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From: "vincent-gcc at vinc17 dot net" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/24021] VRP does not work with floating points
Date: Thu, 10 Feb 2022 14:17:40 +0000	[thread overview]
Message-ID: <bug-24021-4-nMgqanJegs@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-24021-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=24021

--- Comment #18 from Vincent Lefèvre <vincent-gcc at vinc17 dot net> ---
I'm wondering whether it is possible to check on actual code what is needed.
For instance, assume that you have a program that produces always the same
results, e.g. by running it over a fixed dataset. GCC could get some
information about actual FP values (a bit like profile generation). Then check
what benefit you can get by using these data at compile time (contrary to
optimization with profile use, you assume here that the obtained information is
necessarily valid, which is true as long as the program is run on the chosen
dataset). The difficulty is to find whether some benefit can be obtained by
VRP, but this should give an upper bound on the speedup you can hope to get. So
perhaps this can give some useful information about what to focus on.

  parent reply	other threads:[~2022-02-10 14:17 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <bug-24021-4@http.gcc.gnu.org/bugzilla/>
2021-08-25 20:29 ` amacleod at redhat dot com
2022-02-07 16:07 ` aldyh at gcc dot gnu.org
2022-02-09 16:35 ` aldyh at gcc dot gnu.org
2022-02-09 17:04 ` law at gcc dot gnu.org
2022-02-09 17:27 ` aldyh at gcc dot gnu.org
2022-02-09 17:29 ` vincent-gcc at vinc17 dot net
2022-02-09 17:31 ` vincent-gcc at vinc17 dot net
2022-02-09 18:30 ` jakub at gcc dot gnu.org
2022-02-09 18:31 ` amacleod at redhat dot com
2022-02-09 18:35 ` amacleod at redhat dot com
2022-02-09 19:05 ` vincent-gcc at vinc17 dot net
2022-02-10  9:33 ` rguenth at gcc dot gnu.org
2022-02-10 12:02 ` jakub at gcc dot gnu.org
2022-02-10 12:21 ` rguenther at suse dot de
2022-02-10 14:17 ` vincent-gcc at vinc17 dot net [this message]
2022-04-05 19:34 ` amacleod at redhat dot com
2022-04-06  9:34 ` aldyh at gcc dot gnu.org
2022-04-06  9:46 ` jakub at gcc dot gnu.org
2022-04-06  9:57 ` aldyh at gcc dot gnu.org
2022-04-06 10:30 ` aldyh at gcc dot gnu.org
2022-04-06 10:47 ` jakub at gcc dot gnu.org
2022-08-01 13:27 ` aldyh at gcc dot gnu.org
2022-08-01 14:30 ` aldyh at gcc dot gnu.org
2022-11-08 15:54 ` cvs-commit at gcc dot gnu.org
2022-11-08 15:57 ` aldyh at gcc dot gnu.org
2022-11-28 22:15 ` pinskia at gcc dot gnu.org
     [not found] <bug-24021-6528@http.gcc.gnu.org/bugzilla/>
2005-10-23 23:43 ` pinskia at gcc dot gnu dot org

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