diff --git a/llvm/lib/VMCore/Instructions.cpp b/llvm/lib/VMCore/Instructions.cpp index 8ff36cb6fbdb..e72e48cb1a3c 100644 --- a/llvm/lib/VMCore/Instructions.cpp +++ b/llvm/lib/VMCore/Instructions.cpp @@ -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: diff --git a/llvm/test/Transforms/InstCombine/bitcast-sext-vector.ll b/llvm/test/Transforms/InstCombine/bitcast-sext-vector.ll new file mode 100644 index 000000000000..d70bdbaf3727 --- /dev/null +++ b/llvm/test/Transforms/InstCombine/bitcast-sext-vector.ll @@ -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 +}