Re: [PATCH] x86: don't wrongly scale non-8-bit displacements

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Mon, Jul 30, 2018 at 6:37 AM, Jan Beulich <JBeulich@suse.com> wrote:
>>>> On 30.07.18 at 15:19, <hjl.tools@gmail.com> wrote:
>> On Mon, Jul 30, 2018 at 6:13 AM, Jan Beulich <JBeulich@suse.com> wrote:
>>>>>> On 30.07.18 at 15:02, <hjl.tools@gmail.com> wrote:
>>>> On Mon, Jul 30, 2018 at 12:41 AM, Jan Beulich <JBeulich@suse.com> wrote:
>>>>> In commit b5014f7af2 I've removed (instead of replaced) a conditional,
>>>>> resulting in addressing forms not allowing 8-bit displacements to now
>>>>> get their displacements scaled under certain circumstances. Re-add the
>>>>> missing conditional.
>>>>>
>>>>> gas/
>>>>> 2018-07-30  Jan Beulich  <jbeulich@suse.com>
>>>>>
>>>>>         * config/tc-i386.c (output_disp): Restrict scaling.
>>>>>         * testsuite/gas/i386/evex-no-scale.s,
>>>>>           testsuite/gas/i386/evex-no-scale-32.d
>>>>>           testsuite/gas/i386/evex-no-scale-64.d: New.
>>>>>         * testsuite/gas/i386/i386.exp: Run new tests.
>>>>>
>>>>> --- a/gas/config/tc-i386.c
>>>>> +++ b/gas/config/tc-i386.c
>>>>> @@ -7965,7 +7965,8 @@ output_disp (fragS *insn_start_frag, off
>>>>>               int size = disp_size (n);
>>>>>               offsetT val = i.op[n].disps->X_add_number;
>>>>>
>>>>> -             val = offset_in_range (val >> i.memshift, size);
>>>>> +             val = offset_in_range (val >> (size == 1 ? i.memshift : 0),
>>>>> +                                    size);
>>>>>               p = frag_more (size);
>>>>>               md_number_to_chars (p, val, size);
>>>>>             }
>>>>
>>>> Please open a binutils bug against binutils 2.31 first  and mention
>>>> it in ChangeLog.   OK with that change.
>>>
>>> I'm sorry, but no - I'm not going to waste time writing bug reports
>>> just for them to be closed again right away. I also don't think bug
>>> fixes should be blocked upon such a requirement.
>>>
>>
>> Your patch changes assembler behavior to fix a regression in
>> the released binutils.  All regressions should be tracked in
>>
>> https://sourceware.org/bugzilla/
>>
>> It isn't a waste of time.
>
> If there are people who care about such tracking, then they're fine
> creating an entry. Doing so is certainly a waste of _my_ time, and I
> find it (once again) strange that bug fixes get blocked by non-
> technical side issues. In the end you'd force me to hold back fixes
> like this (until whoever else runs into it and it gets fixed it after
> reporting through bugzilla), including the reporting of them.
>

Hi Wei,

Please open an assembler bug against binutils 2.31.

Thanks.


-- 
H.J.