };
-    Ok((const_alloc_to_llvm(cx, alloc), alloc))
-}
-
 impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
     fn fully_evaluate(
         &mut self,
diff --git a/src/librustc_codegen_llvm/mir/mod.rs b/src/librustc_codegen_ssa/mir/mod.rs
index c7e2a5d2af3..3fdc37ee833 100644
--- a/src/librustc_codegen_llvm/mir/mod.rs
+++ b/src/librustc_codegen_ssa/mir/mod.rs
@@ -9,8 +9,6 @@
 // except according to those terms.
 
 use libc::c_uint;
-use llvm;
-use llvm_util;
 use rustc::ty::{self, Ty, TypeFoldable, UpvarSubsts};
 use rustc::ty::layout::{LayoutOf, TyLayout, HasTyCtxt};
 use rustc::mir::{self, Mir};
@@ -18,8 +16,8 @@ use rustc::ty::subst::Substs;
 use rustc::session::config::DebugInfo;
 use base;
 use debuginfo::{self, VariableAccess, VariableKind, FunctionDebugContext};
-use monomorphize::Instance;
-use abi::{FnType, PassMode};
+use rustc_mir::monomorphize::Instance;
+use rustc_target::abi::call::{FnType, PassMode};
 use interfaces::*;
 
 use syntax_pos::{DUMMY_SP, NO_EXPANSION, BytePos, Span};
@@ -30,8 +28,6 @@ use std::iter;
 use rustc_data_structures::bit_set::BitSet;
 use rustc_data_structures::indexed_vec::IndexVec;
 
-pub use self::constant::codegen_static_initializer;
-
 use self::analyze::CleanupKind;
 use self::place::PlaceRef;
 use rustc::mir::traversal;
@@ -171,7 +167,7 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             Some(self.cx.extend_scope_to_file(
                 scope_metadata.unwrap(),
                 &sm.lookup_char_pos(pos).file,
-                defining_crate,
+                defining_crate
             ))
         } else {
             scope_metadata
@@ -616,7 +612,7 @@ fn arg_local_refs<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
             // doesn't actually strip the offset when splitting the closure
             // environment into its components so it ends up out of bounds.
             // (cuviper) It seems to be fine without the alloca on LLVM 6 and later.
-            let env_alloca = !env_ref && llvm_util::get_major_version() < 6;
+            let env_alloca = !env_ref && bx.cx().closure_env_needs_indirect_debuginfo();
             let env_ptr = if env_alloca {
                 let scratch = PlaceRef::alloca(bx,
                     bx.cx().layout_of(tcx.mk_mut_ptr(arg.layout.ty)),
@@ -630,12 +626,7 @@ fn arg_local_refs<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
             for (i, (decl, ty)) in mir.upvar_decls.iter().zip(upvar_tys).enumerate() {
                 let byte_offset_of_var_in_env = closure_layout.fields.offset(i).bytes();
 
-                let ops = unsafe {
-                    [llvm::LLVMRustDIBuilderCreateOpDeref(),
-                     llvm::LLVMRustDIBuilderCreateOpPlusUconst(),
-                     byte_offset_of_var_in_env as i64,
-                     llvm::LLVMRustDIBuilderCreateOpDeref()]
-                };
+                let ops = bx.cx().debuginfo_upvar_decls_ops_sequence(byte_offset_of_var_in_env);
 
                 // The environment and the capture can each be indirect.
 
diff --git a/src/librustc_codegen_llvm/mir/operand.rs b/src/librustc_codegen_ssa/mir/operand.rs
index f2f60315728..8196aba87e4 100644
--- a/src/librustc_codegen_llvm/mir/operand.rs
+++ b/src/librustc_codegen_ssa/mir/operand.rs
@@ -14,7 +14,7 @@ use rustc::ty;
 use rustc::ty::layout::{self, Align, LayoutOf, TyLayout};
 
 use base;
-use builder::MemFlags;
+use MemFlags;
 use glue;
 
 use interfaces::*;
diff --git a/src/librustc_codegen_llvm/mir/place.rs b/src/librustc_codegen_ssa/mir/place.rs
index 8fa35d3aaf2..c976609d929 100644
--- a/src/librustc_codegen_llvm/mir/place.rs
+++ b/src/librustc_codegen_ssa/mir/place.rs
@@ -12,9 +12,8 @@ use rustc::ty::{self, Ty};
 use rustc::ty::layout::{self, Align, TyLayout, LayoutOf, VariantIdx, HasTyCtxt};
 use rustc::mir;
 use rustc::mir::tcx::PlaceTy;
-use builder::MemFlags;
-use rustc_codegen_ssa::common::IntPredicate;
-use type_of::LayoutLlvmExt;
+use MemFlags;
+use common::IntPredicate;
 use glue;
 
 use interfaces::*;
@@ -114,7 +113,7 @@ impl<'a, 'tcx: 'a, V: CodegenObject> PlaceRef<'tcx, V> {
                 assert_eq!(offset, a.value.size(cx).abi_align(b.value.align(cx)));
                 bx.struct_gep(self.llval, 1)
             } else {
-                bx.struct_gep(self.llval, self.layout.llvm_field_index(ix))
+                bx.struct_gep(self.llval, bx.cx().backend_field_index(self.layout, ix))
             };
             PlaceRef {
                 // HACK(eddyb) have to bitcast pointers until LLVM removes pointee types.
diff --git a/src/librustc_codegen_llvm/mir/rvalue.rs b/src/librustc_codegen_ssa/mir/rvalue.rs
index 9870c93a508..69c53879354 100644
--- a/src/librustc_codegen_llvm/mir/rvalue.rs
+++ b/src/librustc_codegen_ssa/mir/rvalue.rs
@@ -17,12 +17,10 @@ use rustc_apfloat::{ieee, Float, Status, Round};
 use std::{u128, i128};
 
 use base;
-use builder::MemFlags;
+use MemFlags;
 use callee;
-use common;
-use rustc_codegen_ssa::common::{RealPredicate, IntPredicate};
-use monomorphize;
-use type_of::LayoutLlvmExt;
+use common::{self, RealPredicate, IntPredicate};
+use rustc_mir::monomorphize;
 
 use interfaces::*;
 
@@ -52,7 +50,7 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             mir::Rvalue::Cast(mir::CastKind::Unsize, ref source, _) => {
                 // The destination necessarily contains a fat pointer, so if
                 // it's a scalar pair, it's a fat pointer or newtype thereof.
-                if dest.layout.is_llvm_scalar_pair() {
+                if bx.cx().is_backend_scalar_pair(dest.layout) {
                     // into-coerce of a thin pointer to a fat pointer - just
                     // use the operand path.
                     let (bx, temp) = self.codegen_rvalue_operand(bx, rvalue);
@@ -241,7 +239,7 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                         operand.val
                     }
                     mir::CastKind::Unsize => {
-                        assert!(cast.is_llvm_scalar_pair());
+                        assert!(bx.cx().is_backend_scalar_pair(cast));
                         match operand.val {
                             OperandValue::Pair(lldata, llextra) => {
                                 // unsize from a fat pointer - this is a
@@ -267,9 +265,9 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                             }
                         }
                     }
-                    mir::CastKind::Misc if operand.layout.is_llvm_scalar_pair() => {
+                    mir::CastKind::Misc if bx.cx().is_backend_scalar_pair(operand.layout) => {
                         if let OperandValue::Pair(data_ptr, meta) = operand.val {
-                            if cast.is_llvm_scalar_pair() {
+                            if bx.cx().is_backend_scalar_pair(cast) {
                                 let data_cast = bx.pointercast(data_ptr,
                                     bx.cx().scalar_pair_element_backend_type(cast, 0, true));
                                 OperandValue::Pair(data_cast, meta)
@@ -285,7 +283,7 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                         }
                     }
                     mir::CastKind::Misc => {
-                        assert!(cast.is_llvm_immediate());
+                        assert!(bx.cx().is_backend_immediate(cast));
                         let ll_t_out = bx.cx().immediate_backend_type(cast);
                         if operand.layout.abi.is_uninhabited() {
                             let val = OperandValue::Immediate(bx.cx().const_undef(ll_t_out));
diff --git a/src/librustc_codegen_llvm/mir/statement.rs b/src/librustc_codegen_ssa/mir/statement.rs
index 40af52c05a3..40af52c05a3 100644
--- a/src/librustc_codegen_llvm/mir/statement.rs
+++ b/src/librustc_codegen_ssa/mir/statement.rs
diff --git a/src/librustc_codegen_ssa/mono_item.rs b/src/librustc_codegen_ssa/mono_item.rs
new file mode 100644
index 00000000000..508055ffc5a
--- /dev/null
+++ b/src/librustc_codegen_ssa/mono_item.rs
@@ -0,0 +1,117 @@
+// Copyright 2016 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.
+
+//! Walks the crate looking for items/impl-items/trait-items that have
+//! either a `rustc_symbol_name` or `rustc_item_path` attribute and
+//! generates an error giving, respectively, the symbol name or
+//! item-path. This is used for unit testing the code that generates
+//! paths etc in all kinds of annoying scenarios.
+
+use base;
+use rustc::hir;
+use rustc::hir::def::Def;
+use rustc::mir::mono::{Linkage, Visibility};
+use rustc::ty::layout::HasTyCtxt;
+use std::fmt;
+use interfaces::*;
+
+pub use rustc::mir::mono::MonoItem;
+
+pub use rustc_mir::monomorphize::item::MonoItemExt as BaseMonoItemExt;
+
+pub trait MonoItemExt<'a, 'tcx: 'a>: fmt::Debug + BaseMonoItemExt<'a, 'tcx> {
+    fn define<Bx: BuilderMethods<'a, 'tcx>>(&self, cx: &'a Bx::CodegenCx) {
+        debug!("BEGIN IMPLEMENTING '{} ({})' in cgu {}",
+               self.to_string(cx.tcx()),
+               self.to_raw_string(),
+               cx.codegen_unit().name());
+
+        match *self.as_mono_item() {
+            MonoItem::Static(def_id) => {
+                let tcx = cx.tcx();
+                let is_mutable = match tcx.describe_def(def_id) {
+                    Some(Def::Static(_, is_mutable)) => is_mutable,
+                    Some(other) => {
+                        bug!("Expected Def::Static, found {:?}", other)
+                    }
+                    None => {
+                        bug!("Expected Def::Static for {:?}, found nothing", def_id)
+                    }
+                };
+                cx.codegen_static(def_id, is_mutable);
+            }
+            MonoItem::GlobalAsm(node_id) => {
+                let item = cx.tcx().hir.expect_item(node_id);
+                if let hir::ItemKind::GlobalAsm(ref ga) = item.node {
+                    cx.codegen_global_asm(ga);
+                } else {
+                    span_bug!(item.span, "Mismatch between hir::Item type and MonoItem type")
+                }
+            }
+            MonoItem::Fn(instance) => {
+                base::codegen_instance::<Bx>(&cx, instance);
+            }
+        }
+
+        debug!("END IMPLEMENTING '{} ({})' in cgu {}",
+               self.to_string(cx.tcx()),
+               self.to_raw_string(),
+               cx.codegen_unit().name());
+    }
+
+    fn predefine<Bx: BuilderMethods<'a, 'tcx>>(
+        &self,
+        cx: &'a Bx::CodegenCx,
+        linkage: Linkage,
+        visibility: Visibility
+    ) {
+        debug!("BEGIN PREDEFINING '{} ({})' in cgu {}",
+               self.to_string(cx.tcx()),
+               self.to_raw_string(),
+               cx.codegen_unit().name());
+
+        let symbol_name = self.symbol_name(cx.tcx()).as_str();
+
+        debug!("symbol {}", &symbol_name);
+
+        match *self.as_mono_item() {
+            MonoItem::Static(def_id) => {
+                cx.predefine_static(def_id, linkage, visibility, &symbol_name);
+            }
+            MonoItem::Fn(instance) => {
+                cx.predefine_fn(instance, linkage, visibility, &symbol_name);
+            }
+            MonoItem::GlobalAsm(..) => {}
+        }
+
+        debug!("END PREDEFINING '{} ({})' in cgu {}",
+               self.to_string(cx.tcx()),
+               self.to_raw_string(),
+               cx.codegen_unit().name());
+    }
+
+    fn to_raw_string(&self) -> String {
+        match *self.as_mono_item() {
+            MonoItem::Fn(instance) => {
+                format!("Fn({:?}, {})",
+                        instance.def,
+                        instance.substs.as_ptr() as usize)
+            }
+            MonoItem::Static(id) => {
+                format!("Static({:?})", id)
+            }
+            MonoItem::GlobalAsm(id) => {
+                format!("GlobalAsm({:?})", id)
+            }
+        }
+    }
+}
+
+impl<'a, 'tcx: 'a> MonoItemExt<'a, 'tcx> for MonoItem<'tcx> {}