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Generalize many transforms to work on ~ of vectors in addition to ~ of

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integer ops.  This implements Transforms/InstCombine/and-or-not.ll
test3/test4, and finishes off PR1510


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37589 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2007-06-15 06:23:19 +00:00
parent 3dcf510ba1
commit 7cbe2ebb21
1 changed files with 31 additions and 29 deletions
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60
lib/Transforms/Scalar/InstructionCombining.cpp
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@ -2050,9 +2050,8 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) {
return BinaryOperator::createMul(LHS, AddOne(C2));
// X + ~X --> -1 since ~X = -X-1
if (dyn_castNotVal(LHS) == RHS ||
dyn_castNotVal(RHS) == LHS)
return ReplaceInstUsesWith(I, ConstantInt::getAllOnesValue(I.getType()));
if (dyn_castNotVal(LHS) == RHS || dyn_castNotVal(RHS) == LHS)
return ReplaceInstUsesWith(I, Constant::getAllOnesValue(I.getType()));
// (A & C1)+(B & C2) --> (A & C1)|(B & C2) iff C1&C2 == 0
@ -3717,7 +3716,7 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
if (isa<UndefValue>(Op1)) // X | undef -> -1
return ReplaceInstUsesWith(I, ConstantInt::getAllOnesValue(I.getType()));
return ReplaceInstUsesWith(I, Constant::getAllOnesValue(I.getType()));
// or X, X = X
if (Op0 == Op1)
@ -3912,16 +3911,14 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
if (match(Op0, m_Not(m_Value(A)))) { // ~A | Op1
if (A == Op1) // ~A | A == -1
return ReplaceInstUsesWith(I,
ConstantInt::getAllOnesValue(I.getType()));
return ReplaceInstUsesWith(I, Constant::getAllOnesValue(I.getType()));
} else {
A = 0;
}
// Note, A is still live here!
if (match(Op1, m_Not(m_Value(B)))) { // Op0 | ~B
if (Op0 == B)
return ReplaceInstUsesWith(I,
ConstantInt::getAllOnesValue(I.getType()));
return ReplaceInstUsesWith(I, Constant::getAllOnesValue(I.getType()));
// (~A | ~B) == (~(A & B)) - De Morgan's Law
if (A && isOnlyUse(Op0) && isOnlyUse(Op1)) {
@ -4135,6 +4132,29 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) {
return ReplaceInstUsesWith(I, Op0); // X ^ <0,0> -> X
}
// Is this a ~ operation?
if (Value *NotOp = dyn_castNotVal(&I)) {
// ~(~X & Y) --> (X | ~Y) - De Morgan's Law
// ~(~X | Y) === (X & ~Y) - De Morgan's Law
if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(NotOp)) {
if (Op0I->getOpcode() == Instruction::And ||
Op0I->getOpcode() == Instruction::Or) {
if (dyn_castNotVal(Op0I->getOperand(1))) Op0I->swapOperands();
if (Value *Op0NotVal = dyn_castNotVal(Op0I->getOperand(0))) {
Instruction *NotY =
BinaryOperator::createNot(Op0I->getOperand(1),
Op0I->getOperand(1)->getName()+".not");
InsertNewInstBefore(NotY, I);
if (Op0I->getOpcode() == Instruction::And)
return BinaryOperator::createOr(Op0NotVal, NotY);
else
return BinaryOperator::createAnd(Op0NotVal, NotY);
}
}
}
}
if (ConstantInt *RHS = dyn_cast<ConstantInt>(Op1)) {
// xor (icmp A, B), true = not (icmp A, B) = !icmp A, B
if (ICmpInst *ICI = dyn_cast<ICmpInst>(Op0))
@ -4151,23 +4171,6 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) {
ConstantInt::get(I.getType(), 1));
return BinaryOperator::createAdd(Op0I->getOperand(1), ConstantRHS);
}
// ~(~X & Y) --> (X | ~Y) - De Morgan's Law
// ~(~X | Y) === (X & ~Y) - De Morgan's Law
if ((Op0I->getOpcode() == Instruction::And ||
Op0I->getOpcode() == Instruction::Or) && RHS->isAllOnesValue()) {
if (dyn_castNotVal(Op0I->getOperand(1))) Op0I->swapOperands();
if (Value *Op0NotVal = dyn_castNotVal(Op0I->getOperand(0))) {
Instruction *NotY =
BinaryOperator::createNot(Op0I->getOperand(1),
Op0I->getOperand(1)->getName()+".not");
InsertNewInstBefore(NotY, I);
if (Op0I->getOpcode() == Instruction::And)
return BinaryOperator::createOr(Op0NotVal, NotY);
else
return BinaryOperator::createAnd(Op0NotVal, NotY);
}
}
if (ConstantInt *Op0CI = dyn_cast<ConstantInt>(Op0I->getOperand(1)))
if (Op0I->getOpcode() == Instruction::Add) {
@ -4212,12 +4215,11 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) {
if (Value *X = dyn_castNotVal(Op0)) // ~A ^ A == -1
if (X == Op1)
return ReplaceInstUsesWith(I,
ConstantInt::getAllOnesValue(I.getType()));
return ReplaceInstUsesWith(I, Constant::getAllOnesValue(I.getType()));
if (Value *X = dyn_castNotVal(Op1)) // A ^ ~A == -1
if (X == Op0)
return ReplaceInstUsesWith(I, ConstantInt::getAllOnesValue(I.getType()));
return ReplaceInstUsesWith(I, Constant::getAllOnesValue(I.getType()));
BinaryOperator *Op1I = dyn_cast<BinaryOperator>(Op1);
@ -7092,7 +7094,7 @@ static Constant *GetSelectFoldableConstant(Instruction *I) {
case Instruction::AShr:
return Constant::getNullValue(I->getType());
case Instruction::And:
return ConstantInt::getAllOnesValue(I->getType());
return Constant::getAllOnesValue(I->getType());
case Instruction::Mul:
return ConstantInt::get(I->getType(), 1);
}