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/Inliner.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 LegacyInlinerBase {
42 
43   InlineParams Params;
44 
45 public:
46   SimpleInliner() : LegacyInlinerBase(ID), Params(llvm::getInlineParams()) {
47     initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
48   }
49 
50   explicit SimpleInliner(InlineParams Params)
51       : LegacyInlinerBase(ID), Params(std::move(Params)) {
52     initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
53   }
54 
55   static char ID; // Pass identification, replacement for typeid
56 
57   InlineCost getInlineCost(CallSite CS) override {
58     Function *Callee = CS.getCalledFunction();
59     TargetTransformInfo &TTI = TTIWP->getTTI(*Callee);
60 
61     bool RemarksEnabled = false;
62     const auto &BBs = CS.getCaller()->getBasicBlockList();
63     if (!BBs.empty()) {
64       auto DI = OptimizationRemark(DEBUG_TYPE, "", DebugLoc(), &BBs.front());
65       if (DI.isEnabled())
66         RemarksEnabled = true;
67     }
68     OptimizationRemarkEmitter ORE(CS.getCaller());
69 
70     std::function<AssumptionCache &(Function &)> GetAssumptionCache =
71         [&](Function &F) -> AssumptionCache & {
72       return ACT->getAssumptionCache(F);
73     };
74     return llvm::getInlineCost(CS, Params, TTI, GetAssumptionCache,
75                                /*GetBFI=*/None, PSI,
76                                RemarksEnabled ? &ORE : nullptr);
77   }
78 
79   bool runOnSCC(CallGraphSCC &SCC) override;
80   void getAnalysisUsage(AnalysisUsage &AU) const override;
81 
82 private:
83   TargetTransformInfoWrapperPass *TTIWP;
84 
85 };
86 
87 } // end anonymous namespace
88 
89 char SimpleInliner::ID = 0;
90 INITIALIZE_PASS_BEGIN(SimpleInliner, "inline", "Function Integration/Inlining",
91                       false, false)
92 INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
93 INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
94 INITIALIZE_PASS_DEPENDENCY(ProfileSummaryInfoWrapperPass)
95 INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
96 INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
97 INITIALIZE_PASS_END(SimpleInliner, "inline", "Function Integration/Inlining",
98                     false, false)
99 
100 Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); }
101 
102 Pass *llvm::createFunctionInliningPass(int Threshold) {
103   return new SimpleInliner(llvm::getInlineParams(Threshold));
104 }
105 
106 Pass *llvm::createFunctionInliningPass(unsigned OptLevel,
107                                        unsigned SizeOptLevel,
108                                        bool DisableInlineHotCallSite) {
109   auto Param = llvm::getInlineParams(OptLevel, SizeOptLevel);
110   if (DisableInlineHotCallSite)
111     Param.HotCallSiteThreshold = 0;
112   return new SimpleInliner(Param);
113 }
114 
115 Pass *llvm::createFunctionInliningPass(InlineParams &Params) {
116   return new SimpleInliner(Params);
117 }
118 
119 bool SimpleInliner::runOnSCC(CallGraphSCC &SCC) {
120   TTIWP = &getAnalysis<TargetTransformInfoWrapperPass>();
121   return LegacyInlinerBase::runOnSCC(SCC);
122 }
123 
124 void SimpleInliner::getAnalysisUsage(AnalysisUsage &AU) const {
125   AU.addRequired<TargetTransformInfoWrapperPass>();
126   LegacyInlinerBase::getAnalysisUsage(AU);
127 }
128