diff options
author | Sanjay Patel <spatel@rotateright.com> | 2017-04-22 18:05:35 +0000 |
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committer | Sanjay Patel <spatel@rotateright.com> | 2017-04-22 18:05:35 +0000 |
commit | 3b863f8a1ec82f4dd4dfcbc5d24b2da83ff516f3 (patch) | |
tree | a3e9531918f1e579c36a4e0316009cd2016a4bae /llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp | |
parent | fc32c3a2c55f3494bd7b9194634797df72c3e162 (diff) | |
download | bcm5719-llvm-3b863f8a1ec82f4dd4dfcbc5d24b2da83ff516f3.tar.gz bcm5719-llvm-3b863f8a1ec82f4dd4dfcbc5d24b2da83ff516f3.zip |
[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.
llvm-svn: 301088
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp')
-rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp | 67 |
1 files changed, 31 insertions, 36 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp index 3a98e8937bd..f320f125bf6 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -2399,44 +2399,39 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) { 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)); } } |