X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=blobdiff_plain;f=lib%2FTransforms%2FIPO%2FInlineSimple.cpp;h=d72edf84805ee0707f441ad504f95314823c7cc0;hp=9e84138b08e34d681eb9c316b2f8c42a66e65609;hb=4ee451de366474b9c228b4e5fa573795a715216d;hpb=c6f3ae5c66c8e0dab6a2bd9601d0e253ef9ba794 diff --git a/lib/Transforms/IPO/InlineSimple.cpp b/lib/Transforms/IPO/InlineSimple.cpp index 9e84138b08e..d72edf84805 100644 --- a/lib/Transforms/IPO/InlineSimple.cpp +++ b/lib/Transforms/IPO/InlineSimple.cpp @@ -1,280 +1,88 @@ -//===- FunctionInlining.cpp - Code to perform function inlining -----------===// +//===- InlineSimple.cpp - Code to perform simple function inlining --------===// // -// This file implements inlining of functions. +// The LLVM Compiler Infrastructure // -// Specifically, this: -// * Exports functionality to inline any function call -// * Inlines functions that consist of a single basic block -// * Is able to inline ANY function call -// . Has a smart heuristic for when to inline a function +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. // -// Notice that: -// * This pass opens up a lot of opportunities for constant propogation. It -// is a good idea to to run a constant propogation pass, then a DCE pass -// sometime after running this pass. +//===----------------------------------------------------------------------===// // -// FIXME: This pass should transform alloca instructions in the called function -// into malloc/free pairs! +// This file implements bottom-up inlining of functions into callees. // //===----------------------------------------------------------------------===// -#include "llvm/Transforms/FunctionInlining.h" +#define DEBUG_TYPE "inline" +#include "llvm/CallingConv.h" +#include "llvm/Instructions.h" +#include "llvm/IntrinsicInst.h" #include "llvm/Module.h" -#include "llvm/Function.h" -#include "llvm/Pass.h" -#include "llvm/iTerminators.h" -#include "llvm/iPHINode.h" -#include "llvm/iOther.h" #include "llvm/Type.h" -#include "llvm/Argument.h" -#include -#include -using std::cerr; +#include "llvm/Analysis/CallGraph.h" +#include "llvm/Support/CallSite.h" +#include "llvm/Support/Compiler.h" +#include "llvm/Transforms/IPO.h" +#include "llvm/Transforms/IPO/InlinerPass.h" +#include "llvm/Transforms/Utils/InlineCost.h" +#include "llvm/ADT/SmallPtrSet.h" -// RemapInstruction - Convert the instruction operands from referencing the -// current values into those specified by ValueMap. -// -static inline void RemapInstruction(Instruction *I, - std::map &ValueMap) { +using namespace llvm; - for (unsigned op = 0, E = I->getNumOperands(); op != E; ++op) { - const Value *Op = I->getOperand(op); - Value *V = ValueMap[Op]; - if (!V && (isa(Op) || isa(Op))) - continue; // Globals and constants don't get relocated +namespace { - if (!V) { - cerr << "Val = \n" << Op << "Addr = " << (void*)Op; - cerr << "\nInst = " << I; + class VISIBILITY_HIDDEN SimpleInliner : public Inliner { + // Functions that are never inlined + SmallPtrSet NeverInline; + InlineCostAnalyzer CA; + public: + SimpleInliner() : Inliner(&ID) {} + static char ID; // Pass identification, replacement for typeid + int getInlineCost(CallSite CS) { + return CA.getInlineCost(CS, NeverInline); } - assert(V && "Referenced value not in value map!"); - I->setOperand(op, V); - } + virtual bool doInitialization(CallGraph &CG); + }; + char SimpleInliner::ID = 0; + RegisterPass X("inline", "Function Integration/Inlining"); } -// InlineFunction - This function forcibly 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 InlineFunction(BasicBlock::iterator CIIt) { - assert(isa(*CIIt) && "InlineFunction only works on CallInst nodes"); - assert((*CIIt)->getParent() && "Instruction not embedded in basic block!"); - assert((*CIIt)->getParent()->getParent() && "Instruction not in function!"); - - CallInst *CI = cast(*CIIt); - const Function *CalledMeth = CI->getCalledFunction(); - if (CalledMeth == 0 || // Can't inline external function or indirect call! - CalledMeth->isExternal()) return false; - - //cerr << "Inlining " << CalledMeth->getName() << " into " - // << CurrentMeth->getName() << "\n"; - - BasicBlock *OrigBB = CI->getParent(); - - // Call splitBasicBlock - The original basic block now ends at the instruction - // immediately before the call. The original basic block now ends with an - // unconditional branch to NewBB, and NewBB starts with the call instruction. - // - BasicBlock *NewBB = OrigBB->splitBasicBlock(CIIt); - NewBB->setName("InlinedFunctionReturnNode"); - - // Remove (unlink) the CallInst from the start of the new basic block. - NewBB->getInstList().remove(CI); - - // If we have a return value generated by this call, convert it into a PHI - // node that gets values from each of the old RET instructions in the original - // function. - // - PHINode *PHI = 0; - if (CalledMeth->getReturnType() != Type::VoidTy) { - PHI = new PHINode(CalledMeth->getReturnType(), CI->getName()); - - // The PHI node should go at the front of the new basic block to merge all - // possible incoming values. - // - NewBB->getInstList().push_front(PHI); - - // Anything that used the result of the function call should now use the PHI - // node as their operand. - // - CI->replaceAllUsesWith(PHI); - } - - // Keep a mapping between the original function's values and the new - // duplicated code's values. This includes all of: Function arguments, - // instruction values, constant pool entries, and basic blocks. - // - std::map ValueMap; +Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); } - // Add the function arguments to the mapping: (start counting at 1 to skip the - // function reference itself) - // - Function::ArgumentListType::const_iterator PTI = - CalledMeth->getArgumentList().begin(); - for (unsigned a = 1, E = CI->getNumOperands(); a != E; ++a, ++PTI) - ValueMap[*PTI] = CI->getOperand(a); +// doInitialization - Initializes the vector of functions that have been +// annotated with the noinline attribute. +bool SimpleInliner::doInitialization(CallGraph &CG) { + + Module &M = CG.getModule(); - ValueMap[NewBB] = NewBB; // Returns get converted to reference NewBB + // Get llvm.noinline + GlobalVariable *GV = M.getNamedGlobal("llvm.noinline"); + + if (GV == 0) + return false; - // Loop over all of the basic blocks in the function, inlining them as - // appropriate. Keep track of the first basic block of the function... - // - for (Function::const_iterator BI = CalledMeth->begin(); - BI != CalledMeth->end(); ++BI) { - const BasicBlock *BB = *BI; - assert(BB->getTerminator() && "BasicBlock doesn't have terminator!?!?"); + // Don't crash on invalid code + if (!GV->hasInitializer()) + return false; + + const ConstantArray *InitList = dyn_cast(GV->getInitializer()); + + if (InitList == 0) + return false; + + // Iterate over each element and add to the NeverInline set + for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { + + // Get Source + const Constant *Elt = InitList->getOperand(i); + + if (const ConstantExpr *CE = dyn_cast(Elt)) + if (CE->getOpcode() == Instruction::BitCast) + Elt = CE->getOperand(0); - // Create a new basic block to copy instructions into! - BasicBlock *IBB = new BasicBlock("", NewBB->getParent()); - if (BB->hasName()) IBB->setName(BB->getName()+".i"); // .i = inlined once - - ValueMap[BB] = IBB; // Add basic block mapping. - - // Make sure to capture the mapping that a return will use... - // TODO: This assumes that the RET is returning a value computed in the same - // basic block as the return was issued from! - // - const TerminatorInst *TI = BB->getTerminator(); - - // Loop over all instructions copying them over... - Instruction *NewInst; - for (BasicBlock::const_iterator II = BB->begin(); - II != (BB->end()-1); ++II) { - IBB->getInstList().push_back((NewInst = (*II)->clone())); - ValueMap[*II] = NewInst; // Add instruction map to value. - if ((*II)->hasName()) - NewInst->setName((*II)->getName()+".i"); // .i = inlined once - } - - // Copy over the terminator now... - switch (TI->getOpcode()) { - case Instruction::Ret: { - const ReturnInst *RI = cast(TI); - - if (PHI) { // The PHI node should include this value! - assert(RI->getReturnValue() && "Ret should have value!"); - assert(RI->getReturnValue()->getType() == PHI->getType() && - "Ret value not consistent in function!"); - PHI->addIncoming((Value*)RI->getReturnValue(), cast(BB)); - } - - // Add a branch to the code that was after the original Call. - IBB->getInstList().push_back(new BranchInst(NewBB)); - break; - } - case Instruction::Br: - IBB->getInstList().push_back(TI->clone()); - break; - - default: - cerr << "FunctionInlining: Don't know how to handle terminator: " << TI; - abort(); - } - } - - - // Loop over all of the instructions in the function, fixing up operand - // references as we go. This uses ValueMap to do all the hard work. - // - for (Function::const_iterator BI = CalledMeth->begin(); - BI != CalledMeth->end(); ++BI) { - const BasicBlock *BB = *BI; - BasicBlock *NBB = (BasicBlock*)ValueMap[BB]; - - // Loop over all instructions, fixing each one as we find it... - // - for (BasicBlock::iterator II = NBB->begin(); II != NBB->end(); II++) - RemapInstruction(*II, ValueMap); - } - - if (PHI) RemapInstruction(PHI, ValueMap); // Fix the PHI node also... - - // Change the branch that used to go to NewBB 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, ValueMap[CalledMeth->front()]); - - // Since we are now done with the CallInst, we can finally delete it. - delete CI; - return true; -} - -bool InlineFunction(CallInst *CI) { - assert(CI->getParent() && "CallInst not embeded in BasicBlock!"); - BasicBlock *PBB = CI->getParent(); - - BasicBlock::iterator CallIt = find(PBB->begin(), PBB->end(), CI); - - assert(CallIt != PBB->end() && - "CallInst has parent that doesn't contain CallInst?!?"); - return InlineFunction(CallIt); -} - -static inline bool ShouldInlineFunction(const CallInst *CI, const Function *F) { - assert(CI->getParent() && CI->getParent()->getParent() && - "Call not embedded into a function!"); - - // Don't inline a recursive call. - if (CI->getParent()->getParent() == F) return false; - - // Don't inline something too big. This is a really crappy heuristic - if (F->size() > 3) return false; - - // Don't inline into something too big. This is a **really** crappy heuristic - if (CI->getParent()->getParent()->size() > 10) return false; - - // Go ahead and try just about anything else. - return true; -} - - -static inline bool DoFunctionInlining(BasicBlock *BB) { - for (BasicBlock::iterator I = BB->begin(); I != BB->end(); ++I) { - if (CallInst *CI = dyn_cast(*I)) { - // Check to see if we should inline this function - Function *F = CI->getCalledFunction(); - if (F && ShouldInlineFunction(CI, F)) - return InlineFunction(I); - } + // Insert into set of functions to never inline + if (const Function *F = dyn_cast(Elt)) + NeverInline.insert(F); } + return false; } -// doFunctionInlining - Use a heuristic based approach to inline functions that -// seem to look good. -// -static bool doFunctionInlining(Function *F) { - bool Changed = false; - - // Loop through now and inline instructions a basic block at a time... - for (Function::iterator I = F->begin(); I != F->end(); ) - if (DoFunctionInlining(*I)) { - Changed = true; - // Iterator is now invalidated by new basic blocks inserted - I = F->begin(); - } else { - ++I; - } - - return Changed; -} - -namespace { - struct FunctionInlining : public FunctionPass { - const char *getPassName() const { return "Function Inlining"; } - virtual bool runOnFunction(Function *F) { - return doFunctionInlining(F); - } - }; -} - -Pass *createFunctionInliningPass() { return new FunctionInlining(); }