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_LIB_TARGET_AMDGPU_AMDGPUALIASANALYSIS_H
14 #define LLVM_LIB_TARGET_AMDGPU_AMDGPUALIASANALYSIS_H
15 
16 #include "AMDGPU.h"
17 #include "llvm/ADT/Triple.h"
18 #include "llvm/Analysis/AliasAnalysis.h"
19 #include "llvm/IR/Function.h"
20 #include "llvm/IR/Module.h"
21 #include "llvm/Pass.h"
22 #include <algorithm>
23 #include <memory>
24 
25 namespace llvm {
26 
27 class DataLayout;
28 class MDNode;
29 class MemoryLocation;
30 
31 /// A simple AA result that uses TBAA metadata to answer queries.
32 class AMDGPUAAResult : public AAResultBase<AMDGPUAAResult> {
33   friend AAResultBase<AMDGPUAAResult>;
34 
35   const DataLayout &DL;
36 
37 public:
AMDGPUAAResult(const DataLayout & DL,Triple T)38   explicit AMDGPUAAResult(const DataLayout &DL, Triple T) : AAResultBase(),
39     DL(DL) {}
AMDGPUAAResult(AMDGPUAAResult && Arg)40   AMDGPUAAResult(AMDGPUAAResult &&Arg)
41       : AAResultBase(std::move(Arg)), DL(Arg.DL) {}
42 
43   /// Handle invalidation events from the new pass manager.
44   ///
45   /// By definition, this result is stateless and so remains valid.
invalidate(Function &,const PreservedAnalyses &)46   bool invalidate(Function &, const PreservedAnalyses &) { return false; }
47 
48   AliasResult alias(const MemoryLocation &LocA, const MemoryLocation &LocB);
49   bool pointsToConstantMemory(const MemoryLocation &Loc, bool OrLocal);
50 
51 private:
52   bool Aliases(const MDNode *A, const MDNode *B) const;
53   bool PathAliases(const MDNode *A, const MDNode *B) const;
54 };
55 
56 /// Analysis pass providing a never-invalidated alias analysis result.
57 class AMDGPUAA : public AnalysisInfoMixin<AMDGPUAA> {
58   friend AnalysisInfoMixin<AMDGPUAA>;
59 
60   static char PassID;
61 
62 public:
63   using Result = AMDGPUAAResult;
64 
run(Function & F,AnalysisManager<Function> & AM)65   AMDGPUAAResult run(Function &F, AnalysisManager<Function> &AM) {
66     return AMDGPUAAResult(F.getParent()->getDataLayout(),
67         Triple(F.getParent()->getTargetTriple()));
68   }
69 };
70 
71 /// Legacy wrapper pass to provide the AMDGPUAAResult object.
72 class AMDGPUAAWrapperPass : public ImmutablePass {
73   std::unique_ptr<AMDGPUAAResult> Result;
74 
75 public:
76   static char ID;
77 
AMDGPUAAWrapperPass()78   AMDGPUAAWrapperPass() : ImmutablePass(ID) {
79     initializeAMDGPUAAWrapperPassPass(*PassRegistry::getPassRegistry());
80   }
81 
getResult()82   AMDGPUAAResult &getResult() { return *Result; }
getResult()83   const AMDGPUAAResult &getResult() const { return *Result; }
84 
doInitialization(Module & M)85   bool doInitialization(Module &M) override {
86     Result.reset(new AMDGPUAAResult(M.getDataLayout(),
87         Triple(M.getTargetTriple())));
88     return false;
89   }
90 
doFinalization(Module & M)91   bool doFinalization(Module &M) override {
92     Result.reset();
93     return false;
94   }
95 
96   void getAnalysisUsage(AnalysisUsage &AU) const override;
97 };
98 
99 // Wrapper around ExternalAAWrapperPass so that the default constructor gets the
100 // callback.
101 class AMDGPUExternalAAWrapper : public ExternalAAWrapperPass {
102 public:
103   static char ID;
104 
AMDGPUExternalAAWrapper()105   AMDGPUExternalAAWrapper() : ExternalAAWrapperPass(
106     [](Pass &P, Function &, AAResults &AAR) {
107       if (auto *WrapperPass = P.getAnalysisIfAvailable<AMDGPUAAWrapperPass>())
108         AAR.addAAResult(WrapperPass->getResult());
109     }) {}
110 };
111 
112 } // end namespace llvm
113 
114 #endif // LLVM_LIB_TARGET_AMDGPU_AMDGPUALIASANALYSIS_H
115