diff options
Diffstat (limited to 'release_23/lib/Transforms/Utils/InlineFunction.cpp')
| -rw-r--r-- | release_23/lib/Transforms/Utils/InlineFunction.cpp | 613 |
1 files changed, 0 insertions, 613 deletions
diff --git a/release_23/lib/Transforms/Utils/InlineFunction.cpp b/release_23/lib/Transforms/Utils/InlineFunction.cpp deleted file mode 100644 index 6c96785aa10b..000000000000 --- a/release_23/lib/Transforms/Utils/InlineFunction.cpp +++ /dev/null @@ -1,613 +0,0 @@ -//===- InlineFunction.cpp - Code to perform function inlining -------------===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// This file implements inlining of a function into a call site, resolving -// parameters and the return value as appropriate. -// -//===----------------------------------------------------------------------===// - -#include "llvm/Transforms/Utils/Cloning.h" -#include "llvm/Constants.h" -#include "llvm/DerivedTypes.h" -#include "llvm/Module.h" -#include "llvm/Instructions.h" -#include "llvm/Intrinsics.h" -#include "llvm/ParameterAttributes.h" -#include "llvm/Analysis/CallGraph.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, const TargetData *TD) { - return InlineFunction(CallSite(CI), CG, TD); -} -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 -/// 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) { - BasicBlock *InvokeDest = II->getUnwindDest(); - std::vector<Value*> InvokeDestPHIValues; - - // If there are PHI nodes in the unwind destination block, we need to - // keep track of which values came into them from this invoke, then remove - // the entry for this block. - BasicBlock *InvokeBlock = II->getParent(); - for (BasicBlock::iterator I = InvokeDest->begin(); isa<PHINode>(I); ++I) { - PHINode *PN = cast<PHINode>(I); - // Save the value to use for this edge. - InvokeDestPHIValues.push_back(PN->getIncomingValueForBlock(InvokeBlock)); - } - - 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 || InlinedCodeInfo.ContainsUnwinds) { - for (Function::iterator BB = FirstNewBlock, E = Caller->end(); - BB != E; ++BB) { - 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 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 = - InvokeInst::Create(CI->getCalledValue(), Split, InvokeDest, - InvokeArgs.begin(), InvokeArgs.end(), - CI->getName(), BB->getTerminator()); - II->setCallingConv(CI->getCallingConv()); - II->setParamAttrs(CI->getParamAttrs()); - - // Make sure that anything using the call now uses the invoke! - CI->replaceAllUsesWith(II); - - // 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; - for (BasicBlock::iterator I = InvokeDest->begin(); - isa<PHINode>(I); ++I, ++i) { - 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. - BranchInst::Create(InvokeDest, UI); - - // Delete the unwind instruction! - UI->getParent()->getInstList().pop_back(); - - // Update any PHI nodes in the exceptional block to indicate that - // there is now a new entry in them. - unsigned i = 0; - for (BasicBlock::iterator I = InvokeDest->begin(); - isa<PHINode>(I); ++I, ++i) { - PHINode *PN = cast<PHINode>(I); - PN->addIncoming(InvokeDestPHIValues[i], BB); - } - } - } - } - - // Now that everything is happy, we have one final detail. The PHI nodes in - // the exception destination block still have entries due to the original - // invoke instruction. Eliminate these entries (which might even delete the - // PHI node) now. - InvokeDest->removePredecessor(II->getParent()); -} - -/// 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, - Function::iterator FirstNewBlock, - DenseMap<const Value*, Value*> &ValueMap, - CallGraph &CG) { - // Update the call graph by deleting the edge from Callee to Caller - 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) { - const Instruction *OrigCall = I->first.getInstruction(); - - 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 - // add. Check for this case. - if (Instruction *NewCall = dyn_cast<Instruction>(VMI->second)) - CallerNode->addCalledFunction(CallSite::get(NewCall), I->second); - } - } -} - - -// 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 -// call. The program is still in a well defined state if this occurs though. -// -// Note that this only does one level of inlining. For example, if the -// instruction 'call B' is inlined, and 'B' calls 'C', then the call to 'C' now -// exists in the instruction stream. Similiarly this will inline a recursive -// function by one level. -// -bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD) { - Instruction *TheCall = CS.getInstruction(); - assert(TheCall->getParent() && TheCall->getParent()->getParent() && - "Instruction not in function!"); - - const Function *CalledFunc = CS.getCalledFunction(); - if (CalledFunc == 0 || // Can't inline external function or indirect - CalledFunc->isDeclaration() || // call, or call to a vararg function! - CalledFunc->getFunctionType()->isVarArg()) return false; - - - // If the call to the callee is a non-tail call, we must clear the 'tail' - // flags on any calls that we inline. - bool MustClearTailCallFlags = - 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->hasCollector()) { - if (!Caller->hasCollector()) - Caller->setCollector(CalledFunc->getCollector()); - else if (CalledFunc->getCollector() != Caller->getCollector()) - return false; - } - - // Get an iterator to the last basic block in the function, which will have - // the new function inlined after it. - // - Function::iterator LastBlock = &Caller->back(); - - // Make sure to capture all of the return instructions from the cloned - // function. - std::vector<ReturnInst*> Returns; - ClonedCodeInfo InlinedFunctionInfo; - Function::iterator FirstNewBlock; - - { // Scope to destroy ValueMap after cloning. - DenseMap<const Value*, Value*> ValueMap; - - assert(std::distance(CalledFunc->arg_begin(), CalledFunc->arg_end()) == - std::distance(CS.arg_begin(), CS.arg_end()) && - "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. - 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, ++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, ParamAttr::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. - Function *MemCpyFn = Intrinsic::getDeclaration(Caller->getParent(), - Intrinsic::memcpy_i64); - 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; - } - - // 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, 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); - } - - // 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 - // instructions at the end of the current alloca list. - // - { - BasicBlock::iterator InsertPoint = Caller->begin()->begin(); - for (BasicBlock::iterator I = FirstNewBlock->begin(), - E = FirstNewBlock->end(); I != E; ) - if (AllocaInst *AI = dyn_cast<AllocaInst>(I++)) { - // If the alloca is now dead, remove it. This often occurs due to code - // specialization. - if (AI->use_empty()) { - 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. - while (isa<AllocaInst>(I) && - isa<Constant>(cast<AllocaInst>(I)->getArraySize())) - ++I; - - // Transfer all of the allocas over in a block. Using splice means - // that the instructions aren't removed from the symbol table, then - // reinserted. - Caller->getEntryBlock().getInstList().splice( - InsertPoint, - FirstNewBlock->getInstList(), - AI, I); - } - } - } - - // If the inlined code contained dynamic alloca instructions, wrap the inlined - // code with llvm.stacksave/llvm.stackrestore intrinsics. - if (InlinedFunctionInfo.ContainsDynamicAllocas) { - Module *M = Caller->getParent(); - // Get the two intrinsics we care about. - Constant *StackSave, *StackRestore; - 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. - CallGraphNode *StackSaveCGN = 0, *StackRestoreCGN = 0, *CallerNode = 0; - if (CG) { - // We know that StackSave/StackRestore are Function*'s, because they are - // intrinsics which must have the right types. - StackSaveCGN = CG->getOrInsertFunction(cast<Function>(StackSave)); - StackRestoreCGN = CG->getOrInsertFunction(cast<Function>(StackRestore)); - CallerNode = (*CG)[Caller]; - } - - // Insert the llvm.stacksave. - 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 = 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())) { - CallInst::Create(StackRestore, SavedPtr, "", UI); - ++NumStackRestores; - } - } - } - - // 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. 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)) { - 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); - - // 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 - // the calling basic block. - if (Returns.size() == 1 && std::distance(FirstNewBlock, Caller->end()) == 1) { - // Move all of the instructions right before the call. - OrigBB->getInstList().splice(TheCall, FirstNewBlock->getInstList(), - FirstNewBlock->begin(), FirstNewBlock->end()); - // Remove the cloned basic block. - Caller->getBasicBlockList().pop_back(); - - // If the call site was an invoke instruction, add a branch to the normal - // destination. - if (InvokeInst *II = dyn_cast<InvokeInst>(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()) { - ReturnInst *R = Returns[0]; - if (isa<StructType>(TheCall->getType())) { - // Multiple return values. - while (!TheCall->use_empty()) { - GetResultInst *GR = cast<GetResultInst>(TheCall->use_back()); - Value *RV = R->getOperand(GR->getIndex()); - GR->replaceAllUsesWith(RV); - GR->eraseFromParent(); - } - } else - TheCall->replaceAllUsesWith(R->getReturnValue()); - } - // Since we are now done with the Call/Invoke, we can delete it. - TheCall->getParent()->getInstList().erase(TheCall); - - // Since we are now done with the return instruction, delete it also. - Returns[0]->getParent()->getInstList().erase(Returns[0]); - - // We are now done with the inlining. - return true; - } - - // Otherwise, we have the normal case, of more than one block to inline or - // multiple return sites. - - // We want to clone the entire callee function into the hole between the - // "starter" and "ender" blocks. How we accomplish this depends on whether - // this is an invoke instruction or a call instruction. - BasicBlock *AfterCallBB; - if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall)) { - - // Add an unconditional branch to make this look like the CallInst case... - 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 - // symmetric to the call case. - AfterCallBB = OrigBB->splitBasicBlock(NewBr, - CalledFunc->getName()+".exit"); - - } else { // It's a call - // If this is a call instruction, we need to split the basic block that - // the call lives in. - // - AfterCallBB = OrigBB->splitBasicBlock(TheCall, - CalledFunc->getName()+".exit"); - } - - // Change the branch that used to go to AfterCallBB to branch to the first - // basic block of the inlined function. - // - TerminatorInst *Br = OrigBB->getTerminator(); - assert(Br && Br->getOpcode() == Instruction::Br && - "splitBasicBlock broken!"); - Br->setOperand(0, FirstNewBlock); - - - // 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(); - const StructType *STy = dyn_cast<StructType>(RTy); - if (Returns.size() > 1 || STy) { - // The PHI node should go at the front of the new basic block to merge all - // possible incoming values. - SmallVector<PHINode *, 4> PHIs; - if (!TheCall->use_empty()) { - if (STy) { - unsigned NumRetVals = STy->getNumElements(); - // Create new phi nodes such that phi node number in the PHIs vector - // match corresponding return value operand number. - Instruction *InsertPt = AfterCallBB->begin(); - for (unsigned i = 0; i < NumRetVals; ++i) { - PHINode *PHI = PHINode::Create(STy->getElementType(i), - TheCall->getName() + "." + utostr(i), - InsertPt); - PHIs.push_back(PHI); - } - // TheCall results are used by GetResult instructions. - while (!TheCall->use_empty()) { - GetResultInst *GR = cast<GetResultInst>(TheCall->use_back()); - GR->replaceAllUsesWith(PHIs[GR->getIndex()]); - GR->eraseFromParent(); - } - } else { - PHINode *PHI = PHINode::Create(RTy, TheCall->getName(), AfterCallBB->begin()); - PHIs.push_back(PHI); - // 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 adding entries to the PHI node as - // appropriate. - if (!PHIs.empty()) { - // There is atleast one return value. - unsigned NumRetVals = 1; - if (STy) - NumRetVals = STy->getNumElements(); - for (unsigned j = 0; j < NumRetVals; ++j) { - PHINode *PHI = PHIs[j]; - // Each PHI node will receive one value from each return instruction. - for(unsigned i = 0, e = Returns.size(); i != e; ++i) { - ReturnInst *RI = Returns[i]; - assert(RI->getReturnValue(j)->getType() == PHI->getType() && - "Ret value not consistent in function!"); - PHI->addIncoming(RI->getReturnValue(j /*PHI number matches operand number*/), - RI->getParent()); - } - } - } - - // Add a branch to the merge points and remove retrun 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()); - - // Splice the code from the return block into the block that it will return - // to, which contains the code that was after the call. - BasicBlock *ReturnBB = Returns[0]->getParent(); - AfterCallBB->getInstList().splice(AfterCallBB->begin(), - ReturnBB->getInstList()); - - // Update PHI nodes that use the ReturnBB to use the AfterCallBB. - ReturnBB->replaceAllUsesWith(AfterCallBB); - - // Delete the return instruction now and empty ReturnBB now. - Returns[0]->eraseFromParent(); - ReturnBB->eraseFromParent(); - } 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())); - } - - // Since we are now done with the Call/Invoke, we can delete it. - TheCall->eraseFromParent(); - - // We should always be able to fold the entry block of the function into the - // single predecessor of the block... - assert(cast<BranchInst>(Br)->isUnconditional() && "splitBasicBlock broken!"); - BasicBlock *CalleeEntry = cast<BranchInst>(Br)->getSuccessor(0); - - // Splice the code entry block into calling block, right before the - // unconditional branch. - OrigBB->getInstList().splice(Br, CalleeEntry->getInstList()); - CalleeEntry->replaceAllUsesWith(OrigBB); // Update PHI nodes - - // Remove the unconditional branch. - OrigBB->getInstList().erase(Br); - - // Now we can remove the CalleeEntry block, which is now empty. - Caller->getBasicBlockList().erase(CalleeEntry); - - return true; -} |