Devang Patel | 6899b31 | 2007-07-25 18:00:25 +0000 | [diff] [blame] | 1 | //===- BasicInliner.cpp - Basic function level inliner --------------------===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
Chris Lattner | 4ee451d | 2007-12-29 20:36:04 +0000 | [diff] [blame^] | 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
Devang Patel | 6899b31 | 2007-07-25 18:00:25 +0000 | [diff] [blame] | 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // This file defines a simple function based inliner that does not use |
| 11 | // call graph information. |
| 12 | // |
| 13 | //===----------------------------------------------------------------------===// |
| 14 | |
| 15 | #define DEBUG_TYPE "basicinliner" |
| 16 | |
| 17 | #include "llvm/Module.h" |
| 18 | #include "llvm/Function.h" |
| 19 | #include "llvm/Transforms/Utils/BasicInliner.h" |
| 20 | #include "llvm/Transforms/Utils/Cloning.h" |
| 21 | #include "llvm/Support/CallSite.h" |
| 22 | #include "llvm/Support/CommandLine.h" |
| 23 | #include "llvm/Support/Debug.h" |
| 24 | #include "llvm/ADT/SmallPtrSet.h" |
| 25 | #include <vector> |
Devang Patel | 6899b31 | 2007-07-25 18:00:25 +0000 | [diff] [blame] | 26 | |
| 27 | using namespace llvm; |
| 28 | |
| 29 | namespace { |
| 30 | cl::opt<unsigned> |
| 31 | BasicInlineThreshold("inline-threshold", cl::Hidden, cl::init(200), |
| 32 | cl::desc("Control the amount of basic inlining to perform (default = 200)")); |
| 33 | } |
| 34 | |
| 35 | namespace llvm { |
| 36 | |
| 37 | /// BasicInlinerImpl - BasicInliner implemantation class. This hides |
| 38 | /// container info, used by basic inliner, from public interface. |
| 39 | struct VISIBILITY_HIDDEN BasicInlinerImpl { |
| 40 | |
| 41 | BasicInlinerImpl(const BasicInlinerImpl&); // DO NOT IMPLEMENT |
| 42 | void operator=(const BasicInlinerImpl&); // DO NO IMPLEMENT |
| 43 | public: |
| 44 | BasicInlinerImpl(TargetData *T) : TD(T) {} |
| 45 | |
| 46 | /// addFunction - Add function into the list of functions to process. |
| 47 | /// All functions must be inserted using this interface before invoking |
| 48 | /// inlineFunctions(). |
| 49 | void addFunction(Function *F) { |
| 50 | Functions.push_back(F); |
| 51 | } |
| 52 | |
| 53 | /// neverInlineFunction - Sometimes a function is never to be inlined |
| 54 | /// because of one or other reason. |
| 55 | void neverInlineFunction(Function *F) { |
| 56 | NeverInline.insert(F); |
| 57 | } |
| 58 | |
| 59 | /// inlineFuctions - Walk all call sites in all functions supplied by |
| 60 | /// client. Inline as many call sites as possible. Delete completely |
| 61 | /// inlined functions. |
| 62 | void inlineFunctions(); |
| 63 | |
| 64 | private: |
| 65 | TargetData *TD; |
| 66 | std::vector<Function *> Functions; |
Devang Patel | 29381fb | 2007-07-27 18:34:27 +0000 | [diff] [blame] | 67 | SmallPtrSet<const Function *, 16> NeverInline; |
Devang Patel | 6899b31 | 2007-07-25 18:00:25 +0000 | [diff] [blame] | 68 | SmallPtrSet<Function *, 8> DeadFunctions; |
| 69 | InlineCostAnalyzer CA; |
| 70 | }; |
| 71 | |
| 72 | /// inlineFuctions - Walk all call sites in all functions supplied by |
| 73 | /// client. Inline as many call sites as possible. Delete completely |
| 74 | /// inlined functions. |
| 75 | void BasicInlinerImpl::inlineFunctions() { |
| 76 | |
| 77 | // Scan through and identify all call sites ahead of time so that we only |
| 78 | // inline call sites in the original functions, not call sites that result |
| 79 | // from inlining other functions. |
| 80 | std::vector<CallSite> CallSites; |
| 81 | |
| 82 | for (std::vector<Function *>::iterator FI = Functions.begin(), |
| 83 | FE = Functions.end(); FI != FE; ++FI) { |
| 84 | Function *F = *FI; |
| 85 | for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) |
| 86 | for (BasicBlock::iterator I = BB->begin(); I != BB->end(); ++I) { |
| 87 | CallSite CS = CallSite::get(I); |
| 88 | if (CS.getInstruction() && CS.getCalledFunction() |
| 89 | && !CS.getCalledFunction()->isDeclaration()) |
| 90 | CallSites.push_back(CS); |
| 91 | } |
| 92 | } |
| 93 | |
| 94 | DOUT << ": " << CallSites.size() << " call sites.\n"; |
| 95 | |
| 96 | // Inline call sites. |
| 97 | bool Changed = false; |
| 98 | do { |
| 99 | Changed = false; |
| 100 | for (unsigned index = 0; index != CallSites.size() && !CallSites.empty(); ++index) { |
| 101 | CallSite CS = CallSites[index]; |
| 102 | if (Function *Callee = CS.getCalledFunction()) { |
| 103 | |
| 104 | // Eliminate calls taht are never inlinable. |
| 105 | if (Callee->isDeclaration() || |
| 106 | CS.getInstruction()->getParent()->getParent() == Callee) { |
| 107 | CallSites.erase(CallSites.begin() + index); |
| 108 | --index; |
| 109 | continue; |
| 110 | } |
| 111 | int InlineCost = CA.getInlineCost(CS, NeverInline); |
| 112 | if (InlineCost >= (int) BasicInlineThreshold) { |
| 113 | DOUT << " NOT Inlining: cost = " << InlineCost |
| 114 | << ", call: " << *CS.getInstruction(); |
| 115 | continue; |
| 116 | } |
| 117 | |
| 118 | DOUT << " Inlining: cost=" << InlineCost |
| 119 | <<", call: " << *CS.getInstruction(); |
| 120 | |
| 121 | // Inline |
| 122 | if (InlineFunction(CS, NULL, TD)) { |
| 123 | if (Callee->use_empty() && Callee->hasInternalLinkage()) |
| 124 | DeadFunctions.insert(Callee); |
| 125 | Changed = true; |
| 126 | CallSites.erase(CallSites.begin() + index); |
| 127 | --index; |
| 128 | } |
| 129 | } |
| 130 | } |
| 131 | } while (Changed); |
| 132 | |
| 133 | // Remove completely inlined functions from module. |
| 134 | for(SmallPtrSet<Function *, 8>::iterator I = DeadFunctions.begin(), |
| 135 | E = DeadFunctions.end(); I != E; ++I) { |
| 136 | Function *D = *I; |
| 137 | Module *M = D->getParent(); |
| 138 | M->getFunctionList().remove(D); |
| 139 | } |
| 140 | } |
| 141 | |
| 142 | BasicInliner::BasicInliner(TargetData *TD) { |
| 143 | Impl = new BasicInlinerImpl(TD); |
| 144 | } |
| 145 | |
| 146 | BasicInliner::~BasicInliner() { |
| 147 | delete Impl; |
| 148 | } |
| 149 | |
| 150 | /// addFunction - Add function into the list of functions to process. |
| 151 | /// All functions must be inserted using this interface before invoking |
| 152 | /// inlineFunctions(). |
| 153 | void BasicInliner::addFunction(Function *F) { |
| 154 | Impl->addFunction(F); |
| 155 | } |
| 156 | |
| 157 | /// neverInlineFunction - Sometimes a function is never to be inlined because |
| 158 | /// of one or other reason. |
| 159 | void BasicInliner::neverInlineFunction(Function *F) { |
| 160 | Impl->neverInlineFunction(F); |
| 161 | } |
| 162 | |
| 163 | /// inlineFuctions - Walk all call sites in all functions supplied by |
| 164 | /// client. Inline as many call sites as possible. Delete completely |
| 165 | /// inlined functions. |
| 166 | void BasicInliner::inlineFunctions() { |
| 167 | Impl->inlineFunctions(); |
| 168 | } |
| 169 | |
| 170 | } |