[Nouveau] Dealing with opencl kernel parameters in nouveau now that RES support is gone

[Ilia Mirkin]

On Mon, Feb 22, 2016 at 8:08 AM, Hans de Goede <hdegoede at redhat.com> wrote:
> Hi,
>
>
> On 22-02-16 14:04, Samuel Pitoiset wrote:
>>
>>
>> On 02/22/2016 01:46 PM, Hans de Goede wrote:
>>>
>>> Hi,
>>>
>>> On 22-02-16 13:41, Samuel Pitoiset wrote:
>>>>
>>>> Hi there,
>>>>
>>>> On 02/22/2016 12:26 PM, Hans de Goede wrote:
>>>
>>>
>>> <snip>
>>>
>>>>> So back to the problem of getting OpenCL(ish) code to work again with
>>>>> the recent mesa changes. For starters I would like to get:
>>>>>
>>>>> src/gallium/tests/trivial/compute.c and then the test with mask 8,
>>>>> test_input_global() to work again, when that is working I should be
>>>>> able to adjust my llvm work (and if necessary clover) to start to
>>>>> work again.
>>>>>
>>>>> Currently the test_input_global() test uses the following bit of
>>>>> TGSI code:
>>>>>
>>>>> COMP
>>>>> DCL SV[0], THREAD_ID[0]
>>>>> DCL TEMP[0], LOCAL
>>>>> DCL TEMP[1], LOCAL
>>>>> IMM UINT32 { 8, 0, 0, 0 }
>>>>>
>>>>>     BGNSUB\n"
>>>>>         UMUL TEMP[0], SV[0], IMM[0]
>>>>>         LOAD TEMP[1].xy, RINPUT, TEMP[0]
>>>>>         LOAD TEMP[0].x, RGLOBAL, TEMP[1].yyyy
>>>>>         UADD TEMP[1].x, TEMP[0], -TEMP[1]
>>>>>         STORE RGLOBAL.x, TEMP[1].yyyy, TEMP[1]
>>>>>         RET
>>>>>     ENDSUB
>>>>>
>>>>>
>>>>> Where by RINPUT and RGLOBAL get replaces by processing the
>>>>> code with cpp and the following defines:
>>>>>
>>>>> #define RGLOBAL        RES[32767]
>>>>> #define RLOCAL         RES[32766]
>>>>> #define RPRIVATE       RES[32765]
>>>>> #define RINPUT         RES[32764]
>>>>>
>>>>> If I understand how memory is supposed to work, then I would need to
>>>>> change the TGSI as follows:
>>>>>
>>>>> COMP
>>>>> DCL SV[0], THREAD_ID[0]
>>>>> DCL MEMORY[0]
>>>>> DCL TEMP[0], LOCAL
>>>>> DCL TEMP[1], LOCAL
>>>>> IMM UINT32 { 8, 0, 0, 0 }
>>>>>
>>>>> BGNSUB\n"
>>>>> UMUL TEMP[0], SV[0], IMM[0]
>>>>> LOAD TEMP[1].xy, RINPUT, TEMP[0]
>>>>> LOAD TEMP[0].x, MEMORY[0], TEMP[1].yyyy
>>>>> UADD TEMP[1].x, TEMP[0], -TEMP[1]
>>>>> STORE MEMORY[0].x, TEMP[1].yyyy, TEMP[1]
>>>>> RET
>>>>> ENDSUB
>>>>
>>>>
>>>> Nope, this won't work because RINPUT is RES[32764]. And you have to
>>>> remove all occurrences to RES because it's not longer supported. In my
>>>> opinion, using BUFFER[0] in a first time should work. Currently, only
>>>> SHARED with MEMORY is supported.
>>>
>>>
>>> Right, as I say below "This only solves the accessing of the global
>>> memory, it does not solve
>>> getting to the kernel input kernel parameters"
>>>
>>>>> This assumes, that as discussed declaring memory without a , SHARED or
>>>>> other
>>>>> flag means the memory is global.
>>>>>
>>>>> So 2 questions:
>>>>>
>>>>> 1) Do the above changes for using the new MEMORY keyword look as
>>>>> intended
>>>>> to you?
>>>>>
>>>>> 2) This only solves the accessing of the global memory, it does not
>>>>> solve
>>>>> getting to the kernel input kernel parameters, how would I deal with
>>>>> those ?
>>>>
>>>>
>>>> The input kernel parameters are directly passed through a call to
>>>> pipe_context::launch_grid. You just have to fill the
>>>> pipe_grid_info::input array with your parameters and they will be
>>>> uploaded by nvXX_compute_upload_input().
>>>
>>>
>>> Right, the uploading side I understand, the question is how to get to
>>> them from
>>> the compute kernel's tgsi code ?
>>
>>
>> Right, I wonder if there is already a DECL INPUT or something like that
>> for input parameters of shaders. Oh yeah, there is TGSI_FILE_INPUT, maybe
>> this is what you want?
>
>
> Yes that sounds right, so now "all" we need to do is make
> nvXX_compute_upload_input() and TGSI_FILE_INPUT work together.

INPUT is for shader inputs which come from fixed function loaders.
This is not what you want. You want CONST. Stick the input params into
a constbuf, and you're done.

  -ilia