1 //===- CodegenCleanup.cpp -------------------------------------------------===//
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 #include "polly/CodeGen/CodegenCleanup.h"
10 
11 #include "llvm/Analysis/ScopedNoAliasAA.h"
12 #include "llvm/Analysis/TypeBasedAliasAnalysis.h"
13 #include "llvm/IR/Function.h"
14 #include "llvm/IR/LegacyPassManager.h"
15 #include "llvm/PassSupport.h"
16 #include "llvm/Support/Debug.h"
17 #include "llvm/Transforms/InstCombine/InstCombine.h"
18 #include "llvm/Transforms/Scalar.h"
19 #include "llvm/Transforms/Scalar/GVN.h"
20 #include "llvm/Transforms/Utils.h"
21 
22 #define DEBUG_TYPE "polly-cleanup"
23 
24 using namespace llvm;
25 using namespace polly;
26 
27 namespace {
28 
29 class CodegenCleanup : public FunctionPass {
30 private:
31   CodegenCleanup(const CodegenCleanup &) = delete;
32   const CodegenCleanup &operator=(const CodegenCleanup &) = delete;
33 
34   llvm::legacy::FunctionPassManager *FPM;
35 
36 public:
37   static char ID;
38   explicit CodegenCleanup() : FunctionPass(ID), FPM(nullptr) {}
39 
40   /// @name FunctionPass interface
41   //@{
42   virtual void getAnalysisUsage(llvm::AnalysisUsage &AU) const override {}
43 
44   virtual bool doInitialization(Module &M) override {
45     assert(!FPM);
46 
47     FPM = new llvm::legacy::FunctionPassManager(&M);
48 
49     // TODO: How to make parent passes discoverable?
50     // TODO: Should be sensitive to compiler options in PassManagerBuilder, to
51     // which we do not have access here.
52     FPM->add(createScopedNoAliasAAWrapperPass());
53     FPM->add(createTypeBasedAAWrapperPass());
54     FPM->add(createAAResultsWrapperPass());
55 
56     // TODO: These are non-conditional passes that run between
57     // EP_ModuleOptimizerEarly and EP_VectorizerStart just to ensure we do not
58     // miss any optimization that would have run after Polly with
59     // -polly-position=early. This can probably be reduced to a more compact set
60     // of passes.
61     FPM->add(createCFGSimplificationPass());
62     FPM->add(createSROAPass());
63     FPM->add(createEarlyCSEPass());
64 
65     FPM->add(createPromoteMemoryToRegisterPass());
66     FPM->add(createInstructionCombiningPass(true));
67     FPM->add(createCFGSimplificationPass());
68     FPM->add(createSROAPass());
69     FPM->add(createEarlyCSEPass(true));
70     FPM->add(createSpeculativeExecutionIfHasBranchDivergencePass());
71     FPM->add(createJumpThreadingPass());
72     FPM->add(createCorrelatedValuePropagationPass());
73     FPM->add(createCFGSimplificationPass());
74     FPM->add(createInstructionCombiningPass(true));
75     FPM->add(createLibCallsShrinkWrapPass());
76     FPM->add(createTailCallEliminationPass());
77     FPM->add(createCFGSimplificationPass());
78     FPM->add(createReassociatePass());
79     FPM->add(createLoopRotatePass(-1));
80     FPM->add(createGVNPass());
81     FPM->add(createLICMPass());
82     FPM->add(createLoopUnswitchPass());
83     FPM->add(createCFGSimplificationPass());
84     FPM->add(createInstructionCombiningPass(true));
85     FPM->add(createIndVarSimplifyPass());
86     FPM->add(createLoopIdiomPass());
87     FPM->add(createLoopDeletionPass());
88     FPM->add(createCFGSimplificationPass());
89     FPM->add(createSimpleLoopUnrollPass(3));
90     FPM->add(createMergedLoadStoreMotionPass());
91     FPM->add(createGVNPass());
92     FPM->add(createMemCpyOptPass());
93     FPM->add(createSCCPPass());
94     FPM->add(createBitTrackingDCEPass());
95     FPM->add(createInstructionCombiningPass(true));
96     FPM->add(createJumpThreadingPass());
97     FPM->add(createCorrelatedValuePropagationPass());
98     FPM->add(createDeadStoreEliminationPass());
99     FPM->add(createLICMPass());
100     FPM->add(createAggressiveDCEPass());
101     FPM->add(createCFGSimplificationPass());
102     FPM->add(createInstructionCombiningPass(true));
103     FPM->add(createFloat2IntPass());
104 
105     return FPM->doInitialization();
106   }
107 
108   virtual bool doFinalization(Module &M) override {
109     bool Result = FPM->doFinalization();
110 
111     delete FPM;
112     FPM = nullptr;
113 
114     return Result;
115   }
116 
117   virtual bool runOnFunction(llvm::Function &F) override {
118     if (!F.hasFnAttribute("polly-optimized")) {
119       LLVM_DEBUG(
120           dbgs() << F.getName()
121                  << ": Skipping cleanup because Polly did not optimize it.");
122       return false;
123     }
124 
125     LLVM_DEBUG(dbgs() << F.getName() << ": Running codegen cleanup...");
126     return FPM->run(F);
127   }
128   //@}
129 };
130 
131 char CodegenCleanup::ID;
132 } // namespace
133 
134 FunctionPass *polly::createCodegenCleanupPass() { return new CodegenCleanup(); }
135 
136 INITIALIZE_PASS_BEGIN(CodegenCleanup, "polly-cleanup",
137                       "Polly - Cleanup after code generation", false, false)
138 INITIALIZE_PASS_END(CodegenCleanup, "polly-cleanup",
139                     "Polly - Cleanup after code generation", false, false)
140