[Mesa-dev] [PATCH mesa v2 3/3] nouveau: codegen: LOAD: Take src swizzle into account

[Hans de Goede]

Hi,

On 22-04-16 10:37, Marek Olšák wrote:
> On Fri, Apr 22, 2016 at 9:23 AM, Hans de Goede <hdegoede at redhat.com> wrote:
>> Hi,
>>
>> On 22-04-16 09:08, Marek Olšák wrote:
>>>
>>> On Thu, Apr 21, 2016 at 7:04 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>>>>
>>>> [+radeon folk]
>>>>
>>>> Marek, Nicolai, Bas - please have a look at the doc change and let us
>>>> know if you think this will cause a problem for radeon.
>>>>
>>>> Hans is solving the issue that he wants to swizzle the data loaded
>>>> from the image/buffer/whatever before sticking it into the dst
>>>> register.
>>>
>>>
>>> Is this something st/mesa needs or just nouveau? If just nouveau needs
>>> it, I don't see a point in updating the TGSI spec, since nouveau can
>>> just add the swizzle when translating from TGSI.
>>
>>
>> This is something which the llvm tgsi backend needs, which we plan to
>> use to add opencl support to nouveau.
>>
>>  From the commit msg:
>>
>> "The llvm TGSI backend uses pointers in registers and does things like:
>>
>> LOAD TEMP[0].y, MEMORY[0], TEMP[0]
>>
>> Expecting the data at address TEMP[0].x to get loaded to
>> TEMP[0].y. But this will cause the data at TEMP[0].x + 4 to be
>> loaded instead.
>>
>> This commit adds support for a swizzle suffix for the 1st source
>> operand, which allows using:
>>
>> LOAD TEMP[0].y, MEMORY[0].xxxx, TEMP[0]
>>
>> And actually getting the desired behavior"
>
> If radeonsi needs no changes and st/mesa doesn't change behavior, it's OK.

Since radeonsi does not use llvm generated tgsi, it should not need any
changes, and these patches do not touch st/mesa.

Regards,

Hans