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Re: mov{s,z}{b,w,l} suffix guessing


>>> On 28.06.16 at 16:44, <hjl.tools@gmail.com> wrote:
> On Tue, Jun 28, 2016 at 7:00 AM, Jan Beulich <JBeulich@suse.com> wrote:
>> H.J.,
>>
>> i386-opc.tbl has "interesting" comments around these, and the
>> assembler as a result provides inconsistent behavior: For one
>> because of the recognition of the suffix-less movzb (as the
>> only exception). And of course with both instruction groups
>> therefore being different from all other instructions with
>> register operands. So the question is: Are these inconsistencies
>> really intended, or wouldn't it be better to enhance things so
>> that at least the final suffix bytes on these two groups won't
>> be required anymore? (Clearly when both operands are
>> registers, one could even aim at making the second from last
>> suffix byte optional too.)
>>
>> And if the current (sorry) state is intentional, shouldn't use of
>> suffix-less movzb at least get warned about, to pave a road
>> towards removing that exception?
> 
> Please open a bug with all these issues you found.  We should
> investigate them.  If changing them doesn't introduce any test
> failures and gcc/glibc/kernel have no issues, we should fix it.

Well, I'm hesitant to do such bureaucracy. I would do it if you
indicated to preferred direction would be to remove movzb. If
however you would, just like I do, prefer to add the missing
ones, then I'd much rather look into adding them instead of
writing a bugzilla entry.

Jan


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