[Mesa-dev] [PATCH 08a/11] nir: clamp-color-output support

[Rob Clark]

On Tue, Feb 2, 2016 at 1:29 PM, Connor Abbott <cwabbott0 at gmail.com> wrote:
> On Tue, Feb 2, 2016 at 1:07 PM, Rob Clark <robdclark at gmail.com> wrote:
>> From: Rob Clark <robclark at freedesktop.org>
>>
>> Handled by tgsi_emulate for glsl->tgsi case.
>>
>> Signed-off-by: Rob Clark <robclark at freedesktop.org>
>> ---
>>  src/compiler/Makefile.sources                    |   1 +
>>  src/compiler/nir/nir.h                           |   1 +
>>  src/compiler/nir/nir_lower_clamp_color_outputs.c | 121 +++++++++++++++++++++++
>>  3 files changed, 123 insertions(+)
>>  create mode 100644 src/compiler/nir/nir_lower_clamp_color_outputs.c
>>
>> diff --git a/src/compiler/Makefile.sources b/src/compiler/Makefile.sources
>> index d859493..e85cde5 100644
>> --- a/src/compiler/Makefile.sources
>> +++ b/src/compiler/Makefile.sources
>> @@ -184,6 +184,7 @@ NIR_FILES = \
>>         nir/nir_lower_alu_to_scalar.c \
>>         nir/nir_lower_atomics.c \
>>         nir/nir_lower_bitmap.c \
>> +       nir/nir_lower_clamp_color_outputs.c \
>>         nir/nir_lower_clip.c \
>>         nir/nir_lower_drawpixels.c \
>>         nir/nir_lower_global_vars_to_local.c \
>> diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
>> index 29c8631..dc31a67 100644
>> --- a/src/compiler/nir/nir.h
>> +++ b/src/compiler/nir/nir.h
>> @@ -2119,6 +2119,7 @@ void nir_lower_clip_fs(nir_shader *shader, unsigned ucp_enables);
>>
>>  void nir_lower_two_sided_color(nir_shader *shader);
>>
>> +void nir_lower_clamp_color_outputs(nir_shader *shader);
>>
>>  typedef struct nir_lower_wpos_ytransform_options {
>>     int state_tokens[5];
>> diff --git a/src/compiler/nir/nir_lower_clamp_color_outputs.c b/src/compiler/nir/nir_lower_clamp_color_outputs.c
>> new file mode 100644
>> index 0000000..0e1add0
>> --- /dev/null
>> +++ b/src/compiler/nir/nir_lower_clamp_color_outputs.c
>> @@ -0,0 +1,121 @@
>> +/*
>> + * Copyright © 2015 Red Hat
>> + *
>> + * Permission is hereby granted, free of charge, to any person obtaining a
>> + * copy of this software and associated documentation files (the "Software"),
>> + * to deal in the Software without restriction, including without limitation
>> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
>> + * and/or sell copies of the Software, and to permit persons to whom the
>> + * Software is furnished to do so, subject to the following conditions:
>> + *
>> + * The above copyright notice and this permission notice (including the next
>> + * paragraph) shall be included in all copies or substantial portions of the
>> + * Software.
>> + *
>> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
>> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
>> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
>> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
>> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
>> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
>> + * SOFTWARE.
>> + */
>> +
>> +
>> +#include "nir.h"
>> +#include "nir_builder.h"
>> +
>> +typedef struct {
>> +   nir_shader *shader;
>> +   nir_builder b;
>> +} lower_state;
>> +
>> +static bool
>> +is_color_output(lower_state *state, nir_variable *out)
>> +{
>> +   switch (state->shader->stage) {
>> +   case MESA_SHADER_VERTEX:
>> +   case MESA_SHADER_GEOMETRY:
>> +      switch (out->data.location) {
>> +      case VARYING_SLOT_COL0:
>> +      case VARYING_SLOT_COL1:
>> +      case VARYING_SLOT_BFC0:
>> +      case VARYING_SLOT_BFC1:
>> +         return true;
>> +      default:
>> +         return false;
>> +      }
>> +      break;
>> +   case MESA_SHADER_FRAGMENT:
>> +      switch (out->data.location) {
>> +      case FRAG_RESULT_COLOR:
>> +         return true;
>> +      default:
>> +         return false;
>> +      }
>> +      break;
>> +   default:
>> +      return false;
>> +   }
>> +}
>> +
>> +static void
>> +lower_intrinsic(lower_state *state, nir_intrinsic_instr *intr)
>> +{
>> +   nir_variable *out;
>> +   nir_builder *b = &state->b;
>> +   nir_ssa_def *s;
>> +
>> +   if (intr->intrinsic != nir_intrinsic_store_var)
>> +      return;
>> +
>> +   out = intr->variables[0]->var;
>> +
>> +   if (out->data.mode != nir_var_shader_out)
>> +      return;
>> +
>> +   /* NOTE: 'out' can be null for types larger than vec4,
>> +    * but these will never be color out's so we can ignore
>> +    */
>
> This comment isn't true (store_var intrinsics will always have a
> non-NULL variable associated with them) and it doesn't seem relevant,
> since even if color out's could be part of a struct/array this would
> still work, so I'd just drop it. Other than that this gets my r-b.

right, and the check for null after already deref'ing it is bonkers
too, so I've dropped that as well..

tbh, I don't even remember where that came from, but I can only guess
an earlier incarnation of the patchset while I still had bugs
elsewhere ;-)

BR,
-R

>> +
>> +   if (out && is_color_output(state, out)) {
>> +      b->cursor = nir_before_instr(&intr->instr);
>> +      s = nir_ssa_for_src(b, intr->src[0], intr->num_components);
>> +      s = nir_fsat(b, s);
>> +      nir_instr_rewrite_src(&intr->instr, &intr->src[0], nir_src_for_ssa(s));
>> +   }
>> +}
>> +
>> +static bool
>> +lower_block(nir_block *block, void *_state)
>> +{
>> +   lower_state *state = _state;
>> +
>> +   nir_foreach_instr_safe(block, instr) {
>> +      if (instr->type == nir_instr_type_intrinsic)
>> +         lower_intrinsic(state, nir_instr_as_intrinsic(instr));
>> +   }
>> +
>> +   return true;
>> +}
>> +static void
>> +lower_impl(lower_state *state, nir_function_impl *impl)
>> +{
>> +   nir_builder_init(&state->b, impl);
>> +
>> +   nir_foreach_block(impl, lower_block, state);
>> +   nir_metadata_preserve(impl, nir_metadata_block_index |
>> +                               nir_metadata_dominance);
>> +}
>> +
>> +void nir_lower_clamp_color_outputs(nir_shader *shader)
>> +{
>> +   lower_state state = {
>> +      .shader = shader,
>> +   };
>> +
>> +   nir_foreach_function(shader, function) {
>> +      if (function->impl)
>> +         lower_impl(&state, function->impl);
>> +   }
>> +}
>> --
>> 2.5.0
>>