Preserve AA metadata when combining (cast (load (...))) -> (load (cast

(...))).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220141 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chandler Carruth 2014-10-18 11:00:12 +00:00
parent 9b2d091a9c
commit 797e9b812e
2 changed files with 28 additions and 0 deletions

View File

@ -319,6 +319,8 @@ static Instruction *combineLoadToOperationType(InstCombiner &IC, LoadInst &LI) {
Value *Ptr = LI.getPointerOperand();
unsigned AS = LI.getPointerAddressSpace();
AAMDNodes AAInfo;
LI.getAAMetadata(AAInfo);
// Fold away bit casts of the loaded value by loading the desired type.
if (LI.hasOneUse())
@ -326,6 +328,7 @@ static Instruction *combineLoadToOperationType(InstCombiner &IC, LoadInst &LI) {
LoadInst *NewLoad = IC.Builder->CreateAlignedLoad(
IC.Builder->CreateBitCast(Ptr, BC->getDestTy()->getPointerTo(AS)),
LI.getAlignment(), LI.getName());
NewLoad->setAAMetadata(AAInfo);
BC->replaceAllUsesWith(NewLoad);
IC.EraseInstFromFunction(*BC);
return &LI;

View File

@ -0,0 +1,25 @@
; RUN: opt -instcombine -S < %s | FileCheck %s
define i32 @test_load_cast_combine_tbaa(float* %ptr) {
; Ensure (cast (load (...))) -> (load (cast (...))) preserves TBAA.
; CHECK-LABEL: @test_load_cast_combine_tbaa(
; CHECK: load i32* %{{.*}}, !tbaa !0
entry:
%l = load float* %ptr, !tbaa !0
%c = bitcast float %l to i32
ret i32 %c
}
define i32 @test_load_cast_combine_noalias(float* %ptr) {
; Ensure (cast (load (...))) -> (load (cast (...))) preserves no-alias metadata.
; CHECK-LABEL: @test_load_cast_combine_noalias(
; CHECK: load i32* %{{.*}}, !alias.scope !2, !noalias !1
entry:
%l = load float* %ptr, !alias.scope !2, !noalias !1
%c = bitcast float %l to i32
ret i32 %c
}
!0 = metadata !{ metadata !1, metadata !1, i64 0 }
!1 = metadata !{ metadata !1 }
!2 = metadata !{ metadata !2, metadata !1 }