[PATCH] x86: Remove support for old (<= 2.8.1) versions of gcc

[H.J. Lu]

On Wed, Mar 7, 2018 at 6:08 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Wed, Mar 7, 2018 at 5:54 AM, Jan Beulich <JBeulich@suse.com> wrote:
>>>>> On 07.03.18 at 14:26, <hjl.tools@gmail.com> wrote:
>>> On Wed, Mar 7, 2018 at 4:54 AM, Jan Beulich <JBeulich@suse.com> wrote:
>>>>>>> On 07.03.18 at 13:39, <hjl.tools@gmail.com> wrote:
>>>>> On Wed, Mar 7, 2018 at 4:36 AM, Jan Beulich <JBeulich@suse.com> wrote:
>>>>>>>>> On 07.03.18 at 13:30, <hjl.tools@gmail.com> wrote:
>>>>>>> On Wed, Mar 7, 2018 at 1:47 AM, Jan Beulich <JBeulich@suse.com> wrote:
>>>>>>>> While the combination of Intel syntax and AT&T mnemonics is bogus
>>>>>>>> anyway, we nevertheless shouldn't mis-encode such insns.
>>>>>>>>
>>>>>>>> gas/
>>>>>>>> 2018-03-07  Jan Beulich  <jbeulich@suse.com>
>>>>>>>>
>>>>>>>>         * testsuite/gas/i386/fsubp.l, testsuite/gas/i386/fsubp.s: New.
>>>>>>>>         * testsuite/gas/i386/i386.exp: Run new test.
>>>>>>>>
>>>>>>>> opcodes/
>>>>>>>> 2018-03-07  Jan Beulich  <jbeulich@suse.com>
>>>>>>>>
>>>>>>>>         * i386-opc.tbl (fsubp): Correct encoding.
>>>>>>>>         * i386-tlb.h: Re-generate.
>>>>>>>>
>>>>>>>
>>>>>>> I assume that no one uses it.  Can't we simply drop it?
>>>>>>
>>>>>> I don't know, and would dare to chance it. But perhaps you know
>>>>>> better than me. Of course, if we drop this one, there are others to
>>>>>> be dropped at the same time.
>>>>>
>>>>> We are changing their encodings.  If we can't drop them, it means
>>>>> that someone is depending on their old encodings.
>>>>
>>>> Well, no, not exactly: If we do as you suggest, we should remove
>>>> more than just this broken encoding. People may use some of the
>>>> others, or may have happened to use the one here only with odd
>>>> numbered registers. But again - I'm not entirely opposed to dropping
>>>> the whole OldGcc logic, it's just that (at least at this point in time) it's
>>>> not going to be me to do it. Hence rather than leaving things broken,
>>>> I'd prefer to fix them. (As a side note, patch 3 and maybe also patch
>>>> 4 of this series would probably need changing, just like a number of
>>>> existing test cases.)
>>>
>>> We should drop the broken encoding.  If people do use them, they
>>> will get an assembler error.  Otherwise, they will get a run-time
>>> error which is much harder to track down.
>>
>> Well, again - we should drop all that OldGcc cruft, or keep it and fix
>> it. Leaving something broken around is simply bad, and leaving OldGcc
>> partially implemented isn't much better.
>>
>
> Let me work on dropping OldGcc.
>

Here is a patch which does that.

Any comments?


-- 
H.J.
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