[llvm] r301088 - [InstCombine] use 'match' to reduce code; NFCI
Sanjay Patel via llvm-commits
llvm-commits at lists.llvm.org
Sat Apr 22 11:05:35 PDT 2017
Author: spatel
Date: Sat Apr 22 13:05:35 2017
New Revision: 301088
URL: http://llvm.org/viewvc/llvm-project?rev=301088&view=rev
Log:
[InstCombine] use 'match' to reduce code; NFCI
The later uses of dyn_castNotVal in this block are either
incomplete (doesn't handle vector constants) or overstepping
(shouldn't handle constants at all), but this first use is
just unnecessary. 'I' is obviously not a constant, and it
can't be a not-of-a-not because that would already be
instsimplified.
Modified:
llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp?rev=301088&r1=301087&r2=301088&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp Sat Apr 22 13:05:35 2017
@@ -2399,44 +2399,39 @@ Instruction *InstCombiner::visitXor(Bina
if (Value *V = SimplifyBSwap(I))
return replaceInstUsesWith(I, V);
- // Is this a ~ operation?
- if (Value *NotOp = dyn_castNotVal(&I)) {
- if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(NotOp)) {
- if (Op0I->getOpcode() == Instruction::And ||
- Op0I->getOpcode() == Instruction::Or) {
- // ~(~X & Y) --> (X | ~Y) - De Morgan's Law
- // ~(~X | Y) === (X & ~Y) - De Morgan's Law
- if (dyn_castNotVal(Op0I->getOperand(1)))
- Op0I->swapOperands();
- if (Value *Op0NotVal = dyn_castNotVal(Op0I->getOperand(0))) {
- Value *NotY =
- Builder->CreateNot(Op0I->getOperand(1),
- Op0I->getOperand(1)->getName()+".not");
- if (Op0I->getOpcode() == Instruction::And)
- return BinaryOperator::CreateOr(Op0NotVal, NotY);
- return BinaryOperator::CreateAnd(Op0NotVal, NotY);
- }
-
- // ~(X & Y) --> (~X | ~Y) - De Morgan's Law
- // ~(X | Y) === (~X & ~Y) - De Morgan's Law
- if (IsFreeToInvert(Op0I->getOperand(0),
- Op0I->getOperand(0)->hasOneUse()) &&
- IsFreeToInvert(Op0I->getOperand(1),
- Op0I->getOperand(1)->hasOneUse())) {
- Value *NotX =
- Builder->CreateNot(Op0I->getOperand(0), "notlhs");
- Value *NotY =
- Builder->CreateNot(Op0I->getOperand(1), "notrhs");
- if (Op0I->getOpcode() == Instruction::And)
- return BinaryOperator::CreateOr(NotX, NotY);
- return BinaryOperator::CreateAnd(NotX, NotY);
- }
+ // Is this a 'not' (~) fed by a binary operator?
+ BinaryOperator *NotOp;
+ if (match(&I, m_Not(m_BinOp(NotOp)))) {
+ if (NotOp->getOpcode() == Instruction::And ||
+ NotOp->getOpcode() == Instruction::Or) {
+ // ~(~X & Y) --> (X | ~Y) - De Morgan's Law
+ // ~(~X | Y) === (X & ~Y) - De Morgan's Law
+ if (dyn_castNotVal(NotOp->getOperand(1)))
+ NotOp->swapOperands();
+ if (Value *Op0NotVal = dyn_castNotVal(NotOp->getOperand(0))) {
+ Value *NotY = Builder->CreateNot(
+ NotOp->getOperand(1), NotOp->getOperand(1)->getName() + ".not");
+ if (NotOp->getOpcode() == Instruction::And)
+ return BinaryOperator::CreateOr(Op0NotVal, NotY);
+ return BinaryOperator::CreateAnd(Op0NotVal, NotY);
+ }
- } else if (Op0I->getOpcode() == Instruction::AShr) {
- // ~(~X >>s Y) --> (X >>s Y)
- if (Value *Op0NotVal = dyn_castNotVal(Op0I->getOperand(0)))
- return BinaryOperator::CreateAShr(Op0NotVal, Op0I->getOperand(1));
+ // ~(X & Y) --> (~X | ~Y) - De Morgan's Law
+ // ~(X | Y) === (~X & ~Y) - De Morgan's Law
+ if (IsFreeToInvert(NotOp->getOperand(0),
+ NotOp->getOperand(0)->hasOneUse()) &&
+ IsFreeToInvert(NotOp->getOperand(1),
+ NotOp->getOperand(1)->hasOneUse())) {
+ Value *NotX = Builder->CreateNot(NotOp->getOperand(0), "notlhs");
+ Value *NotY = Builder->CreateNot(NotOp->getOperand(1), "notrhs");
+ if (NotOp->getOpcode() == Instruction::And)
+ return BinaryOperator::CreateOr(NotX, NotY);
+ return BinaryOperator::CreateAnd(NotX, NotY);
}
+ } else if (NotOp->getOpcode() == Instruction::AShr) {
+ // ~(~X >>s Y) --> (X >>s Y)
+ if (Value *Op0NotVal = dyn_castNotVal(NotOp->getOperand(0)))
+ return BinaryOperator::CreateAShr(Op0NotVal, NotOp->getOperand(1));
}
}
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