[Mesa-dev] [PATCH 15/57] i965/fs: Handle fixed HW GRF subnr in reg_offset().

[Francisco Jerez]

Iago Toral <itoral at igalia.com> writes:

> On Wed, 2016-09-07 at 18:48 -0700, Francisco Jerez wrote:
>> This will be useful later on when we start using reg_offset() on
>> fixed
>> hardware registers.
>> ---
>>  src/mesa/drivers/dri/i965/brw_ir_fs.h | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>> 
>> diff --git a/src/mesa/drivers/dri/i965/brw_ir_fs.h
>> b/src/mesa/drivers/dri/i965/brw_ir_fs.h
>> index 2e5c8e5..4ac9baa 100644
>> --- a/src/mesa/drivers/dri/i965/brw_ir_fs.h
>> +++ b/src/mesa/drivers/dri/i965/brw_ir_fs.h
>> @@ -187,7 +187,8 @@ static inline unsigned
>>  reg_offset(const fs_reg &r)
>>  {
>>     return (r.file == VGRF || r.file == IMM ? 0 : r.nr) *
>> -          (r.file == UNIFORM ? 4 : REG_SIZE) + r.offset;
>> +          (r.file == UNIFORM ? 4 : REG_SIZE) + r.offset +
>> +          (r.file == ARF || r.file == FIXED_GRF ? r.subnr : 0);
>
> I guess that for ARF and FIXED_GRF r.offset is expected to be 0, right?

It doesn't really matter as far as this function is concerned: If it's
zero it won't affect the result of the function, if it's non-zero it
will be taken into account correctly.  Some other back-end code may
break though if a fixed grf register has non-zero offset, but I'd call
that code responsible for asserting "offset == 0" if it's unable to deal
with it.

> In that case, should we make it more explicit here by adding an assert,
> and/or maybe separating the offset calculation for these register types
> (so it only uses nr and subnr) from the others?
>
> Iago
>
>>  }
>>  
>>  /**
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 212 bytes
Desc: not available
URL: <https://lists.freedesktop.org/archives/mesa-dev/attachments/20160909/c211179d/attachment.sig>