From: Jakub Jelinek <jakub@redhat.com>
To: Richard Biener <rguenther@suse.de>, Uros Bizjak <ubizjak@gmail.com>
Cc: gcc-patches@gcc.gnu.org
Subject: [PATCH] i386: Use no-mmx,no-sse for LIBGCC2_UNWIND_ATTRIBUTE [PR104890]
Date: Tue, 15 Mar 2022 10:18:41 +0100 [thread overview]
Message-ID: <YjBZ8VM09Vlf4AYV@tucnak> (raw)
Hi!
Regardless of the outcome of the general-regs-only stuff in x86gprintrin.h,
apparently general-regs-only is much bigger hammer than no-sse, and e.g.
using 387 instructions in the unwinder isn't a big deal, it never needs
to realign the stack because of it.
So, the following patch uses no-sse (and adds no-mmx to it, even when not
strictly needed).
Bootstrapped/regtested on x86_64-linux and i686-linux, on the latter
both normally and with -msse2 -mfpmath=sse -mstackrealign in the options and
--enable-cet, ok for trunk?
2022-03-15 Jakub Jelinek <jakub@redhat.com>
PR target/104890
* config/i386/i386.h (LIBGCC2_UNWIND_ATTRIBUTE): Use no-mmx,no-sse
instead of general-regs-only.
--- gcc/config/i386/i386.h.jj 2022-03-09 15:25:28.355498493 +0100
+++ gcc/config/i386/i386.h 2022-03-14 15:27:33.831976579 +0100
@@ -2848,10 +2848,10 @@ extern enum attr_cpu ix86_schedule;
#define NUM_X86_64_MS_CLOBBERED_REGS 12
#endif
-/* __builtin_eh_return can't handle stack realignment, so restrict to
- general regs in 32-bit libgcc functions that call it. */
+/* __builtin_eh_return can't handle stack realignment, so disable MMX/SSE
+ in 32-bit libgcc functions that call it. */
#ifndef __x86_64__
-#define LIBGCC2_UNWIND_ATTRIBUTE __attribute__((target ("general-regs-only")))
+#define LIBGCC2_UNWIND_ATTRIBUTE __attribute__((target ("no-mmx,no-sse")))
#endif
/*
Jakub
next reply other threads:[~2022-03-15 9:18 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-15 9:18 Jakub Jelinek [this message]
2022-03-15 9:22 ` Richard Biener
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=YjBZ8VM09Vlf4AYV@tucnak \
--to=jakub@redhat.com \
--cc=gcc-patches@gcc.gnu.org \
--cc=rguenther@suse.de \
--cc=ubizjak@gmail.com \
/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).