From: "H.J. Lu" <hjl.tools@gmail.com>
To: Jan Beulich <jbeulich@suse.com>
Cc: Binutils <binutils@sourceware.org>
Subject: Re: [PATCH 5/7] x86: re-work insn/suffix recognition
Date: Wed, 28 Sep 2022 12:33:26 -0700 [thread overview]
Message-ID: <CAMe9rOq-fcNKwKcxKctR0XZ+0A_0PhpBgckhe9MqqCt8T-ebWA@mail.gmail.com> (raw)
In-Reply-To: <93622263-1a05-07e7-4a96-c33cffb0796b@suse.com>
On Wed, Sep 28, 2022 at 5:49 AM Jan Beulich <jbeulich@suse.com> wrote:
>
> On 27.09.2022 01:52, H.J. Lu wrote:
> > Sorry for the delay. I was on vacation. My main concern is to call
> > strdup and free for each instruction. I prefer to add new entries to
> > deal with rare cases instead of penalizing all instructions.
>
> Hmm, I think I can take care of this concern: As it looks, at least
> parse_insn() leaves the input buffer undisturbed, so minimally I ought
> to be able to limit the strdup() to just a very small set of
> mnemonics. I'm not sure yet if I may even be able to avoid the copying
> altogether; I'll have to check quite carefully in particular
> parse_operands() and the functions it calls. But perhaps relying on
> this would be risky looking forward, so I guess we better don't make
> assumptions here and instead flag mnemonics (in the templates) where
> retrying may be necessary when no match was found during the 1st pass.
This sounds reasonable.
> FTAOD - I take it calling free() with a NULL argument is not a concern?
We can use free (NULL).
> I guess to prove (and going forward guarantee) the apparent behavior of
> parse_insn() I'd like to constify its first parameter. This might
> involve adding a cast (to drop const-ness again after the call), which
> I generally would like to avoid, or some "interesting" pointer
> arithmetic. If you have any opinion here up front, please let me know.
Can we avoid it by adding some new entries to the opcode table?
I don't think we need many such entries.
--
H.J.
next prev parent reply other threads:[~2022-09-28 19:34 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-16 7:27 [PATCH 0/7] x86: suffix handling changes Jan Beulich
2022-08-16 7:30 ` [PATCH 1/7] x86/Intel: restrict suffix derivation Jan Beulich
2022-08-17 19:19 ` H.J. Lu
2022-08-18 6:07 ` Jan Beulich
2022-08-18 14:46 ` H.J. Lu
2022-08-19 8:19 ` Jan Beulich
2022-08-19 14:23 ` H.J. Lu
2022-08-19 14:49 ` Jan Beulich
2022-08-19 17:00 ` H.J. Lu
2022-08-22 9:34 ` Jan Beulich
2022-08-22 14:38 ` H.J. Lu
2022-08-16 7:30 ` [PATCH 2/7] x86: insert "no error" enumerator in i386_error enumeration Jan Beulich
2022-08-17 19:19 ` H.J. Lu
2022-08-16 7:31 ` [PATCH 3/7] x86: move / quiesce pre-386 non-16-bit warning Jan Beulich
2022-08-17 19:21 ` H.J. Lu
2022-08-18 7:21 ` Jan Beulich
2022-08-18 15:30 ` H.J. Lu
2022-08-19 6:13 ` Jan Beulich
2022-08-19 14:18 ` H.J. Lu
2022-08-16 7:32 ` [PATCH 4/7] x86: improve match_template()'s diagnostics Jan Beulich
2022-08-17 20:24 ` H.J. Lu
2022-08-18 6:14 ` Jan Beulich
2022-08-18 14:51 ` H.J. Lu
2022-08-16 7:32 ` [PATCH 5/7] x86: re-work insn/suffix recognition Jan Beulich
2022-08-17 20:29 ` H.J. Lu
2022-08-18 6:24 ` Jan Beulich
2022-08-18 15:14 ` H.J. Lu
2022-08-19 8:28 ` Jan Beulich
2022-08-23 2:00 ` H.J. Lu
2022-08-26 9:26 ` Jan Beulich
2022-08-26 18:46 ` H.J. Lu
2022-09-06 6:40 ` Jan Beulich
2022-09-06 21:53 ` H.J. Lu
2022-09-07 7:17 ` Jan Beulich
2022-09-26 23:52 ` H.J. Lu
2022-09-28 12:49 ` Jan Beulich
2022-09-28 19:33 ` H.J. Lu [this message]
2022-09-29 8:08 ` Jan Beulich
2022-09-29 16:00 ` H.J. Lu
2022-09-29 16:06 ` Jan Beulich
2022-09-29 16:20 ` H.J. Lu
2022-08-16 7:33 ` [PATCH 6/7] x86-64: further re-work insn/suffix recognition to also cover MOVSL Jan Beulich
2022-08-16 7:34 ` [PATCH 7/7] ix86: don't recognize/derive Q suffix in the common case Jan Beulich
2022-08-17 20:36 ` H.J. Lu
2022-08-18 6:29 ` Jan Beulich
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