//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Utils/UnifyFunctionExitNodes.h"
-#include "llvm/Transforms/Scalar.h"
-#include "llvm/BasicBlock.h"
-#include "llvm/Function.h"
-#include "llvm/Instructions.h"
-#include "llvm/Type.h"
-#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringExtras.h"
+#include "llvm/IR/BasicBlock.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Type.h"
+#include "llvm/Transforms/Scalar.h"
using namespace llvm;
char UnifyFunctionExitNodes::ID = 0;
-static RegisterPass<UnifyFunctionExitNodes>
-X("mergereturn", "Unify function exit nodes");
-
-int UnifyFunctionExitNodes::stub;
+INITIALIZE_PASS(UnifyFunctionExitNodes, "mergereturn",
+ "Unify function exit nodes", false, false)
Pass *llvm::createUnifyFunctionExitNodesPass() {
return new UnifyFunctionExitNodes();
// We preserve the non-critical-edgeness property
AU.addPreservedID(BreakCriticalEdgesID);
// This is a cluster of orthogonal Transforms
- AU.addPreservedID(PromoteMemoryToRegisterID);
+ AU.addPreserved("mem2reg");
AU.addPreservedID(LowerSwitchID);
}
// return.
//
std::vector<BasicBlock*> ReturningBlocks;
- std::vector<BasicBlock*> UnwindingBlocks;
std::vector<BasicBlock*> UnreachableBlocks;
for(Function::iterator I = F.begin(), E = F.end(); I != E; ++I)
if (isa<ReturnInst>(I->getTerminator()))
ReturningBlocks.push_back(I);
- else if (isa<UnwindInst>(I->getTerminator()))
- UnwindingBlocks.push_back(I);
else if (isa<UnreachableInst>(I->getTerminator()))
UnreachableBlocks.push_back(I);
- // Handle unwinding blocks first.
- if (UnwindingBlocks.empty()) {
- UnwindBlock = 0;
- } else if (UnwindingBlocks.size() == 1) {
- UnwindBlock = UnwindingBlocks.front();
- } else {
- UnwindBlock = BasicBlock::Create("UnifiedUnwindBlock", &F);
- new UnwindInst(UnwindBlock);
-
- for (std::vector<BasicBlock*>::iterator I = UnwindingBlocks.begin(),
- E = UnwindingBlocks.end(); I != E; ++I) {
- BasicBlock *BB = *I;
- BB->getInstList().pop_back(); // Remove the unwind insn
- BranchInst::Create(UnwindBlock, BB);
- }
- }
-
// Then unreachable blocks.
if (UnreachableBlocks.empty()) {
UnreachableBlock = 0;
} else if (UnreachableBlocks.size() == 1) {
UnreachableBlock = UnreachableBlocks.front();
} else {
- UnreachableBlock = BasicBlock::Create("UnifiedUnreachableBlock", &F);
- new UnreachableInst(UnreachableBlock);
+ UnreachableBlock = BasicBlock::Create(F.getContext(),
+ "UnifiedUnreachableBlock", &F);
+ new UnreachableInst(F.getContext(), UnreachableBlock);
for (std::vector<BasicBlock*>::iterator I = UnreachableBlocks.begin(),
E = UnreachableBlocks.end(); I != E; ++I) {
// nodes (if the function returns values), and convert all of the return
// instructions into unconditional branches.
//
- BasicBlock *NewRetBlock = BasicBlock::Create("UnifiedReturnBlock", &F);
+ BasicBlock *NewRetBlock = BasicBlock::Create(F.getContext(),
+ "UnifiedReturnBlock", &F);
- SmallVector<Value *, 4> Phis;
- unsigned NumRetVals = ReturningBlocks[0]->getTerminator()->getNumOperands();
- if (NumRetVals == 0)
- ReturnInst::Create(NULL, NewRetBlock);
- else if (const StructType *STy = dyn_cast<StructType>(F.getReturnType())) {
- Instruction *InsertPt = NULL;
- if (NumRetVals == 0)
- InsertPt = NewRetBlock->getFirstNonPHI();
- PHINode *PN = NULL;
- for (unsigned i = 0; i < NumRetVals; ++i) {
- if (InsertPt)
- PN = PHINode::Create(STy->getElementType(i), "UnifiedRetVal."
- + utostr(i), InsertPt);
- else
- PN = PHINode::Create(STy->getElementType(i), "UnifiedRetVal."
- + utostr(i), NewRetBlock);
- Phis.push_back(PN);
- InsertPt = PN;
- }
- ReturnInst::Create(&Phis[0], NumRetVals, NewRetBlock);
- }
- else {
+ PHINode *PN = 0;
+ if (F.getReturnType()->isVoidTy()) {
+ ReturnInst::Create(F.getContext(), NULL, NewRetBlock);
+ } else {
// If the function doesn't return void... add a PHI node to the block...
- PHINode *PN = PHINode::Create(F.getReturnType(), "UnifiedRetVal");
+ PN = PHINode::Create(F.getReturnType(), ReturningBlocks.size(),
+ "UnifiedRetVal");
NewRetBlock->getInstList().push_back(PN);
- Phis.push_back(PN);
- ReturnInst::Create(PN, NewRetBlock);
+ ReturnInst::Create(F.getContext(), PN, NewRetBlock);
}
// Loop over all of the blocks, replacing the return instruction with an
// Add an incoming element to the PHI node for every return instruction that
// is merging into this new block...
- if (!Phis.empty()) {
- for (unsigned i = 0; i < NumRetVals; ++i)
- cast<PHINode>(Phis[i])->addIncoming(BB->getTerminator()->getOperand(i),
- BB);
- }
+ if (PN)
+ PN->addIncoming(BB->getTerminator()->getOperand(0), BB);
BB->getInstList().pop_back(); // Remove the return insn
BranchInst::Create(NewRetBlock, BB);