src/mesa/state_tracker/st_nir_lower_tex_src_plane.c

   1 /*
   2  * Copyright © 2016 Red Hat
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  21  * SOFTWARE.
  22  */
  23
  24 /* Lowers the additional tex_src_plane src, generated by nir_lower_tex
  25  * for planar YUV textures, into separate samplers, matching the logic
  26  * that mesa/st uses to insert additional sampler view/state (since both
  27  * sides need to agree).
  28  *
  29  * This should run after nir_lower_samplers.
  30  */
  31
  32 #include "util/u_string.h"
  33 #include "compiler/nir/nir.h"
  34 #include "compiler/nir/nir_builder.h"
  35 #include "st_nir.h"
  36
  37 typedef struct {
  38    struct nir_shader *shader;
  39
  40    unsigned lower_2plane;
  41    unsigned lower_3plane;
  42
  43    /* Maps a primary sampler (used for Y) to the U or UV sampler.  In
  44     * case of 3-plane YUV format, the V plane is next sampler after U.
  45     */
  46    unsigned char sampler_map[PIPE_MAX_SAMPLERS][2];
  47 } lower_tex_src_state;
  48
  49 static nir_variable *
  50 find_sampler(lower_tex_src_state *state, unsigned samp)
  51 {
  52    /* NOTE: arrays of samplerExternalOES do not appear to be allowed: */
  53    nir_foreach_uniform_variable(var, state->shader)
  54       if (var->data.binding == samp)
  55          return var;
  56    return NULL;
  57 }
  58
  59 static void
  60 add_sampler(lower_tex_src_state *state, unsigned orig_binding,
  61             unsigned new_binding, const char *ext)
  62 {
  63    const struct glsl_type *samplerExternalOES =
  64       glsl_sampler_type(GLSL_SAMPLER_DIM_EXTERNAL, false, false, GLSL_TYPE_FLOAT);
  65    nir_variable *new_sampler, *orig_sampler =
  66          find_sampler(state, orig_binding);
  67    char *name;
  68
  69    UNUSED int r = asprintf(&name, "%s:%s", orig_sampler->name, ext);
  70    new_sampler = nir_variable_create(state->shader, nir_var_uniform,
  71                              samplerExternalOES, name);
  72    free(name);
  73
  74    new_sampler->data.binding = new_binding;
  75 }
  76
  77 static void
  78 assign_extra_samplers(lower_tex_src_state *state, unsigned free_slots)
  79 {
  80    unsigned mask = state->lower_2plane | state->lower_3plane;
  81
  82    while (mask) {
  83       unsigned extra, y_samp = u_bit_scan(&mask);
  84
  85       if (state->lower_3plane & (1 << y_samp)) {
  86          /* two additional planes (U and V): */
  87          extra = u_bit_scan(&free_slots);
  88          state->sampler_map[y_samp][0] = extra;
  89
  90          add_sampler(state, y_samp, extra, "u");
  91
  92          extra = u_bit_scan(&free_slots);
  93          state->sampler_map[y_samp][1] = extra;
  94
  95          add_sampler(state, y_samp, extra, "v");
  96       } else {
  97          /* single additional UV plane: */
  98          extra = u_bit_scan(&free_slots);
  99          state->sampler_map[y_samp][0] = extra;
 100
 101          add_sampler(state, y_samp, extra, "uv");
 102       }
 103    }
 104 }
 105
 106 static void
 107 lower_tex_src_plane_block(nir_builder *b, lower_tex_src_state *state, nir_block *block)
 108 {
 109    nir_foreach_instr(instr, block) {
 110       if (instr->type != nir_instr_type_tex)
 111          continue;
 112
 113       nir_tex_instr *tex = nir_instr_as_tex(instr);
 114       int plane_index = nir_tex_instr_src_index(tex, nir_tex_src_plane);
 115
 116       if (plane_index < 0)
 117          continue;
 118
 119       nir_const_value *plane = nir_src_as_const_value(tex->src[plane_index].src);
 120       assume(plane);
 121
 122       if (plane[0].i32 > 0) {
 123          unsigned y_samp = tex->texture_index;
 124
 125          assume(tex->texture_index == tex->sampler_index);
 126          assume(((state->lower_3plane & (1 << y_samp)) && plane[0].i32 < 3) ||
 127                (plane[0].i32 < 2));
 128
 129          tex->texture_index = tex->sampler_index =
 130                state->sampler_map[y_samp][plane[0].i32 - 1];
 131
 132          state->shader->info.textures_used |= 1u << tex->texture_index;
 133
 134          /* For drivers using PIPE_CAP_NIR_SAMPLERS_AS_DEREF, we need
 135           * to reference the correct sampler nir variable.
 136           */
 137          int tex_index = nir_tex_instr_src_index(tex, nir_tex_src_texture_deref);
 138          int samp_index = nir_tex_instr_src_index(tex, nir_tex_src_sampler_deref);
 139          if (tex_index >= 0 && samp_index >= 0) {
 140             b->cursor = nir_before_instr(&tex->instr);
 141
 142             nir_variable* samp = find_sampler(state, plane[0].i32);
 143             assert(samp);
 144
 145             nir_deref_instr *tex_deref_instr = nir_build_deref_var(b, samp);
 146             nir_ssa_def *tex_deref = &tex_deref_instr->dest.ssa;
 147
 148             nir_instr_rewrite_src(&tex->instr,
 149                                   &tex->src[tex_index].src,
 150                                   nir_src_for_ssa(tex_deref));
 151             nir_instr_rewrite_src(&tex->instr,
 152                                   &tex->src[samp_index].src,
 153                                   nir_src_for_ssa(tex_deref));
 154          }
 155       }
 156
 157       nir_tex_instr_remove_src(tex, plane_index);
 158    }
 159 }
 160
 161 static void
 162 lower_tex_src_plane_impl(lower_tex_src_state *state, nir_function_impl *impl)
 163 {
 164    nir_builder b;
 165    nir_builder_init(&b, impl);
 166
 167    nir_foreach_block(block, impl) {
 168       lower_tex_src_plane_block(&b, state, block);
 169    }
 170
 171    nir_metadata_preserve(impl, nir_metadata_block_index |
 172                                nir_metadata_dominance);
 173 }
 174
 175 void
 176 st_nir_lower_tex_src_plane(struct nir_shader *shader, unsigned free_slots,
 177                            unsigned lower_2plane, unsigned lower_3plane)
 178 {
 179    lower_tex_src_state state = {0};
 180
 181    state.shader = shader;
 182    state.lower_2plane = lower_2plane;
 183    state.lower_3plane = lower_3plane;
 184
 185    assign_extra_samplers(&state, free_slots);
 186
 187    nir_foreach_function(function, shader) {
 188       if (function->impl)
 189          lower_tex_src_plane_impl(&state, function->impl);
 190    }
 191 }