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From: "ubizjak at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/103008] poor inlined builtin_fmod on x86_64
Date: Sat, 12 Feb 2022 22:07:31 +0000	[thread overview]
Message-ID: <bug-103008-4-WLZtnTmAFc@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-103008-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008

--- Comment #14 from Uroš Bizjak <ubizjak at gmail dot com> ---
Created attachment 52428
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52428&action=edit
Proposed patch

The attached patch implements:

fmod (a, p) = a - trunc (a/p) * p
drem (a, p) = a - roundeven (a/p) * p

using SSE4 round instruction (and uses fnma when available).

Timings with Polyhedron ac.f90 on IvyBridge-E, Fedora-34, glibc 2.33-21.fc34

-Ofast:
       6,150082000 seconds user

-Ofast -mno-80387:
      18,354654000 seconds user

-Ofast -msse4:
       5,722511000 seconds user

  parent reply	other threads:[~2022-02-12 22:07 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-30 18:51 [Bug target/103008] New: " fx at gnu dot org
2021-10-30 18:52 ` [Bug target/103008] " fx at gnu dot org
2021-10-30 18:55 ` fx at gnu dot org
2021-10-30 18:56 ` fx at gnu dot org
2021-10-30 20:15 ` fx at gnu dot org
2021-10-30 20:39 ` anlauf at gcc dot gnu.org
2021-10-31 20:05 ` ubizjak at gmail dot com
2021-11-01  8:23 ` ubizjak at gmail dot com
2022-02-10 14:18 ` rguenth at gcc dot gnu.org
2022-02-10 14:22 ` rguenth at gcc dot gnu.org
2022-02-10 18:09 ` ubizjak at gmail dot com
2022-02-10 20:50 ` joseph at codesourcery dot com
2022-02-11  7:59 ` rguenth at gcc dot gnu.org
2022-02-11 15:47 ` ubizjak at gmail dot com
2022-02-12 22:07 ` ubizjak at gmail dot com [this message]
2022-02-13 21:00 ` Dave.Love at manchester dot ac.uk
2022-02-14  7:12 ` rguenther at suse dot de
2022-02-14  7:35 ` rguenth at gcc dot gnu.org

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