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/AliasAnalysis.h"
16#include "llvm/Analysis/AssumptionCache.h"
17#include "llvm/Analysis/CallGraph.h"
18#include "llvm/Analysis/InlineCost.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
28using namespace llvm;
29
30#define DEBUG_TYPE "inline"
31
32namespace {
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.
39class SimpleInliner : public Inliner {
40  InlineCostAnalysis *ICA;
41
42public:
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
62static 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
75char SimpleInliner::ID = 0;
76INITIALIZE_PASS_BEGIN(SimpleInliner, "inline",
77                "Function Integration/Inlining", false, false)
78INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
79INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
80INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
81INITIALIZE_PASS_DEPENDENCY(InlineCostAnalysis)
82INITIALIZE_PASS_END(SimpleInliner, "inline",
83                "Function Integration/Inlining", false, false)
84
85Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); }
86
87Pass *llvm::createFunctionInliningPass(int Threshold) {
88  return new SimpleInliner(Threshold);
89}
90
91Pass *llvm::createFunctionInliningPass(unsigned OptLevel,
92                                       unsigned SizeOptLevel) {
93  return new SimpleInliner(
94      computeThresholdFromOptLevels(OptLevel, SizeOptLevel));
95}
96
97bool SimpleInliner::runOnSCC(CallGraphSCC &SCC) {
98  ICA = &getAnalysis<InlineCostAnalysis>();
99  return Inliner::runOnSCC(SCC);
100}
101
102void SimpleInliner::getAnalysisUsage(AnalysisUsage &AU) const {
103  AU.addRequired<InlineCostAnalysis>();
104  Inliner::getAnalysisUsage(AU);
105}
106