From: Andrew Haley <aph@redhat.com>
To: gcc-help@gcc.gnu.org
Subject: Re: -march=x86_64 -mtune=generic question
Date: Thu, 26 May 2022 08:11:43 +0100 [thread overview]
Message-ID: <d1e7eb6d-7b6a-06d4-c8ca-6a479174a732@redhat.com> (raw)
In-Reply-To: <CAG_eJLcU1AVOu=4vHO1zKTqt+xkSt=HmMPZrr_ivV76_qWAVtg@mail.gmail.com>
On 5/25/22 19:58, Tom Kacvinsky via Gcc-help wrote:
> Does anyone have a quick rundown on what would have changed between GCC
> 8.3.0 and 12.1.0 in terms of what -mtune=generic does for optimizations?
There was a vast amount of work done on many things, so we can't easily
say what affected you. Generally speaking GCC gets better release to release,
but bear in mind that compiler optimizations are often based on heuristics.
That is to say, they make code better on average, but sometimes they might
make things worse. If your degradation is slight overall, there might be an
actual regression in the compiler, but chances are you just got unlucky.
--
Andrew Haley (he/him)
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
https://keybase.io/andrewhaley
EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671
next prev parent reply other threads:[~2022-05-26 7:11 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-25 18:58 Tom Kacvinsky
2022-05-26 7:11 ` Andrew Haley [this message]
2022-05-26 10:13 ` Tom Kacvinsky
2022-05-26 11:05 ` Jonathan Wakely
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