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[InstCombine] Create new insts in foldICmpEqIntrinsicWithConstant; NFCI 

In line with current conventions, create new instructions rather
than modify two operands in place and performing manual worklist
management.

This should be NFC apart from possible worklist order changes.
This commit is contained in:
Nikita Popov 2020-01-30 22:54:35 +01:00
parent 01943a59f5
commit cad91074a6
1 changed files with 15 additions and 27 deletions
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42
llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
View File

@ -3025,20 +3025,16 @@ Instruction *InstCombiner::foldICmpEqIntrinsicWithConstant(ICmpInst &Cmp,
unsigned BitWidth = C.getBitWidth();
switch (II->getIntrinsicID()) {
case Intrinsic::bswap:
Worklist.Add(II);
Cmp.setOperand(0, II->getArgOperand(0));
Cmp.setOperand(1, ConstantInt::get(Ty, C.byteSwap()));
return &Cmp;
// bswap(A) == C -> A == bswap(C)
return new ICmpInst(Cmp.getPredicate(), II->getArgOperand(0),
ConstantInt::get(Ty, C.byteSwap()));
case Intrinsic::ctlz:
case Intrinsic::cttz: {
// ctz(A) == bitwidth(A) -> A == 0 and likewise for !=
if (C == BitWidth) {
Worklist.Add(II);
Cmp.setOperand(0, II->getArgOperand(0));
Cmp.setOperand(1, ConstantInt::getNullValue(Ty));
return &Cmp;
}
if (C == BitWidth)
return new ICmpInst(Cmp.getPredicate(), II->getArgOperand(0),
ConstantInt::getNullValue(Ty));
// ctz(A) == C -> A & Mask1 == Mask2, where Mask2 only has bit C set
// and Mask1 has bits 0..C+1 set. Similar for ctl, but for high bits.
@ -3051,10 +3047,9 @@ Instruction *InstCombiner::foldICmpEqIntrinsicWithConstant(ICmpInst &Cmp,
APInt Mask2 = IsTrailing
? APInt::getOneBitSet(BitWidth, Num)
: APInt::getOneBitSet(BitWidth, BitWidth - Num - 1);
Cmp.setOperand(0, Builder.CreateAnd(II->getArgOperand(0), Mask1));
Cmp.setOperand(1, ConstantInt::get(Ty, Mask2));
Worklist.Add(II);
return &Cmp;
return new ICmpInst(Cmp.getPredicate(),
Builder.CreateAnd(II->getArgOperand(0), Mask1),
ConstantInt::get(Ty, Mask2));
}
break;
}
@ -3063,14 +3058,10 @@ Instruction *InstCombiner::foldICmpEqIntrinsicWithConstant(ICmpInst &Cmp,
// popcount(A) == 0 -> A == 0 and likewise for !=
// popcount(A) == bitwidth(A) -> A == -1 and likewise for !=
bool IsZero = C.isNullValue();
if (IsZero || C == BitWidth) {
Worklist.Add(II);
Cmp.setOperand(0, II->getArgOperand(0));
auto *NewOp =
IsZero ? Constant::getNullValue(Ty) : Constant::getAllOnesValue(Ty);
Cmp.setOperand(1, NewOp);
return &Cmp;
}
if (IsZero || C == BitWidth)
return new ICmpInst(Cmp.getPredicate(), II->getArgOperand(0),
IsZero ? Constant::getNullValue(Ty) : Constant::getAllOnesValue(Ty));
break;
}
@ -3078,9 +3069,7 @@ Instruction *InstCombiner::foldICmpEqIntrinsicWithConstant(ICmpInst &Cmp,
// uadd.sat(a, b) == 0 -> (a | b) == 0
if (C.isNullValue()) {
Value *Or = Builder.CreateOr(II->getArgOperand(0), II->getArgOperand(1));
return replaceInstUsesWith(Cmp, Builder.CreateICmp(
Cmp.getPredicate(), Or, Constant::getNullValue(Ty)));
return new ICmpInst(Cmp.getPredicate(), Or, Constant::getNullValue(Ty));
}
break;
}
@ -3090,8 +3079,7 @@ Instruction *InstCombiner::foldICmpEqIntrinsicWithConstant(ICmpInst &Cmp,
if (C.isNullValue()) {
ICmpInst::Predicate NewPred = Cmp.getPredicate() == ICmpInst::ICMP_EQ
? ICmpInst::ICMP_ULE : ICmpInst::ICMP_UGT;
return ICmpInst::Create(Instruction::ICmp, NewPred,
II->getArgOperand(0), II->getArgOperand(1));
return new ICmpInst(NewPred, II->getArgOperand(0), II->getArgOperand(1));
}
break;
}