public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "liuhongt at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/114591] [12/13/14 Regression] register allocators introduce an extra load operation since gcc-12
Date: Wed, 10 Apr 2024 08:17:21 +0000 [thread overview]
Message-ID: <bug-114591-4-bIl7qQFz0y@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-114591-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114591
Hongtao Liu <liuhongt at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |liuhongt at gcc dot gnu.org
--- Comment #4 from Hongtao Liu <liuhongt at gcc dot gnu.org> ---
(In reply to Uroš Bizjak from comment #3)
> (In reply to Jakub Jelinek from comment #2)
> > This changed with r12-5584-gca5667e867252db3c8642ee90f55427149cd92b6
>
> Strange, if I revert the constraints to the previous setting with:
>
> --cut here--
> diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
> index 10ae3113ae8..262dd25a8e0 100644
> --- a/gcc/config/i386/i386.md
> +++ b/gcc/config/i386/i386.md
> @@ -2870,9 +2870,9 @@ (define_peephole2
>
> (define_insn "*movhi_internal"
> [(set (match_operand:HI 0 "nonimmediate_operand"
> - "=r,r,r,m ,*k,*k ,r ,m ,*k ,?r,?*v,*Yv,*v,*v,jm,m")
> + "=r,r,r,m ,*k,*k ,*r ,*m ,*k ,?r,?v,*Yv,*v,*v,*jm,*m")
> (match_operand:HI 1 "general_operand"
> - "r ,n,m,rn,r ,*km,*k,*k,CBC,*v,r ,C ,*v,m ,*x,*v"))]
> + "r ,n,m,rn,*r ,*km,*k,*k,CBC,v,r ,C ,v,m ,x,v"))]
> "!(MEM_P (operands[0]) && MEM_P (operands[1]))
> && ix86_hardreg_mov_ok (operands[0], operands[1])"
> {
> --cut here--
>
> I still get:
>
> movl v1(%rip), %eax # 6 [c=6 l=6] *zero_extendsidi2/3
> movq %rax, v2(%rip) # 16 [c=4 l=7] *movdi_internal/5
> movzwl v1(%rip), %eax # 7 [c=5 l=7] *movhi_internal/2
My experience is memory cost for the operand with rm or separate r, m is
different which impacts RA decision.
https://gcc.gnu.org/pipermail/gcc-patches/2022-May/595573.html
next prev parent reply other threads:[~2024-04-10 8:17 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-04 18:57 [Bug rtl-optimization/114591] New: rtl-reload " absoler at smail dot nju.edu.cn
2024-04-04 19:03 ` [Bug target/114591] " pinskia at gcc dot gnu.org
2024-04-04 19:07 ` [Bug target/114591] [12/13/14 Regression] " pinskia at gcc dot gnu.org
2024-04-05 2:32 ` [Bug target/114591] [12/13/14 Regression] register allocators " law at gcc dot gnu.org
2024-04-08 15:02 ` jakub at gcc dot gnu.org
2024-04-10 7:51 ` ubizjak at gmail dot com
2024-04-10 8:17 ` liuhongt at gcc dot gnu.org [this message]
2024-04-10 8:30 ` liuhongt at gcc dot gnu.org
2024-04-10 8:36 ` ubizjak at gmail dot com
2024-04-10 8:40 ` ubizjak at gmail dot com
2024-04-10 8:47 ` ubizjak at gmail dot com
2024-04-10 8:52 ` liuhongt at gcc dot gnu.org
2024-04-10 9:07 ` ubizjak at gmail dot com
2024-04-10 9:12 ` liuhongt at gcc dot gnu.org
2024-04-11 6:33 ` liuhongt at gcc dot gnu.org
2024-04-11 6:54 ` ubizjak at gmail dot com
2024-04-11 7:08 ` pinskia at gcc dot gnu.org
2024-04-11 7:28 ` liuhongt at gcc dot gnu.org
2024-04-11 7:37 ` liuhongt 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-114591-4-bIl7qQFz0y@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).