[llvm-commits] CVS: llvm/lib/Transforms/Scalar/InstructionCombining.cpp
Chris Lattner
lattner at cs.uiuc.edu
Sun Jan 23 12:27:11 PST 2005
Changes in directory llvm/lib/Transforms/Scalar:
InstructionCombining.cpp updated: 1.309 -> 1.310
---
Log message:
Get rid of a several dozen more and instructions in specint.
---
Diffs of the changes: (+36 -5)
InstructionCombining.cpp | 41 ++++++++++++++++++++++++++++++++++++-----
1 files changed, 36 insertions(+), 5 deletions(-)
Index: llvm/lib/Transforms/Scalar/InstructionCombining.cpp
diff -u llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.309 llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.310
--- llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.309 Fri Jan 21 17:06:49 2005
+++ llvm/lib/Transforms/Scalar/InstructionCombining.cpp Sun Jan 23 14:26:55 2005
@@ -1298,6 +1298,14 @@
if (ConstantExpr::getAnd(CI, Mask)->isNullValue())
return true;
break;
+ case Instruction::Or:
+ // If the LHS and the RHS are MaskedValueIsZero, the result is also zero.
+ return MaskedValueIsZero(I->getOperand(1), Mask) &&
+ MaskedValueIsZero(I->getOperand(0), Mask);
+ case Instruction::Select:
+ // If the T and F values are MaskedValueIsZero, the result is also zero.
+ return MaskedValueIsZero(I->getOperand(2), Mask) &&
+ MaskedValueIsZero(I->getOperand(1), Mask);
case Instruction::Cast: {
const Type *SrcTy = I->getOperand(0)->getType();
if (SrcTy->isIntegral()) {
@@ -1535,9 +1543,9 @@
if (Op0 == Op1)
return ReplaceInstUsesWith(I, Op1);
- // and X, -1 == X
if (ConstantIntegral *AndRHS = dyn_cast<ConstantIntegral>(Op1)) {
- if (AndRHS->isAllOnesValue()) // and X, -1 == X
+ // and X, -1 == X
+ if (AndRHS->isAllOnesValue())
return ReplaceInstUsesWith(I, Op0);
if (MaskedValueIsZero(Op0, AndRHS)) // LHS & RHS == 0
@@ -1545,9 +1553,10 @@
// If the mask is not masking out any bits, there is no reason to do the
// and in the first place.
- if (MaskedValueIsZero(Op0,
- cast<ConstantIntegral>(ConstantExpr::getNot(AndRHS))))
- return ReplaceInstUsesWith(I, Op0);
+ ConstantIntegral *NotAndRHS =
+ cast<ConstantIntegral>(ConstantExpr::getNot(AndRHS));
+ if (MaskedValueIsZero(Op0, NotAndRHS))
+ return ReplaceInstUsesWith(I, Op0);
// Optimize a variety of ((val OP C1) & C2) combinations...
if (isa<BinaryOperator>(Op0) || isa<ShiftInst>(Op0)) {
@@ -1563,6 +1572,28 @@
return BinaryOperator::createAnd(Op0RHS, AndRHS);
if (MaskedValueIsZero(Op0RHS, AndRHS))
return BinaryOperator::createAnd(Op0LHS, AndRHS);
+
+ // If the mask is only needed on one incoming arm, push it up.
+ if (Op0I->hasOneUse()) {
+ if (MaskedValueIsZero(Op0LHS, NotAndRHS)) {
+ // Not masking anything out for the LHS, move to RHS.
+ Instruction *NewRHS = BinaryOperator::createAnd(Op0RHS, AndRHS,
+ Op0RHS->getName()+".masked");
+ InsertNewInstBefore(NewRHS, I);
+ return BinaryOperator::create(
+ cast<BinaryOperator>(Op0I)->getOpcode(), Op0LHS, NewRHS);
+ }
+ if (!isa<Constant>(NotAndRHS) &&
+ MaskedValueIsZero(Op0RHS, NotAndRHS)) {
+ // Not masking anything out for the RHS, move to LHS.
+ Instruction *NewLHS = BinaryOperator::createAnd(Op0LHS, AndRHS,
+ Op0LHS->getName()+".masked");
+ InsertNewInstBefore(NewLHS, I);
+ return BinaryOperator::create(
+ cast<BinaryOperator>(Op0I)->getOpcode(), NewLHS, Op0RHS);
+ }
+ }
+
break;
case Instruction::And:
// (X & V) & C2 --> 0 iff (V & C2) == 0
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