[PATCH] D103372: [InstrProfiling] If no value profiling, make data variable private and (for Windows) use one comdat

[Reid Kleckner via Phabricator via cfe-commits]

rnk added a comment.

I think MachO doesn't have comdats, so we need to leave the `__profd_` linkage as it was. I think private linkage also prevents atomization, which inhibits GC / dead stripping. I don't think this change really makes sense for MachO, so you could reasonably reland with that change.



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Comment at: llvm/test/Instrumentation/InstrProfiling/linkage.ll:64
 ; MACHO: @__profc_foo_inline = linkonce_odr hidden global
-; MACHO: @__profd_foo_inline = linkonce_odr hidden global
+; MACHO: @__profd_foo_inline = private global
 ; COFF: @__profc_foo_inline = linkonce_odr hidden global{{.*}} section ".lprfc$M", align 8
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I think we don't want this change for macho. If we make `__profd_` private on Mac, the linker won't be able to deduplicate these `__profd` globals, and there will be multiple copies pointing to the same counters.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D103372/new/

https://reviews.llvm.org/D103372