[PATCH] D157944: [InstrProf] Single byte counters in coverage

[Gulfem Savrun Yeniceri via Phabricator via cfe-commits]

gulfem created this revision.
Herald added subscribers: wlei, ellis, wenlei.
Herald added a project: All.
gulfem requested review of this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.

This patch inserts 1-byte counters instead of an 8-byte counters
into llvm profiles for source-based code coverage. The origial idea
was proposed as "block-cov" for PGO, and this patch repurposes that
idea for coverage: https://groups.google.com/g/llvm-dev/c/r03Z6JoN7d4

The current 8-byte counters mechanism add counters to minimal regions,
and infer the counters in the remaining regions via adding or
subtracting counters. For example, it infers the counter in the `if.else`
region by subtracting the counters between `if.entry` and `if.then` regions
in an if statement. Whenever there is a control-flow merge, it adds
the counters from all the incoming regions. However, we are not going to be
able to infer counters by subtracting two execution counts when using
single-byte counters. Therefore, this patch conservatively inserts additional
counters for the cases where we need to add or subtract counters.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D157944

Files:
  clang/lib/CodeGen/CGExprAgg.cpp
  clang/lib/CodeGen/CGExprComplex.cpp
  clang/lib/CodeGen/CGExprScalar.cpp
  clang/lib/CodeGen/CGStmt.cpp
  clang/lib/CodeGen/CodeGenFunction.cpp
  clang/lib/CodeGen/CodeGenFunction.h
  clang/lib/CodeGen/CodeGenModule.cpp
  clang/lib/CodeGen/CodeGenPGO.cpp
  clang/lib/CodeGen/CodeGenPGO.h
  clang/lib/CodeGen/CoverageMappingGen.cpp
  clang/test/CoverageMapping/single-byte-counters.cpp

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D157944.550162.patch
Type: text/x-patch
Size: 45982 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20230815/f37c2186/attachment-0001.bin>