Instruction *InstCombiner::visitBranchInst(BranchInst &BI) {
// Change br (not X), label True, label False to: br X, label False, True
- if (BI.isConditional() && !isa<Constant>(BI.getCondition()))
+ if (BI.isConditional() && !isa<Constant>(BI.getCondition())) {
if (Value *V = dyn_castNotVal(BI.getCondition())) {
BasicBlock *TrueDest = BI.getSuccessor(0);
BasicBlock *FalseDest = BI.getSuccessor(1);
BI.setSuccessor(0, FalseDest);
BI.setSuccessor(1, TrueDest);
return &BI;
+ } else if (SetCondInst *I = dyn_cast<SetCondInst>(BI.getCondition())) {
+ // Cannonicalize setne -> seteq
+ if ((I->getOpcode() == Instruction::SetNE ||
+ I->getOpcode() == Instruction::SetLE ||
+ I->getOpcode() == Instruction::SetGE) && I->hasOneUse()) {
+ std::string Name = I->getName(); I->setName("");
+ Instruction::BinaryOps NewOpcode =
+ SetCondInst::getInverseCondition(I->getOpcode());
+ Value *NewSCC = BinaryOperator::create(NewOpcode, I->getOperand(0),
+ I->getOperand(1), Name, I);
+ BasicBlock *TrueDest = BI.getSuccessor(0);
+ BasicBlock *FalseDest = BI.getSuccessor(1);
+ // Swap Destinations and condition...
+ BI.setCondition(NewSCC);
+ BI.setSuccessor(0, FalseDest);
+ BI.setSuccessor(1, TrueDest);
+ removeFromWorkList(I);
+ I->getParent()->getInstList().erase(I);
+ WorkList.push_back(cast<Instruction>(NewSCC));
+ return &BI;
+ }
}
+ }
return 0;
}