namespace {
/// LowerSwitch Pass - Replace all SwitchInst instructions with chained branch
- /// instructions. Note that this cannot be a BasicBlock pass because it
- /// modifies the CFG!
+ /// instructions.
class LowerSwitch : public FunctionPass {
public:
static char ID; // Pass identification, replacement for typeid
- LowerSwitch() : FunctionPass(&ID) {}
+ LowerSwitch() : FunctionPass(ID) {
+ initializeLowerSwitchPass(*PassRegistry::getPassRegistry());
+ }
virtual bool runOnFunction(Function &F);
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
// This is a cluster of orthogonal Transforms
AU.addPreserved<UnifyFunctionExitNodes>();
- AU.addPreservedID(PromoteMemoryToRegisterID);
+ AU.addPreserved("mem2reg");
AU.addPreservedID(LowerInvokePassID);
}
Constant* High;
BasicBlock* BB;
- CaseRange() : Low(0), High(0), BB(0) { }
- CaseRange(Constant* low, Constant* high, BasicBlock* bb) :
+ CaseRange(Constant *low = 0, Constant *high = 0, BasicBlock *bb = 0) :
Low(low), High(high), BB(bb) { }
};
BasicBlock* OrigBlock, BasicBlock* Default);
unsigned Clusterify(CaseVector& Cases, SwitchInst *SI);
};
-
- /// The comparison function for sorting the switch case values in the vector.
- /// WARNING: Case ranges should be disjoint!
- struct CaseCmp {
- bool operator () (const LowerSwitch::CaseRange& C1,
- const LowerSwitch::CaseRange& C2) {
-
- const ConstantInt* CI1 = cast<const ConstantInt>(C1.Low);
- const ConstantInt* CI2 = cast<const ConstantInt>(C2.High);
- return CI1->getValue().slt(CI2->getValue());
- }
- };
}
char LowerSwitch::ID = 0;
-static RegisterPass<LowerSwitch>
-X("lowerswitch", "Lower SwitchInst's to branches");
+INITIALIZE_PASS(LowerSwitch, "lowerswitch",
+ "Lower SwitchInst's to branches", false, false)
-// Publically exposed interface to pass...
-const PassInfo *const llvm::LowerSwitchID = &X;
+// Publicly exposed interface to pass...
+char &llvm::LowerSwitchID = LowerSwitch::ID;
// createLowerSwitchPass - Interface to this file...
FunctionPass *llvm::createLowerSwitchPass() {
return new LowerSwitch();
// operator<< - Used for debugging purposes.
//
static raw_ostream& operator<<(raw_ostream &O,
- const LowerSwitch::CaseVector &C) ATTRIBUTE_USED;
+ const LowerSwitch::CaseVector &C)
+ LLVM_ATTRIBUTE_USED;
static raw_ostream& operator<<(raw_ostream &O,
const LowerSwitch::CaseVector &C) {
O << "[";
Function::iterator FI = OrigBlock;
F->getBasicBlockList().insert(++FI, NewNode);
- ICmpInst* Comp = new ICmpInst(ICmpInst::ICMP_SLT,
+ ICmpInst* Comp = new ICmpInst(ICmpInst::ICMP_ULT,
Val, Pivot.Low, "Pivot");
NewNode->getInstList().push_back(Comp);
BranchInst::Create(LBranch, RBranch, Comp, NewNode);
// Clusterify - Transform simple list of Cases into list of CaseRange's
unsigned LowerSwitch::Clusterify(CaseVector& Cases, SwitchInst *SI) {
- unsigned numCmps = 0;
- // Start with "simple" cases
- for (unsigned i = 1; i < SI->getNumSuccessors(); ++i)
- Cases.push_back(CaseRange(SI->getSuccessorValue(i),
- SI->getSuccessorValue(i),
- SI->getSuccessor(i)));
- std::sort(Cases.begin(), Cases.end(), CaseCmp());
-
- // Merge case into clusters
- if (Cases.size()>=2)
- for (CaseItr I=Cases.begin(), J=llvm::next(Cases.begin()); J!=Cases.end(); ) {
- int64_t nextValue = cast<ConstantInt>(J->Low)->getSExtValue();
- int64_t currentValue = cast<ConstantInt>(I->High)->getSExtValue();
- BasicBlock* nextBB = J->BB;
- BasicBlock* currentBB = I->BB;
-
- // If the two neighboring cases go to the same destination, merge them
- // into a single case.
- if ((nextValue-currentValue==1) && (currentBB == nextBB)) {
- I->High = J->High;
- J = Cases.erase(J);
- } else {
- I = J++;
- }
- }
+ IntegersSubsetToBB TheClusterifier;
- for (CaseItr I=Cases.begin(), E=Cases.end(); I!=E; ++I, ++numCmps) {
- if (I->Low != I->High)
+ // Start with "simple" cases
+ for (SwitchInst::CaseIt i = SI->case_begin(), e = SI->case_end();
+ i != e; ++i) {
+ BasicBlock *SuccBB = i.getCaseSuccessor();
+ IntegersSubset CaseRanges = i.getCaseValueEx();
+ TheClusterifier.add(CaseRanges, SuccBB);
+ }
+
+ TheClusterifier.optimize();
+
+ size_t numCmps = 0;
+ for (IntegersSubsetToBB::RangeIterator i = TheClusterifier.begin(),
+ e = TheClusterifier.end(); i != e; ++i, ++numCmps) {
+ IntegersSubsetToBB::Cluster &C = *i;
+
+ // FIXME: Currently work with ConstantInt based numbers.
+ // Changing it to APInt based is a pretty heavy for this commit.
+ Cases.push_back(CaseRange(C.first.getLow().toConstantInt(),
+ C.first.getHigh().toConstantInt(), C.second));
+ if (C.first.isSingleNumber())
// A range counts double, since it requires two compares.
++numCmps;
}
- return numCmps;
+ return numCmps;
}
// processSwitchInst - Replace the specified switch instruction with a sequence
BasicBlock *CurBlock = SI->getParent();
BasicBlock *OrigBlock = CurBlock;
Function *F = CurBlock->getParent();
- Value *Val = SI->getOperand(0); // The value we are switching on...
+ Value *Val = SI->getCondition(); // The value we are switching on...
BasicBlock* Default = SI->getDefaultDest();
// If there is only the default destination, don't bother with the code below.
- if (SI->getNumOperands() == 2) {
+ if (!SI->getNumCases()) {
BranchInst::Create(SI->getDefaultDest(), CurBlock);
CurBlock->getInstList().erase(SI);
return;