1 //===- AMDGPUAliasAnalysis ---------------------------------------*- C++ -*-==//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 /// \file
10 /// This is the AMGPU address space based alias analysis pass.
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_ANALYSIS_AMDGPUALIASANALYSIS_H
14 #define LLVM_ANALYSIS_AMDGPUALIASANALYSIS_H
15 
16 #include "AMDGPU.h"
17 #include "llvm/Analysis/AliasAnalysis.h"
18 #include "llvm/IR/Function.h"
19 #include "llvm/IR/Module.h"
20 #include "llvm/Pass.h"
21 
22 namespace llvm {
23 
24 /// A simple AA result that uses TBAA metadata to answer queries.
25 class AMDGPUAAResult : public AAResultBase<AMDGPUAAResult> {
26   friend AAResultBase<AMDGPUAAResult>;
27 
28   const DataLayout &DL;
29   AMDGPUAS AS;
30 
31 public:
32   explicit AMDGPUAAResult(const DataLayout &DL, Triple T) : AAResultBase(),
33     DL(DL), AS(AMDGPU::getAMDGPUAS(T)), ASAliasRules(AS, T.getArch()) {}
34   AMDGPUAAResult(AMDGPUAAResult &&Arg)
35       : AAResultBase(std::move(Arg)), DL(Arg.DL), AS(Arg.AS),
36         ASAliasRules(Arg.ASAliasRules){}
37 
38   /// Handle invalidation events from the new pass manager.
39   ///
40   /// By definition, this result is stateless and so remains valid.
41   bool invalidate(Function &, const PreservedAnalyses &) { return false; }
42 
43   AliasResult alias(const MemoryLocation &LocA, const MemoryLocation &LocB);
44   bool pointsToConstantMemory(const MemoryLocation &Loc, bool OrLocal);
45 
46 private:
47   bool Aliases(const MDNode *A, const MDNode *B) const;
48   bool PathAliases(const MDNode *A, const MDNode *B) const;
49 
50   class ASAliasRulesTy {
51   public:
52     ASAliasRulesTy(AMDGPUAS AS_, Triple::ArchType Arch_);
53     AliasResult getAliasResult(unsigned AS1, unsigned AS2) const;
54   private:
55     Triple::ArchType Arch;
56     AMDGPUAS AS;
57     const AliasResult (*ASAliasRules)[6][6];
58   } ASAliasRules;
59 };
60 
61 /// Analysis pass providing a never-invalidated alias analysis result.
62 class AMDGPUAA : public AnalysisInfoMixin<AMDGPUAA> {
63   friend AnalysisInfoMixin<AMDGPUAA>;
64   static char PassID;
65 
66 public:
67   typedef AMDGPUAAResult Result;
68 
69   AMDGPUAAResult run(Function &F, AnalysisManager<Function> &AM) {
70     return AMDGPUAAResult(F.getParent()->getDataLayout(),
71         Triple(F.getParent()->getTargetTriple()));
72   }
73 };
74 
75 /// Legacy wrapper pass to provide the AMDGPUAAResult object.
76 class AMDGPUAAWrapperPass : public ImmutablePass {
77   std::unique_ptr<AMDGPUAAResult> Result;
78 
79 public:
80   static char ID;
81 
82   AMDGPUAAWrapperPass() : ImmutablePass(ID) {
83     initializeAMDGPUAAWrapperPassPass(*PassRegistry::getPassRegistry());
84   }
85 
86   AMDGPUAAResult &getResult() { return *Result; }
87   const AMDGPUAAResult &getResult() const { return *Result; }
88 
89   bool doInitialization(Module &M) override {
90     Result.reset(new AMDGPUAAResult(M.getDataLayout(),
91         Triple(M.getTargetTriple())));
92     return false;
93   }
94   bool doFinalization(Module &M) override {
95     Result.reset();
96     return false;
97   }
98   void getAnalysisUsage(AnalysisUsage &AU) const override;
99 };
100 
101 }
102 #endif // LLVM_ANALYSIS_AMDGPUALIASANALYSIS_H
103