1/*
2 * Copyright © 2021 Intel Corporation
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
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 */
23
24/**
25 * This lowering pass supports (as configured via nir_lower_image_options)
26 * image related conversions:
27 *   + cube array size lowering. The size operation is converted from cube
28 *     size to a 2d-array with the z component divided by 6.
29 */
30
31#include "nir.h"
32#include "nir_builder.h"
33
34static void
35lower_cube_size(nir_builder *b, nir_intrinsic_instr *intrin)
36{
37   assert(nir_intrinsic_image_dim(intrin) == GLSL_SAMPLER_DIM_CUBE);
38
39   b->cursor = nir_before_instr(&intrin->instr);
40
41   nir_intrinsic_instr *_2darray_size =
42      nir_instr_as_intrinsic(nir_instr_clone(b->shader, &intrin->instr));
43   nir_intrinsic_set_image_dim(_2darray_size, GLSL_SAMPLER_DIM_2D);
44   nir_intrinsic_set_image_array(_2darray_size, true);
45   nir_builder_instr_insert(b, &_2darray_size->instr);
46
47   nir_ssa_def *size = nir_instr_ssa_def(&_2darray_size->instr);
48   nir_ssa_scalar comps[NIR_MAX_VEC_COMPONENTS] = { 0 };
49   unsigned coord_comps = intrin->dest.ssa.num_components;
50   for (unsigned c = 0; c < coord_comps; c++) {
51      if (c == 2) {
52         comps[2] = nir_get_ssa_scalar(nir_idiv(b, nir_channel(b, size, 2), nir_imm_int(b, 6)), 0);
53      } else {
54         comps[c] = nir_get_ssa_scalar(size, c);
55      }
56   }
57
58   nir_ssa_def *vec = nir_vec_scalars(b, comps, intrin->dest.ssa.num_components);
59   nir_ssa_def_rewrite_uses(&intrin->dest.ssa, vec);
60   nir_instr_remove(&intrin->instr);
61   nir_instr_free(&intrin->instr);
62}
63
64static bool
65lower_image_instr(nir_builder *b, nir_instr *instr, void *state)
66{
67   if (instr->type != nir_instr_type_intrinsic)
68      return false;
69
70   const nir_lower_image_options *options = state;
71   nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
72
73   switch (intrin->intrinsic) {
74   case nir_intrinsic_image_size:
75   case nir_intrinsic_image_deref_size:
76   case nir_intrinsic_bindless_image_size:
77      if (options->lower_cube_size &&
78          nir_intrinsic_image_dim(intrin) == GLSL_SAMPLER_DIM_CUBE) {
79         lower_cube_size(b, intrin);
80         return true;
81      }
82      return false;
83
84   default:
85      return false;
86   }
87}
88
89bool
90nir_lower_image(nir_shader *nir, const nir_lower_image_options *options)
91{
92   return nir_shader_instructions_pass(nir, lower_image_instr,
93                                       nir_metadata_block_index |
94                                       nir_metadata_dominance, (void*)options);
95}
96