From: dnkl <dnkl@users.noreply.github.com>
To: ml@inbox.vuxu.org
Subject: Re: foot: Add PGO build option
Date: Fri, 02 Jul 2021 08:02:54 +0200 [thread overview]
Message-ID: <20210702060254.rdEUaU8Z_ffpkebSp27RbyMh3ujkibTrwPhj_B0kEUY@z> (raw)
In-Reply-To: <gh-mailinglist-notifications-41a7ca26-5023-4802-975b-f1789d68868e-void-packages-29526@inbox.vuxu.org>
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New comment by dnkl on void-packages repository
https://github.com/void-linux/void-packages/issues/29526#issuecomment-872740075
Comment:
> since PGO is affected by the CPU that's being used.
It's actually not. PGO counts functions and branches executed, and helps re-organize the code; it clusters "hot" functions, to improve cache locality. It can also re-arrange code within a function to make the "normal" path the fast path (i.e. placing the not-often executed branches at e.g. the end of the function). But PGO in itself does not emit CPU specific instructions, nor does it depend on CPU-specific knowledge for e.g. instruction scheduling.
Over at nix, @sternenseemann has been able to do reproducable PGO builds. That is, builds on different systems produce identical output. I can't for my life find the issue, or comment, where I saw this, but pretty sure sterni can fill in the details, if needed.
Oh, and as a bonus, PGO builds tend to be smaller (in binary size) than regular release builds. This is _at least_ true for LTO builds (which I strongly recommend building foot with, with or without PGO).
next prev parent reply other threads:[~2021-07-02 6:02 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-17 8:17 [ISSUE] " travankor
2021-04-27 23:49 ` ericonr
2021-07-02 6:02 ` dnkl [this message]
2021-07-02 8:05 ` sternenseemann
2021-07-02 8:05 ` sternenseemann
2022-05-09 2:13 ` github-actions
2022-05-10 2:44 ` ericonr
2022-05-10 11:10 ` ifreund
2022-08-09 2:13 ` github-actions
2022-08-24 2:14 ` [ISSUE] [CLOSED] " github-actions
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