[PATCH v2 1/9] x86: Remove unused SFrame CFI RA register variable

[Jens Remus]

Am 26.02.2024 um 14:01 schrieb Jan Beulich:
> On 24.02.2024 08:38, Indu Bhagat wrote:
>> On 2/23/24 09:07, Jens Remus wrote:
>>> gas/
>>> 	* config/tc-i386.c: Remove unused SFrame CFI RA register
>>> 	  variable.
>>>
>>
>> The ChangeLog formatting is a bit off here and in the rest of the
>> patches in this series.
>>
>> The indentation of each line should be such that all content lines up
>> below the *, like so:
>>
>> <TAB>* xyz.c: first line content
>> <TAB>next line content
>>
>> Other than that, LGTM.
> 
> Just to clarify: It's not actually a missing SFRAME_CFA_RA_REG define
> (and initialization of the variable)?

My understanding is that on x86 AMD64 SFrame assumes the return address 
to be always passed on the stack at fixed offset -8 from CFA (see 
x86_sframe_cfa_ra_offset). That is why SFrame does not use 
SFRAME_CFA_RA_REG (= DWARF2_DEFAULT_RETURN_COLUMN) on that architecture 
to track the return address being saved on the stack (see 
x86_sframe_ra_tracking_p). SFrame only supports either FP/RA tracking or 
fixed offset to CFA.

Regards,
Jens
-- 
Jens Remus
Linux on Z Development (D3303) and z/VSE Support
+49-7031-16-1128 Office
jremus@de.ibm.com

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