1 //===- InlineSimple.cpp - Code to perform simple function inlining --------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements bottom-up inlining of functions into callees.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/Analysis/AssumptionCache.h"
14 #include "llvm/Analysis/InlineCost.h"
15 #include "llvm/Analysis/OptimizationRemarkEmitter.h"
16 #include "llvm/Analysis/TargetTransformInfo.h"
17 #include "llvm/InitializePasses.h"
18 #include "llvm/Transforms/IPO.h"
19 #include "llvm/Transforms/IPO/Inliner.h"
20 
21 using namespace llvm;
22 
23 #define DEBUG_TYPE "inline"
24 
25 namespace {
26 
27 /// Actual inliner pass implementation.
28 ///
29 /// The common implementation of the inlining logic is shared between this
30 /// inliner pass and the always inliner pass. The two passes use different cost
31 /// analyses to determine when to inline.
32 class SimpleInliner : public LegacyInlinerBase {
33 
34   InlineParams Params;
35 
36 public:
37   SimpleInliner() : LegacyInlinerBase(ID), Params(llvm::getInlineParams()) {
38     initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
39   }
40 
41   explicit SimpleInliner(InlineParams Params)
42       : LegacyInlinerBase(ID), Params(std::move(Params)) {
43     initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
44   }
45 
46   static char ID; // Pass identification, replacement for typeid
47 
48   InlineCost getInlineCost(CallBase &CB) override {
49     Function *Callee = CB.getCalledFunction();
50     TargetTransformInfo &TTI = TTIWP->getTTI(*Callee);
51 
52     bool RemarksEnabled = false;
53     const auto &BBs = CB.getCaller()->getBasicBlockList();
54     if (!BBs.empty()) {
55       auto DI = OptimizationRemark(DEBUG_TYPE, "", DebugLoc(), &BBs.front());
56       if (DI.isEnabled())
57         RemarksEnabled = true;
58     }
59     OptimizationRemarkEmitter ORE(CB.getCaller());
60 
61     std::function<AssumptionCache &(Function &)> GetAssumptionCache =
62         [&](Function &F) -> AssumptionCache & {
63       return ACT->getAssumptionCache(F);
64     };
65     return llvm::getInlineCost(CB, Params, TTI, GetAssumptionCache, GetTLI,
66                                /*GetBFI=*/nullptr, PSI,
67                                RemarksEnabled ? &ORE : nullptr);
68   }
69 
70   bool runOnSCC(CallGraphSCC &SCC) override;
71   void getAnalysisUsage(AnalysisUsage &AU) const override;
72 
73 private:
74   TargetTransformInfoWrapperPass *TTIWP;
75 
76 };
77 
78 } // end anonymous namespace
79 
80 char SimpleInliner::ID = 0;
81 INITIALIZE_PASS_BEGIN(SimpleInliner, "inline", "Function Integration/Inlining",
82                       false, false)
83 INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
84 INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
85 INITIALIZE_PASS_DEPENDENCY(ProfileSummaryInfoWrapperPass)
86 INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
87 INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
88 INITIALIZE_PASS_END(SimpleInliner, "inline", "Function Integration/Inlining",
89                     false, false)
90 
91 Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); }
92 
93 Pass *llvm::createFunctionInliningPass(int Threshold) {
94   return new SimpleInliner(llvm::getInlineParams(Threshold));
95 }
96 
97 Pass *llvm::createFunctionInliningPass(unsigned OptLevel,
98                                        unsigned SizeOptLevel,
99                                        bool DisableInlineHotCallSite) {
100   auto Param = llvm::getInlineParams(OptLevel, SizeOptLevel);
101   if (DisableInlineHotCallSite)
102     Param.HotCallSiteThreshold = 0;
103   return new SimpleInliner(Param);
104 }
105 
106 Pass *llvm::createFunctionInliningPass(InlineParams &Params) {
107   return new SimpleInliner(Params);
108 }
109 
110 bool SimpleInliner::runOnSCC(CallGraphSCC &SCC) {
111   TTIWP = &getAnalysis<TargetTransformInfoWrapperPass>();
112   return LegacyInlinerBase::runOnSCC(SCC);
113 }
114 
115 void SimpleInliner::getAnalysisUsage(AnalysisUsage &AU) const {
116   AU.addRequired<TargetTransformInfoWrapperPass>();
117   LegacyInlinerBase::getAnalysisUsage(AU);
118 }
119