[Intel-gfx] [PATCH] drm/i915: Drop platform_mask

[Lucas De Marchi]

On Fri, Mar 15, 2019 at 08:19:58PM +0200, Ville Syrjälä wrote:
>On Fri, Mar 15, 2019 at 07:13:49AM +0000, Tvrtko Ursulin wrote:
>>
>> On 15/03/2019 06:56, Tvrtko Ursulin wrote:
>> >
>> > On 15/03/2019 00:52, Chris Wilson wrote:
>> >> Quoting José Roberto de Souza (2019-03-15 00:42:35)
>> >>> We don't have any platform that is composed by 2 or more platforms so
>> >>> we don't need a mask, lets drop it and remove the actual limit of 32
>> >>> platforms.
>> >
>> > Platform mask was a nifty trick to compile tests like IS_SKYLAKE ||
>> > IS_BROADWELL etc into a single conditional.
>> >
>> >> gcc doesn't entirely agree, this is a net loss here (i.e. code size
>> >> increases).
>> >
>> > Perhaps the size re-gain of dropping the platform mask could be checked
>> > against the size gain of making the mask 64 bit.
>>
>> One possible alternative could be splitting the 64-bit platform mask
>> into two 32-bit dwords. Like:
>>
>>    u32 platform_mask[2];
>>
>>    #define IS_PLATFORM(p) (platform_mask[p / 32] & BIT(p % 32))
>
>This is fast approaching nih bitmap.h territory.

I would be a little less opposed to this whole idea if it was in
bitmap.h indeed.

Lucas De Marchi

>
>-- 
>Ville Syrjälä
>Intel