[all-commits] [llvm/llvm-project] 86fb40: [ProfileData] Implement contains in SampleProfileN...

[Kazu Hirata via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 86fb40ddfa3c7cd5c32d758f4b1709d01028a7db
      https://github.com/llvm/llvm-project/commit/86fb40ddfa3c7cd5c32d758f4b1709d01028a7db
  Author: Kazu Hirata <kazu at google.com>
  Date:   2026-07-29 (Wed, 29 Jul 2026)

  Changed paths:
    M llvm/include/llvm/ProfileData/SampleProfReader.h
    M llvm/lib/Transforms/IPO/SampleProfile.cpp
    M llvm/lib/Transforms/IPO/SampleProfileMatcher.cpp
    M llvm/unittests/ProfileData/SampleProfTest.cpp

  Log Message:
  -----------
  [ProfileData] Implement contains in SampleProfileNameTable (NFC) (#211995)

This patch implements contains(StringRef) and contains(uint64_t) in
SampleProfileNameTable and SampleProfileReader to serve symbol
membership queries directly from the reader -- "is this symbol in the
name table?".

Without this patch, users of the sample profile reader, namely
SampleProfileLoader::doInitialization and SampleProfileNameSet, each
construct their own StringSet<> containing all name table entries.
That is, we end up with two instances of StringSet<> with identical
contents.  Since these instances hold their own copies of symbol
strings on the heap, both the constructor and destructor take up a
large portion of compilation time.

This patch teaches SampleProfileReader::contains to directly serve
symbol membership queries.

- For EytzingerSampleProfileNameTable, contains performs binary search
  directly across the three concatenated Eytzinger table spans
  (CSKeys, FlatKeys, and Inlinees) in a cache-friendly manner.

- Other representations of the name table lazily construct an internal
  DenseSet on demand.

This patch updates existing customers to call Reader->contains.

RFC:
https://discourse.llvm.org/t/rfc-faster-sample-profile-loading/90957/8

Assisted-by: Antigravity



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