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Use IRBuilder while simplifying branch. 

llvm-svn: 131598
This commit is contained in:
Devang Patel 2011-05-18 23:18:47 +00:00
parent 6fc94dd687
commit 7de6c4bf75
1 changed files with 13 additions and 12 deletions
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25
llvm/lib/Transforms/Utils/SimplifyCFG.cpp
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@ -2023,7 +2023,8 @@ static bool TryToSimplifyUncondBranchWithICmpInIt(ICmpInst *ICI,
/// SimplifyBranchOnICmpChain - The specified branch is a conditional branch.
/// Check to see if it is branching on an or/and chain of icmp instructions, and
/// fold it into a switch instruction if so.
static bool SimplifyBranchOnICmpChain(BranchInst *BI, const TargetData *TD) {
static bool SimplifyBranchOnICmpChain(BranchInst *BI, const TargetData *TD,
IRBuilder<> &Builder) {
Instruction *Cond = dyn_cast<Instruction>(BI->getCondition());
if (Cond == 0) return false;
@ -2079,11 +2080,12 @@ static bool SimplifyBranchOnICmpChain(BranchInst *BI, const TargetData *TD) {
BasicBlock *NewBB = BB->splitBasicBlock(BI, "switch.early.test");
// Remove the uncond branch added to the old block.
TerminatorInst *OldTI = BB->getTerminator();
Builder.SetInsertPoint(OldTI);
if (TrueWhenEqual)
BranchInst::Create(EdgeBB, NewBB, ExtraCase, OldTI);
Builder.CreateCondBr(ExtraCase, EdgeBB, NewBB);
else
BranchInst::Create(NewBB, EdgeBB, ExtraCase, OldTI);
Builder.CreateCondBr(ExtraCase, NewBB, EdgeBB);
OldTI->eraseFromParent();
@ -2095,19 +2097,18 @@ static bool SimplifyBranchOnICmpChain(BranchInst *BI, const TargetData *TD) {
<< "\nEXTRABB = " << *BB);
BB = NewBB;
}
Builder.SetInsertPoint(BI);
// Convert pointer to int before we switch.
if (CompVal->getType()->isPointerTy()) {
assert(TD && "Cannot switch on pointer without TargetData");
CompVal = new PtrToIntInst(CompVal,
TD->getIntPtrType(CompVal->getContext()),
"magicptr", BI);
cast<PtrToIntInst>(CompVal)->setDebugLoc(BI->getDebugLoc());
CompVal = Builder.CreatePtrToInt(CompVal,
TD->getIntPtrType(CompVal->getContext()),
"magicptr");
}
// Create the new switch instruction now.
SwitchInst *New = SwitchInst::Create(CompVal, DefaultBB, Values.size(), BI);
New->setDebugLoc(BI->getDebugLoc());
SwitchInst *New = Builder.CreateSwitch(CompVal, DefaultBB, Values.size());
// Add all of the 'cases' to the switch instruction.
for (unsigned i = 0, e = Values.size(); i != e; ++i)
@ -2574,7 +2575,7 @@ bool SimplifyCFGOpt::SimplifyCondBranch(BranchInst *BI, IRBuilder<> &Builder) {
}
// Try to turn "br (X == 0 | X == 1), T, F" into a switch instruction.
if (SimplifyBranchOnICmpChain(BI, TD))
if (SimplifyBranchOnICmpChain(BI, TD, Builder))
return true;
// We have a conditional branch to two blocks that are only reachable