Fix a vectorshuffle instcombine bug introduced by r55995.

Patch by Nicolas Capens!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56129 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman 2008-09-11 22:47:57 +00:00
parent 363f53f3ec
commit 3139ff8f7b
3 changed files with 43 additions and 1 deletions

View File

@ -11311,8 +11311,11 @@ Instruction *InstCombiner::visitShuffleVectorInst(ShuffleVectorInst &SVI) {
unsigned VWidth = cast<VectorType>(SVI.getType())->getNumElements();
uint64_t AllOnesEltMask = ~0ULL >> (64-VWidth);
if (VWidth <= 64 &&
SimplifyDemandedVectorElts(&SVI, AllOnesEltMask, UndefElts))
SimplifyDemandedVectorElts(&SVI, AllOnesEltMask, UndefElts)) {
LHS = SVI.getOperand(0);
RHS = SVI.getOperand(1);
MadeChange = true;
}
// Canonicalize shuffle(x ,x,mask) -> shuffle(x, undef,mask')
// Canonicalize shuffle(undef,x,mask) -> shuffle(x, undef,mask').

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@ -0,0 +1,39 @@
; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep shufflevector
; PR2645
; instcombine shouldn't delete the shufflevector.
define internal void @""(i8*, i32, i8*) {
; <label>:3
br label %4
; <label>:4 ; preds = %6, %3
%.0 = phi i32 [ 0, %3 ], [ %19, %6 ] ; <i32> [#uses=4]
%5 = icmp slt i32 %.0, %1 ; <i1> [#uses=1]
br i1 %5, label %6, label %20
; <label>:6 ; preds = %4
%7 = getelementptr i8* %2, i32 %.0 ; <i8*> [#uses=1]
%8 = bitcast i8* %7 to <4 x i16>* ; <<4 x i16>*> [#uses=1]
%9 = load <4 x i16>* %8, align 1 ; <<4 x i16>> [#uses=1]
%10 = bitcast <4 x i16> %9 to <1 x i64> ; <<1 x i64>> [#uses=1]
%11 = call <2 x i64> @foo(<1 x i64> %10)
; <<2 x i64>> [#uses=1]
%12 = bitcast <2 x i64> %11 to <4 x i32> ; <<4 x i32>> [#uses=1]
%13 = bitcast <4 x i32> %12 to <8 x i16> ; <<8 x i16>> [#uses=2]
%14 = shufflevector <8 x i16> %13, <8 x i16> %13, <8 x i32> < i32 0, i32 0, i32 1, i32 1, i32 2, i32 2, i32 3, i32 3 > ; <<8 x i16>> [#uses=1]
%15 = bitcast <8 x i16> %14 to <4 x i32> ; <<4 x i32>> [#uses=1]
%16 = sitofp <4 x i32> %15 to <4 x float> ; <<4 x float>> [#uses=1]
%17 = getelementptr i8* %0, i32 %.0 ; <i8*> [#uses=1]
%18 = bitcast i8* %17 to <4 x float>* ; <<4 x float>*> [#uses=1]
store <4 x float> %16, <4 x float>* %18, align 1
%19 = add i32 %.0, 1 ; <i32> [#uses=1]
br label %4
; <label>:20 ; preds = %4
call void @llvm.x86.mmx.emms( )
ret void
}
declare <2 x i64> @foo(<1 x i64>)
declare void @llvm.x86.mmx.emms( )