[Mesa-dev] [PATCH v2 01/10] tgsi: add MEMBAR opcode to handle memoryBarrier* GLSL intrinsics

[Roland Scheidegger]

Am 19.01.2016 um 18:26 schrieb Ilia Mirkin:
> This is designed to map the GLSL intrinsics. Should one have a desire
> to also support d3d11, one could figure out what the overlap is and
> rejigger the arguments so that both sets of desires are expressible. I
> glanced at SM5 sync before doing this, and TBH I couldn't really make
> sense of it:
> 
> https://urldefense.proofpoint.com/v2/url?u=https-3A__msdn.microsoft.com_en-2Dus_library_windows_desktop_hh447241-28v-3Dvs.85-29.aspx&d=BQIFaQ&c=Sqcl0Ez6M0X8aeM67LKIiDJAXVeAw-YihVMNtXt-uEs&r=Vjtt0vs_iqoI31UfJxBl7yv9I2FeiaeAYgMTLKRBc_I&m=SMet2U2OIJ5oy5jQStnU-uILuZtC-MlPv4zHcWrYWVQ&s=xCCXURzgP9o6ovwd20TIT_Xmi1Bvv56cA4H6B1ItAIg&e= 
> 
> If you can interpret it and make concrete recommendations for change,
> I'm happy to accommodate.
I can't make all that much sense out of it neither (I don't even see how
the mapping is from the HLSL functions).
Albeit the thread group and shared memory sync seem close. I suppose for
shader storage buffers, atomic buffers, and images d3d11 would use all
the same sync, as it is all UAV. Albeit it can distinguish there from
per-group or global sync (the former more looks like TGSI_OPCODE_BARRIER?).
Anyway, I don't have any objections to this.

Roland



> 
> On Tue, Jan 19, 2016 at 12:04 PM, Roland Scheidegger <sroland at vmware.com> wrote:
>> I am actually wondering how well that would work for d3d11.
>> d3d11 just has AllMemoryBarrier, DeviceMemoryBarrier plus
>> GroupMemoryBarrier - and for each of them also a "WithGroupSync"
>> version. Hmm.
>>
>> Roland
>>
>> Am 19.01.2016 um 03:30 schrieb Ilia Mirkin:
>>> Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
>>> Reviewed-by: Marek Olšák <marek.olsak at amd.com> (v1)
>>>
>>> v1 -> v2: add defines for the various bits
>>> ---
>>>  src/gallium/auxiliary/tgsi/tgsi_info.c     |  2 +-
>>>  src/gallium/docs/source/tgsi.rst           | 17 +++++++++++++++++
>>>  src/gallium/include/pipe/p_shader_tokens.h |  7 ++++++-
>>>  3 files changed, 24 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/src/gallium/auxiliary/tgsi/tgsi_info.c b/src/gallium/auxiliary/tgsi/tgsi_info.c
>>> index b270dd7..46b296f 100644
>>> --- a/src/gallium/auxiliary/tgsi/tgsi_info.c
>>> +++ b/src/gallium/auxiliary/tgsi/tgsi_info.c
>>> @@ -149,7 +149,7 @@ static const struct tgsi_opcode_info opcode_info[TGSI_OPCODE_LAST] =
>>>     { 1, 2, 0, 0, 0, 0, 0, COMP, "FSGE", TGSI_OPCODE_FSGE },
>>>     { 1, 2, 0, 0, 0, 0, 0, COMP, "FSLT", TGSI_OPCODE_FSLT },
>>>     { 1, 2, 0, 0, 0, 0, 0, COMP, "FSNE", TGSI_OPCODE_FSNE },
>>> -   { 0, 1, 0, 0, 0, 0, 1, NONE, "", 112 },      /* removed */
>>> +   { 0, 1, 0, 0, 0, 0, 0, OTHR, "MEMBAR", TGSI_OPCODE_MEMBAR },
>>>     { 0, 1, 0, 0, 0, 0, 0, NONE, "CALLNZ", TGSI_OPCODE_CALLNZ },
>>>     { 0, 1, 0, 0, 0, 0, 0, NONE, "", 114 },     /* removed */
>>>     { 0, 1, 0, 0, 0, 0, 0, NONE, "BREAKC", TGSI_OPCODE_BREAKC },
>>> diff --git a/src/gallium/docs/source/tgsi.rst b/src/gallium/docs/source/tgsi.rst
>>> index 7810a3e..489cbb0 100644
>>> --- a/src/gallium/docs/source/tgsi.rst
>>> +++ b/src/gallium/docs/source/tgsi.rst
>>> @@ -2372,6 +2372,23 @@ programs.
>>>    the program.  Results are unspecified if any of the remaining
>>>    threads terminates or never reaches an executed BARRIER instruction.
>>>
>>> +.. opcode:: MEMBAR - Memory barrier
>>> +
>>> +  ``MEMBAR type``
>>> +
>>> +  This opcode waits for the completion of all memory accesses based on
>>> +  the type passed in. The type is an immediate bitfield with the following
>>> +  meaning:
>>> +
>>> +  Bit 0: Shader storage buffers
>>> +  Bit 1: Atomic buffers
>>> +  Bit 2: Images
>>> +  Bit 3: Shared memory
>>> +  Bit 4: Thread group
>>> +
>>> +  These may be passed in in any combination. An implementation is free to not
>>> +  distinguish between these as it sees fit. However these map to all the
>>> +  possibilities made available by GLSL.
>>>
>>>  .. _atomopcodes:
>>>
>>> diff --git a/src/gallium/include/pipe/p_shader_tokens.h b/src/gallium/include/pipe/p_shader_tokens.h
>>> index f300207..6539017 100644
>>> --- a/src/gallium/include/pipe/p_shader_tokens.h
>>> +++ b/src/gallium/include/pipe/p_shader_tokens.h
>>> @@ -420,7 +420,7 @@ struct tgsi_property_data {
>>>  #define TGSI_OPCODE_FSLT                110
>>>  #define TGSI_OPCODE_FSNE                111
>>>
>>> -                                /* gap */
>>> +#define TGSI_OPCODE_MEMBAR              112
>>>  #define TGSI_OPCODE_CALLNZ              113
>>>                                  /* gap */
>>>  #define TGSI_OPCODE_BREAKC              115
>>> @@ -744,6 +744,11 @@ struct tgsi_instruction_memory
>>>     unsigned Padding   : 29;
>>>  };
>>>
>>> +#define TGSI_MEMBAR_SHADER_BUFFER (1 << 0)
>>> +#define TGSI_MEMBAR_ATOMIC_BUFFER (1 << 1)
>>> +#define TGSI_MEMBAR_SHADER_IMAGE  (1 << 2)
>>> +#define TGSI_MEMBAR_SHARED        (1 << 3)
>>> +#define TGSI_MEMBAR_THREAD_GROUP  (1 << 4)
>>>
>>>  #ifdef __cplusplus
>>>  }
>>>
>>