//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
+#include "llvm/LLVMContext.h"
#include "llvm/Module.h"
#include "llvm/Instructions.h"
+#include "llvm/IntrinsicInst.h"
#include "llvm/Intrinsics.h"
+#include "llvm/Attributes.h"
#include "llvm/Analysis/CallGraph.h"
+#include "llvm/Analysis/DebugInfo.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringExtras.h"
#include "llvm/Support/CallSite.h"
using namespace llvm;
-bool llvm::InlineFunction(CallInst *CI, CallGraph *CG) {
- return InlineFunction(CallSite(CI), CG);
+bool llvm::InlineFunction(CallInst *CI, CallGraph *CG, const TargetData *TD) {
+ return InlineFunction(CallSite(CI), CG, TD);
}
-bool llvm::InlineFunction(InvokeInst *II, CallGraph *CG) {
- return InlineFunction(CallSite(II), CG);
+bool llvm::InlineFunction(InvokeInst *II, CallGraph *CG, const TargetData *TD) {
+ return InlineFunction(CallSite(II), CG, TD);
}
/// HandleInlinedInvoke - If we inlined an invoke site, we need to convert calls
/// in the body of the inlined function into invokes and turn unwind
/// instructions into branches to the invoke unwind dest.
///
-/// II is the invoke instruction begin inlined. FirstNewBlock is the first
+/// II is the invoke instruction being inlined. FirstNewBlock is the first
/// block of the inlined code (the last block is the end of the function),
/// and InlineCodeInfo is information about the code that got inlined.
static void HandleInlinedInvoke(InvokeInst *II, BasicBlock *FirstNewBlock,
- ClonedCodeInfo &InlinedCodeInfo) {
+ ClonedCodeInfo &InlinedCodeInfo,
+ CallGraph *CG) {
BasicBlock *InvokeDest = II->getUnwindDest();
std::vector<Value*> InvokeDestPHIValues;
}
Function *Caller = FirstNewBlock->getParent();
-
+
// The inlined code is currently at the end of the function, scan from the
// start of the inlined code to its end, checking for stuff we need to
// rewrite.
if (InlinedCodeInfo.ContainsCalls) {
for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E; ){
Instruction *I = BBI++;
-
+
// We only need to check for function calls: inlined invoke
// instructions require no special handling.
if (!isa<CallInst>(I)) continue;
CallInst *CI = cast<CallInst>(I);
- // If this is an intrinsic function call, don't convert it to an
- // invoke.
- if (CI->getCalledFunction() &&
- CI->getCalledFunction()->getIntrinsicID())
+ // If this call cannot unwind, don't convert it to an invoke.
+ if (CI->doesNotThrow())
continue;
-
+
// Convert this function call into an invoke instruction.
// First, split the basic block.
BasicBlock *Split = BB->splitBasicBlock(CI, CI->getName()+".noexc");
-
+
// Next, create the new invoke instruction, inserting it at the end
// of the old basic block.
+ SmallVector<Value*, 8> InvokeArgs(CI->op_begin()+1, CI->op_end());
InvokeInst *II =
- new InvokeInst(CI->getCalledValue(), Split, InvokeDest,
- std::vector<Value*>(CI->op_begin()+1, CI->op_end()),
- CI->getName(), BB->getTerminator());
+ InvokeInst::Create(CI->getCalledValue(), Split, InvokeDest,
+ InvokeArgs.begin(), InvokeArgs.end(),
+ CI->getName(), BB->getTerminator());
II->setCallingConv(CI->getCallingConv());
-
+ II->setAttributes(CI->getAttributes());
+
// Make sure that anything using the call now uses the invoke!
CI->replaceAllUsesWith(II);
-
+
+ // Update the callgraph.
+ if (CG) {
+ // We should be able to do this:
+ // (*CG)[Caller]->replaceCallSite(CI, II);
+ // but that fails if the old call site isn't in the call graph,
+ // which, because of LLVM bug 3601, it sometimes isn't.
+ CallGraphNode *CGN = (*CG)[Caller];
+ for (CallGraphNode::iterator NI = CGN->begin(), NE = CGN->end();
+ NI != NE; ++NI) {
+ if (NI->first == CI) {
+ NI->first = II;
+ break;
+ }
+ }
+ }
+
// Delete the unconditional branch inserted by splitBasicBlock
BB->getInstList().pop_back();
Split->getInstList().pop_front(); // Delete the original call
-
+
// Update any PHI nodes in the exceptional block to indicate that
// there is now a new entry in them.
unsigned i = 0;
PHINode *PN = cast<PHINode>(I);
PN->addIncoming(InvokeDestPHIValues[i], BB);
}
-
+
// This basic block is now complete, start scanning the next one.
break;
}
}
-
+
if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator())) {
// An UnwindInst requires special handling when it gets inlined into an
// invoke site. Once this happens, we know that the unwind would cause
// a control transfer to the invoke exception destination, so we can
// transform it into a direct branch to the exception destination.
- new BranchInst(InvokeDest, UI);
-
+ BranchInst::Create(InvokeDest, UI);
+
// Delete the unwind instruction!
- UI->getParent()->getInstList().pop_back();
-
+ UI->eraseFromParent();
+
// Update any PHI nodes in the exceptional block to indicate that
// there is now a new entry in them.
unsigned i = 0;
/// UpdateCallGraphAfterInlining - Once we have cloned code over from a callee
/// into the caller, update the specified callgraph to reflect the changes we
/// made. Note that it's possible that not all code was copied over, so only
-/// some edges of the callgraph will be remain.
-static void UpdateCallGraphAfterInlining(const Function *Caller,
- const Function *Callee,
+/// some edges of the callgraph may remain.
+static void UpdateCallGraphAfterInlining(CallSite CS,
Function::iterator FirstNewBlock,
- std::map<const Value*, Value*> &ValueMap,
+ DenseMap<const Value*, Value*> &ValueMap,
CallGraph &CG) {
- // Update the call graph by deleting the edge from Callee to Caller
+ const Function *Caller = CS.getInstruction()->getParent()->getParent();
+ const Function *Callee = CS.getCalledFunction();
CallGraphNode *CalleeNode = CG[Callee];
CallGraphNode *CallerNode = CG[Caller];
- CallerNode->removeCallEdgeTo(CalleeNode);
-
+
// Since we inlined some uninlined call sites in the callee into the caller,
// add edges from the caller to all of the callees of the callee.
- for (CallGraphNode::iterator I = CalleeNode->begin(),
- E = CalleeNode->end(); I != E; ++I) {
+ CallGraphNode::iterator I = CalleeNode->begin(), E = CalleeNode->end();
+
+ // Consider the case where CalleeNode == CallerNode.
+ CallGraphNode::CalledFunctionsVector CallCache;
+ if (CalleeNode == CallerNode) {
+ CallCache.assign(I, E);
+ I = CallCache.begin();
+ E = CallCache.end();
+ }
+
+ for (; I != E; ++I) {
const Instruction *OrigCall = I->first.getInstruction();
-
- std::map<const Value*, Value*>::iterator VMI = ValueMap.find(OrigCall);
+
+ DenseMap<const Value*, Value*>::iterator VMI = ValueMap.find(OrigCall);
// Only copy the edge if the call was inlined!
if (VMI != ValueMap.end() && VMI->second) {
// If the call was inlined, but then constant folded, there is no edge to
CallerNode->addCalledFunction(CallSite::get(NewCall), I->second);
}
}
+ // Update the call graph by deleting the edge from Callee to Caller. We must
+ // do this after the loop above in case Caller and Callee are the same.
+ CallerNode->removeCallEdgeFor(CS);
}
+/// findFnRegionEndMarker - This is a utility routine that is used by
+/// InlineFunction. Return llvm.dbg.region.end intrinsic that corresponds
+/// to the llvm.dbg.func.start of the function F. Otherwise return NULL.
+static const DbgRegionEndInst *findFnRegionEndMarker(const Function *F) {
+
+ GlobalVariable *FnStart = NULL;
+ const DbgRegionEndInst *FnEnd = NULL;
+ for (Function::const_iterator FI = F->begin(), FE =F->end(); FI != FE; ++FI)
+ for (BasicBlock::const_iterator BI = FI->begin(), BE = FI->end(); BI != BE;
+ ++BI) {
+ if (FnStart == NULL) {
+ if (const DbgFuncStartInst *FSI = dyn_cast<DbgFuncStartInst>(BI)) {
+ DISubprogram SP(cast<GlobalVariable>(FSI->getSubprogram()));
+ assert (SP.isNull() == false && "Invalid llvm.dbg.func.start");
+ if (SP.describes(F))
+ FnStart = SP.getGV();
+ }
+ } else {
+ if (const DbgRegionEndInst *REI = dyn_cast<DbgRegionEndInst>(BI))
+ if (REI->getContext() == FnStart)
+ FnEnd = REI;
+ }
+ }
+ return FnEnd;
+}
// InlineFunction - This function inlines the called function into the basic
// block of the caller. This returns false if it is not possible to inline this
// exists in the instruction stream. Similiarly this will inline a recursive
// function by one level.
//
-bool llvm::InlineFunction(CallSite CS, CallGraph *CG) {
+bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD) {
Instruction *TheCall = CS.getInstruction();
+ LLVMContext &Context = TheCall->getContext();
assert(TheCall->getParent() && TheCall->getParent()->getParent() &&
"Instruction not in function!");
CalledFunc->getFunctionType()->isVarArg()) return false;
- // If the call to the callee is a non-tail call, we must clear the 'tail'
+ // If the call to the callee is not a tail call, we must clear the 'tail'
// flags on any calls that we inline.
bool MustClearTailCallFlags =
- isa<CallInst>(TheCall) && !cast<CallInst>(TheCall)->isTailCall();
+ !(isa<CallInst>(TheCall) && cast<CallInst>(TheCall)->isTailCall());
+
+ // If the call to the callee cannot throw, set the 'nounwind' flag on any
+ // calls that we inline.
+ bool MarkNoUnwind = CS.doesNotThrow();
BasicBlock *OrigBB = TheCall->getParent();
Function *Caller = OrigBB->getParent();
+ // GC poses two hazards to inlining, which only occur when the callee has GC:
+ // 1. If the caller has no GC, then the callee's GC must be propagated to the
+ // caller.
+ // 2. If the caller has a differing GC, it is invalid to inline.
+ if (CalledFunc->hasGC()) {
+ if (!Caller->hasGC())
+ Caller->setGC(CalledFunc->getGC());
+ else if (CalledFunc->getGC() != Caller->getGC())
+ return false;
+ }
+
// Get an iterator to the last basic block in the function, which will have
// the new function inlined after it.
//
std::vector<ReturnInst*> Returns;
ClonedCodeInfo InlinedFunctionInfo;
Function::iterator FirstNewBlock;
-
+
{ // Scope to destroy ValueMap after cloning.
- std::map<const Value*, Value*> ValueMap;
+ DenseMap<const Value*, Value*> ValueMap;
+
+ assert(CalledFunc->arg_size() == CS.arg_size() &&
+ "No varargs calls can be inlined!");
// Calculate the vector of arguments to pass into the function cloner, which
// matches up the formal to the actual argument values.
- assert(std::distance(CalledFunc->arg_begin(), CalledFunc->arg_end()) ==
- std::distance(CS.arg_begin(), CS.arg_end()) &&
- "No varargs calls can be inlined!");
CallSite::arg_iterator AI = CS.arg_begin();
+ unsigned ArgNo = 0;
for (Function::const_arg_iterator I = CalledFunc->arg_begin(),
- E = CalledFunc->arg_end(); I != E; ++I, ++AI)
- ValueMap[I] = *AI;
+ E = CalledFunc->arg_end(); I != E; ++I, ++AI, ++ArgNo) {
+ Value *ActualArg = *AI;
+
+ // When byval arguments actually inlined, we need to make the copy implied
+ // by them explicit. However, we don't do this if the callee is readonly
+ // or readnone, because the copy would be unneeded: the callee doesn't
+ // modify the struct.
+ if (CalledFunc->paramHasAttr(ArgNo+1, Attribute::ByVal) &&
+ !CalledFunc->onlyReadsMemory()) {
+ const Type *AggTy = cast<PointerType>(I->getType())->getElementType();
+ const Type *VoidPtrTy = PointerType::getUnqual(Type::Int8Ty);
+
+ // Create the alloca. If we have TargetData, use nice alignment.
+ unsigned Align = 1;
+ if (TD) Align = TD->getPrefTypeAlignment(AggTy);
+ Value *NewAlloca = new AllocaInst(AggTy, 0, Align,
+ I->getName(),
+ &*Caller->begin()->begin());
+ // Emit a memcpy.
+ const Type *Tys[] = { Type::Int64Ty };
+ Function *MemCpyFn = Intrinsic::getDeclaration(Caller->getParent(),
+ Intrinsic::memcpy,
+ Tys, 1);
+ Value *DestCast = new BitCastInst(NewAlloca, VoidPtrTy, "tmp", TheCall);
+ Value *SrcCast = new BitCastInst(*AI, VoidPtrTy, "tmp", TheCall);
+
+ Value *Size;
+ if (TD == 0)
+ Size = ConstantExpr::getSizeOf(AggTy);
+ else
+ Size = ConstantInt::get(Type::Int64Ty,
+ TD->getTypeStoreSize(AggTy));
+
+ // Always generate a memcpy of alignment 1 here because we don't know
+ // the alignment of the src pointer. Other optimizations can infer
+ // better alignment.
+ Value *CallArgs[] = {
+ DestCast, SrcCast, Size, ConstantInt::get(Type::Int32Ty, 1)
+ };
+ CallInst *TheMemCpy =
+ CallInst::Create(MemCpyFn, CallArgs, CallArgs+4, "", TheCall);
+
+ // If we have a call graph, update it.
+ if (CG) {
+ CallGraphNode *MemCpyCGN = CG->getOrInsertFunction(MemCpyFn);
+ CallGraphNode *CallerNode = (*CG)[Caller];
+ CallerNode->addCalledFunction(TheMemCpy, MemCpyCGN);
+ }
+
+ // Uses of the argument in the function should use our new alloca
+ // instead.
+ ActualArg = NewAlloca;
+ }
+
+ ValueMap[I] = ActualArg;
+ }
+
+ // Adjust llvm.dbg.region.end. If the CalledFunc has region end
+ // marker then clone that marker after next stop point at the
+ // call site. The function body cloner does not clone original
+ // region end marker from the CalledFunc. This will ensure that
+ // inlined function's scope ends at the right place.
+ const DbgRegionEndInst *DREI = findFnRegionEndMarker(CalledFunc);
+ if (DREI) {
+ for (BasicBlock::iterator BI = TheCall,
+ BE = TheCall->getParent()->end(); BI != BE; ++BI) {
+ if (DbgStopPointInst *DSPI = dyn_cast<DbgStopPointInst>(BI)) {
+ if (DbgRegionEndInst *NewDREI =
+ dyn_cast<DbgRegionEndInst>(DREI->clone(Context)))
+ NewDREI->insertAfter(DSPI);
+ break;
+ }
+ }
+ }
// We want the inliner to prune the code as it copies. We would LOVE to
// have no dead or constant instructions leftover after inlining occurs
// (which can happen, e.g., because an argument was constant), but we'll be
// happy with whatever the cloner can do.
CloneAndPruneFunctionInto(Caller, CalledFunc, ValueMap, Returns, ".i",
- &InlinedFunctionInfo);
-
+ &InlinedFunctionInfo, TD);
+
// Remember the first block that is newly cloned over.
FirstNewBlock = LastBlock; ++FirstNewBlock;
-
+
// Update the callgraph if requested.
if (CG)
- UpdateCallGraphAfterInlining(Caller, CalledFunc, FirstNewBlock, ValueMap,
- *CG);
+ UpdateCallGraphAfterInlining(CS, FirstNewBlock, ValueMap, *CG);
}
-
+
// If there are any alloca instructions in the block that used to be the entry
// block for the callee, move them to the entry block of the caller. First
// calculate which instruction they should be inserted before. We insert the
AI->eraseFromParent();
continue;
}
-
+
if (isa<Constant>(AI->getArraySize())) {
// Scan for the block of allocas that we can move over, and move them
// all at once.
++I;
// Transfer all of the allocas over in a block. Using splice means
- // that they instructions aren't removed from the symbol table, then
+ // that the instructions aren't removed from the symbol table, then
// reinserted.
- Caller->front().getInstList().splice(InsertPoint,
- FirstNewBlock->getInstList(),
- AI, I);
+ Caller->getEntryBlock().getInstList().splice(
+ InsertPoint,
+ FirstNewBlock->getInstList(),
+ AI, I);
}
}
}
// code with llvm.stacksave/llvm.stackrestore intrinsics.
if (InlinedFunctionInfo.ContainsDynamicAllocas) {
Module *M = Caller->getParent();
- const Type *BytePtr = PointerType::get(Type::Int8Ty);
// Get the two intrinsics we care about.
Constant *StackSave, *StackRestore;
- StackSave = M->getOrInsertFunction("llvm.stacksave", BytePtr, NULL);
- StackRestore = M->getOrInsertFunction("llvm.stackrestore", Type::VoidTy,
- BytePtr, NULL);
+ StackSave = Intrinsic::getDeclaration(M, Intrinsic::stacksave);
+ StackRestore = Intrinsic::getDeclaration(M, Intrinsic::stackrestore);
// If we are preserving the callgraph, add edges to the stacksave/restore
// functions for the calls we insert.
StackRestoreCGN = CG->getOrInsertFunction(cast<Function>(StackRestore));
CallerNode = (*CG)[Caller];
}
-
+
// Insert the llvm.stacksave.
- CallInst *SavedPtr = new CallInst(StackSave, "savedstack",
- FirstNewBlock->begin());
+ CallInst *SavedPtr = CallInst::Create(StackSave, "savedstack",
+ FirstNewBlock->begin());
if (CG) CallerNode->addCalledFunction(SavedPtr, StackSaveCGN);
-
+
// Insert a call to llvm.stackrestore before any return instructions in the
// inlined function.
for (unsigned i = 0, e = Returns.size(); i != e; ++i) {
- CallInst *CI = new CallInst(StackRestore, SavedPtr, "", Returns[i]);
+ CallInst *CI = CallInst::Create(StackRestore, SavedPtr, "", Returns[i]);
if (CG) CallerNode->addCalledFunction(CI, StackRestoreCGN);
}
// Count the number of StackRestore calls we insert.
unsigned NumStackRestores = Returns.size();
-
+
// If we are inlining an invoke instruction, insert restores before each
// unwind. These unwinds will be rewritten into branches later.
if (InlinedFunctionInfo.ContainsUnwinds && isa<InvokeInst>(TheCall)) {
for (Function::iterator BB = FirstNewBlock, E = Caller->end();
BB != E; ++BB)
if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator())) {
- new CallInst(StackRestore, SavedPtr, "", UI);
+ CallInst::Create(StackRestore, SavedPtr, "", UI);
++NumStackRestores;
}
}
}
- // If we are inlining tail call instruction through a call site that isn't
+ // If we are inlining tail call instruction through a call site that isn't
// marked 'tail', we must remove the tail marker for any calls in the inlined
- // code.
- if (MustClearTailCallFlags && InlinedFunctionInfo.ContainsCalls) {
+ // code. Also, calls inlined through a 'nounwind' call site should be marked
+ // 'nounwind'.
+ if (InlinedFunctionInfo.ContainsCalls &&
+ (MustClearTailCallFlags || MarkNoUnwind)) {
for (Function::iterator BB = FirstNewBlock, E = Caller->end();
BB != E; ++BB)
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
- if (CallInst *CI = dyn_cast<CallInst>(I))
- CI->setTailCall(false);
+ if (CallInst *CI = dyn_cast<CallInst>(I)) {
+ if (MustClearTailCallFlags)
+ CI->setTailCall(false);
+ if (MarkNoUnwind)
+ CI->setDoesNotThrow();
+ }
}
+ // If we are inlining through a 'nounwind' call site then any inlined 'unwind'
+ // instructions are unreachable.
+ if (InlinedFunctionInfo.ContainsUnwinds && MarkNoUnwind)
+ for (Function::iterator BB = FirstNewBlock, E = Caller->end();
+ BB != E; ++BB) {
+ TerminatorInst *Term = BB->getTerminator();
+ if (isa<UnwindInst>(Term)) {
+ new UnreachableInst(Term);
+ BB->getInstList().erase(Term);
+ }
+ }
+
// If we are inlining for an invoke instruction, we must make sure to rewrite
// any inlined 'unwind' instructions into branches to the invoke exception
// destination, and call instructions into invoke instructions.
if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall))
- HandleInlinedInvoke(II, FirstNewBlock, InlinedFunctionInfo);
+ HandleInlinedInvoke(II, FirstNewBlock, InlinedFunctionInfo, CG);
// If we cloned in _exactly one_ basic block, and if that block ends in a
// return instruction, we splice the body of the inlined callee directly into
// If the call site was an invoke instruction, add a branch to the normal
// destination.
if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall))
- new BranchInst(II->getNormalDest(), TheCall);
+ BranchInst::Create(II->getNormalDest(), TheCall);
// If the return instruction returned a value, replace uses of the call with
// uses of the returned value.
- if (!TheCall->use_empty())
- TheCall->replaceAllUsesWith(Returns[0]->getReturnValue());
-
+ if (!TheCall->use_empty()) {
+ ReturnInst *R = Returns[0];
+ if (TheCall == R->getReturnValue())
+ TheCall->replaceAllUsesWith(Context.getUndef(TheCall->getType()));
+ else
+ TheCall->replaceAllUsesWith(R->getReturnValue());
+ }
// Since we are now done with the Call/Invoke, we can delete it.
- TheCall->getParent()->getInstList().erase(TheCall);
+ TheCall->eraseFromParent();
// Since we are now done with the return instruction, delete it also.
- Returns[0]->getParent()->getInstList().erase(Returns[0]);
+ Returns[0]->eraseFromParent();
// We are now done with the inlining.
return true;
if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall)) {
// Add an unconditional branch to make this look like the CallInst case...
- BranchInst *NewBr = new BranchInst(II->getNormalDest(), TheCall);
+ BranchInst *NewBr = BranchInst::Create(II->getNormalDest(), TheCall);
// Split the basic block. This guarantees that no PHI nodes will have to be
// updated due to new incoming edges, and make the invoke case more
// Now that the function is correct, make it a little bit nicer. In
// particular, move the basic blocks inserted from the end of the function
// into the space made by splitting the source basic block.
- //
Caller->getBasicBlockList().splice(AfterCallBB, Caller->getBasicBlockList(),
FirstNewBlock, Caller->end());
// Handle all of the return instructions that we just cloned in, and eliminate
// any users of the original call/invoke instruction.
+ const Type *RTy = CalledFunc->getReturnType();
+
if (Returns.size() > 1) {
// The PHI node should go at the front of the new basic block to merge all
// possible incoming values.
- //
PHINode *PHI = 0;
if (!TheCall->use_empty()) {
- PHI = new PHINode(CalledFunc->getReturnType(),
- TheCall->getName(), AfterCallBB->begin());
-
+ PHI = PHINode::Create(RTy, TheCall->getName(),
+ AfterCallBB->begin());
// Anything that used the result of the function call should now use the
// PHI node as their operand.
- //
TheCall->replaceAllUsesWith(PHI);
}
- // Loop over all of the return instructions, turning them into unconditional
- // branches to the merge point now, and adding entries to the PHI node as
- // appropriate.
- for (unsigned i = 0, e = Returns.size(); i != e; ++i) {
- ReturnInst *RI = Returns[i];
-
- if (PHI) {
- assert(RI->getReturnValue() && "Ret should have value!");
+ // Loop over all of the return instructions adding entries to the PHI node
+ // as appropriate.
+ if (PHI) {
+ for (unsigned i = 0, e = Returns.size(); i != e; ++i) {
+ ReturnInst *RI = Returns[i];
assert(RI->getReturnValue()->getType() == PHI->getType() &&
"Ret value not consistent in function!");
PHI->addIncoming(RI->getReturnValue(), RI->getParent());
}
-
- // Add a branch to the merge point where the PHI node lives if it exists.
- new BranchInst(AfterCallBB, RI);
-
- // Delete the return instruction now
- RI->getParent()->getInstList().erase(RI);
}
+ // Add a branch to the merge points and remove return instructions.
+ for (unsigned i = 0, e = Returns.size(); i != e; ++i) {
+ ReturnInst *RI = Returns[i];
+ BranchInst::Create(AfterCallBB, RI);
+ RI->eraseFromParent();
+ }
} else if (!Returns.empty()) {
// Otherwise, if there is exactly one return value, just replace anything
// using the return value of the call with the computed value.
- if (!TheCall->use_empty())
- TheCall->replaceAllUsesWith(Returns[0]->getReturnValue());
+ if (!TheCall->use_empty()) {
+ if (TheCall == Returns[0]->getReturnValue())
+ TheCall->replaceAllUsesWith(Context.getUndef(TheCall->getType()));
+ else
+ TheCall->replaceAllUsesWith(Returns[0]->getReturnValue());
+ }
// Splice the code from the return block into the block that it will return
// to, which contains the code that was after the call.
} else if (!TheCall->use_empty()) {
// No returns, but something is using the return value of the call. Just
// nuke the result.
- TheCall->replaceAllUsesWith(UndefValue::get(TheCall->getType()));
+ TheCall->replaceAllUsesWith(Context.getUndef(TheCall->getType()));
}
// Since we are now done with the Call/Invoke, we can delete it.
// Now we can remove the CalleeEntry block, which is now empty.
Caller->getBasicBlockList().erase(CalleeEntry);
-
+
return true;
}