This is the generic walker interface for walkers of MemorySSA. More...
#include "llvm/Analysis/MemorySSA.h"
Public Types | |
| using | MemoryAccessSet = SmallVector< MemoryAccess *, 8 > |
Public Member Functions | |
| MemorySSAWalker (MemorySSA *) | |
| virtual | ~MemorySSAWalker ()=default |
| MemoryAccess * | getClobberingMemoryAccess (const Instruction *I) |
| Given a memory Mod/Ref/ModRef'ing instruction, calling this will give you the nearest dominating MemoryAccess that Mod's the location the instruction accesses (by skipping any def which AA can prove does not alias the location(s) accessed by the instruction given). More... | |
| virtual MemoryAccess * | getClobberingMemoryAccess (MemoryAccess *)=0 |
| Does the same thing as getClobberingMemoryAccess(const Instruction *I), but takes a MemoryAccess instead of an Instruction. More... | |
| virtual MemoryAccess * | getClobberingMemoryAccess (MemoryAccess *, const MemoryLocation &)=0 |
| Given a potentially clobbering memory access and a new location, calling this will give you the nearest dominating clobbering MemoryAccess (by skipping non-aliasing def links). More... | |
| virtual void | invalidateInfo (MemoryAccess *) |
| Given a memory access, invalidate anything this walker knows about that access. More... | |
| virtual void | verify (const MemorySSA *MSSA) |
Protected Attributes | |
| MemorySSA * | MSSA |
Friends | |
| class | MemorySSA |
Detailed Description
This is the generic walker interface for walkers of MemorySSA.
Walkers are used to be able to further disambiguate the def-use chains MemorySSA gives you, or otherwise produce better info than MemorySSA gives you. In particular, while the def-use chains provide basic information, and are guaranteed to give, for example, the nearest may-aliasing MemoryDef for a MemoryUse as AliasAnalysis considers it, a user mant want better or other information. In particular, they may want to use SCEV info to further disambiguate memory accesses, or they may want the nearest dominating may-aliasing MemoryDef for a call or a store. This API enables a standardized interface to getting and using that info.
Definition at line 987 of file MemorySSA.h.
Member Typedef Documentation
◆ MemoryAccessSet
| using llvm::MemorySSAWalker::MemoryAccessSet = SmallVector<MemoryAccess *, 8> |
Definition at line 992 of file MemorySSA.h.
Constructor & Destructor Documentation
◆ MemorySSAWalker()
| MemorySSAWalker::MemorySSAWalker | ( | MemorySSA * | M | ) |
Definition at line 2207 of file MemorySSA.cpp.
◆ ~MemorySSAWalker()
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virtualdefault |
Member Function Documentation
◆ getClobberingMemoryAccess() [1/3]
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inline |
Given a memory Mod/Ref/ModRef'ing instruction, calling this will give you the nearest dominating MemoryAccess that Mod's the location the instruction accesses (by skipping any def which AA can prove does not alias the location(s) accessed by the instruction given).
Note that this will return a single access, and it must dominate the Instruction, so if an operand of a MemoryPhi node Mod's the instruction, this will return the MemoryPhi, not the operand. This means that given: if (a) { 1 = MemoryDef(liveOnEntry) store a } else { 2 = MemoryDef(liveOnEntry) store b } 3 = MemoryPhi(2, 1) MemoryUse(3) load a
calling this API on load(a) will return the MemoryPhi, not the MemoryDef in the if (a) branch.
Definition at line 1016 of file MemorySSA.h.
References assert().
Referenced by llvm::MemorySSA::CachingWalker::CachingWalker(), llvm::canSinkOrHoistInst(), pointerInvalidatedByLoopWithMSSA(), and llvm::MemorySSA::SkipSelfWalker::SkipSelfWalker().
◆ getClobberingMemoryAccess() [2/3]
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pure virtual |
Does the same thing as getClobberingMemoryAccess(const Instruction *I), but takes a MemoryAccess instead of an Instruction.
Implemented in llvm::DoNothingMemorySSAWalker, llvm::MemorySSA::SkipSelfWalker, and llvm::MemorySSA::CachingWalker.
◆ getClobberingMemoryAccess() [3/3]
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pure virtual |
Given a potentially clobbering memory access and a new location, calling this will give you the nearest dominating clobbering MemoryAccess (by skipping non-aliasing def links).
This version of the function is mainly used to disambiguate phi translated pointers, where the value of a pointer may have changed from the initial memory access. Note that this expects to be handed either a MemoryUse, or an already potentially clobbering access. Unlike the above API, if given a MemoryDef that clobbers the pointer as the starting access, it will return that MemoryDef, whereas the above would return the clobber starting from the use side of the memory def.
Implemented in llvm::DoNothingMemorySSAWalker, llvm::MemorySSA::SkipSelfWalker, and llvm::MemorySSA::CachingWalker.
◆ invalidateInfo()
|
inlinevirtual |
Given a memory access, invalidate anything this walker knows about that access.
This API is used by walkers that store information to perform basic cache invalidation. This will be called by MemorySSA at appropriate times for the walker it uses or returns.
Reimplemented in llvm::MemorySSA::SkipSelfWalker, and llvm::MemorySSA::CachingWalker.
Definition at line 1045 of file MemorySSA.h.
◆ verify()
Reimplemented in llvm::MemorySSA::SkipSelfWalker, and llvm::MemorySSA::CachingWalker.
Definition at line 1047 of file MemorySSA.h.
References assert().
Referenced by llvm::MemorySSA::CachingWalker::verify(), and llvm::MemorySSA::SkipSelfWalker::verify().
Friends And Related Function Documentation
◆ MemorySSA
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friend |
Definition at line 1050 of file MemorySSA.h.
Member Data Documentation
◆ MSSA
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protected |
Definition at line 1052 of file MemorySSA.h.
Referenced by llvm::MemorySSA::ClobberWalkerBase::getClobberingMemoryAccessBase().
The documentation for this class was generated from the following files:
- include/llvm/Analysis/MemorySSA.h
- lib/Analysis/MemorySSA.cpp
