X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTransforms%2FUtils%2FInlineFunction.cpp;h=3d31f71300ac7855ff59c48afd10c3b6b27156c7;hb=ece2c04d532d46405c085769d03173b392813eb3;hp=5ca9577c8c1f3ab74bbdceb3e37d7c59d46428eb;hpb=3799ed83b4cb80695a81294da6a7d18cf0884f5e;p=oota-llvm.git diff --git a/lib/Transforms/Utils/InlineFunction.cpp b/lib/Transforms/Utils/InlineFunction.cpp index 5ca9577c8c1..3d31f71300a 100644 --- a/lib/Transforms/Utils/InlineFunction.cpp +++ b/lib/Transforms/Utils/InlineFunction.cpp @@ -10,9 +10,6 @@ // This file implements inlining of a function into a call site, resolving // parameters and the return value as appropriate. // -// FIXME: This pass should transform alloca instructions in the called function -// into alloca/dealloca pairs! Or perhaps it should refuse to inline them! -// //===----------------------------------------------------------------------===// #include "llvm/Transforms/Utils/Cloning.h" @@ -21,11 +18,156 @@ #include "llvm/Module.h" #include "llvm/Instructions.h" #include "llvm/Intrinsics.h" +#include "llvm/Analysis/CallGraph.h" +#include "llvm/ADT/SmallVector.h" #include "llvm/Support/CallSite.h" using namespace llvm; -bool llvm::InlineFunction(CallInst *CI) { return InlineFunction(CallSite(CI)); } -bool llvm::InlineFunction(InvokeInst *II) {return InlineFunction(CallSite(II));} +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 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(I); ++I) { + PHINode *PN = cast(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(I)) continue; + CallInst *CI = cast(I); + + // If this call cannot unwind, don't convert it to an invoke. + if (CI->isNoUnwind()) + 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 InvokeArgs(CI->op_begin()+1, CI->op_end()); + InvokeInst *II = + new InvokeInst(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(I); ++I, ++i) { + PHINode *PN = cast(I); + PN->addIncoming(InvokeDestPHIValues[i], BB); + } + + // This basic block is now complete, start scanning the next one. + break; + } + } + + if (UnwindInst *UI = dyn_cast(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); + + // 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(I); ++I, ++i) { + PHINode *PN = cast(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 &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::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(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 @@ -36,14 +178,14 @@ bool llvm::InlineFunction(InvokeInst *II) {return InlineFunction(CallSite(II));} // exists in the instruction stream. Similiarly this will inline a recursive // function by one level. // -bool llvm::InlineFunction(CallSite CS) { +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->isExternal() || // call, or call to a vararg function! + CalledFunc->isDeclaration() || // call, or call to a vararg function! CalledFunc->getFunctionType()->isVarArg()) return false; @@ -63,52 +205,126 @@ bool llvm::InlineFunction(CallSite CS) { // Make sure to capture all of the return instructions from the cloned // function. std::vector Returns; + ClonedCodeInfo InlinedFunctionInfo; + Function::iterator FirstNewBlock; + { // Scope to destroy ValueMap after cloning. - // Calculate the vector of arguments to pass into the function cloner... - std::map ValueMap; + DenseMap ValueMap; + + // 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(); for (Function::const_arg_iterator I = CalledFunc->arg_begin(), E = CalledFunc->arg_end(); I != E; ++I, ++AI) ValueMap[I] = *AI; - // Clone the entire body of the callee into the caller. - CloneFunctionInto(Caller, CalledFunc, ValueMap, Returns, ".i"); + // 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); } - - // Remember the first block that is newly cloned over. - Function::iterator FirstNewBlock = LastBlock; ++FirstNewBlock; - + // 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. // - if (isa(FirstNewBlock->begin())) { + { BasicBlock::iterator InsertPoint = Caller->begin()->begin(); for (BasicBlock::iterator I = FirstNewBlock->begin(), E = FirstNewBlock->end(); I != E; ) - if (AllocaInst *AI = dyn_cast(I++)) + if (AllocaInst *AI = dyn_cast(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(AI->getArraySize())) { - // Scan for the block of allocas that we can move over. + // Scan for the block of allocas that we can move over, and move them + // all at once. while (isa(I) && isa(cast(I)->getArraySize())) ++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); } + } } - // If we are inlining tail call instruction through an invoke or - if (MustClearTailCallFlags) { + // 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(); + 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); + + // 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(StackSave)); + StackRestoreCGN = CG->getOrInsertFunction(cast(StackRestore)); + CallerNode = (*CG)[Caller]; + } + + // Insert the llvm.stacksave. + CallInst *SavedPtr = new CallInst(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]); + 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(TheCall)) { + for (Function::iterator BB = FirstNewBlock, E = Caller->end(); + BB != E; ++BB) + if (UnwindInst *UI = dyn_cast(BB->getTerminator())) { + new CallInst(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. + if (MustClearTailCallFlags && InlinedFunctionInfo.ContainsCalls) { for (Function::iterator BB = FirstNewBlock, E = Caller->end(); BB != E; ++BB) for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) @@ -119,92 +335,8 @@ bool llvm::InlineFunction(CallSite CS) { // 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(TheCall)) { - BasicBlock *InvokeDest = II->getUnwindDest(); - std::vector InvokeDestPHIValues; - - // If there are PHI nodes in the exceptional destination block, we need to - // keep track of which values came into them from this invoke, then remove - // the entry for this block. - for (BasicBlock::iterator I = InvokeDest->begin(); isa(I); ++I) { - PHINode *PN = cast(I); - // Save the value to use for this edge... - InvokeDestPHIValues.push_back(PN->getIncomingValueForBlock(OrigBB)); - } - - for (Function::iterator BB = FirstNewBlock, E = Caller->end(); - BB != E; ++BB) { - for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) { - // We only need to check for function calls: inlined invoke instructions - // require no special handling... - if (CallInst *CI = dyn_cast(I)) { - // Convert this function call into an invoke instruction... if it's - // not an intrinsic function call (which are known to not unwind). - if (CI->getCalledFunction() && - CI->getCalledFunction()->getIntrinsicID()) { - ++I; - } else { - // 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. - InvokeInst *II = - new InvokeInst(CI->getCalledValue(), Split, InvokeDest, - std::vector(CI->op_begin()+1, CI->op_end()), - CI->getName(), BB->getTerminator()); - - // 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(I); ++I, ++i) { - PHINode *PN = cast(I); - PN->addIncoming(InvokeDestPHIValues[i], BB); - } - - // This basic block is now complete, start scanning the next one. - break; - } - } else { - ++I; - } - } - - if (UnwindInst *UI = dyn_cast(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); - - // 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(I); ++I, ++i) { - PHINode *PN = cast(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()); - } + if (InvokeInst *II = dyn_cast(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 @@ -357,5 +489,6 @@ bool llvm::InlineFunction(CallSite CS) { // Now we can remove the CalleeEntry block, which is now empty. Caller->getBasicBlockList().erase(CalleeEntry); + return true; }