Commit bcbf19f9 authored by Hans Wennborg's avatar Hans Wennborg
Browse files

Merging r245365 and r245369: 

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r245365 | majnemer | 2015-08-18 15:07:25 -0700 (Tue, 18 Aug 2015) | 4 lines

[InstSimplify] Don't assume getAggregateElement will succeed

It isn't always possible to get a value from getAggregateElement.
This fixes PR24488.
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r245369 | majnemer | 2015-08-18 15:18:22 -0700 (Tue, 18 Aug 2015) | 3 lines

[InstSimplify] Remove unused variable

No functionality change is intended.
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llvm-svn: 245572
parent 69272ee8

llvm/lib/Analysis/InstructionSimplify.cpp

+2 −11
Original line number Diff line number Diff line
@@ -3574,18 +3574,9 @@ static Value *SimplifyExtractElementInst(Value *Vec, Value *Idx, const Query &, 


  // If extracting a specified index from the vector, see if we can recursively

  // find a previously computed scalar that was inserted into the vector.

  if (auto *IdxC = dyn_cast<ConstantInt>(Idx)) {

    unsigned IndexVal = IdxC->getZExtValue();

    unsigned VectorWidth = Vec->getType()->getVectorNumElements();



    // If this is extracting an invalid index, turn this into undef, to avoid

    // crashing the code below.

    if (IndexVal >= VectorWidth)

      return UndefValue::get(Vec->getType()->getVectorElementType());



    if (Value *Elt = findScalarElement(Vec, IndexVal))

  if (auto *IdxC = dyn_cast<ConstantInt>(Idx))

    if (Value *Elt = findScalarElement(Vec, IdxC->getZExtValue()))

      return Elt;

  }



  return nullptr;

}

llvm/lib/Analysis/VectorUtils.cpp

+3 −2
Original line number Diff line number Diff line
@@ -402,7 +402,8 @@ llvm::Value *llvm::findScalarElement(llvm::Value *V, unsigned EltNo) { 
  if (match(V,

            llvm::PatternMatch::m_Add(llvm::PatternMatch::m_Value(Val),

                                      llvm::PatternMatch::m_Constant(Con)))) {

    if (Con->getAggregateElement(EltNo)->isNullValue())

    if (Constant *Elt = Con->getAggregateElement(EltNo))

      if (Elt->isNullValue())

        return findScalarElement(Val, EltNo);

  }

llvm/test/Transforms/InstSimplify/2011-09-05-InsertExtractValue.ll

+10 −0
Original line number Diff line number Diff line
@@ -36,3 +36,13 @@ define i32 @test3(i32 %a, float %b) { 
; CHECK-LABEL: @test3(

; CHECK: ret i32 %a

}



define i8 @test4(<8 x i8> %V) {

  %add     = add <8 x i8> %V, bitcast (double 0x319BEB8FD172E36 to <8 x i8>)

  %extract = extractelement <8 x i8> %add, i32 6

  ret i8 %extract

; CHECK-LABEL: @test4(

; CHECK: %[[add:.*]] = add <8 x i8> %V, bitcast (<1 x double> <double 0x319BEB8FD172E36> to <8 x i8>)

; CHECK-NEXT: %[[extract:.*]] = extractelement <8 x i8> %[[add]], i32 6

; CHECK-NEXT: ret i8 %[[extract]]

}