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/ProfileSummaryInfo.h"
16 #include "llvm/Analysis/TargetLibraryInfo.h"
17 #include "llvm/Analysis/TargetTransformInfo.h"
18 #include "llvm/IR/CallingConv.h"
19 #include "llvm/IR/DataLayout.h"
20 #include "llvm/IR/Instructions.h"
21 #include "llvm/IR/Module.h"
22 #include "llvm/IR/Type.h"
23 #include "llvm/InitializePasses.h"
24 #include "llvm/Transforms/IPO.h"
25 #include "llvm/Transforms/IPO/Inliner.h"
26 
27 using namespace llvm;
28 
29 #define DEBUG_TYPE "inline"
30 
31 namespace {
32 
33 /// Actual inliner pass implementation.
34 ///
35 /// The common implementation of the inlining logic is shared between this
36 /// inliner pass and the always inliner pass. The two passes use different cost
37 /// analyses to determine when to inline.
38 class SimpleInliner : public LegacyInlinerBase {
39 
40   InlineParams Params;
41 
42 public:
SimpleInliner()43   SimpleInliner() : LegacyInlinerBase(ID), Params(llvm::getInlineParams()) {
44     initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
45   }
46 
SimpleInliner(InlineParams Params)47   explicit SimpleInliner(InlineParams Params)
48       : LegacyInlinerBase(ID), Params(std::move(Params)) {
49     initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
50   }
51 
52   static char ID; // Pass identification, replacement for typeid
53 
getInlineCost(CallBase & CB)54   InlineCost getInlineCost(CallBase &CB) override {
55     Function *Callee = CB.getCalledFunction();
56     TargetTransformInfo &TTI = TTIWP->getTTI(*Callee);
57 
58     bool RemarksEnabled = false;
59     const auto &BBs = CB.getCaller()->getBasicBlockList();
60     if (!BBs.empty()) {
61       auto DI = OptimizationRemark(DEBUG_TYPE, "", DebugLoc(), &BBs.front());
62       if (DI.isEnabled())
63         RemarksEnabled = true;
64     }
65     OptimizationRemarkEmitter ORE(CB.getCaller());
66 
67     std::function<AssumptionCache &(Function &)> GetAssumptionCache =
68         [&](Function &F) -> AssumptionCache & {
69       return ACT->getAssumptionCache(F);
70     };
71     return llvm::getInlineCost(CB, Params, TTI, GetAssumptionCache, GetTLI,
72                                /*GetBFI=*/nullptr, PSI,
73                                RemarksEnabled ? &ORE : nullptr);
74   }
75 
76   bool runOnSCC(CallGraphSCC &SCC) override;
77   void getAnalysisUsage(AnalysisUsage &AU) const override;
78 
79 private:
80   TargetTransformInfoWrapperPass *TTIWP;
81 
82 };
83 
84 } // end anonymous namespace
85 
86 char SimpleInliner::ID = 0;
87 INITIALIZE_PASS_BEGIN(SimpleInliner, "inline", "Function Integration/Inlining",
88                       false, false)
INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)89 INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
90 INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
91 INITIALIZE_PASS_DEPENDENCY(ProfileSummaryInfoWrapperPass)
92 INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
93 INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
94 INITIALIZE_PASS_END(SimpleInliner, "inline", "Function Integration/Inlining",
95                     false, false)
96 
97 Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); }
98 
createFunctionInliningPass(int Threshold)99 Pass *llvm::createFunctionInliningPass(int Threshold) {
100   return new SimpleInliner(llvm::getInlineParams(Threshold));
101 }
102 
createFunctionInliningPass(unsigned OptLevel,unsigned SizeOptLevel,bool DisableInlineHotCallSite)103 Pass *llvm::createFunctionInliningPass(unsigned OptLevel,
104                                        unsigned SizeOptLevel,
105                                        bool DisableInlineHotCallSite) {
106   auto Param = llvm::getInlineParams(OptLevel, SizeOptLevel);
107   if (DisableInlineHotCallSite)
108     Param.HotCallSiteThreshold = 0;
109   return new SimpleInliner(Param);
110 }
111 
createFunctionInliningPass(InlineParams & Params)112 Pass *llvm::createFunctionInliningPass(InlineParams &Params) {
113   return new SimpleInliner(Params);
114 }
115 
runOnSCC(CallGraphSCC & SCC)116 bool SimpleInliner::runOnSCC(CallGraphSCC &SCC) {
117   TTIWP = &getAnalysis<TargetTransformInfoWrapperPass>();
118   return LegacyInlinerBase::runOnSCC(SCC);
119 }
120 
getAnalysisUsage(AnalysisUsage & AU) const121 void SimpleInliner::getAnalysisUsage(AnalysisUsage &AU) const {
122   AU.addRequired<TargetTransformInfoWrapperPass>();
123   LegacyInlinerBase::getAnalysisUsage(AU);
124 }
125