[PATCH][AArch64] Add more cfi annotations to tlsdesc entry points

[Richard Henderson]

On 12/13/2016 07:05 AM, Florian Weimer wrote:
> On 12/09/2016 06:38 PM, Richard Henderson wrote:
>> On 12/09/2016 05:23 AM, Szabolcs Nagy wrote:
>>>      stp    x1,  x2, [sp, #32+16*0]
>>> +    cfi_rel_offset (x1, 32)
>>> +    cfi_rel_offset (x2, 32+8)
>>>      stp    x3,  x4, [sp, #32+16*1]
>>> +    cfi_rel_offset (x3, 32+16)
>>> +    cfi_rel_offset (x4, 32+24)
>>
>> FWIW, you'll produce equivalent, but smaller unwind info if you put all of the
>> cfi_rel_offsets together (constrained by the assembly for when the original
>> register values change.  So
>>
>>     stp    x1, x2, [sp, #32+16*0]
>>     stp    x3, x4, [sp, #32+16*1]
>>     cfi_rel_offset (x1, 32)
>>     cfi_rel_offset (x2, 32+8)
>>     cfi_rel_offset (x3, 32+16)
>>     cfi_rel_offset (x4, 32+24)
>
> Will this cause problems with async cancellation?

No, because the registers have not been modified.  All this does is eliminate 
extra "advance" opcodes.

r~