From: "H. J. Lu" <hjl@lucon.org>
To: "David S. Miller" <davem@redhat.com>
Cc: aoliva@redhat.com, rsandifo@redhat.com,
linux-mips@linux-mips.org, gcc@gcc.gnu.org,
binutils@sources.redhat.com
Subject: Re: MIPS gas relaxation still doesn't work
Date: Mon, 14 Oct 2002 14:14:00 -0000 [thread overview]
Message-ID: <20021014130932.A32693@lucon.org> (raw)
In-Reply-To: <20021014.125134.98070597.davem@redhat.com>; from davem@redhat.com on Mon, Oct 14, 2002 at 12:51:34PM -0700
On Mon, Oct 14, 2002 at 12:51:34PM -0700, David S. Miller wrote:
> From: "H. J. Lu" <hjl@lucon.org>
> Date: Mon, 14 Oct 2002 12:55:49 -0700
>
> .set noreorder
> .set nomacro
>
> bne $2,$0,$L7493
> nop
> j $L2
> nop
>
> .set macro
> .set reorder
>
> answer your question?
>
>
> What instruction would you like to place in the bne's delay
> slot? 'j' cannot go into a delay slot.
>
> And likewise, 'bne' cannot go into j's delay slot.
If gcc just emits
bne $2,$0,$L7493
j $L2
gas will fill the delay slot with nop or branch relaxation. For
bar:
foo:
.space 0x20000
bne $2,$0,bar
j foo
gas generates
foo.o: file format elf32-tradlittlemips
Disassembly of section .text:
00000000 <bar>:
...
20000: 10400005 beqz v0,20018 <bar+0x20018>
20004: 00000000 nop
20008: 8f810000 lw at,0(gp)
20008: R_MIPS_GOT16 .text
2000c: 00000000 nop
20010: 24210000 addiu at,at,0
20010: R_MIPS_LO16 .text
20014: 00200008 jr at
20018: 00000000 nop
2001c: 8f810000 lw at,0(gp)
2001c: R_MIPS_GOT16 .text
20020: 00000000 nop
20024: 24210000 addiu at,at,0
20024: R_MIPS_LO16 .text
20028: 00200008 jr at
2002c: 00000000 nop
H.J.
next prev parent reply other threads:[~2002-10-14 20:09 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20021012113423.A27894@lucon.org>
[not found] ` <20021013145423.A10174@lucon.org>
2002-10-14 9:23 ` H. J. Lu
2002-10-14 9:35 ` Richard Sandiford
2002-10-14 9:37 ` H. J. Lu
2002-10-14 10:04 ` Richard Sandiford
2002-10-14 10:43 ` H. J. Lu
2002-10-14 10:50 ` David S. Miller
2002-10-14 10:53 ` H. J. Lu
2002-10-14 11:13 ` Alexandre Oliva
2002-10-14 11:21 ` H. J. Lu
2002-10-14 12:28 ` Alexandre Oliva
2002-10-14 12:37 ` H. J. Lu
2002-10-14 12:58 ` Alexandre Oliva
2002-10-14 13:00 ` H. J. Lu
2002-10-14 13:08 ` David S. Miller
2002-10-14 13:23 ` H. J. Lu
2002-10-14 14:04 ` David S. Miller
2002-10-14 14:14 ` H. J. Lu [this message]
2002-10-14 14:17 ` Alexandre Oliva
2002-10-14 14:18 ` H. J. Lu
2002-10-14 15:37 ` Alexandre Oliva
2002-10-14 15:40 ` H. J. Lu
2002-10-15 1:08 ` Alexandre Oliva
2002-10-15 2:53 ` Dominic Sweetman
2002-10-15 8:12 ` Alexandre Oliva
2002-10-15 14:18 ` Jim Wilson
2002-10-15 13:27 ` Maciej W. Rozycki
2002-10-15 16:37 ` Jim Wilson
2002-10-16 6:39 ` Maciej W. Rozycki
2002-10-16 10:38 ` Jim Wilson
2002-10-15 18:40 ` Alexandre Oliva
2002-10-16 7:01 ` Maciej W. Rozycki
2002-10-16 7:47 ` Alexandre Oliva
2002-10-16 8:06 ` Maciej W. Rozycki
2002-10-14 17:02 ` Eric Christopher
2002-10-15 1:15 ` Alexandre Oliva
2002-10-14 14:44 ` Michael Matz
2002-10-15 13:28 ` Jim Wilson
2002-10-15 13:45 ` Paul Koning
2002-10-15 14:32 ` Maciej W. Rozycki
2002-10-15 15:33 ` Alexandre Oliva
2002-10-16 5:32 ` Maciej W. Rozycki
2002-10-15 14:00 ` Daniel Jacobowitz
2002-10-15 14:56 ` Eric Christopher
2002-10-15 15:05 ` Daniel Jacobowitz
2002-10-16 7:53 ` Paul Koning
2002-10-16 8:11 ` Maciej W. Rozycki
2002-10-15 15:23 ` Jim Wilson
2002-10-16 5:38 ` Maciej W. Rozycki
2002-10-16 10:37 ` Jim Wilson
2002-10-16 11:04 ` Maciej W. Rozycki
2002-10-15 16:54 ` Richard Henderson
2002-10-14 9:40 ` Alexandre Oliva
2002-10-14 9:44 ` H. J. Lu
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=20021014130932.A32693@lucon.org \
--to=hjl@lucon.org \
--cc=aoliva@redhat.com \
--cc=binutils@sources.redhat.com \
--cc=davem@redhat.com \
--cc=gcc@gcc.gnu.org \
--cc=linux-mips@linux-mips.org \
--cc=rsandifo@redhat.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).