[PATCH v3 10/10] x86-64: Intel64 adjustments for insns dealing with far pointers

[Jan Beulich]

On 17.01.2020 19:06, H.J. Lu wrote:
> On Fri, Jan 17, 2020 at 3:48 AM Jan Beulich <jbeulich@suse.com> wrote:
>>
>> On 16.01.2020 21:24,  H.J. Lu  wrote:
>>> We should improve gas documentation.  The current far branches
>>> work fine.  Why bother to add new far branches without giving
>>> developer a clue how to use them?
>>
>> That's the subject of CPU documentation, not that of any assembler.
>> The current far branches "work fine" as far as they're being made
>> accessible (encodable) by gas. The 64-bit forms Intel CPUs support
>> didn't work fine at all (because one had to use hand crafted REX.W
>> prefixes), as per Andrew's bug report. There's no difference here
>> to the prior work you did to support the Intel64 / AMD64
>> differences for certain other insns - you've simply made gas
>> capable of properly encoding them in a vendor dependent manner.
>> You didn't accompany this with any documentation explaining "how
>> to use" these. If, retroactively, you think this should have been
>> accompanied by such documentation, may I ask that you add such,
> 
> Yes, it is not very obvious how to use them, we should add some
> documentation.   Which one do you have in mind?

All which currently have the Intel64 or AMD64 attribute. If all
present ones had extra documentation, then (as said) it would be
more obvious that _and_ what documentation needs/wants adding
for ones covered anew.

Jan