Re: [PATCH] x86: don't allow invalid operand combinations for VGATHER

["Jan Beulich" <JBeulich at suse dot com>]

>>> On 31.07.12 at 17:43, "H.J. Lu" <hjl.tools@gmail.com> wrote:
> On Tue, Jul 31, 2012 at 12:49 AM, Jan Beulich <JBeulich@suse.com> wrote:
>>>>> On 30.07.12 at 18:10, "H.J. Lu" <hjl.tools@gmail.com> wrote:
>>> On Tue, Jul 24, 2012 at 7:18 AM, Jan Beulich <JBeulich@suse.com> wrote:
>>>> The VGATHER group of instructions requires that all three involved
>>>> xmm/ymm registers are distinct. This patch adds code to check for this,
>>>> and at once eliminates a superfluous check for not using PC-relative
>>>> addressing for these instructions (the fact that an index register is
>>>> required here already excludes valid PC-relative addresses).
>>>>
>>>
>>> The assembler should only check the operands which can't be
>>> encoded.  It should shouldn't check if operands are functional
>>> correct.  However, I don't mind to issue an error which is controlled
>>> by a command line option.
>>
>> Hmm, not sure. Is there any precedent to such behavior? I as a
>> programmer would appreciate if the assembler rejected anything
>> that's invalid.
>>
>> In the case you stay on that position, would making the new
>> diagnostic an unconditional warning be acceptable instead?
>>
> 
> Can you also add a command line option to turn it off and
> turn warning into error?

That should be possible, yes.

Jan