[Mesa-dev] [PATCH 1/2] tgsi: texture types

Roland Scheidegger sroland at vmware.com
Mon Jun 8 19:36:32 PDT 2015


Am 09.06.2015 um 04:20 schrieb Rob Clark:
> On Mon, Jun 8, 2015 at 9:40 PM, Roland Scheidegger <sroland at vmware.com> wrote:
>> Am 09.06.2015 um 03:20 schrieb Rob Clark:
>>> On Mon, Jun 8, 2015 at 8:35 PM, Roland Scheidegger <sroland at vmware.com> wrote:
>>>> Am 08.06.2015 um 20:15 schrieb Rob Clark:
>>>>> From: Rob Clark <robclark at freedesktop.org>
>>>>>
>>>>> Freedreno needs sampler type information to deal with int/uint textures.
>>>>> To accomplish this, start creating sampler-view declarations, as
>>>>> suggested here:
>>>>>
>>>>>  http://lists.freedesktop.org/archives/mesa-dev/2014-November/071583.html
>>>>>
>>>>> create a sampler-view with index matching the sampler, to encode the
>>>>> texture type (ie. SINT/UINT/FLOAT).  Ie:
>>>>>
>>>>>    DCL SVIEW[n], 2D, UINT
>>>>>    DCL SAMP[n]
>>>>>    TEX OUT[1], IN[1], SAMP[n]
>>>>>
>>>>> For tgsi texture instructions which do not take an explicit SVIEW
>>>>> argument, the SVIEW index is implied by the SAMP index.
>>>> I wonder if there should be some doc update somewhere.
>>>>
>>>
>>> yeah, perhaps.. I wasn't quite sure where, tgsi.rst only talks about
>>> SVIEW in terms of the SAMPLE and related opc's (ie. the ones which do
>>> take an SVIEW arg), and the way things are with this patch, other
>>> drivers simply need to ignore the extra SVIEW decl's and not randomly
>>> assert for things to continue working as before..
>>>
>>> hypothetically if something in tree actually created SVIEW decl
>>> currently, and the shader also had TEX* style instructions, it would
>>> have to take care to not have conflicting SVIEW's.  But afaict nothing
>>> in-tree creates sampler view decl's currently.
>>>
>>>>>
>>>>> Signed-off-by: Rob Clark <robclark at freedesktop.org>
>>>>> ---
>>>>>  src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 29 +++++++++++++++++++++++++++++
>>>>>  1 file changed, 29 insertions(+)
>>>>>
>>>>> diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
>>>>> index 0e60d95..ce8f2ea 100644
>>>>> --- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
>>>>> +++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
>>>>> @@ -239,6 +239,7 @@ public:
>>>>>     st_src_reg sampler; /**< sampler register */
>>>>>     int sampler_array_size; /**< 1-based size of sampler array, 1 if not array */
>>>>>     int tex_target; /**< One of TEXTURE_*_INDEX */
>>>>> +   glsl_base_type tex_type;
>>>>>     GLboolean tex_shadow;
>>>>>
>>>>>     st_src_reg tex_offsets[MAX_GLSL_TEXTURE_OFFSET];
>>>>> @@ -345,6 +346,8 @@ public:
>>>>>
>>>>>     int num_address_regs;
>>>>>     int samplers_used;
>>>>> +   glsl_base_type sampler_types[PIPE_MAX_SAMPLERS];
>>>>> +   int sampler_targets[PIPE_MAX_SAMPLERS];   /**< One of TGSI_TEXTURE_* */
>>>>>     bool indirect_addr_consts;
>>>>>     int wpos_transform_const;
>>>>>
>>>>> @@ -3323,6 +3326,8 @@ glsl_to_tgsi_visitor::visit(ir_texture *ir)
>>>>>        assert(!"Should not get here.");
>>>>>     }
>>>>>
>>>>> +   inst->tex_type = ir->type->base_type;
>>>>> +
>>>>>     this->result = result_src;
>>>>>  }
>>>>>
>>>>> @@ -3471,6 +3476,11 @@ count_resources(glsl_to_tgsi_visitor *v, gl_program *prog)
>>>>>           for (int i = 0; i < inst->sampler_array_size; i++) {
>>>>>              v->samplers_used |= 1 << (inst->sampler.index + i);
>>>>>
>>>>> +            debug_assert(i < (int)ARRAY_SIZE(v->sampler_types));
>>>>> +            v->sampler_types[i] = inst->tex_type;
>>>>> +            v->sampler_targets[i] =
>>>>> +               st_translate_texture_target(inst->tex_target, inst->tex_shadow);
>>>>> +
>>>>>              if (inst->tex_shadow) {
>>>>>                 prog->ShadowSamplers |= 1 << (inst->sampler.index + i);
>>>>>              }
>>>>> @@ -5529,7 +5539,26 @@ st_translate_program(
>>>>>     /* texture samplers */
>>>>>     for (i = 0; i < ctx->Const.Program[MESA_SHADER_FRAGMENT].MaxTextureImageUnits; i++) {
>>>>>        if (program->samplers_used & (1 << i)) {
>>>>> +         unsigned type;
>>>>> +
>>>>>           t->samplers[i] = ureg_DECL_sampler(ureg, i);
>>>>> +
>>>>> +         switch (program->sampler_types[i]) {
>>>>> +         case GLSL_TYPE_INT:
>>>>> +            type = TGSI_RETURN_TYPE_SINT;
>>>>> +            break;
>>>>> +         case GLSL_TYPE_UINT:
>>>>> +            type = TGSI_RETURN_TYPE_UINT;
>>>>> +            break;
>>>>> +         case GLSL_TYPE_FLOAT:
>>>>> +            type = TGSI_RETURN_TYPE_FLOAT;
>>>>> +            break;
>>>>> +         default:
>>>>> +            unreachable("not reached");
>>>>> +         }
>>>>> +
>>>>> +         ureg_DECL_sampler_view( ureg, i, program->sampler_targets[i],
>>>>> +                                 type, type, type, type );
>>>>>        }
>>>>>     }
>>>>>
>>>>>
>>>>
>>>> This indeed seems like a consistent solution. Hopefully drivers don't
>>>> assert when they see sampler view dcls...
>>>
>>> well, tgsi_to_nir did before I fixed it :-(
>>>
>>> (mostly just because of liberal debug_assert() usage)
>>>
>>> it's at least not something I'd land right before a release branch
>>> point.  But I guess the fix is easy enough (ie. remove a bogus
>>> assert), and 10.7 branch point is quite some time from now..
>>>
>>>> I am also somewhat worried that this only changes the glsl-to-tgsi path,
>>>> not other paths. llvmpipe and draw rely on either having sview
>>>> declarations for all (sample) instructions or for none, and with draw
>>>> possibly inserting tex opcodes (for aalines etc.) on its own this could
>>>> probably break (these draw paths aren't used with d3d10 sample opcodes
>>>> as it's more or less illegal to use tex and sample opcodes in the same
>>>> shader, but that doesn't really matter here). I think using sview
>>>> declarations is the right thing to do but it probably should be illegal
>>>> then to NOT have them in some places.
>>>
>>> fwiw, the way I implemented it in tgsi_to_nir (and what I'd recommend
>>> for other drivers) is that for the "tex style" opcodes, if there is
>>> not a matching SVIEW decl, assume float.  That seemed more sane than
>>> fixing up *all* the other state trackers..
>>>
>>
>> Yeah but for llvmpipe/draw it's not just the type. The problem is how
>> they are parsing this stuff - if there's at least one sview decl they'll
>> construct the static texture state based on the defined sampler views,
>> but if there's none (up to now for gl state tracker) they'll do this
>> based on the defined samplers, and for some there simply won't be any
>> such definitions (if draw inserted some stage). llvmpipe can handle tex
>> opcodes without sview dcls, it should also be able to handle them if you
>> have them (but I wouldn't bet on it without testing as that's definitely
>> going to hit some code paths never seen before), but it can't handle
>> having "some" sview dcls (see for example lp_state_fs.c, line 3050 and
>> following why it can't work). This is fixable but only with some
>> awkwardness (since due to d3d10 sample opcodes not having 1:1 mapping
>> between samplers and sampler views). Hence my proposal of making it
>> mandatory to have sview decls instead of having them optionally. That
>> way could also ditch that code which distinguishes having sviews or not.
> 
> hmm, I could squash in something like:
> 
> ----
> diff --git a/src/gallium/drivers/llvmpipe/lp_state_fs.c
> b/src/gallium/drivers/llvmpipe/lp_state_fs.c
> index b5ce868..2878c49 100644
> --- a/src/gallium/drivers/llvmpipe/lp_state_fs.c
> +++ b/src/gallium/drivers/llvmpipe/lp_state_fs.c
> @@ -3059,27 +3059,11 @@ make_variant_key(struct llvmpipe_context *lp,
>        }
>     }
> 
> -   /*
> -    * XXX If TGSI_FILE_SAMPLER_VIEW exists assume all texture opcodes
> -    * are dx10-style? Can't really have mixed opcodes, at least not
> -    * if we want to skip the holes here (without rescanning tgsi).
> -    */
> -   if (shader->info.base.file_max[TGSI_FILE_SAMPLER_VIEW] != -1) {
> -      key->nr_sampler_views =
> shader->info.base.file_max[TGSI_FILE_SAMPLER_VIEW] + 1;
> -      for(i = 0; i < key->nr_sampler_views; ++i) {
> -         if(shader->info.base.file_mask[TGSI_FILE_SAMPLER_VIEW] & (1 << i)) {
> -            lp_sampler_static_texture_state(&key->state[i].texture_state,
> -
> lp->sampler_views[PIPE_SHADER_FRAGMENT][i]);
> -         }
> -      }
> -   }
> -   else {
> -      key->nr_sampler_views = key->nr_samplers;
> -      for(i = 0; i < key->nr_sampler_views; ++i) {
> -         if(shader->info.base.file_mask[TGSI_FILE_SAMPLER] & (1 << i)) {
> -            lp_sampler_static_texture_state(&key->state[i].texture_state,
> -
> lp->sampler_views[PIPE_SHADER_FRAGMENT][i]);
> -         }
> +   key->nr_sampler_views = key->nr_samplers;
> +   for(i = 0; i < key->nr_sampler_views; ++i) {
> +      if(shader->info.base.file_mask[TGSI_FILE_SAMPLER] & (1 << i)) {
> +         lp_sampler_static_texture_state(&key->state[i].texture_state,
> +
> lp->sampler_views[PIPE_SHADER_FRAGMENT][i]);
>        }
>     }
>  }
No that won't work for d3d10 state trackers, where you typically have more
views than samplers (though the opposite is possible as well and you can
have holes in both). I think it really would look nicer if you could
just rely on sampler views being present.

Roland


> 
> I'd have to check if other spots need similar fixes..
> 





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