[PATCH] D36351: [lld][ELF] Add profile guided section layout

[Rafael Avila de Espindola via llvm-commits]

Rui Ueyama via Phabricator <reviews at reviews.llvm.org> writes:

> ruiu added a comment.
>
> How can I test this? I wonder how to create profiling data to feed this feature.
>

To test this separately from the llvm side I am using perf to create
a complete call graph:

$ perf record -e intel_pt//u ....

# collect ifunc calls
$ perf script --no-demangle -Fip,sym,addr,flags |
   grep '\(^ *jmp.*\[unknown\] =>\)' | sort -u

# collect regular calls
$ perf script --no-demangle -Fip,sym,addr,flags | grep '\(^ *call\)'

With that the attached python script creates a call graph.

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Cheers,
Rafael