1 //===---- Canonicalization.cpp - Run canonicalization passes --------------===//
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 // Run the set of default canonicalization passes.
10 //
11 // This pass is mainly used for debugging.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "polly/Canonicalization.h"
16 #include "polly/LinkAllPasses.h"
17 #include "polly/Options.h"
18 #include "llvm/Analysis/GlobalsModRef.h"
19 #include "llvm/Analysis/ProfileSummaryInfo.h"
20 #include "llvm/IR/LegacyPassManager.h"
21 #include "llvm/Transforms/IPO.h"
22 #include "llvm/Transforms/IPO/FunctionAttrs.h"
23 #include "llvm/Transforms/InstCombine/InstCombine.h"
24 #include "llvm/Transforms/Scalar.h"
25 #include "llvm/Transforms/Scalar/EarlyCSE.h"
26 #include "llvm/Transforms/Scalar/IndVarSimplify.h"
27 #include "llvm/Transforms/Scalar/LoopRotation.h"
28 #include "llvm/Transforms/Scalar/Reassociate.h"
29 #include "llvm/Transforms/Scalar/SimplifyCFG.h"
30 #include "llvm/Transforms/Scalar/TailRecursionElimination.h"
31 #include "llvm/Transforms/Utils.h"
32 #include "llvm/Transforms/Utils/Mem2Reg.h"
33 
34 using namespace llvm;
35 using namespace polly;
36 
37 static cl::opt<bool>
38     PollyInliner("polly-run-inliner",
39                  cl::desc("Run an early inliner pass before Polly"), cl::Hidden,
40                  cl::cat(PollyCategory));
41 
registerCanonicalicationPasses(llvm::legacy::PassManagerBase & PM)42 void polly::registerCanonicalicationPasses(llvm::legacy::PassManagerBase &PM) {
43   bool UseMemSSA = true;
44   PM.add(llvm::createPromoteMemoryToRegisterPass());
45   PM.add(llvm::createEarlyCSEPass(UseMemSSA));
46   PM.add(llvm::createInstructionCombiningPass());
47   PM.add(llvm::createCFGSimplificationPass());
48   PM.add(llvm::createTailCallEliminationPass());
49   PM.add(llvm::createCFGSimplificationPass());
50   PM.add(llvm::createReassociatePass());
51   PM.add(llvm::createLoopRotatePass());
52   if (PollyInliner) {
53     PM.add(llvm::createFunctionInliningPass(200));
54     PM.add(llvm::createPromoteMemoryToRegisterPass());
55     PM.add(llvm::createCFGSimplificationPass());
56     PM.add(llvm::createInstructionCombiningPass());
57     PM.add(createBarrierNoopPass());
58   }
59   PM.add(llvm::createInstructionCombiningPass());
60   PM.add(llvm::createIndVarSimplifyPass());
61 }
62 
63 /// Adapted from llvm::PassBuilder::buildInlinerPipeline
64 static ModuleInlinerWrapperPass
buildInlinePasses(llvm::OptimizationLevel Level)65 buildInlinePasses(llvm::OptimizationLevel Level) {
66   InlineParams IP = getInlineParams(200);
67   ModuleInlinerWrapperPass MIWP(IP);
68 
69   // Require the GlobalsAA analysis for the module so we can query it within
70   // the CGSCC pipeline.
71   MIWP.addModulePass(RequireAnalysisPass<GlobalsAA, Module>());
72   // Invalidate AAManager so it can be recreated and pick up the newly available
73   // GlobalsAA.
74   MIWP.addModulePass(
75       createModuleToFunctionPassAdaptor(InvalidateAnalysisPass<AAManager>()));
76 
77   // Require the ProfileSummaryAnalysis for the module so we can query it within
78   // the inliner pass.
79   MIWP.addModulePass(RequireAnalysisPass<ProfileSummaryAnalysis, Module>());
80 
81   // Now begin the main postorder CGSCC pipeline.
82   // FIXME: The current CGSCC pipeline has its origins in the legacy pass
83   // manager and trying to emulate its precise behavior. Much of this doesn't
84   // make a lot of sense and we should revisit the core CGSCC structure.
85   CGSCCPassManager &MainCGPipeline = MIWP.getPM();
86 
87   // Now deduce any function attributes based in the current code.
88   MainCGPipeline.addPass(PostOrderFunctionAttrsPass());
89 
90   return MIWP;
91 }
92 
93 FunctionPassManager
buildCanonicalicationPassesForNPM(llvm::ModulePassManager & MPM,llvm::OptimizationLevel Level)94 polly::buildCanonicalicationPassesForNPM(llvm::ModulePassManager &MPM,
95                                          llvm::OptimizationLevel Level) {
96   FunctionPassManager FPM;
97 
98   bool UseMemSSA = true;
99   FPM.addPass(PromotePass());
100   FPM.addPass(EarlyCSEPass(UseMemSSA));
101   FPM.addPass(InstCombinePass());
102   FPM.addPass(SimplifyCFGPass());
103   FPM.addPass(TailCallElimPass());
104   FPM.addPass(SimplifyCFGPass());
105   FPM.addPass(ReassociatePass());
106   {
107     LoopPassManager LPM;
108     LPM.addPass(LoopRotatePass(Level != OptimizationLevel::Oz));
109     FPM.addPass(createFunctionToLoopPassAdaptor<LoopPassManager>(
110         std::move(LPM), /*UseMemorySSA=*/false,
111         /*UseBlockFrequencyInfo=*/false));
112   }
113   if (PollyInliner) {
114     MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
115     MPM.addPass(buildInlinePasses(Level));
116     FPM = FunctionPassManager();
117 
118     FPM.addPass(PromotePass());
119     FPM.addPass(SimplifyCFGPass());
120     FPM.addPass(InstCombinePass());
121   }
122   FPM.addPass(InstCombinePass());
123   {
124     LoopPassManager LPM;
125     LPM.addPass(IndVarSimplifyPass());
126     FPM.addPass(createFunctionToLoopPassAdaptor<LoopPassManager>(
127         std::move(LPM), /*UseMemorySSA=*/false,
128         /*UseBlockFrequencyInfo=*/true));
129   }
130 
131   return FPM;
132 }
133 
134 namespace {
135 class PollyCanonicalize final : public ModulePass {
136   PollyCanonicalize(const PollyCanonicalize &) = delete;
137   const PollyCanonicalize &operator=(const PollyCanonicalize &) = delete;
138 
139 public:
140   static char ID;
141 
PollyCanonicalize()142   explicit PollyCanonicalize() : ModulePass(ID) {}
143   ~PollyCanonicalize();
144 
145   /// @name FunctionPass interface.
146   //@{
147   void getAnalysisUsage(AnalysisUsage &AU) const override;
148   void releaseMemory() override;
149   bool runOnModule(Module &M) override;
150   void print(raw_ostream &OS, const Module *) const override;
151   //@}
152 };
153 } // namespace
154 
~PollyCanonicalize()155 PollyCanonicalize::~PollyCanonicalize() {}
156 
getAnalysisUsage(AnalysisUsage & AU) const157 void PollyCanonicalize::getAnalysisUsage(AnalysisUsage &AU) const {}
158 
releaseMemory()159 void PollyCanonicalize::releaseMemory() {}
160 
runOnModule(Module & M)161 bool PollyCanonicalize::runOnModule(Module &M) {
162   legacy::PassManager PM;
163   registerCanonicalicationPasses(PM);
164   PM.run(M);
165 
166   return true;
167 }
168 
print(raw_ostream & OS,const Module *) const169 void PollyCanonicalize::print(raw_ostream &OS, const Module *) const {}
170 
171 char PollyCanonicalize::ID = 0;
172 
createPollyCanonicalizePass()173 Pass *polly::createPollyCanonicalizePass() { return new PollyCanonicalize(); }
174 
175 INITIALIZE_PASS_BEGIN(PollyCanonicalize, "polly-canonicalize",
176                       "Polly - Run canonicalization passes", false, false)
177 INITIALIZE_PASS_END(PollyCanonicalize, "polly-canonicalize",
178                     "Polly - Run canonicalization passes", false, false)
179