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

[Connor Abbott]

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.

> +
> +   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
>