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/Analysis/AssumptionCache.h"
  15 #include "llvm/Analysis/CallGraph.h"
  16 #include "llvm/Analysis/InlineCost.h"
  17 #include "llvm/Analysis/TargetLibraryInfo.h"
  18 #include "llvm/Analysis/TargetTransformInfo.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.h"
  27 #include "llvm/Transforms/IPO/InlinerPass.h"
  28
  29 using namespace llvm;
  30
  31 #define DEBUG_TYPE "inline"
  32
  33 namespace {
  34
  35 /// \brief Actual inliner pass implementation.
  36 ///
  37 /// The common implementation of the inlining logic is shared between this
  38 /// inliner pass and the always inliner pass. The two passes use different cost
  39 /// analyses to determine when to inline.
  40 class SimpleInliner : public Inliner {
  41
  42 public:
  43   SimpleInliner() : Inliner(ID) {
  44     initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
  45   }
  46
  47   SimpleInliner(int Threshold)
  48       : Inliner(ID, Threshold, /*InsertLifetime*/ true) {
  49     initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
  50   }
  51
  52   static char ID; // Pass identification, replacement for typeid
  53
  54   InlineCost getInlineCost(CallSite CS) override {
  55     Function *Callee = CS.getCalledFunction();
  56     TargetTransformInfo &TTI = TTIWP->getTTI(*Callee);
  57     return llvm::getInlineCost(CS, getInlineThreshold(CS), TTI, ACT);
  58   }
  59
  60   bool runOnSCC(CallGraphSCC &SCC) override;
  61   void getAnalysisUsage(AnalysisUsage &AU) const override;
  62
  63 private:
  64   TargetTransformInfoWrapperPass *TTIWP;
  65 };
  66
  67 static int computeThresholdFromOptLevels(unsigned OptLevel,
  68                                          unsigned SizeOptLevel) {
  69   if (OptLevel > 2)
  70     return 275;
  71   if (SizeOptLevel == 1) // -Os
  72     return 75;
  73   if (SizeOptLevel == 2) // -Oz
  74     return 25;
  75   return 225;
  76 }
  77
  78 } // end anonymous namespace
  79
  80 char SimpleInliner::ID = 0;
  81 INITIALIZE_PASS_BEGIN(SimpleInliner, "inline",
  82                 "Function Integration/Inlining", false, false)
  83 INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
  84 INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
  85 INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
  86 INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
  87 INITIALIZE_PASS_END(SimpleInliner, "inline",
  88                 "Function Integration/Inlining", false, false)
  89
  90 Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); }
  91
  92 Pass *llvm::createFunctionInliningPass(int Threshold) {
  93   return new SimpleInliner(Threshold);
  94 }
  95
  96 Pass *llvm::createFunctionInliningPass(unsigned OptLevel,
  97                                        unsigned SizeOptLevel) {
  98   return new SimpleInliner(
  99       computeThresholdFromOptLevels(OptLevel, SizeOptLevel));
 100 }
 101
 102 bool SimpleInliner::runOnSCC(CallGraphSCC &SCC) {
 103   TTIWP = &getAnalysis<TargetTransformInfoWrapperPass>();
 104   return Inliner::runOnSCC(SCC);
 105 }
 106
 107 void SimpleInliner::getAnalysisUsage(AnalysisUsage &AU) const {
 108   AU.addRequired<TargetTransformInfoWrapperPass>();
 109   Inliner::getAnalysisUsage(AU);
 110 }