public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/113326] Optimize vector shift with constant delta on shifting-count operand
Date: Thu, 11 Jan 2024 07:30:05 +0000 [thread overview]
Message-ID: <bug-113326-4-1bQGSgsyD9@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-113326-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113326
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |missed-optimization
Component|tree-optimization |target
Severity|normal |enhancement
Last reconfirmed| |2024-01-11
Ever confirmed|0 |1
Status|UNCONFIRMED |NEW
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Note on aarch64 with SVE, you should be able to generate those constants
without a load, using the index instruction. Though aarch64 does not generate
them currently. So this is definitely target specific and all.
Plus this is simplification happens after the vectorizer which produces:
```
<bb 3> [local count: 252544065]:
# i_13 = PHI <i_10(5), 0(2)>
# ivtmp_3 = PHI <ivtmp_2(5), 16(2)>
# vect_vec_iv_.4_11 = PHI <_16(5), { 0, 1, 2, 3 }(2)>
# vectp_array.6_19 = PHI <vectp_array.6_20(5), &array(2)>
# ivtmp_22 = PHI <ivtmp_23(5), 0(2)>
_16 = vect_vec_iv_.4_11 + { 4, 4, 4, 4 };
vect__1.5_18 = vect_cst__17 >> vect_vec_iv_.4_11;
_1 = value_8(D) >> i_13;
MEM <vector(4) int> [(int *)vectp_array.6_19] = vect__1.5_18;
i_10 = i_13 + 1;
ivtmp_2 = ivtmp_3 - 1;
vectp_array.6_20 = vectp_array.6_19 + 16;
ivtmp_23 = ivtmp_22 + 1;
if (ivtmp_23 < 4)
goto <bb 5>; [75.00%]
else
goto <bb 4>; [25.00%]
```
next prev parent reply other threads:[~2024-01-11 7:30 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-11 7:13 [Bug tree-optimization/113326] New: " fxue at os dot amperecomputing.com
2024-01-11 7:30 ` pinskia at gcc dot gnu.org [this message]
2024-01-11 7:44 ` [Bug target/113326] " pinskia at gcc dot gnu.org
2024-01-11 7:52 ` fxue at os dot amperecomputing.com
2024-01-11 7:56 ` pinskia at gcc dot gnu.org
2024-01-11 8:10 ` pinskia at gcc dot gnu.org
2024-01-11 9:13 ` rguenth at gcc dot gnu.org
2024-01-11 9:58 ` fxue at os dot amperecomputing.com
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=bug-113326-4-1bQGSgsyD9@http.gcc.gnu.org/bugzilla/ \
--to=gcc-bugzilla@gcc.gnu.org \
--cc=gcc-bugs@gcc.gnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).