InlineSimple.cpp revision 36b56886974eae4f9c5ebc96befd3e7bfe5de338 
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#define DEBUG_TYPE "inline"
15#include "llvm/Transforms/IPO.h"
16#include "llvm/Analysis/CallGraph.h"
17#include "llvm/Analysis/InlineCost.h"
18#include "llvm/IR/CallSite.h"
19#include "llvm/IR/CallingConv.h"
20#include "llvm/IR/DataLayout.h"
21#include "llvm/IR/Instructions.h"
22#include "llvm/IR/IntrinsicInst.h"
23#include "llvm/IR/Module.h"
24#include "llvm/IR/Type.h"
25#include "llvm/Transforms/IPO/InlinerPass.h"
26
27using namespace llvm;
28
29namespace {
30
31/// \brief Actual inliner pass implementation.
32///
33/// The common implementation of the inlining logic is shared between this
34/// inliner pass and the always inliner pass. The two passes use different cost
35/// analyses to determine when to inline.
36class SimpleInliner : public Inliner {
37  InlineCostAnalysis *ICA;
38
39public:
40  SimpleInliner() : Inliner(ID), ICA(0) {
41    initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
42  }
43
44  SimpleInliner(int Threshold)
45      : Inliner(ID, Threshold, /*InsertLifetime*/ true), ICA(0) {
46    initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
47  }
48
49  static char ID; // Pass identification, replacement for typeid
50
51  InlineCost getInlineCost(CallSite CS) override {
52    return ICA->getInlineCost(CS, getInlineThreshold(CS));
53  }
54
55  bool runOnSCC(CallGraphSCC &SCC) override;
56  void getAnalysisUsage(AnalysisUsage &AU) const override;
57};
58
59static int computeThresholdFromOptLevels(unsigned OptLevel,
60                                         unsigned SizeOptLevel) {
61  if (OptLevel > 2)
62    return 275;
63  if (SizeOptLevel == 1) // -Os
64    return 75;
65  if (SizeOptLevel == 2) // -Oz
66    return 25;
67  return 225;
68}
69
70} // end anonymous namespace
71
72char SimpleInliner::ID = 0;
73INITIALIZE_PASS_BEGIN(SimpleInliner, "inline",
74                "Function Integration/Inlining", false, false)
75INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
76INITIALIZE_PASS_DEPENDENCY(InlineCostAnalysis)
77INITIALIZE_PASS_END(SimpleInliner, "inline",
78                "Function Integration/Inlining", false, false)
79
80Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); }
81
82Pass *llvm::createFunctionInliningPass(int Threshold) {
83  return new SimpleInliner(Threshold);
84}
85
86Pass *llvm::createFunctionInliningPass(unsigned OptLevel,
87                                       unsigned SizeOptLevel) {
88  return new SimpleInliner(
89      computeThresholdFromOptLevels(OptLevel, SizeOptLevel));
90}
91
92bool SimpleInliner::runOnSCC(CallGraphSCC &SCC) {
93  ICA = &getAnalysis<InlineCostAnalysis>();
94  return Inliner::runOnSCC(SCC);
95}
96
97void SimpleInliner::getAnalysisUsage(AnalysisUsage &AU) const {
98  AU.addRequired<InlineCostAnalysis>();
99  Inliner::getAnalysisUsage(AU);
100}
101