6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-01-27 14:34:58 +00:00
Code Issues Projects Releases Wiki Activity

Implement InstCombine/add.ll:test28, transforming C1-(X+C2) --> (C1-C2)-X.

Browse Source 
This occurs several dozen times in specint2k, particularly in crafty and gcc
apparently.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21136 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2005-04-07 16:28:01 +00:00
parent 3d173b3638
commit 08954a26e4
1 changed files with 8 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
lib/Transforms/Scalar/InstructionCombining.cpp
View File

@ -795,10 +795,16 @@ Instruction *InstCombiner::visitSub(BinaryOperator &I) {
if (BinaryOperator *Op1I = dyn_cast<BinaryOperator>(Op1)) { if (BinaryOperator *Op1I = dyn_cast<BinaryOperator>(Op1)) {
if (Op1I->getOpcode() == Instruction::Add && if (Op1I->getOpcode() == Instruction::Add &&
!Op0->getType()->isFloatingPoint()) { !Op0->getType()->isFloatingPoint()) {
if (Op1I->getOperand(0) == Op0) // X-(X+Y) == -Y if (Op1I->getOperand(0) == Op0) // X-(X+Y) == -Y
return BinaryOperator::createNeg(Op1I->getOperand(1), I.getName()); return BinaryOperator::createNeg(Op1I->getOperand(1), I.getName());
else if (Op1I->getOperand(1) == Op0) // X-(Y+X) == -Y else if (Op1I->getOperand(1) == Op0) // X-(Y+X) == -Y
return BinaryOperator::createNeg(Op1I->getOperand(0), I.getName()); return BinaryOperator::createNeg(Op1I->getOperand(0), I.getName());
else if (ConstantInt *CI1 = dyn_cast<ConstantInt>(I.getOperand(0))) {
if (ConstantInt *CI2 = dyn_cast<ConstantInt>(Op1I->getOperand(1)))
// C1-(X+C2) --> (C1-C2)-X
return BinaryOperator::createSub(ConstantExpr::getSub(CI1, CI2),
Op1I->getOperand(0));
}
} }
if (Op1I->hasOneUse()) { if (Op1I->hasOneUse()) {