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/CallGraph.h"
16 #include "llvm/Analysis/InlineCost.h"
17 #include "llvm/IR/CallSite.h"
18 #include "llvm/IR/CallingConv.h"
19 #include "llvm/IR/DataLayout.h"
20 #include "llvm/IR/Instructions.h"
21 #include "llvm/IR/IntrinsicInst.h"
22 #include "llvm/IR/Module.h"
23 #include "llvm/IR/Type.h"
24 #include "llvm/Transforms/IPO/InlinerPass.h"
25
26 using namespace llvm;
27
28 #define DEBUG_TYPE "inline"
29
30 namespace {
31
32 /// \brief Actual inliner pass implementation.
33 ///
34 /// The common implementation of the inlining logic is shared between this
35 /// inliner pass and the always inliner pass. The two passes use different cost
36 /// analyses to determine when to inline.
37 class SimpleInliner : public Inliner {
38 InlineCostAnalysis *ICA;
39
40 public:
SimpleInliner()41 SimpleInliner() : Inliner(ID), ICA(nullptr) {
42 initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
43 }
44
SimpleInliner(int Threshold)45 SimpleInliner(int Threshold)
46 : Inliner(ID, Threshold, /*InsertLifetime*/ true), ICA(nullptr) {
47 initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
48 }
49
50 static char ID; // Pass identification, replacement for typeid
51
getInlineCost(CallSite CS)52 InlineCost getInlineCost(CallSite CS) override {
53 return ICA->getInlineCost(CS, getInlineThreshold(CS));
54 }
55
56 bool runOnSCC(CallGraphSCC &SCC) override;
57 void getAnalysisUsage(AnalysisUsage &AU) const override;
58 };
59
computeThresholdFromOptLevels(unsigned OptLevel,unsigned SizeOptLevel)60 static int computeThresholdFromOptLevels(unsigned OptLevel,
61 unsigned SizeOptLevel) {
62 if (OptLevel > 2)
63 return 275;
64 if (SizeOptLevel == 1) // -Os
65 return 75;
66 if (SizeOptLevel == 2) // -Oz
67 return 25;
68 return 225;
69 }
70
71 } // end anonymous namespace
72
73 char SimpleInliner::ID = 0;
74 INITIALIZE_PASS_BEGIN(SimpleInliner, "inline",
75 "Function Integration/Inlining", false, false)
INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)76 INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
77 INITIALIZE_PASS_DEPENDENCY(InlineCostAnalysis)
78 INITIALIZE_PASS_END(SimpleInliner, "inline",
79 "Function Integration/Inlining", false, false)
80
81 Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); }
82
createFunctionInliningPass(int Threshold)83 Pass *llvm::createFunctionInliningPass(int Threshold) {
84 return new SimpleInliner(Threshold);
85 }
86
createFunctionInliningPass(unsigned OptLevel,unsigned SizeOptLevel)87 Pass *llvm::createFunctionInliningPass(unsigned OptLevel,
88 unsigned SizeOptLevel) {
89 return new SimpleInliner(
90 computeThresholdFromOptLevels(OptLevel, SizeOptLevel));
91 }
92
runOnSCC(CallGraphSCC & SCC)93 bool SimpleInliner::runOnSCC(CallGraphSCC &SCC) {
94 ICA = &getAnalysis<InlineCostAnalysis>();
95 return Inliner::runOnSCC(SCC);
96 }
97
getAnalysisUsage(AnalysisUsage & AU) const98 void SimpleInliner::getAnalysisUsage(AnalysisUsage &AU) const {
99 AU.addRequired<InlineCostAnalysis>();
100 Inliner::getAnalysisUsage(AU);
101 }
102