From: "H.J. Lu" <hjl.tools@gmail.com>
To: Roland McGrath <mcgrathr@google.com>
Cc: Victor Khimenko <khim@google.com>, binutils@sourceware.org
Subject: Re: [RFC PATCH] Fix decoding of superfluous data32 prefix before superfluous rex.W prefix before push.
Date: Sat, 04 Aug 2012 00:30:00 -0000 [thread overview]
Message-ID: <CAMe9rOqLJ+vb2HoP_jQk-PDqMcdqwKVKA=-20S85wM9bmvFd0w@mail.gmail.com> (raw)
In-Reply-To: <CAMe9rOoDxX0hY-AUTJY1N69CwRfyVof06Rrc0z0f3Su2R-J1Ag@mail.gmail.com>
On Fri, Aug 3, 2012 at 4:24 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Fri, Aug 3, 2012 at 3:59 PM, Roland McGrath <mcgrathr@google.com> wrote:
>> I noticed that since you used #pass in the .d files, one could add more
>> cases to the end of x86-64-stack.s and not notice if one failed to update
>> all the .d files appropriately. So I added a nop at the end, to make sure
>> that's matched last.
>>
>> What I was hoping is that you could tell me how to change:
>>
>> 0: 66 48 6a ff data32 pushq $0xffffffffffffffff
>> 4: 66 48 68 01 02 03 04 data32 pushq $0x4030201
>>
>> into:
>>
>> 0: 66 48 6a ff data32 rex.W pushq $0xffffffffffffffff
>> 4: 66 48 68 01 02 03 04 data32 rex.W pushq $0x4030201
>>
>> i.e., recognize that the rex.W prefix was not used, as it already
>> does when there is no data32 prefix before it. Do you have an idea
>> to fix that?
>>
>
> There are
>
> /* Bits of REX we've already used. */
> static int rex_used;
>
> Please make sure that it isn't set for push.
This seems to work:
diff --git a/opcodes/i386-dis.c b/opcodes/i386-dis.c
index 685e968..ed79d92 100644
--- a/opcodes/i386-dis.c
+++ b/opcodes/i386-dis.c
@@ -12275,7 +12275,7 @@ case_L:
case 'T':
if (!intel_syntax
&& address_mode == mode_64bit
- && (sizeflag & DFLAG))
+ && ((rex & REX_W) || (sizeflag & DFLAG)))
{
*obufp++ = 'q';
break;
We need to update some testcases.
--
H.J.
next prev parent reply other threads:[~2012-08-03 23:36 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-03 18:47 Roland McGrath
2012-08-03 18:54 ` H.J. Lu
2012-08-03 19:52 ` H.J. Lu
2012-08-03 21:55 ` Roland McGrath
2012-08-03 22:10 ` H.J. Lu
2012-08-03 23:24 ` Roland McGrath
2012-08-03 23:36 ` H.J. Lu
2012-08-04 0:30 ` H.J. Lu [this message]
2012-08-06 20:02 ` Roland McGrath
2012-08-06 20:20 ` H.J. Lu
2012-08-06 20:34 ` Roland McGrath
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