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-rw-r--r--lib/Transforms/IPO/StructRetPromotion.cpp65
1 files changed, 39 insertions, 26 deletions
diff --git a/lib/Transforms/IPO/StructRetPromotion.cpp b/lib/Transforms/IPO/StructRetPromotion.cpp
index e28fc42ed2..4c4c6d6828 100644
--- a/lib/Transforms/IPO/StructRetPromotion.cpp
+++ b/lib/Transforms/IPO/StructRetPromotion.cpp
@@ -49,15 +49,15 @@ namespace {
CallGraphSCCPass::getAnalysisUsage(AU);
}
- virtual bool runOnSCC(const std::vector<CallGraphNode *> &SCC);
+ virtual bool runOnSCC(std::vector<CallGraphNode *> &SCC);
static char ID; // Pass identification, replacement for typeid
SRETPromotion() : CallGraphSCCPass(&ID) {}
private:
- bool PromoteReturn(CallGraphNode *CGN);
+ CallGraphNode *PromoteReturn(CallGraphNode *CGN);
bool isSafeToUpdateAllCallers(Function *F);
Function *cloneFunctionBody(Function *F, const StructType *STy);
- void updateCallSites(Function *F, Function *NF);
+ CallGraphNode *updateCallSites(Function *F, Function *NF);
bool nestedStructType(const StructType *STy);
};
}
@@ -70,44 +70,47 @@ Pass *llvm::createStructRetPromotionPass() {
return new SRETPromotion();
}
-bool SRETPromotion::runOnSCC(const std::vector<CallGraphNode *> &SCC) {
+bool SRETPromotion::runOnSCC(std::vector<CallGraphNode *> &SCC) {
bool Changed = false;
for (unsigned i = 0, e = SCC.size(); i != e; ++i)
- Changed |= PromoteReturn(SCC[i]);
+ if (CallGraphNode *NewNode = PromoteReturn(SCC[i])) {
+ SCC[i] = NewNode;
+ Changed = true;
+ }
return Changed;
}
/// PromoteReturn - This method promotes function that uses StructRet paramater
-/// into a function that uses mulitple return value.
-bool SRETPromotion::PromoteReturn(CallGraphNode *CGN) {
+/// into a function that uses multiple return values.
+CallGraphNode *SRETPromotion::PromoteReturn(CallGraphNode *CGN) {
Function *F = CGN->getFunction();
if (!F || F->isDeclaration() || !F->hasLocalLinkage())
- return false;
+ return 0;
// Make sure that function returns struct.
if (F->arg_size() == 0 || !F->hasStructRetAttr() || F->doesNotReturn())
- return false;
+ return 0;
DEBUG(errs() << "SretPromotion: Looking at sret function "
<< F->getName() << "\n");
- assert (F->getReturnType() == Type::getVoidTy(F->getContext()) &&
- "Invalid function return type");
+ assert(F->getReturnType() == Type::getVoidTy(F->getContext()) &&
+ "Invalid function return type");
Function::arg_iterator AI = F->arg_begin();
const llvm::PointerType *FArgType = dyn_cast<PointerType>(AI->getType());
- assert (FArgType && "Invalid sret parameter type");
+ assert(FArgType && "Invalid sret parameter type");
const llvm::StructType *STy =
dyn_cast<StructType>(FArgType->getElementType());
- assert (STy && "Invalid sret parameter element type");
+ assert(STy && "Invalid sret parameter element type");
// Check if it is ok to perform this promotion.
if (isSafeToUpdateAllCallers(F) == false) {
DEBUG(errs() << "SretPromotion: Not all callers can be updated\n");
NumRejectedSRETUses++;
- return false;
+ return 0;
}
DEBUG(errs() << "SretPromotion: sret argument will be promoted\n");
@@ -135,11 +138,13 @@ bool SRETPromotion::PromoteReturn(CallGraphNode *CGN) {
Function *NF = cloneFunctionBody(F, STy);
// [4] Update all call sites to use new function
- updateCallSites(F, NF);
+ CallGraphNode *NF_CFN = updateCallSites(F, NF);
- F->eraseFromParent();
- getAnalysis<CallGraph>().changeFunction(F, NF);
- return true;
+ CallGraph &CG = getAnalysis<CallGraph>();
+ NF_CFN->stealCalledFunctionsFrom(CG[F]);
+
+ delete CG.removeFunctionFromModule(F);
+ return NF_CFN;
}
// Check if it is ok to perform this promotion.
@@ -247,23 +252,26 @@ Function *SRETPromotion::cloneFunctionBody(Function *F,
Function::arg_iterator NI = NF->arg_begin();
++I;
while (I != E) {
- I->replaceAllUsesWith(NI);
- NI->takeName(I);
- ++I;
- ++NI;
+ I->replaceAllUsesWith(NI);
+ NI->takeName(I);
+ ++I;
+ ++NI;
}
return NF;
}
/// updateCallSites - Update all sites that call F to use NF.
-void SRETPromotion::updateCallSites(Function *F, Function *NF) {
+CallGraphNode *SRETPromotion::updateCallSites(Function *F, Function *NF) {
CallGraph &CG = getAnalysis<CallGraph>();
SmallVector<Value*, 16> Args;
// Attributes - Keep track of the parameter attributes for the arguments.
SmallVector<AttributeWithIndex, 8> ArgAttrsVec;
+ // Get a new callgraph node for NF.
+ CallGraphNode *NF_CGN = CG.getOrInsertFunction(NF);
+
while (!F->use_empty()) {
CallSite CS = CallSite::get(*F->use_begin());
Instruction *Call = CS.getInstruction();
@@ -313,7 +321,7 @@ void SRETPromotion::updateCallSites(Function *F, Function *NF) {
New->takeName(Call);
// Update the callgraph to know that the callsite has been transformed.
- CG[Call->getParent()->getParent()]->replaceCallSite(Call, New);
+ CG[Call->getParent()->getParent()]->replaceCallSite(Call, New, NF_CGN);
// Update all users of sret parameter to extract value using extractvalue.
for (Value::use_iterator UI = FirstCArg->use_begin(),
@@ -322,7 +330,8 @@ void SRETPromotion::updateCallSites(Function *F, Function *NF) {
CallInst *C2 = dyn_cast<CallInst>(U2);
if (C2 && (C2 == Call))
continue;
- else if (GetElementPtrInst *UGEP = dyn_cast<GetElementPtrInst>(U2)) {
+
+ if (GetElementPtrInst *UGEP = dyn_cast<GetElementPtrInst>(U2)) {
ConstantInt *Idx = dyn_cast<ConstantInt>(UGEP->getOperand(2));
assert (Idx && "Unexpected getelementptr index!");
Value *GR = ExtractValueInst::Create(New, Idx->getZExtValue(),
@@ -335,11 +344,15 @@ void SRETPromotion::updateCallSites(Function *F, Function *NF) {
L->eraseFromParent();
}
UGEP->eraseFromParent();
+ continue;
}
- else assert( 0 && "Unexpected sret parameter use");
+
+ assert(0 && "Unexpected sret parameter use");
}
Call->eraseFromParent();
}
+
+ return NF_CGN;
}
/// nestedStructType - Return true if STy includes any