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do not try to analyze bitcasts from i64 to <2 x i32> in ComputedMaskedBits. While 

we could do this, doing so requires adjusting the demanded mask and the code isn't 
doing that yet.  This fixes PR4495

llvm-svn: 74699
This commit is contained in:
Chris Lattner 2009-07-02 16:04:08 +00:00
parent f3f6aaa2c3
commit edb8407f0c
2 changed files with 19 additions and 1 deletions
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5
llvm/lib/Analysis/ValueTracking.cpp
View File

@ -249,7 +249,10 @@ void llvm::ComputeMaskedBits(Value *V, const APInt &Mask,
}
case Instruction::BitCast: {
const Type *SrcTy = I->getOperand(0)->getType();
if (SrcTy->isInteger() || isa<PointerType>(SrcTy)) {
if ((SrcTy->isInteger() || isa<PointerType>(SrcTy)) &&
// TODO: For now, not handling conversions like:
// (bitcast i64 %x to <2 x i32>)
!isa<VectorType>(I->getType())) {
ComputeMaskedBits(I->getOperand(0), Mask, KnownZero, KnownOne, TD,
Depth+1);
return;

15
llvm/test/Transforms/InstCombine/2009-07-02-MaskedIntVector.ll Normal file
View File

@ -0,0 +1,15 @@
; RUN: llvm-as < %s | opt -instcombine | llvm-dis
; PR4495
define i32 @test(i64 %test) {
entry:
%0 = bitcast <4 x i32> undef to <16 x i8> ; <<16 x i8>> [#uses=1]
%t12 = shufflevector <16 x i8> %0, <16 x i8> zeroinitializer, <16 x i32> <i32 0, i32 16, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0> ; <<16 x i8>> [#uses=1]
%t11 = bitcast <16 x i8> %t12 to <2 x i64> ; <<2 x i64>> [#uses=1]
%t9 = extractelement <2 x i64> %t11, i32 0 ; <i64> [#uses=1]
%t10 = bitcast i64 %t9 to <2 x i32> ; <<2 x i32>> [#uses=1]
%t7 = bitcast i64 %test to <2 x i32> ; <<2 x i32>> [#uses=1]
%t6 = xor <2 x i32> %t10, %t7 ; <<2 x i32>> [#uses=1]
%t1 = extractelement <2 x i32> %t6, i32 0 ; <i32> [#uses=1]
ret i32 %t1
}