Instruction *visitPHINode(PHINode &PN);
Instruction *visitGetElementPtrInst(GetElementPtrInst &GEP);
Instruction *visitAllocationInst(AllocationInst &AI);
+ Instruction *visitBranchInst(BranchInst &BI);
// visitInstruction - Specify what to return for unhandled instructions...
Instruction *visitInstruction(Instruction &I) { return 0; }
return 0;
}
+Instruction *InstCombiner::visitBranchInst(BranchInst &BI) {
+ // Change br (not X), label True, label False to: br X, label False, True
+ if (BI.isConditional() && BinaryOperator::isNot(BI.getCondition())) {
+ BasicBlock *TrueDest = BI.getSuccessor(0);
+ BasicBlock *FalseDest = BI.getSuccessor(1);
+ // Swap Destinations and condition...
+ BI.setCondition(BinaryOperator::getNotArgument(cast<BinaryOperator>(BI.getCondition())));
+ BI.setSuccessor(0, FalseDest);
+ BI.setSuccessor(1, TrueDest);
+ return &BI;
+ }
+ return 0;
+}
void InstCombiner::removeFromWorkList(Instruction *I) {