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/ProfileSummaryInfo.h"
18 #include "llvm/Analysis/TargetLibraryInfo.h"
19 #include "llvm/Analysis/TargetTransformInfo.h"
20 #include "llvm/IR/CallSite.h"
21 #include "llvm/IR/CallingConv.h"
22 #include "llvm/IR/DataLayout.h"
23 #include "llvm/IR/Instructions.h"
24 #include "llvm/IR/IntrinsicInst.h"
25 #include "llvm/IR/Module.h"
26 #include "llvm/IR/Type.h"
27 #include "llvm/Transforms/IPO.h"
28 #include "llvm/Transforms/IPO/InlinerPass.h"
29 
30 using namespace llvm;
31 
32 #define DEBUG_TYPE "inline"
33 
34 namespace {
35 
36 /// \brief Actual inliner pass implementation.
37 ///
38 /// The common implementation of the inlining logic is shared between this
39 /// inliner pass and the always inliner pass. The two passes use different cost
40 /// analyses to determine when to inline.
41 class SimpleInliner : public Inliner {
42   // This field is populated based on one of the following:
43   //  * optimization or size-optimization levels,
44   //  * the --inline-threshold flag, or
45   //  * a user specified value.
46   int DefaultThreshold;
47 
48 public:
49   SimpleInliner()
50       : Inliner(ID), DefaultThreshold(llvm::getDefaultInlineThreshold()) {
51     initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
52   }
53 
54   explicit SimpleInliner(int Threshold)
55       : Inliner(ID), DefaultThreshold(Threshold) {
56     initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
57   }
58 
59   static char ID; // Pass identification, replacement for typeid
60 
61   InlineCost getInlineCost(CallSite CS) override {
62     Function *Callee = CS.getCalledFunction();
63     TargetTransformInfo &TTI = TTIWP->getTTI(*Callee);
64     std::function<AssumptionCache &(Function &)> GetAssumptionCache = [&](
65         Function &F) -> AssumptionCache & {
66       return ACT->getAssumptionCache(F);
67     };
68     return llvm::getInlineCost(CS, DefaultThreshold, TTI, GetAssumptionCache,
69                                PSI);
70   }
71 
72   bool runOnSCC(CallGraphSCC &SCC) override;
73   void getAnalysisUsage(AnalysisUsage &AU) const override;
74 
75 private:
76   TargetTransformInfoWrapperPass *TTIWP;
77 };
78 
79 } // end anonymous namespace
80 
81 char SimpleInliner::ID = 0;
82 INITIALIZE_PASS_BEGIN(SimpleInliner, "inline",
83                 "Function Integration/Inlining", false, false)
84 INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
85 INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
86 INITIALIZE_PASS_DEPENDENCY(ProfileSummaryInfoWrapperPass)
87 INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
88 INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
89 INITIALIZE_PASS_END(SimpleInliner, "inline",
90                 "Function Integration/Inlining", false, false)
91 
92 Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); }
93 
94 Pass *llvm::createFunctionInliningPass(int Threshold) {
95   return new SimpleInliner(Threshold);
96 }
97 
98 Pass *llvm::createFunctionInliningPass(unsigned OptLevel,
99                                        unsigned SizeOptLevel) {
100   return new SimpleInliner(
101       llvm::computeThresholdFromOptLevels(OptLevel, SizeOptLevel));
102 }
103 
104 bool SimpleInliner::runOnSCC(CallGraphSCC &SCC) {
105   TTIWP = &getAnalysis<TargetTransformInfoWrapperPass>();
106   return Inliner::runOnSCC(SCC);
107 }
108 
109 void SimpleInliner::getAnalysisUsage(AnalysisUsage &AU) const {
110   AU.addRequired<TargetTransformInfoWrapperPass>();
111   Inliner::getAnalysisUsage(AU);
112 }
113