[Mesa-dev] [RFC]: gallium: add new float comparison opcodes returning integer booleans

[Brian Paul]

Tying this to PIPE_SHADER_CAP_INTEGERS sounds good to me.

And yeah, st_glsl_to_tgsi.cpp will need some work one of these days...

-Brian

On 08/09/2013 01:17 PM, Roland Scheidegger wrote:
> I was thinking it should just be part of the native_integer support
> (glsl 1.30 basically) so it must be supported if you support that, and
> it is always preferred in that case.
> Though I won't implement it for other drivers (just llvmpipe/softpipe),
> and just hope everybody will implement it so glsl can be switched to use
> the new opcodes (so will only be used by internal code for now) as I
> think this really makes sense. If not I guess could add a pipe flag and
> make glsl act accordingly.
>
> Roland
>
>
> Am 09.08.2013 21:01, schrieb Brian Paul:
>> Looks good to me.
>>
>> Will you be a adding a new PIPE_SHADER_CAP_ flag so the driver can tell
>> the state tracker which kind of comparison instructions it wants?
>>
>> -Brian
>>
>> On 08/09/2013 12:42 PM, Roland Scheidegger wrote:
>>> This is a proposal for new comparison instructions, as the old ones
>>> don't really fit modern (graphic or opencl I guess for that matter)
>>> languages well.
>>> If you've got objections, think the naming is crazy or whatnot I'm open
>>> for suggestions :-). I would think this is not just a much better fit
>>> for d3d10/glsl but for hw as well.
>>>
>>> Roland
>>>
>>> Am 09.08.2013 20:40, schrieb sroland at vmware.com:
>>>> From: Roland Scheidegger <sroland at vmware.com>
>>>>
>>>> The old float comparison opcodes always return floats 0.0 and 1.0
>>>> (clarified
>>>> in docs these were really floats, was always the case) for legacy
>>>> graphics.
>>>> But everybody else (opengl,opencl,d3d10) just has to work around their
>>>> return results (converting the returned float back to int/boolean).
>>>> ---
>>>>    src/gallium/docs/source/tgsi.rst |   84
>>>> ++++++++++++++++++++++++++++++--------
>>>>    1 file changed, 68 insertions(+), 16 deletions(-)
>>>>
>>>> diff --git a/src/gallium/docs/source/tgsi.rst
>>>> b/src/gallium/docs/source/tgsi.rst
>>>> index 949ad89..b7c40cf 100644
>>>> --- a/src/gallium/docs/source/tgsi.rst
>>>> +++ b/src/gallium/docs/source/tgsi.rst
>>>> @@ -512,13 +512,13 @@ This instruction replicates its result.
>>>>
>>>>    .. math::
>>>>
>>>> -  dst.x = (src0.x == src1.x) ? 1 : 0
>>>> +  dst.x = (src0.x == src1.x) ? 1.0F : 0.0F
>>>>
>>>> -  dst.y = (src0.y == src1.y) ? 1 : 0
>>>> +  dst.y = (src0.y == src1.y) ? 1.0F : 0.0F
>>>>
>>>> -  dst.z = (src0.z == src1.z) ? 1 : 0
>>>> +  dst.z = (src0.z == src1.z) ? 1.0F : 0.0F
>>>>
>>>> -  dst.w = (src0.w == src1.w) ? 1 : 0
>>>> +  dst.w = (src0.w == src1.w) ? 1.0F : 0.0F
>>>>
>>>>
>>>>    .. opcode:: SFL - Set On False
>>>> @@ -538,13 +538,13 @@ This instruction replicates its result.
>>>>
>>>>    .. math::
>>>>
>>>> -  dst.x = (src0.x > src1.x) ? 1 : 0
>>>> +  dst.x = (src0.x > src1.x) ? 1.0F : 0.0F
>>>>
>>>> -  dst.y = (src0.y > src1.y) ? 1 : 0
>>>> +  dst.y = (src0.y > src1.y) ? 1.0F : 0.0F
>>>>
>>>> -  dst.z = (src0.z > src1.z) ? 1 : 0
>>>> +  dst.z = (src0.z > src1.z) ? 1.0F : 0.0F
>>>>
>>>> -  dst.w = (src0.w > src1.w) ? 1 : 0
>>>> +  dst.w = (src0.w > src1.w) ? 1.0F : 0.0F
>>>>
>>>>
>>>>    .. opcode:: SIN - Sine
>>>> @@ -560,26 +560,26 @@ This instruction replicates its result.
>>>>
>>>>    .. math::
>>>>
>>>> -  dst.x = (src0.x <= src1.x) ? 1 : 0
>>>> +  dst.x = (src0.x <= src1.x) ? 1.0F : 0.0F
>>>>
>>>> -  dst.y = (src0.y <= src1.y) ? 1 : 0
>>>> +  dst.y = (src0.y <= src1.y) ? 1.0F : 0.0F
>>>>
>>>> -  dst.z = (src0.z <= src1.z) ? 1 : 0
>>>> +  dst.z = (src0.z <= src1.z) ? 1.0F : 0.0F
>>>>
>>>> -  dst.w = (src0.w <= src1.w) ? 1 : 0
>>>> +  dst.w = (src0.w <= src1.w) ? 1.0F : 0.0F
>>>>
>>>>
>>>>    .. opcode:: SNE - Set On Not Equal
>>>>
>>>>    .. math::
>>>>
>>>> -  dst.x = (src0.x != src1.x) ? 1 : 0
>>>> +  dst.x = (src0.x != src1.x) ? 1.0F : 0.0F
>>>>
>>>> -  dst.y = (src0.y != src1.y) ? 1 : 0
>>>> +  dst.y = (src0.y != src1.y) ? 1.0F : 0.0F
>>>>
>>>> -  dst.z = (src0.z != src1.z) ? 1 : 0
>>>> +  dst.z = (src0.z != src1.z) ? 1.0F : 0.0F
>>>>
>>>> -  dst.w = (src0.w != src1.w) ? 1 : 0
>>>> +  dst.w = (src0.w != src1.w) ? 1.0F : 0.0F
>>>>
>>>>
>>>>    .. opcode:: STR - Set On True
>>>> @@ -1325,6 +1325,19 @@ Support for these opcodes indicated by
>>>> PIPE_SHADER_CAP_INTEGERS (all of them?)
>>>>
>>>>
>>>>
>>>> +.. opcode:: FSLT - Float Set On Less Than (ordered)
>>>> +
>>>> +.. math::
>>>> +
>>>> +  dst.x = (src0.x < src1.x) ? ~0 : 0
>>>> +
>>>> +  dst.y = (src0.y < src1.y) ? ~0 : 0
>>>> +
>>>> +  dst.z = (src0.z < src1.z) ? ~0 : 0
>>>> +
>>>> +  dst.w = (src0.w < src1.w) ? ~0 : 0
>>>> +
>>>> +
>>>>    .. opcode:: ISLT - Signed Integer Set On Less Than
>>>>
>>>>    .. math::
>>>> @@ -1351,6 +1364,19 @@ Support for these opcodes indicated by
>>>> PIPE_SHADER_CAP_INTEGERS (all of them?)
>>>>      dst.w = (src0.w < src1.w) ? ~0 : 0
>>>>
>>>>
>>>> +.. opcode:: FSGE - Float Set On Greater Equal Than (ordered)
>>>> +
>>>> +.. math::
>>>> +
>>>> +  dst.x = (src0.x >= src1.x) ? ~0 : 0
>>>> +
>>>> +  dst.y = (src0.y >= src1.y) ? ~0 : 0
>>>> +
>>>> +  dst.z = (src0.z >= src1.z) ? ~0 : 0
>>>> +
>>>> +  dst.w = (src0.w >= src1.w) ? ~0 : 0
>>>> +
>>>> +
>>>>    .. opcode:: ISGE - Signed Integer Set On Greater Equal Than
>>>>
>>>>    .. math::
>>>> @@ -1377,6 +1403,19 @@ Support for these opcodes indicated by
>>>> PIPE_SHADER_CAP_INTEGERS (all of them?)
>>>>      dst.w = (src0.w >= src1.w) ? ~0 : 0
>>>>
>>>>
>>>> +.. opcode:: FSEQ - Float Set On Equal (ordered)
>>>> +
>>>> +.. math::
>>>> +
>>>> +  dst.x = (src0.x == src1.x) ? ~0 : 0
>>>> +
>>>> +  dst.y = (src0.y == src1.y) ? ~0 : 0
>>>> +
>>>> +  dst.z = (src0.z == src1.z) ? ~0 : 0
>>>> +
>>>> +  dst.w = (src0.w == src1.w) ? ~0 : 0
>>>> +
>>>> +
>>>>    .. opcode:: USEQ - Integer Set On Equal
>>>>
>>>>    .. math::
>>>> @@ -1390,6 +1429,19 @@ Support for these opcodes indicated by
>>>> PIPE_SHADER_CAP_INTEGERS (all of them?)
>>>>      dst.w = (src0.w == src1.w) ? ~0 : 0
>>>>
>>>>
>>>> +.. opcode:: FSNE - Float Set On Not Equal (unordered)
>>>> +
>>>> +.. math::
>>>> +
>>>> +  dst.x = (src0.x != src1.x) ? ~0 : 0
>>>> +
>>>> +  dst.y = (src0.y != src1.y) ? ~0 : 0
>>>> +
>>>> +  dst.z = (src0.z != src1.z) ? ~0 : 0
>>>> +
>>>> +  dst.w = (src0.w != src1.w) ? ~0 : 0
>>>> +
>>>> +
>>>>    .. opcode:: USNE - Integer Set On Not Equal
>>>>
>>>>    .. math::
>>>>