InstCombine should not fold sext/zext of a vector and a bitcast to a scalar to a sext/zext

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94280 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Mon P Wang 2010-01-23 04:35:57 +00:00
parent b2dc8f3b00
commit e4a0a151a5
2 changed files with 14 additions and 2 deletions

View File

@ -2079,8 +2079,9 @@ unsigned CastInst::isEliminableCastPair(
return secondOp;
case 3:
// no-op cast in second op implies firstOp as long as the DestTy
// is integer
if (DstTy->isInteger())
// is integer and we are not converting between a vector and a
// non vector type
if (SrcTy->getTypeID() != Type::VectorTyID && DstTy->isInteger())
return firstOp;
return 0;
case 4:

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@ -0,0 +1,11 @@
; RUN: opt < %s -instcombine -S | FileCheck %s
; CHECK: sext
; Don't fold zero/sign extensions with a bitcast between a vector and scalar.
define i32 @t(<4 x i8> %src1, <4 x i8> %src2) nounwind readonly {
entry:
%cmp = icmp eq <4 x i8> %src1, %src2; <<4 x i1>> [#uses=1]
%sext = sext <4 x i1> %cmp to <4 x i8>
%val = bitcast <4 x i8> %sext to i32
ret i32 %val
}