[IRPGO] [Draft] Import vtable definitions in ThinTLO and use more efficient vtable comparison sequence with cost-benefit analysis #69141
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…used to do virtual table address comparision for indirect-call-promotion.
The changes include:
1) Insert value profile intrinsics and lowering them.
- Introduced INSTR_PROF_VTABLE_DATA to record per-vtable data.
- Modified LLVM_PROF_RAW_HEADER to record the metadata for vtable profiles.
- Test case in llvm/test/Transforms/PGOProfile/vtable_profile.ll
2) Tooling support in llvm-profdata to show the added vtable information
- Changes are made in {raw,text,indexed} prof reader and/or writer to read/write vtable profile data.
- Test cases added in llvm/test/tools/llvm-profdata
- In IndirectCallVisitor, instrument vtables and skip the rest (e.g., function pointers, etc). - Add brief comments for helper functions, remove debugging logs and rename vtable name section to vtabnames.
…ntrol vtable instrumentation, and record address range of vtables (in VTableAddRangeToMD5Map). - The new option is used in PGOInstrumentation.cpp and InstrProfiling.cpp to flag-control the instrumentation of static and runtime information. Static information includes vtable address range and name md5 hash, runtime information are types of a vtable value. - Before this commit, VTableAddrToMD5Map records start and end of vtable address individually. After this commit, the map records a range to return MD5 iff the address is within the range. This is more accurate when runtime address is collected in one module but static vtable information is not recorded.
1. Format the code indentation in IndirectCallVisitor.h, and add a FIXME to do more efficient vtable instrumentation. 2. In InstrProfSymtab::finalizeSymtab, sort and uniquify VTableAddrRangeToMD5Map (somehow forgot this when preparing this patch, the full prototype includes profile-use did this already.)
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Close this stale patch and won't merge conflicts in this one. Working on #81442 now. |
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Parent patch is #66825