[Mesa-dev] [PATCH 00/17] radv: Support for subgroup_vote and shader_ballot

[Nicolai Hähnle]

FYI, somehow your mails don't show up in a single thread for me. They're 
in groups of 00-04, 05-09, 10-14, 15-17. Not sure what's up with that.

On 10.06.2017 01:43, Connor Abbott wrote:
> From: Connor Abbott <cwabbott0 at gmail.com>
> 
> This series adds all the bits to enable EXT_shader_subgroup_vote and
> EXT_shader_subgroup_ballot for radv. It's based on my previous series to
> fix some 64-bit bugs in radv and anv, since nothing would work without
> them.
> 
> Patches 1-4 are a resend of my previous series to add ARB_shader_ballot
> and ARB_shader_group_vote support to NIR, with some changes suggested by
> Jason and minor bugfixes. Patches 5-8 add SPIRV-to-NIR support for the
> SPIR-V extensions. Finally, the rest of the patches move some of the
> existing logic for ARB_shader_ballot and ARB_shader_group_vote into ac
> when appropriate and turn on the extension for radv.
> 
> One question I had was about how to handle the differences between
> SPIR-V and GL here. SPIR-V decided to make the things that return a
> bitmask of invocations return a uvec4, whereas in the GL extension they
> return a uint64_t. Right now, in NIR, we use the GL semantics, and we
> translate that in vtn. I'm open to changing that, though.

Pragmatically, I'd say stick with the GL semantics for now. We'd only 
ever have to change that if somebody decides to build a GPU with 
128-wide waves, but given how having wider waves increasingly hurts with 
divergence, that seems unlikely to happen.


> I wrote a few crucible tests to test the extension (mostly copied from
> the piglit ARB_shader_ballot and ARB_shader_group_vote coverage), which
> I'll send out shortly. One of the tests is crashing because of
> https://github.com/KhronosGroup/glslang/issues/930, but other than that
> it passes the tests.

Looks like an alternative GLSL-to-SPIRV compiler would really be nice to 
have...

I've sent comments on some of the patches, mostly the NIR attribute 
stuff. Sorry I didn't notice that sooner.

Cheers,
Nicolai


> I also made sure I didn't regress piglit on
> radeonsi. It might be a good idea to run it on Intel's CI system,
> especially given patches 5 and 6.
> 
> This series is also available at:
> git://people.freedesktop.org/~cwabbott0/mesa radv-shader-ballot
> 
> Connor Abbott (17):
>    nir: introduce new convergent and cross-thread attributes
>    nir/gcm: use the new cross-thread attribute
>    nir: take cross-thread operations into account into a few places
>    nir: add ARB_shader_ballot and ARB_shader_group_vote instructions
>    mesa: fix 64-bit issues with system_values_read
>    compiler: add new system values for SPV_KHR_shader_ballot
>    nir/lower_system_values: handle SPIR-V shader_ballot system values
>    nir/spirv: add plumbing for KHR_shader_ballot and KHR_subgroup_vote
>    ac: add i32_0 convenience member to ac_llvm_context
>    radeonsi: move llvm_get_type_size() to ac
>    radeonsi: move emit_optimization_barrier() to ac
>    ac: add i64 type to ac_llvm_context
>    radeonsi: move si_emit_ballot() to ac
>    ac: add i32_1 convenience member to ac_llvm_context
>    radeonsi: move the guts of ARB_shader_group_vote emission to ac
>    ac: enable the AMDGPU asm parser
>    radv/ac: enable EXT_shader_subgroup_ballot and
>      EXT_shader_subgroup_vote
> 
>   src/amd/common/ac_llvm_build.c             | 127 +++++++++++++++++++++++++++
>   src/amd/common/ac_llvm_build.h             |  18 ++++
>   src/amd/common/ac_llvm_util.c              |   4 +
>   src/amd/common/ac_nir_to_llvm.c            |  75 ++++++++++++++++
>   src/amd/vulkan/radv_device.c               |   8 ++
>   src/amd/vulkan/radv_pipeline.c             |   2 +
>   src/compiler/nir/nir.c                     |  28 ++++++
>   src/compiler/nir/nir.h                     |  80 +++++++++++++++++
>   src/compiler/nir/nir_instr_set.c           |  22 +++++
>   src/compiler/nir/nir_intrinsics.h          |  30 +++++++
>   src/compiler/nir/nir_lower_system_values.c |  38 ++++++++
>   src/compiler/nir/nir_opt_gcm.c             |  72 +++++----------
>   src/compiler/nir/nir_opt_peephole_select.c |  11 +++
>   src/compiler/shader_enums.c                |   5 ++
>   src/compiler/shader_enums.h                |  11 +++
>   src/compiler/spirv/nir_spirv.h             |   2 +
>   src/compiler/spirv/spirv_to_nir.c          |  80 +++++++++++++++++
>   src/compiler/spirv/vtn_variables.c         |  28 ++++++
>   src/gallium/auxiliary/nir/tgsi_to_nir.c    |   2 +-
>   src/gallium/drivers/radeonsi/si_shader.c   | 136 +++--------------------------
>   src/intel/compiler/brw_vec4_gs_visitor.cpp |   3 +-
>   src/mesa/program/programopt.c              |   2 +-
>   src/mesa/state_tracker/st_glsl_to_tgsi.cpp |   9 +-
>   src/mesa/state_tracker/st_mesa_to_tgsi.c   |   6 +-
>   24 files changed, 617 insertions(+), 182 deletions(-)
> 


-- 
Lerne, wie die Welt wirklich ist,
Aber vergiss niemals, wie sie sein sollte.