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   // This field is populated based on one of the following:
42   //  optimization or size optimization levels,
43   //  --inline-threshold flag,
44   //  user specified value.
45   int DefaultThreshold;
46 
47 public:
48   SimpleInliner()
49       : Inliner(ID), DefaultThreshold(llvm::getDefaultInlineThreshold()) {
50     initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
51   }
52 
53   SimpleInliner(int Threshold) : Inliner(ID), DefaultThreshold(Threshold) {
54     initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
55   }
56 
57   static char ID; // Pass identification, replacement for typeid
58 
59   InlineCost getInlineCost(CallSite CS) override {
60     Function *Callee = CS.getCalledFunction();
61     TargetTransformInfo &TTI = TTIWP->getTTI(*Callee);
62     return llvm::getInlineCost(CS, DefaultThreshold, TTI, ACT);
63   }
64 
65   bool runOnSCC(CallGraphSCC &SCC) override;
66   void getAnalysisUsage(AnalysisUsage &AU) const override;
67 
68 private:
69   TargetTransformInfoWrapperPass *TTIWP;
70 };
71 
72 } // end anonymous namespace
73 
74 char SimpleInliner::ID = 0;
75 INITIALIZE_PASS_BEGIN(SimpleInliner, "inline",
76                 "Function Integration/Inlining", false, false)
77 INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
78 INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
79 INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
80 INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
81 INITIALIZE_PASS_END(SimpleInliner, "inline",
82                 "Function Integration/Inlining", false, false)
83 
84 Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); }
85 
86 Pass *llvm::createFunctionInliningPass(int Threshold) {
87   return new SimpleInliner(Threshold);
88 }
89 
90 Pass *llvm::createFunctionInliningPass(unsigned OptLevel,
91                                        unsigned SizeOptLevel) {
92   return new SimpleInliner(
93       llvm::computeThresholdFromOptLevels(OptLevel, SizeOptLevel));
94 }
95 
96 bool SimpleInliner::runOnSCC(CallGraphSCC &SCC) {
97   TTIWP = &getAnalysis<TargetTransformInfoWrapperPass>();
98   return Inliner::runOnSCC(SCC);
99 }
100 
101 void SimpleInliner::getAnalysisUsage(AnalysisUsage &AU) const {
102   AU.addRequired<TargetTransformInfoWrapperPass>();
103   Inliner::getAnalysisUsage(AU);
104 }
105