Fix a bug where scalarrepl would discard offset if type would match.

In practice this can only happen on code with already undefined behavior, 
but this is still a good thing to handle correctly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46539 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2008-01-30 00:39:15 +00:00
parent b625f2f896
commit b10e0da065
2 changed files with 23 additions and 2 deletions

View File

@ -1078,7 +1078,7 @@ void SROA::ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, unsigned Offset) {
if (LoadInst *LI = dyn_cast<LoadInst>(User)) {
// The load is a bit extract from NewAI shifted right by Offset bits.
Value *NV = new LoadInst(NewAI, LI->getName(), LI);
if (NV->getType() == LI->getType()) {
if (NV->getType() == LI->getType() && Offset == 0) {
// We win, no conversion needed.
} else if (const VectorType *PTy = dyn_cast<VectorType>(NV->getType())) {
// If the result alloca is a vector type, this is either an element
@ -1232,7 +1232,7 @@ void SROA::ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, unsigned Offset) {
SI->eraseFromParent();
} else if (BitCastInst *CI = dyn_cast<BitCastInst>(User)) {
ConvertUsesToScalar(CI, NewAI, Offset);
ConvertUsesToScalar(CI, NewAI, Offset);
CI->eraseFromParent();
} else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(User)) {
const PointerType *AggPtrTy =

View File

@ -0,0 +1,21 @@
; RUN: llvm-as < %s | opt -scalarrepl -instcombine | llvm-dis | grep {ret i8 17}
; rdar://5707076
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
target triple = "i386-apple-darwin9.1.0"
%struct.T = type <{ i8, [3 x i8] }>
define i8 @f() {
entry:
%s = alloca [1 x %struct.T], align 4 ; <[1 x %struct.T]*> [#uses=2]
%T3 = bitcast [1 x %struct.T]* %s to i32*
store i32 -61184, i32* %T3
%tmp16 = getelementptr [1 x %struct.T]* %s, i32 0, i32 0 ; <%struct.T*> [#uses=1]
%tmp17 = getelementptr %struct.T* %tmp16, i32 0, i32 1 ; <[3 x i8]*> [#uses=1]
%tmp1718 = bitcast [3 x i8]* %tmp17 to i32* ; <i32*> [#uses=1]
%tmp19 = load i32* %tmp1718, align 4 ; <i32> [#uses=1]
%mask = and i32 %tmp19, 16777215 ; <i32> [#uses=2]
%mask2324 = trunc i32 %mask to i8 ; <i8> [#uses=1]
ret i8 %mask2324
}