[PATCH] D126586: [InstrProf] Single byte counters in coverage

[Gulfem Savrun Yeniceri via Phabricator via llvm-commits]

gulfem marked an inline comment as done.
gulfem added inline comments.


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Comment at: clang/lib/CodeGen/CodeGenPGO.cpp:1080-1081
+void CodeGenPGO::setProfileVersion(llvm::Module &M) {
+  if (CGM.getCodeGenOpts().hasProfileClangInstr() &&
+      llvm::EnableSingleByteCoverage) {
+    const StringRef VarName(INSTR_PROF_QUOTE(INSTR_PROF_RAW_VERSION_VAR));
----------------
zequanwu wrote:
> I thinkit's better to emit the profile version global variable in `CoverageMappingModuleGen::emit` so this check `CGM.getCodeGenOpts().hasProfileClangInstr()` is not necessary. 
> 
> Also we should always emit the profile version global variable so that the runtime/backend knows if single byte coverage is enabled or not by looking at the version.
`CoverageMappingModuleGen` is only invoked when `-fcoverage-mapping` flag is provided, and single byte counters are emitted when `-fprofile-instr-generate` flag is provided. We provide both flags for coverage purposes, but if we move this global to `CoverageMappingModuleGen::emit`, single byte counters won't work if `-fcoverage-mapping` is not provided. I don't know whether there will be such use cases, but for this reason it might not be a good idea to put that into `CoverageMappingModuleGen`.


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  https://reviews.llvm.org/D126586/new/

https://reviews.llvm.org/D126586