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/CallSite.h"
19 #include "llvm/IR/CallingConv.h"
20 #include "llvm/IR/DataLayout.h"
21 #include "llvm/IR/Instructions.h"
22 #include "llvm/IR/Module.h"
23 #include "llvm/IR/Type.h"
24 #include "llvm/InitializePasses.h"
25 #include "llvm/Transforms/IPO.h"
26 #include "llvm/Transforms/IPO/Inliner.h"
27 
28 using namespace llvm;
29 
30 #define DEBUG_TYPE "inline"
31 
32 namespace {
33 
34 /// Actual inliner pass implementation.
35 ///
36 /// The common implementation of the inlining logic is shared between this
37 /// inliner pass and the always inliner pass. The two passes use different cost
38 /// analyses to determine when to inline.
39 class SimpleInliner : public LegacyInlinerBase {
40 
41   InlineParams Params;
42 
43 public:
44   SimpleInliner() : LegacyInlinerBase(ID), Params(llvm::getInlineParams()) {
45     initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
46   }
47 
48   explicit SimpleInliner(InlineParams Params)
49       : LegacyInlinerBase(ID), Params(std::move(Params)) {
50     initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
51   }
52 
53   static char ID; // Pass identification, replacement for typeid
54 
55   InlineCost getInlineCost(CallSite CS) override {
56     Function *Callee = CS.getCalledFunction();
57     TargetTransformInfo &TTI = TTIWP->getTTI(*Callee);
58 
59     bool RemarksEnabled = false;
60     const auto &BBs = CS.getCaller()->getBasicBlockList();
61     if (!BBs.empty()) {
62       auto DI = OptimizationRemark(DEBUG_TYPE, "", DebugLoc(), &BBs.front());
63       if (DI.isEnabled())
64         RemarksEnabled = true;
65     }
66     OptimizationRemarkEmitter ORE(CS.getCaller());
67 
68     std::function<AssumptionCache &(Function &)> GetAssumptionCache =
69         [&](Function &F) -> AssumptionCache & {
70       return ACT->getAssumptionCache(F);
71     };
72     return llvm::getInlineCost(
73         cast<CallBase>(*CS.getInstruction()), Params, TTI, GetAssumptionCache,
74         /*GetBFI=*/None, PSI, RemarksEnabled ? &ORE : nullptr);
75   }
76 
77   bool runOnSCC(CallGraphSCC &SCC) override;
78   void getAnalysisUsage(AnalysisUsage &AU) const override;
79 
80 private:
81   TargetTransformInfoWrapperPass *TTIWP;
82 
83 };
84 
85 } // end anonymous namespace
86 
87 char SimpleInliner::ID = 0;
88 INITIALIZE_PASS_BEGIN(SimpleInliner, "inline", "Function Integration/Inlining",
89                       false, false)
90 INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
91 INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
92 INITIALIZE_PASS_DEPENDENCY(ProfileSummaryInfoWrapperPass)
93 INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
94 INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
95 INITIALIZE_PASS_END(SimpleInliner, "inline", "Function Integration/Inlining",
96                     false, false)
97 
98 Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); }
99 
100 Pass *llvm::createFunctionInliningPass(int Threshold) {
101   return new SimpleInliner(llvm::getInlineParams(Threshold));
102 }
103 
104 Pass *llvm::createFunctionInliningPass(unsigned OptLevel,
105                                        unsigned SizeOptLevel,
106                                        bool DisableInlineHotCallSite) {
107   auto Param = llvm::getInlineParams(OptLevel, SizeOptLevel);
108   if (DisableInlineHotCallSite)
109     Param.HotCallSiteThreshold = 0;
110   return new SimpleInliner(Param);
111 }
112 
113 Pass *llvm::createFunctionInliningPass(InlineParams &Params) {
114   return new SimpleInliner(Params);
115 }
116 
117 bool SimpleInliner::runOnSCC(CallGraphSCC &SCC) {
118   TTIWP = &getAnalysis<TargetTransformInfoWrapperPass>();
119   return LegacyInlinerBase::runOnSCC(SCC);
120 }
121 
122 void SimpleInliner::getAnalysisUsage(AnalysisUsage &AU) const {
123   AU.addRequired<TargetTransformInfoWrapperPass>();
124   LegacyInlinerBase::getAnalysisUsage(AU);
125 }
126