[Mesa-dev] [Mesa-stable] [PATCH] glsl: remove ARB_compute_shader ext, always allow local_size_* qualifiers

[Matt Turner]

On Wed, Aug 24, 2016 at 12:57 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
> On Wed, Aug 24, 2016 at 3:40 PM, Ian Romanick <idr at freedesktop.org> wrote:
>> On 08/24/2016 10:40 AM, Ilia Mirkin wrote:
>>> The GL_ARB_compute_shader spec does not make a mention of a #extension
>>> enable, nor a #define with the ext name. It follows that local_size_*
>>> should always be allowed in a compute shader stage, and the #extension
>>> support removed.
>>>
>>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97447#c7
>>> Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
>>> Cc: mesa-stable at lists.freedesktop.org
>>> ---
>>>
>>> The change to exposing the gl_MaxCompute* constants is a little dodgy, arguably
>>> it should be exposed everywhere when compute functionality is available, but
>>> that is a little annoying to do, and is no worse than the previous state of
>>> things.
>>>
>>>  src/compiler/glsl/builtin_variables.cpp  | 2 +-
>>>  src/compiler/glsl/glsl_lexer.ll          | 4 ++--
>>>  src/compiler/glsl/glsl_parser.yy         | 5 ++---
>>>  src/compiler/glsl/glsl_parser_extras.cpp | 1 -
>>>  src/compiler/glsl/glsl_parser_extras.h   | 7 -------
>>>  5 files changed, 5 insertions(+), 14 deletions(-)
>>>
>>> diff --git a/src/compiler/glsl/builtin_variables.cpp b/src/compiler/glsl/builtin_variables.cpp
>>> index c9d8b1c..4f88170 100644
>>> --- a/src/compiler/glsl/builtin_variables.cpp
>>> +++ b/src/compiler/glsl/builtin_variables.cpp
>>> @@ -789,7 +789,7 @@ builtin_variable_generator::generate_constants()
>>>        }
>>>     }
>>>
>>> -   if (state->is_version(430, 310) || state->ARB_compute_shader_enable) {
>>> +   if (state->is_version(430, 310) || state->stage == MESA_SHADER_COMPUTE) {
>>>        add_const("gl_MaxComputeAtomicCounterBuffers",
>>>                  state->Const.MaxComputeAtomicCounterBuffers);
>>>        add_const("gl_MaxComputeAtomicCounters",
>>> diff --git a/src/compiler/glsl/glsl_lexer.ll b/src/compiler/glsl/glsl_lexer.ll
>>> index 7be2b89..3324cde 100644
>>> --- a/src/compiler/glsl/glsl_lexer.ll
>>> +++ b/src/compiler/glsl/glsl_lexer.ll
>>> @@ -410,7 +410,7 @@ writeonly      KEYWORD_WITH_ALT(420, 300, 420, 310, yyextra->ARB_shader_image_lo
>>>
>>>  atomic_uint     KEYWORD_WITH_ALT(420, 300, 420, 310, yyextra->ARB_shader_atomic_counters_enable, ATOMIC_UINT);
>>>
>>> -shared          KEYWORD_WITH_ALT(430, 310, 430, 310, yyextra->ARB_compute_shader_enable, SHARED);
>>> +shared          KEYWORD_WITH_ALT(430, 310, 430, 310, yyextra->stage == MESA_SHADER_COMPUTE, SHARED);
>>>
>>>  struct               return STRUCT;
>>>  void         return VOID_TOK;
>>> @@ -425,7 +425,7 @@ layout            {
>>>                     || yyextra->ARB_uniform_buffer_object_enable
>>>                     || yyextra->ARB_fragment_coord_conventions_enable
>>>                        || yyextra->ARB_shading_language_420pack_enable
>>> -                      || yyextra->ARB_compute_shader_enable
>>> +                      || yyextra->stage == MESA_SHADER_COMPUTE
>>>                        || yyextra->ARB_tessellation_shader_enable) {
>>>                     return LAYOUT_TOK;
>>>                  } else {
>>> diff --git a/src/compiler/glsl/glsl_parser.yy b/src/compiler/glsl/glsl_parser.yy
>>> index 4f4a83c..cf2fb60 100644
>>> --- a/src/compiler/glsl/glsl_parser.yy
>>> +++ b/src/compiler/glsl/glsl_parser.yy
>>> @@ -1570,10 +1570,9 @@ layout_qualifier_id:
>>>        for (int i = 0; i < 3; i++) {
>>>           if (match_layout_qualifier(local_size_qualifiers[i], $1,
>>>                                      state) == 0) {
>>> -            if (!state->has_compute_shader()) {
>>> +            if (state->stage != MESA_SHADER_COMPUTE) {
>>>                 _mesa_glsl_error(& @3, state,
>>> -                                "%s qualifier requires GLSL 4.30 or "
>>> -                                "GLSL ES 3.10 or ARB_compute_shader",
>>> +                                "%s qualifier only valid in a compute shader",
>>>                                  local_size_qualifiers[i]);
>>>                 YYERROR;
>>>              } else {
>>> diff --git a/src/compiler/glsl/glsl_parser_extras.cpp b/src/compiler/glsl/glsl_parser_extras.cpp
>>> index 14a5540..37aff38 100644
>>> --- a/src/compiler/glsl/glsl_parser_extras.cpp
>>> +++ b/src/compiler/glsl/glsl_parser_extras.cpp
>>> @@ -578,7 +578,6 @@ static const _mesa_glsl_extension _mesa_glsl_supported_extensions[] = {
>>>     EXT(ARB_ES3_1_compatibility),
>>>     EXT(ARB_ES3_2_compatibility),
>>>     EXT(ARB_arrays_of_arrays),
>>> -   EXT(ARB_compute_shader),
>>
>> I think this will mean that having
>>
>> #extension GL_ARB_compute_shader: require
>>
>> will not compile.  That seems bad.
>
> I see no indication that that should ever have worked in the first place.

That might be true, but a Google search indicates that quite a few
people seem to expect it to work. Given those results, I would expect
that the proprietary drivers don't throw an error.