Hi Jeff,

I revived profile_merger tool in http://github.com/google/autofdo and re-worked the patch to merge profiles for compiling the libraries.

Please take a look at the attached patch.

Thanks,

Eugene

-----Original Message-----
From: Jeff Law <jeffreyalaw@gmail.com> 
Sent: Tuesday, November 22, 2022 10:16 PM
To: Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com>; gcc-patches@gcc.gnu.org; Andi Kleen <ak@linux.intel.com>
Subject: Re: [EXTERNAL] Re: [PATCH] Fix autoprofiledbootstrap build

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On 11/22/22 14:20, Eugene Rozenfeld wrote:
> I took another look at this. We actually collect perf data when building the libraries. So, we have ./prev-gcc/perf.data, ./prev-libcpp/perf.data, ./prev-libiberty/perf.data, etc. But when creating gcov data for  -fauto-profile build of cc1plus or cc1 we only use ./prev-gcc/perf.data . So, a better solution would be either having a single perf.data for all builds (gcc and libraries) or merging perf.data files before attempting autostagefeedback. What would you recommend?

ISTM that if neither approach loses data, then they're functionally equivalent -- meaning that we can select whichever is easier to wire into our build system.

A single perf.data might serialize the build.  So perhaps separate, then merge right before autostagefeedback.


But I'm willing to go with whatever you think is best.

Jeff