1 /*
2 * Copyright © 2016 Red Hat.
3 * Copyright © 2016 Bas Nieuwenhuizen
4 * Copyright © 2023 Valve Corporation
5 *
6 * SPDX-License-Identifier: MIT
7 */
8
9 #include "nir.h"
10 #include "nir_builder.h"
11 #include "radv_nir.h"
12 #include "radv_shader.h"
13 #include "radv_shader_args.h"
14 #include "radv_shader_info.h"
15 bool
radv_nir_lower_fs_intrinsics(nir_shader * nir,const struct radv_shader_stage * fs_stage,const struct radv_graphics_state_key * gfx_state)16 radv_nir_lower_fs_intrinsics(nir_shader *nir, const struct radv_shader_stage *fs_stage,
17 const struct radv_graphics_state_key *gfx_state)
18 {
19 const struct radv_shader_info *info = &fs_stage->info;
20 const struct radv_shader_args *args = &fs_stage->args;
21 nir_function_impl *impl = nir_shader_get_entrypoint(nir);
22 bool progress = false;
23
24 nir_builder b = nir_builder_create(impl);
25
26 nir_foreach_block (block, impl) {
27 nir_foreach_instr_safe (instr, block) {
28 if (instr->type != nir_instr_type_intrinsic)
29 continue;
30
31 nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
32 b.cursor = nir_after_instr(&intrin->instr);
33
34 switch (intrin->intrinsic) {
35 case nir_intrinsic_load_sample_mask_in: {
36 nir_def *sample_coverage = nir_load_vector_arg_amd(&b, 1, .base = args->ac.sample_coverage.arg_index);
37
38 nir_def *def = NULL;
39 if (info->ps.uses_sample_shading || gfx_state->ms.sample_shading_enable) {
40 /* gl_SampleMaskIn[0] = (SampleCoverage & (PsIterMask << gl_SampleID)). */
41 nir_def *ps_state = nir_load_scalar_arg_amd(&b, 1, .base = args->ps_state.arg_index);
42 nir_def *ps_iter_mask =
43 nir_ubfe_imm(&b, ps_state, PS_STATE_PS_ITER_MASK__SHIFT, util_bitcount(PS_STATE_PS_ITER_MASK__MASK));
44 nir_def *sample_id = nir_load_sample_id(&b);
45 def = nir_iand(&b, sample_coverage, nir_ishl(&b, ps_iter_mask, sample_id));
46 } else {
47 def = sample_coverage;
48 }
49
50 nir_def_rewrite_uses(&intrin->def, def);
51
52 nir_instr_remove(instr);
53 progress = true;
54 break;
55 }
56 case nir_intrinsic_load_frag_coord: {
57 if (!gfx_state->adjust_frag_coord_z)
58 continue;
59
60 if (!(nir_def_components_read(&intrin->def) & (1 << 2)))
61 continue;
62
63 nir_def *frag_z = nir_channel(&b, &intrin->def, 2);
64
65 /* adjusted_frag_z = dFdxFine(frag_z) * 0.0625 + frag_z */
66 nir_def *adjusted_frag_z = nir_ddx_fine(&b, frag_z);
67 adjusted_frag_z = nir_ffma_imm1(&b, adjusted_frag_z, 0.0625f, frag_z);
68
69 /* VRS Rate X = Ancillary[2:3] */
70 nir_def *ancillary = nir_load_vector_arg_amd(&b, 1, .base = args->ac.ancillary.arg_index);
71 nir_def *x_rate = nir_ubfe_imm(&b, ancillary, 2, 2);
72
73 /* xRate = xRate == 0x1 ? adjusted_frag_z : frag_z. */
74 nir_def *cond = nir_ieq_imm(&b, x_rate, 1);
75 frag_z = nir_bcsel(&b, cond, adjusted_frag_z, frag_z);
76
77 nir_def *new_dest = nir_vector_insert_imm(&b, &intrin->def, frag_z, 2);
78 nir_def_rewrite_uses_after(&intrin->def, new_dest, new_dest->parent_instr);
79
80 progress = true;
81 break;
82 }
83 case nir_intrinsic_load_barycentric_at_sample: {
84 nir_def *num_samples = nir_load_rasterization_samples_amd(&b);
85 nir_def *new_dest;
86
87 if (gfx_state->dynamic_rasterization_samples) {
88 nir_def *res1, *res2;
89
90 nir_push_if(&b, nir_ieq_imm(&b, num_samples, 1));
91 {
92 res1 = nir_load_barycentric_pixel(&b, 32, .interp_mode = nir_intrinsic_interp_mode(intrin));
93 }
94 nir_push_else(&b, NULL);
95 {
96 nir_def *sample_pos = nir_load_sample_positions_amd(&b, 32, intrin->src[0].ssa, num_samples);
97
98 /* sample_pos -= 0.5 */
99 sample_pos = nir_fadd_imm(&b, sample_pos, -0.5f);
100
101 res2 = nir_load_barycentric_at_offset(&b, 32, sample_pos,
102 .interp_mode = nir_intrinsic_interp_mode(intrin));
103 }
104 nir_pop_if(&b, NULL);
105
106 new_dest = nir_if_phi(&b, res1, res2);
107 } else {
108 if (!gfx_state->ms.rasterization_samples) {
109 new_dest = nir_load_barycentric_pixel(&b, 32, .interp_mode = nir_intrinsic_interp_mode(intrin));
110 } else {
111 nir_def *sample_pos = nir_load_sample_positions_amd(&b, 32, intrin->src[0].ssa, num_samples);
112
113 /* sample_pos -= 0.5 */
114 sample_pos = nir_fadd_imm(&b, sample_pos, -0.5f);
115
116 new_dest = nir_load_barycentric_at_offset(&b, 32, sample_pos,
117 .interp_mode = nir_intrinsic_interp_mode(intrin));
118 }
119 }
120
121 nir_def_rewrite_uses(&intrin->def, new_dest);
122 nir_instr_remove(instr);
123
124 progress = true;
125 break;
126 }
127 default:
128 break;
129 }
130 }
131 }
132
133 if (progress)
134 nir_metadata_preserve(impl, 0);
135 else
136 nir_metadata_preserve(impl, nir_metadata_all);
137
138 return progress;
139 }
140