public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/106892] [11/12/13 Regression] Wrong code at -O3 on x86_64-linux-gnu since r11-963-g80d6f89e78fc3b77
Date: Fri, 09 Sep 2022 09:05:29 +0000 [thread overview]
Message-ID: <bug-106892-4-HY9DKmfISD@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-106892-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106892
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org
Status|NEW |ASSIGNED
--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
-fno-gcse-lm fixes the testcase. The only difference from the bisected
revision is
(insn 56 55 57 15 (set (mem:SI (plus:DI (mult:DI (reg:DI 102)
(const_int 4 [0x4]))
- (reg/f:DI 99)) [1 f S4 A32])
+ (reg/f:DI 99)) [1 f[_137]+0 S4 A32])
(reg:SI 105)) "t.c":19:21 -1
(nil))
and PRE then does
-PRE GCSE of j, 23 basic blocks, 3800 bytes needed, 0 substs, 0 insns created
+scanning new insn with uid = 106.
+deleting insn with uid = 54.
+PRE: redundant insn 54 (expression 5) in bb 15, reaching reg is 107
+PRE: edge (14,15), copy expression 5
+scanning new insn with uid = 107.
+PRE GCSE of j, 23 basic blocks, 3848 bytes needed, 1 substs, 1 insns created
it looks like RTL PRE hoists
(insn 54 50 55 15 (set (reg:SI 106 [ MEM[(int *)_20 + 16B] ])
(mem:SI (plus:DI (reg/f:DI 86 [ _20 ])
(const_int 16 [0x10])) [1 MEM[(int *)_20 + 16B]+0 S4 A32]))
"t.c":19:21 67 {*movsi_internal}
(nil))
out of the loop, across
(insn 56 55 57 15 (set (mem:SI (plus:DI (mult:DI (reg:DI 102)
(const_int 4 [0x4]))
(symbol_ref:DI ("f") [flags 0x2] <var_decl 0x7fb59de26e10 f>))
[1 f[_137]+0 S4 A32])
(reg:SI 105)) "t.c":19:21 67 {*movsi_internal}
(expr_list:REG_DEAD (reg:SI 105)
(expr_list:REG_DEAD (reg:DI 102)
(expr_list:REG_DEAD (reg/f:DI 99)
(nil)))))
I will see why exactly.
next prev parent reply other threads:[~2022-09-09 9:05 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-08 21:37 [Bug c/106892] New: Wrong code at -O3 on x86_64-linux-gnu shaohua.li at inf dot ethz.ch
2022-09-08 22:02 ` [Bug c/106892] " jakub at gcc dot gnu.org
2022-09-09 7:40 ` rguenth at gcc dot gnu.org
2022-09-09 7:53 ` shaohua.li at inf dot ethz.ch
2022-09-09 8:15 ` rguenth at gcc dot gnu.org
2022-09-09 8:20 ` marxin at gcc dot gnu.org
2022-09-09 8:20 ` jakub at gcc dot gnu.org
2022-09-09 8:31 ` [Bug c/106892] [11/12/13 Regression] Wrong code at -O3 on x86_64-linux-gnu since r11-963-g80d6f89e78fc3b77 rguenth at gcc dot gnu.org
2022-09-09 8:32 ` [Bug middle-end/106892] " rguenth at gcc dot gnu.org
2022-09-09 9:05 ` rguenth at gcc dot gnu.org [this message]
2022-09-09 9:31 ` rguenth at gcc dot gnu.org
2022-09-09 10:04 ` rguenth at gcc dot gnu.org
2022-09-09 12:43 ` rguenth at gcc dot gnu.org
2022-09-10 13:14 ` [Bug middle-end/106892] [11/12 " mikpelinux at gmail dot com
2022-09-12 7:53 ` marxin at gcc dot gnu.org
2022-10-11 12:06 ` cvs-commit at gcc dot gnu.org
2022-10-17 13:28 ` [Bug middle-end/106892] [11 " cvs-commit at gcc dot gnu.org
2022-10-17 13:29 ` rguenth at gcc dot gnu.org
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-106892-4-HY9DKmfISD@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).