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-rw-r--r--compiler/rustc_codegen_ssa/src/lib.rs2
-rw-r--r--compiler/rustc_codegen_ssa/src/mir/block.rs3
-rw-r--r--compiler/rustc_codegen_ssa/src/mir/intrinsic.rs596
-rw-r--r--compiler/rustc_codegen_ssa/src/mir/mod.rs1
4 files changed, 599 insertions, 3 deletions
diff --git a/compiler/rustc_codegen_ssa/src/lib.rs b/compiler/rustc_codegen_ssa/src/lib.rs
index 73e33369175..a87ce1446ba 100644
--- a/compiler/rustc_codegen_ssa/src/lib.rs
+++ b/compiler/rustc_codegen_ssa/src/lib.rs
@@ -8,8 +8,6 @@
 #![feature(or_patterns)]
 #![feature(trusted_len)]
 #![feature(associated_type_bounds)]
-#![feature(const_fn)] // for rustc_index::newtype_index
-#![feature(const_panic)] // for rustc_index::newtype_index
 #![recursion_limit = "256"]
 
 //! This crate contains codegen code that is used by all codegen backends (LLVM and others).
diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs
index 23269f7245d..703a17b200a 100644
--- a/compiler/rustc_codegen_ssa/src/mir/block.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/block.rs
@@ -687,7 +687,8 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 })
                 .collect();
 
-            bx.codegen_intrinsic_call(
+            Self::codegen_intrinsic_call(
+                &mut bx,
                 *instance.as_ref().unwrap(),
                 &fn_abi,
                 &args,
diff --git a/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs b/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs
new file mode 100644
index 00000000000..14f1ed59a67
--- /dev/null
+++ b/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs
@@ -0,0 +1,596 @@
+use super::operand::{OperandRef, OperandValue};
+use super::place::PlaceRef;
+use super::FunctionCx;
+use crate::common::{span_invalid_monomorphization_error, IntPredicate};
+use crate::glue;
+use crate::traits::*;
+use crate::MemFlags;
+
+use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_span::{sym, Span};
+use rustc_target::abi::call::{FnAbi, PassMode};
+
+fn copy_intrinsic<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
+    bx: &mut Bx,
+    allow_overlap: bool,
+    volatile: bool,
+    ty: Ty<'tcx>,
+    dst: Bx::Value,
+    src: Bx::Value,
+    count: Bx::Value,
+) {
+    let layout = bx.layout_of(ty);
+    let size = layout.size;
+    let align = layout.align.abi;
+    let size = bx.mul(bx.const_usize(size.bytes()), count);
+    let flags = if volatile { MemFlags::VOLATILE } else { MemFlags::empty() };
+    if allow_overlap {
+        bx.memmove(dst, align, src, align, size, flags);
+    } else {
+        bx.memcpy(dst, align, src, align, size, flags);
+    }
+}
+
+fn memset_intrinsic<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
+    bx: &mut Bx,
+    volatile: bool,
+    ty: Ty<'tcx>,
+    dst: Bx::Value,
+    val: Bx::Value,
+    count: Bx::Value,
+) {
+    let layout = bx.layout_of(ty);
+    let size = layout.size;
+    let align = layout.align.abi;
+    let size = bx.mul(bx.const_usize(size.bytes()), count);
+    let flags = if volatile { MemFlags::VOLATILE } else { MemFlags::empty() };
+    bx.memset(dst, val, size, align, flags);
+}
+
+impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
+    pub fn codegen_intrinsic_call(
+        bx: &mut Bx,
+        instance: ty::Instance<'tcx>,
+        fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
+        args: &[OperandRef<'tcx, Bx::Value>],
+        llresult: Bx::Value,
+        span: Span,
+    ) {
+        let callee_ty = instance.ty(bx.tcx(), ty::ParamEnv::reveal_all());
+
+        let (def_id, substs) = match *callee_ty.kind() {
+            ty::FnDef(def_id, substs) => (def_id, substs),
+            _ => bug!("expected fn item type, found {}", callee_ty),
+        };
+
+        let sig = callee_ty.fn_sig(bx.tcx());
+        let sig = bx.tcx().normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), &sig);
+        let arg_tys = sig.inputs();
+        let ret_ty = sig.output();
+        let name = bx.tcx().item_name(def_id);
+        let name_str = &*name.as_str();
+
+        let llret_ty = bx.backend_type(bx.layout_of(ret_ty));
+        let result = PlaceRef::new_sized(llresult, fn_abi.ret.layout);
+
+        let llval = match name {
+            sym::assume => {
+                bx.assume(args[0].immediate());
+                return;
+            }
+            sym::abort => {
+                bx.abort();
+                return;
+            }
+
+            sym::unreachable => {
+                return;
+            }
+            sym::va_start => bx.va_start(args[0].immediate()),
+            sym::va_end => bx.va_end(args[0].immediate()),
+            sym::size_of_val => {
+                let tp_ty = substs.type_at(0);
+                if let OperandValue::Pair(_, meta) = args[0].val {
+                    let (llsize, _) = glue::size_and_align_of_dst(bx, tp_ty, Some(meta));
+                    llsize
+                } else {
+                    bx.const_usize(bx.layout_of(tp_ty).size.bytes())
+                }
+            }
+            sym::min_align_of_val => {
+                let tp_ty = substs.type_at(0);
+                if let OperandValue::Pair(_, meta) = args[0].val {
+                    let (_, llalign) = glue::size_and_align_of_dst(bx, tp_ty, Some(meta));
+                    llalign
+                } else {
+                    bx.const_usize(bx.layout_of(tp_ty).align.abi.bytes())
+                }
+            }
+            sym::size_of
+            | sym::pref_align_of
+            | sym::min_align_of
+            | sym::needs_drop
+            | sym::type_id
+            | sym::type_name
+            | sym::variant_count => {
+                let value = bx
+                    .tcx()
+                    .const_eval_instance(ty::ParamEnv::reveal_all(), instance, None)
+                    .unwrap();
+                OperandRef::from_const(bx, value, ret_ty).immediate_or_packed_pair(bx)
+            }
+            // Effectively no-op
+            sym::forget => {
+                return;
+            }
+            sym::offset => {
+                let ptr = args[0].immediate();
+                let offset = args[1].immediate();
+                bx.inbounds_gep(ptr, &[offset])
+            }
+            sym::arith_offset => {
+                let ptr = args[0].immediate();
+                let offset = args[1].immediate();
+                bx.gep(ptr, &[offset])
+            }
+
+            sym::copy_nonoverlapping => {
+                copy_intrinsic(
+                    bx,
+                    false,
+                    false,
+                    substs.type_at(0),
+                    args[1].immediate(),
+                    args[0].immediate(),
+                    args[2].immediate(),
+                );
+                return;
+            }
+            sym::copy => {
+                copy_intrinsic(
+                    bx,
+                    true,
+                    false,
+                    substs.type_at(0),
+                    args[1].immediate(),
+                    args[0].immediate(),
+                    args[2].immediate(),
+                );
+                return;
+            }
+            sym::write_bytes => {
+                memset_intrinsic(
+                    bx,
+                    false,
+                    substs.type_at(0),
+                    args[0].immediate(),
+                    args[1].immediate(),
+                    args[2].immediate(),
+                );
+                return;
+            }
+
+            sym::volatile_copy_nonoverlapping_memory => {
+                copy_intrinsic(
+                    bx,
+                    false,
+                    true,
+                    substs.type_at(0),
+                    args[0].immediate(),
+                    args[1].immediate(),
+                    args[2].immediate(),
+                );
+                return;
+            }
+            sym::volatile_copy_memory => {
+                copy_intrinsic(
+                    bx,
+                    true,
+                    true,
+                    substs.type_at(0),
+                    args[0].immediate(),
+                    args[1].immediate(),
+                    args[2].immediate(),
+                );
+                return;
+            }
+            sym::volatile_set_memory => {
+                memset_intrinsic(
+                    bx,
+                    true,
+                    substs.type_at(0),
+                    args[0].immediate(),
+                    args[1].immediate(),
+                    args[2].immediate(),
+                );
+                return;
+            }
+            sym::volatile_store => {
+                let dst = args[0].deref(bx.cx());
+                args[1].val.volatile_store(bx, dst);
+                return;
+            }
+            sym::unaligned_volatile_store => {
+                let dst = args[0].deref(bx.cx());
+                args[1].val.unaligned_volatile_store(bx, dst);
+                return;
+            }
+            sym::add_with_overflow
+            | sym::sub_with_overflow
+            | sym::mul_with_overflow
+            | sym::wrapping_add
+            | sym::wrapping_sub
+            | sym::wrapping_mul
+            | sym::unchecked_div
+            | sym::unchecked_rem
+            | sym::unchecked_shl
+            | sym::unchecked_shr
+            | sym::unchecked_add
+            | sym::unchecked_sub
+            | sym::unchecked_mul
+            | sym::exact_div => {
+                let ty = arg_tys[0];
+                match int_type_width_signed(ty, bx.tcx()) {
+                    Some((_width, signed)) => match name {
+                        sym::add_with_overflow
+                        | sym::sub_with_overflow
+                        | sym::mul_with_overflow => {
+                            let op = match name {
+                                sym::add_with_overflow => OverflowOp::Add,
+                                sym::sub_with_overflow => OverflowOp::Sub,
+                                sym::mul_with_overflow => OverflowOp::Mul,
+                                _ => bug!(),
+                            };
+                            let (val, overflow) =
+                                bx.checked_binop(op, ty, args[0].immediate(), args[1].immediate());
+                            // Convert `i1` to a `bool`, and write it to the out parameter
+                            let val = bx.from_immediate(val);
+                            let overflow = bx.from_immediate(overflow);
+
+                            let dest = result.project_field(bx, 0);
+                            bx.store(val, dest.llval, dest.align);
+                            let dest = result.project_field(bx, 1);
+                            bx.store(overflow, dest.llval, dest.align);
+
+                            return;
+                        }
+                        sym::wrapping_add => bx.add(args[0].immediate(), args[1].immediate()),
+                        sym::wrapping_sub => bx.sub(args[0].immediate(), args[1].immediate()),
+                        sym::wrapping_mul => bx.mul(args[0].immediate(), args[1].immediate()),
+                        sym::exact_div => {
+                            if signed {
+                                bx.exactsdiv(args[0].immediate(), args[1].immediate())
+                            } else {
+                                bx.exactudiv(args[0].immediate(), args[1].immediate())
+                            }
+                        }
+                        sym::unchecked_div => {
+                            if signed {
+                                bx.sdiv(args[0].immediate(), args[1].immediate())
+                            } else {
+                                bx.udiv(args[0].immediate(), args[1].immediate())
+                            }
+                        }
+                        sym::unchecked_rem => {
+                            if signed {
+                                bx.srem(args[0].immediate(), args[1].immediate())
+                            } else {
+                                bx.urem(args[0].immediate(), args[1].immediate())
+                            }
+                        }
+                        sym::unchecked_shl => bx.shl(args[0].immediate(), args[1].immediate()),
+                        sym::unchecked_shr => {
+                            if signed {
+                                bx.ashr(args[0].immediate(), args[1].immediate())
+                            } else {
+                                bx.lshr(args[0].immediate(), args[1].immediate())
+                            }
+                        }
+                        sym::unchecked_add => {
+                            if signed {
+                                bx.unchecked_sadd(args[0].immediate(), args[1].immediate())
+                            } else {
+                                bx.unchecked_uadd(args[0].immediate(), args[1].immediate())
+                            }
+                        }
+                        sym::unchecked_sub => {
+                            if signed {
+                                bx.unchecked_ssub(args[0].immediate(), args[1].immediate())
+                            } else {
+                                bx.unchecked_usub(args[0].immediate(), args[1].immediate())
+                            }
+                        }
+                        sym::unchecked_mul => {
+                            if signed {
+                                bx.unchecked_smul(args[0].immediate(), args[1].immediate())
+                            } else {
+                                bx.unchecked_umul(args[0].immediate(), args[1].immediate())
+                            }
+                        }
+                        _ => bug!(),
+                    },
+                    None => {
+                        span_invalid_monomorphization_error(
+                            bx.tcx().sess,
+                            span,
+                            &format!(
+                                "invalid monomorphization of `{}` intrinsic: \
+                                      expected basic integer type, found `{}`",
+                                name, ty
+                            ),
+                        );
+                        return;
+                    }
+                }
+            }
+            sym::fadd_fast | sym::fsub_fast | sym::fmul_fast | sym::fdiv_fast | sym::frem_fast => {
+                match float_type_width(arg_tys[0]) {
+                    Some(_width) => match name {
+                        sym::fadd_fast => bx.fadd_fast(args[0].immediate(), args[1].immediate()),
+                        sym::fsub_fast => bx.fsub_fast(args[0].immediate(), args[1].immediate()),
+                        sym::fmul_fast => bx.fmul_fast(args[0].immediate(), args[1].immediate()),
+                        sym::fdiv_fast => bx.fdiv_fast(args[0].immediate(), args[1].immediate()),
+                        sym::frem_fast => bx.frem_fast(args[0].immediate(), args[1].immediate()),
+                        _ => bug!(),
+                    },
+                    None => {
+                        span_invalid_monomorphization_error(
+                            bx.tcx().sess,
+                            span,
+                            &format!(
+                                "invalid monomorphization of `{}` intrinsic: \
+                                      expected basic float type, found `{}`",
+                                name, arg_tys[0]
+                            ),
+                        );
+                        return;
+                    }
+                }
+            }
+
+            sym::float_to_int_unchecked => {
+                if float_type_width(arg_tys[0]).is_none() {
+                    span_invalid_monomorphization_error(
+                        bx.tcx().sess,
+                        span,
+                        &format!(
+                            "invalid monomorphization of `float_to_int_unchecked` \
+                                  intrinsic: expected basic float type, \
+                                  found `{}`",
+                            arg_tys[0]
+                        ),
+                    );
+                    return;
+                }
+                let (_width, signed) = match int_type_width_signed(ret_ty, bx.tcx()) {
+                    Some(pair) => pair,
+                    None => {
+                        span_invalid_monomorphization_error(
+                            bx.tcx().sess,
+                            span,
+                            &format!(
+                                "invalid monomorphization of `float_to_int_unchecked` \
+                                      intrinsic:  expected basic integer type, \
+                                      found `{}`",
+                                ret_ty
+                            ),
+                        );
+                        return;
+                    }
+                };
+                if signed {
+                    bx.fptosi(args[0].immediate(), llret_ty)
+                } else {
+                    bx.fptoui(args[0].immediate(), llret_ty)
+                }
+            }
+
+            sym::discriminant_value => {
+                if ret_ty.is_integral() {
+                    args[0].deref(bx.cx()).codegen_get_discr(bx, ret_ty)
+                } else {
+                    span_bug!(span, "Invalid discriminant type for `{:?}`", arg_tys[0])
+                }
+            }
+
+            // This requires that atomic intrinsics follow a specific naming pattern:
+            // "atomic_<operation>[_<ordering>]", and no ordering means SeqCst
+            name if name_str.starts_with("atomic_") => {
+                use crate::common::AtomicOrdering::*;
+                use crate::common::{AtomicRmwBinOp, SynchronizationScope};
+
+                let split: Vec<&str> = name_str.split('_').collect();
+
+                let is_cxchg = split[1] == "cxchg" || split[1] == "cxchgweak";
+                let (order, failorder) = match split.len() {
+                    2 => (SequentiallyConsistent, SequentiallyConsistent),
+                    3 => match split[2] {
+                        "unordered" => (Unordered, Unordered),
+                        "relaxed" => (Monotonic, Monotonic),
+                        "acq" => (Acquire, Acquire),
+                        "rel" => (Release, Monotonic),
+                        "acqrel" => (AcquireRelease, Acquire),
+                        "failrelaxed" if is_cxchg => (SequentiallyConsistent, Monotonic),
+                        "failacq" if is_cxchg => (SequentiallyConsistent, Acquire),
+                        _ => bx.sess().fatal("unknown ordering in atomic intrinsic"),
+                    },
+                    4 => match (split[2], split[3]) {
+                        ("acq", "failrelaxed") if is_cxchg => (Acquire, Monotonic),
+                        ("acqrel", "failrelaxed") if is_cxchg => (AcquireRelease, Monotonic),
+                        _ => bx.sess().fatal("unknown ordering in atomic intrinsic"),
+                    },
+                    _ => bx.sess().fatal("Atomic intrinsic not in correct format"),
+                };
+
+                let invalid_monomorphization = |ty| {
+                    span_invalid_monomorphization_error(
+                        bx.tcx().sess,
+                        span,
+                        &format!(
+                            "invalid monomorphization of `{}` intrinsic: \
+                                  expected basic integer type, found `{}`",
+                            name, ty
+                        ),
+                    );
+                };
+
+                match split[1] {
+                    "cxchg" | "cxchgweak" => {
+                        let ty = substs.type_at(0);
+                        if int_type_width_signed(ty, bx.tcx()).is_some() {
+                            let weak = split[1] == "cxchgweak";
+                            let pair = bx.atomic_cmpxchg(
+                                args[0].immediate(),
+                                args[1].immediate(),
+                                args[2].immediate(),
+                                order,
+                                failorder,
+                                weak,
+                            );
+                            let val = bx.extract_value(pair, 0);
+                            let success = bx.extract_value(pair, 1);
+                            let val = bx.from_immediate(val);
+                            let success = bx.from_immediate(success);
+
+                            let dest = result.project_field(bx, 0);
+                            bx.store(val, dest.llval, dest.align);
+                            let dest = result.project_field(bx, 1);
+                            bx.store(success, dest.llval, dest.align);
+                            return;
+                        } else {
+                            return invalid_monomorphization(ty);
+                        }
+                    }
+
+                    "load" => {
+                        let ty = substs.type_at(0);
+                        if int_type_width_signed(ty, bx.tcx()).is_some() {
+                            let size = bx.layout_of(ty).size;
+                            bx.atomic_load(args[0].immediate(), order, size)
+                        } else {
+                            return invalid_monomorphization(ty);
+                        }
+                    }
+
+                    "store" => {
+                        let ty = substs.type_at(0);
+                        if int_type_width_signed(ty, bx.tcx()).is_some() {
+                            let size = bx.layout_of(ty).size;
+                            bx.atomic_store(args[1].immediate(), args[0].immediate(), order, size);
+                            return;
+                        } else {
+                            return invalid_monomorphization(ty);
+                        }
+                    }
+
+                    "fence" => {
+                        bx.atomic_fence(order, SynchronizationScope::CrossThread);
+                        return;
+                    }
+
+                    "singlethreadfence" => {
+                        bx.atomic_fence(order, SynchronizationScope::SingleThread);
+                        return;
+                    }
+
+                    // These are all AtomicRMW ops
+                    op => {
+                        let atom_op = match op {
+                            "xchg" => AtomicRmwBinOp::AtomicXchg,
+                            "xadd" => AtomicRmwBinOp::AtomicAdd,
+                            "xsub" => AtomicRmwBinOp::AtomicSub,
+                            "and" => AtomicRmwBinOp::AtomicAnd,
+                            "nand" => AtomicRmwBinOp::AtomicNand,
+                            "or" => AtomicRmwBinOp::AtomicOr,
+                            "xor" => AtomicRmwBinOp::AtomicXor,
+                            "max" => AtomicRmwBinOp::AtomicMax,
+                            "min" => AtomicRmwBinOp::AtomicMin,
+                            "umax" => AtomicRmwBinOp::AtomicUMax,
+                            "umin" => AtomicRmwBinOp::AtomicUMin,
+                            _ => bx.sess().fatal("unknown atomic operation"),
+                        };
+
+                        let ty = substs.type_at(0);
+                        if int_type_width_signed(ty, bx.tcx()).is_some() {
+                            bx.atomic_rmw(atom_op, args[0].immediate(), args[1].immediate(), order)
+                        } else {
+                            return invalid_monomorphization(ty);
+                        }
+                    }
+                }
+            }
+
+            sym::nontemporal_store => {
+                let dst = args[0].deref(bx.cx());
+                args[1].val.nontemporal_store(bx, dst);
+                return;
+            }
+
+            sym::ptr_guaranteed_eq | sym::ptr_guaranteed_ne => {
+                let a = args[0].immediate();
+                let b = args[1].immediate();
+                if name == sym::ptr_guaranteed_eq {
+                    bx.icmp(IntPredicate::IntEQ, a, b)
+                } else {
+                    bx.icmp(IntPredicate::IntNE, a, b)
+                }
+            }
+
+            sym::ptr_offset_from => {
+                let ty = substs.type_at(0);
+                let pointee_size = bx.layout_of(ty).size;
+
+                // This is the same sequence that Clang emits for pointer subtraction.
+                // It can be neither `nsw` nor `nuw` because the input is treated as
+                // unsigned but then the output is treated as signed, so neither works.
+                let a = args[0].immediate();
+                let b = args[1].immediate();
+                let a = bx.ptrtoint(a, bx.type_isize());
+                let b = bx.ptrtoint(b, bx.type_isize());
+                let d = bx.sub(a, b);
+                let pointee_size = bx.const_usize(pointee_size.bytes());
+                // this is where the signed magic happens (notice the `s` in `exactsdiv`)
+                bx.exactsdiv(d, pointee_size)
+            }
+
+            _ => {
+                // Need to use backend-specific things in the implementation.
+                bx.codegen_intrinsic_call(instance, fn_abi, args, llresult, span);
+                return;
+            }
+        };
+
+        if !fn_abi.ret.is_ignore() {
+            if let PassMode::Cast(ty) = fn_abi.ret.mode {
+                let ptr_llty = bx.type_ptr_to(bx.cast_backend_type(&ty));
+                let ptr = bx.pointercast(result.llval, ptr_llty);
+                bx.store(llval, ptr, result.align);
+            } else {
+                OperandRef::from_immediate_or_packed_pair(bx, llval, result.layout)
+                    .val
+                    .store(bx, result);
+            }
+        }
+    }
+}
+
+// Returns the width of an int Ty, and if it's signed or not
+// Returns None if the type is not an integer
+// FIXME: there’s multiple of this functions, investigate using some of the already existing
+// stuffs.
+fn int_type_width_signed(ty: Ty<'_>, tcx: TyCtxt<'_>) -> Option<(u64, bool)> {
+    match ty.kind() {
+        ty::Int(t) => Some((t.bit_width().unwrap_or(u64::from(tcx.sess.target.ptr_width)), true)),
+        ty::Uint(t) => Some((t.bit_width().unwrap_or(u64::from(tcx.sess.target.ptr_width)), false)),
+        _ => None,
+    }
+}
+
+// Returns the width of a float Ty
+// Returns None if the type is not a float
+fn float_type_width(ty: Ty<'_>) -> Option<u64> {
+    match ty.kind() {
+        ty::Float(t) => Some(t.bit_width()),
+        _ => None,
+    }
+}
diff --git a/compiler/rustc_codegen_ssa/src/mir/mod.rs b/compiler/rustc_codegen_ssa/src/mir/mod.rs
index c1e7cfd80ef..64d456fb7aa 100644
--- a/compiler/rustc_codegen_ssa/src/mir/mod.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/mod.rs
@@ -486,6 +486,7 @@ mod block;
 pub mod constant;
 pub mod coverageinfo;
 pub mod debuginfo;
+mod intrinsic;
 pub mod operand;
 pub mod place;
 mod rvalue;