Commit b3c29bd1 authored by Hans Wennborg's avatar Hans Wennborg
Browse files

Back-port r276209: 

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r276209 | spatel | 2016-07-20 16:40:01 -0700 (Wed, 20 Jul 2016) | 4 lines

[InstSimplify][InstCombine] don't crash when folding vector selects of icmp

Differential Revision: https://reviews.llvm.org/D22602

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llvm-svn: 276986
parent c6d28602

llvm/lib/Analysis/InstructionSimplify.cpp

+4 −1
Original line number Diff line number Diff line
@@ -3400,7 +3400,10 @@ static Value *SimplifySelectInst(Value *CondVal, Value *TrueVal, 
    return TrueVal;



  if (const auto *ICI = dyn_cast<ICmpInst>(CondVal)) {

    unsigned BitWidth = Q.DL.getTypeSizeInBits(TrueVal->getType());

    // FIXME: This code is nearly duplicated in InstCombine. Using/refactoring

    // decomposeBitTestICmp() might help.

    unsigned BitWidth =

        Q.DL.getTypeSizeInBits(TrueVal->getType()->getScalarType());

    ICmpInst::Predicate Pred = ICI->getPredicate();

    Value *CmpLHS = ICI->getOperand(0);

    Value *CmpRHS = ICI->getOperand(1);

llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp

+4 −1
Original line number Diff line number Diff line
@@ -553,8 +553,11 @@ Instruction *InstCombiner::visitSelectInstWithICmp(SelectInst &SI, 
    }

  }



  // FIXME: This code is nearly duplicated in InstSimplify. Using/refactoring

  // decomposeBitTestICmp() might help.

  {

    unsigned BitWidth = DL.getTypeSizeInBits(TrueVal->getType());

    unsigned BitWidth =

        DL.getTypeSizeInBits(TrueVal->getType()->getScalarType());

    APInt MinSignedValue = APInt::getSignBit(BitWidth);

    Value *X;

    const APInt *Y, *C;

llvm/test/Transforms/InstCombine/select.ll

+23 −0
Original line number Diff line number Diff line
@@ -1737,3 +1737,26 @@ define i32 @PR27137(i32 %a) { 
  %s1 = select i1 %c1, i32 %s0, i32 -1

  ret i32 %s1

}



define i32 @select_icmp_slt0_xor(i32 %x) {

; CHECK-LABEL: @select_icmp_slt0_xor(

; CHECK-NEXT:    [[TMP1:%.*]] = or i32 %x, -2147483648

; CHECK-NEXT:    ret i32 [[TMP1]]

;

  %cmp = icmp slt i32 %x, zeroinitializer

  %xor = xor i32 %x, 2147483648

  %x.xor = select i1 %cmp, i32 %x, i32 %xor

  ret i32 %x.xor

}



define <2 x i32> @select_icmp_slt0_xor_vec(<2 x i32> %x) {

; CHECK-LABEL: @select_icmp_slt0_xor_vec(

; CHECK-NEXT:    [[TMP1:%.*]] = or <2 x i32> %x, <i32 -2147483648, i32 -2147483648>

; CHECK-NEXT:    ret <2 x i32> [[TMP1]]

;

  %cmp = icmp slt <2 x i32> %x, zeroinitializer

  %xor = xor <2 x i32> %x, <i32 2147483648, i32 2147483648>

  %x.xor = select <2 x i1> %cmp, <2 x i32> %x, <2 x i32> %xor

  ret <2 x i32> %x.xor

}