Mirror of the gdb-patches mailing list
 help / color / mirror / Atom feed
From: Randolph Chung <randolph@tausq.org>
To: gdb-patches@sources.redhat.com
Subject: Re: [patch/RFA] multiarch INSTRUCTION_NULLIFIED
Date: Wed, 01 Dec 2004 16:25:00 -0000	[thread overview]
Message-ID: <20041201162524.GD6359@tausq.org> (raw)

In-Reply-To: <BDD32F47.81A3%schlie@comcast.net>

> A point that may be worth considering is that on architectures which support
> jump/branch delay slots, the branch and delay slot is actually logically
> executed as single compound instruction, treated by the machine as a unified
> whole.

i don't think this is true for hppa. for instance you can do a hardware
singlestep into the delay slot of a branch insn by setting the recovery
counter appropriately. this will cause an hardware interruption which
the kernel can translate to a SIGTRAP.

nullification is also a more general concept on hppa which doesn't only
apply to branch instructions. A lot of ALU instructions can also
conditioanlly nullify the next insn, which potentially could belong to a
different line of source code. gcc uses this to implement if-conversion,
for example.

randolph
-- 
Randolph Chung
Debian GNU/Linux Developer, hppa/ia64 ports
http://www.tausq.org/


             reply	other threads:[~2004-12-01 16:25 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-12-01 16:25 Randolph Chung [this message]
  -- strict thread matches above, loose matches on Subject: below --
2004-12-01 13:32 Paul Schlie
2004-11-18  0:02 Randolph Chung
2004-11-18 14:26 ` Andrew Cagney
2004-11-18 16:21   ` Randolph Chung
2004-11-18 16:56     ` Mark Kettenis
2004-11-19  9:25       ` Orjan Friberg
2004-11-23 17:50       ` Randolph Chung
2004-11-23 19:33         ` Mark Kettenis
2004-11-28 17:26         ` Andrew Cagney
2004-11-28 18:41           ` Randolph Chung
2004-11-28 19:55             ` Andrew Cagney
2004-11-29  3:30               ` Randolph Chung
2004-11-29 15:12                 ` Andrew Cagney
2004-11-30  6:56                   ` Randolph Chung
2004-11-30 14:51                     ` Andrew Cagney
2004-11-30 16:44                       ` Randolph Chung
2004-11-30 16:59                         ` Andrew Cagney
2004-11-30 17:38                           ` Randolph Chung
2004-12-01 21:29                             ` Andrew Cagney
2004-12-01 22:33                               ` Randolph Chung
2004-12-01 23:32                                 ` Andrew Cagney
2004-12-02  5:24                                   ` Randolph Chung
2004-12-02 14:27                                     ` Daniel Jacobowitz
2004-12-03 18:11                                     ` Andrew Cagney
2004-12-03 18:15                                       ` Randolph Chung
2004-12-03 18:57                                         ` Daniel Jacobowitz
2004-12-03 19:57                                           ` Randolph Chung
2004-12-03 21:40                                       ` Randolph Chung
2004-12-03 21:58                                         ` Andrew Cagney
2004-12-03 22:52                                           ` Daniel Jacobowitz
2004-12-04  0:00                                           ` Randolph Chung
2004-12-04  0:55                                           ` Randolph Chung
2004-12-04 11:27                                             ` Mark Kettenis
2004-12-01  6:19                   ` Randolph Chung
2004-12-01 17:11                     ` Daniel Jacobowitz
2004-12-01 17:17                       ` Randolph Chung
2004-12-01 17:19                         ` Daniel Jacobowitz
2004-12-01 17:25                           ` Randolph Chung
2004-12-01 17:28                             ` Daniel Jacobowitz
2004-12-01 17:30                               ` Randolph Chung
2004-12-01 17:35                               ` Randolph Chung
2004-12-01 18:14                                 ` Randolph Chung
2004-12-01 21:25                       ` Andrew Cagney

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=20041201162524.GD6359@tausq.org \
    --to=randolph@tausq.org \
    --cc=gdb-patches@sources.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