lib/Transforms/IPO/InlineSimple.cpp

   1 //===- InlineSimple.cpp - Code to perform simple function inlining --------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file implements bottom-up inlining of functions into callees.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Transforms/IPO.h"
  15 #include "llvm/Analysis/AssumptionCache.h"
  16 #include "llvm/Analysis/CallGraph.h"
  17 #include "llvm/Analysis/InlineCost.h"
  18 #include "llvm/Analysis/TargetLibraryInfo.h"
  19 #include "llvm/IR/CallSite.h"
  20 #include "llvm/IR/CallingConv.h"
  21 #include "llvm/IR/DataLayout.h"
  22 #include "llvm/IR/Instructions.h"
  23 #include "llvm/IR/IntrinsicInst.h"
  24 #include "llvm/IR/Module.h"
  25 #include "llvm/IR/Type.h"
  26 #include "llvm/Transforms/IPO/InlinerPass.h"
  27
  28 using namespace llvm;
  29
  30 #define DEBUG_TYPE "inline"
  31
  32 namespace {
  33
  34 /// \brief Actual inliner pass implementation.
  35 ///
  36 /// The common implementation of the inlining logic is shared between this
  37 /// inliner pass and the always inliner pass. The two passes use different cost
  38 /// analyses to determine when to inline.
  39 class SimpleInliner : public Inliner {
  40   InlineCostAnalysis *ICA;
  41
  42 public:
  43   SimpleInliner() : Inliner(ID), ICA(nullptr) {
  44     initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
  45   }
  46
  47   SimpleInliner(int Threshold)
  48       : Inliner(ID, Threshold, /*InsertLifetime*/ true), ICA(nullptr) {
  49     initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
  50   }
  51
  52   static char ID; // Pass identification, replacement for typeid
  53
  54   InlineCost getInlineCost(CallSite CS) override {
  55     return ICA->getInlineCost(CS, getInlineThreshold(CS));
  56   }
  57
  58   bool runOnSCC(CallGraphSCC &SCC) override;
  59   void getAnalysisUsage(AnalysisUsage &AU) const override;
  60 };
  61
  62 static int computeThresholdFromOptLevels(unsigned OptLevel,
  63                                          unsigned SizeOptLevel) {
  64   if (OptLevel > 2)
  65     return 275;
  66   if (SizeOptLevel == 1) // -Os
  67     return 75;
  68   if (SizeOptLevel == 2) // -Oz
  69     return 25;
  70   return 225;
  71 }
  72
  73 } // end anonymous namespace
  74
  75 char SimpleInliner::ID = 0;
  76 INITIALIZE_PASS_BEGIN(SimpleInliner, "inline",
  77                 "Function Integration/Inlining", false, false)
  78 INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
  79 INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
  80 INITIALIZE_PASS_DEPENDENCY(InlineCostAnalysis)
  81 INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
  82 INITIALIZE_PASS_END(SimpleInliner, "inline",
  83                 "Function Integration/Inlining", false, false)
  84
  85 Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); }
  86
  87 Pass *llvm::createFunctionInliningPass(int Threshold) {
  88   return new SimpleInliner(Threshold);
  89 }
  90
  91 Pass *llvm::createFunctionInliningPass(unsigned OptLevel,
  92                                        unsigned SizeOptLevel) {
  93   return new SimpleInliner(
  94       computeThresholdFromOptLevels(OptLevel, SizeOptLevel));
  95 }
  96
  97 bool SimpleInliner::runOnSCC(CallGraphSCC &SCC) {
  98   ICA = &getAnalysis<InlineCostAnalysis>();
  99   return Inliner::runOnSCC(SCC);
 100 }
 101
 102 void SimpleInliner::getAnalysisUsage(AnalysisUsage &AU) const {
 103   AU.addRequired<InlineCostAnalysis>();
 104   Inliner::getAnalysisUsage(AU);
 105 }