From 6a5ee110276aa0f24e569c15d10172e3fc40752f Mon Sep 17 00:00:00 2001
From: Luqman Aden <me@luqman.ca>
Date: Thu, 15 Dec 2022 23:18:25 -0800
Subject: [PATCH] Don't bitcast aggregate field.
---
compiler/rustc_codegen_ssa/src/mir/operand.rs | 27 ++++++++++++++++++-
1 file changed, 26 insertions(+), 1 deletion(-)
diff --git a/compiler/rustc_codegen_ssa/src/mir/operand.rs b/compiler/rustc_codegen_ssa/src/mir/operand.rs
index 957ec8629fa..7623daeb96f 100644
--- a/compiler/rustc_codegen_ssa/src/mir/operand.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/operand.rs
@@ -237,13 +237,18 @@ impl<'a, 'tcx, V: CodegenObject> OperandRef<'tcx, V> {
};
match (&mut val, field.abi) {
- (OperandValue::Immediate(llval), _) => {
+ (
+ OperandValue::Immediate(llval),
+ Abi::Scalar(_) | Abi::ScalarPair(..) | Abi::Vector { .. },
+ ) => {
// Bools in union fields needs to be truncated.
*llval = bx.to_immediate(*llval, field);
// HACK(eddyb) have to bitcast pointers until LLVM removes pointee types.
let ty = bx.cx().immediate_backend_type(field);
if bx.type_kind(ty) == TypeKind::Pointer {
*llval = bx.pointercast(*llval, ty);
+ } else {
+ *llval = bx.bitcast(*llval, ty);
}
}
(OperandValue::Pair(a, b), Abi::ScalarPair(a_abi, b_abi)) => {
@@ -255,11 +260,31 @@ impl<'a, 'tcx, V: CodegenObject> OperandRef<'tcx, V> {
let b_ty = bx.cx().scalar_pair_element_backend_type(field, 1, true);
if bx.type_kind(a_ty) == TypeKind::Pointer {
*a = bx.pointercast(*a, a_ty);
+ } else {
+ *a = bx.bitcast(*a, a_ty);
}
if bx.type_kind(b_ty) == TypeKind::Pointer {
*b = bx.pointercast(*b, b_ty);
+ } else {
+ *b = bx.bitcast(*b, b_ty);
}
}
+ // Newtype vector of array, e.g. #[repr(simd)] struct S([i32; 4]);
+ (OperandValue::Immediate(llval), Abi::Aggregate { sized: true }) => {
+ assert!(matches!(self.layout.abi, Abi::Vector { .. }));
+
+ let llty = bx.cx().backend_type(self.layout);
+ let llfield_ty = bx.cx().backend_type(field);
+
+ // Can't bitcast an aggregate, so round trip through memory.
+ let lltemp = bx.alloca(llfield_ty, field.align.abi);
+ let llptr = bx.pointercast(lltemp, bx.cx().type_ptr_to(llty));
+ bx.store(*llval, llptr, field.align.abi);
+ *llval = bx.load(llfield_ty, lltemp, field.align.abi);
+ }
+ (OperandValue::Immediate(_), Abi::Uninhabited | Abi::Aggregate { sized: false }) => {
+ bug!()
+ }
(OperandValue::Pair(..), _) => bug!(),
(OperandValue::Ref(..), _) => bug!(),
}