[PATCH 2/2] x86: adjust disassembly of insns operating on selector values

[Jan Beulich]

On 17.07.2023 04:04, Jiang, Haochen wrote:
>> --- a/gas/testsuite/gas/i386/opcode-suffix.d
>> +++ b/gas/testsuite/gas/i386/opcode-suffix.d
>> @@ -102,7 +102,7 @@ Disassembly of section .text:
>>   *[0-9a-f]+:	60[ 	]+pushal
>>   *[0-9a-f]+:	61[ 	]+popal
>>   *[0-9a-f]+:	62 90 90 90 90 90[ 	]+boundl %edx,-0x6f6f6f70\(%eax\)
>> - *[0-9a-f]+:	63 90 90 90 90 90[ 	]+arpl[ 	]+%dx,-0x6f6f6f70\(%eax\)
>> + *[0-9a-f]+:	63 90 90 90 90 90[ 	]+arpll[ 	]+%edx,-
>> 0x6f6f6f70\(%eax\)
>>   *[0-9a-f]+:	68 90 90 90 90[ 	]+pushl[ 	]+\$0x90909090
>>   *[0-9a-f]+:	69 90 90 90 90 90 90 90 90 90[ 	]+imull[
>> 	]+\$0x90909090,-0x6f6f6f70\(%eax\),%edx
>>   *[0-9a-f]+:	6a 90[ 	]+pushl[ 	]+\$0xffffff90
>> @@ -248,7 +248,7 @@ Disassembly of section .text:
>>   *[0-9a-f]+:	fc[ 	]+cld
>>   *[0-9a-f]+:	fd[ 	]+std
>>   *[0-9a-f]+:	ff 90 90 90 90 90[ 	]+calll[ 	]+\*-0x6f6f6f70\(%eax\)
>> - *[0-9a-f]+:	0f 00 90 90 90 90 90[ 	]+lldt[ 	]+-0x6f6f6f70\(%eax\)
>> + *[0-9a-f]+:	0f 00 90 90 90 90 90[ 	]+lldtw[ 	]+-0x6f6f6f70\(%eax\)
> 
> H.J. is on vacation till Wednesday but I suppose H.J. has this question in my patch
> before and he might raise again if he is here.
> 
> Is this suffix needed since m16 is the only allowed memory here?

All suffixes should be appended in suffix-always mode. The question
of whether one can be omitted arises only in the default mode, where
optional suffixes are left off (for clarity / ease of reading). Plus
please recall that the changes here are for consistency, and e.g. in

 *[0-9a-f]+:	8c 90 90 90 90 90[ 	]+movw[ 	]+%ss,-0x6f6f6f70\(%eax\)

the suffix is also present, no matter that only m16 is possible.

In any event I'm not intending to commit this before the end of the
week, so H.J. will have a chance to voice his opinion.

Jan