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 "compiler/nir/nir.h"
  33 #include "st_nir.h"
  34
  35 typedef struct {
  36    unsigned lower_2plane;
  37    unsigned lower_3plane;
  38
  39    /* Maps a primary sampler (used for Y) to the U or UV sampler.  In
  40     * case of 3-plane YUV format, the V plane is next sampler after U.
  41     */
  42    unsigned char sampler_map[PIPE_MAX_SAMPLERS][2];
  43 } lower_tex_src_state;
  44
  45 static void
  46 assign_extra_samplers(lower_tex_src_state *state, unsigned free_slots)
  47 {
  48    unsigned mask = state->lower_2plane | state->lower_3plane;
  49
  50    while (mask) {
  51       unsigned extra, y_samp = u_bit_scan(&mask);
  52
  53       extra = u_bit_scan(&free_slots);
  54       state->sampler_map[y_samp][0] = extra;
  55
  56       if (state->lower_3plane & (1 << y_samp)) {
  57          extra = u_bit_scan(&free_slots);
  58          state->sampler_map[y_samp][1] = extra;
  59       }
  60    }
  61 }
  62
  63 static void
  64 lower_tex_src_plane_block(lower_tex_src_state *state, nir_block *block)
  65 {
  66    nir_foreach_instr(instr, block) {
  67       if (instr->type != nir_instr_type_tex)
  68          continue;
  69
  70       nir_tex_instr *tex = nir_instr_as_tex(instr);
  71       int plane_index = nir_tex_instr_src_index(tex, nir_tex_src_plane);
  72
  73       if (plane_index < 0)
  74          continue;
  75
  76       nir_const_value *plane = nir_src_as_const_value(tex->src[plane_index].src);
  77       assume(plane);
  78
  79       if (plane->i32[0] > 0) {
  80          unsigned y_samp = tex->texture_index;
  81
  82          assume(tex->texture_index == tex->sampler_index);
  83          assume(((state->lower_3plane & (1 << y_samp)) && plane->i32[0] < 3) ||
  84                (plane->i32[0] < 2));
  85
  86          tex->texture_index = tex->sampler_index =
  87                state->sampler_map[y_samp][plane->i32[0] - 1];
  88       }
  89
  90       nir_tex_instr_remove_src(tex, plane_index);
  91    }
  92 }
  93
  94 static void
  95 lower_tex_src_plane_impl(lower_tex_src_state *state, nir_function_impl *impl)
  96 {
  97    nir_foreach_block(block, impl) {
  98       lower_tex_src_plane_block(state, block);
  99    }
 100
 101    nir_metadata_preserve(impl, nir_metadata_block_index |
 102                                nir_metadata_dominance);
 103 }
 104
 105 void
 106 st_nir_lower_tex_src_plane(struct nir_shader *shader, unsigned free_slots,
 107                            unsigned lower_2plane, unsigned lower_3plane)
 108 {
 109    lower_tex_src_state state = {0};
 110
 111    state.lower_2plane = lower_2plane;
 112    state.lower_3plane = lower_3plane;
 113
 114    assign_extra_samplers(&state, free_slots);
 115
 116    nir_foreach_function(function, shader) {
 117       if (function->impl)
 118          lower_tex_src_plane_impl(&state, function->impl);
 119    }
 120 }