1 /*
2 * Copyright 2024 Valve Corporation
3 * Copyright 2019 Collabora, Ltd.
4 * SPDX-License-Identifier: MIT
5 */
6
7 #include "nir.h"
8 #include "nir_builder.h"
9
10 /*
11 * Lowers SSBOs to global memory. SSBO base addresses are passed via
12 * load_ssbo_address. Run nir_lower_robust_access first for bounds checks.
13 */
14
15 static nir_def *
calc_address(nir_builder * b,nir_intrinsic_instr * intr)16 calc_address(nir_builder *b, nir_intrinsic_instr *intr)
17 {
18 unsigned index_src = intr->intrinsic == nir_intrinsic_store_ssbo ? 1 : 0;
19 nir_def *base = nir_load_ssbo_address(b, 1, 64, intr->src[index_src].ssa);
20
21 return nir_iadd(b, base, nir_u2u64(b, nir_get_io_offset_src(intr)->ssa));
22 }
23
24 static bool
pass(nir_builder * b,nir_intrinsic_instr * intr,UNUSED void * data)25 pass(nir_builder *b, nir_intrinsic_instr *intr, UNUSED void *data)
26 {
27 b->cursor = nir_before_instr(&intr->instr);
28
29 nir_def *def = NULL;
30 switch (intr->intrinsic) {
31 case nir_intrinsic_load_ssbo:
32 def = nir_build_load_global(b, intr->def.num_components,
33 intr->def.bit_size, calc_address(b, intr),
34 .align_mul = nir_intrinsic_align_mul(intr),
35 .align_offset = nir_intrinsic_align_offset(intr));
36 break;
37
38 case nir_intrinsic_store_ssbo:
39 nir_build_store_global(b, intr->src[0].ssa, calc_address(b, intr),
40 .align_mul = nir_intrinsic_align_mul(intr),
41 .align_offset = nir_intrinsic_align_offset(intr),
42 .write_mask = nir_intrinsic_write_mask(intr));
43 break;
44
45 case nir_intrinsic_ssbo_atomic:
46 def = nir_global_atomic(b, intr->def.bit_size, calc_address(b, intr),
47 intr->src[2].ssa,
48 .atomic_op = nir_intrinsic_atomic_op(intr));
49 break;
50
51 case nir_intrinsic_ssbo_atomic_swap:
52 def = nir_global_atomic_swap(b, intr->def.bit_size, calc_address(b, intr),
53 intr->src[2].ssa, intr->src[3].ssa,
54 .atomic_op = nir_intrinsic_atomic_op(intr));
55 break;
56
57 default:
58 return false;
59 }
60
61 if (def)
62 nir_def_rewrite_uses(&intr->def, def);
63
64 nir_instr_remove(&intr->instr);
65 return true;
66 }
67
68 bool
nir_lower_ssbo(nir_shader * shader)69 nir_lower_ssbo(nir_shader *shader)
70 {
71 return nir_shader_intrinsics_pass(shader, pass,
72 nir_metadata_dominance |
73 nir_metadata_block_index,
74 NULL);
75 }
76