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,const nir_lower_ssbo_options * opts)16 calc_address(nir_builder *b, nir_intrinsic_instr *intr,
17 const nir_lower_ssbo_options *opts)
18 {
19 unsigned index_src = intr->intrinsic == nir_intrinsic_store_ssbo ? 1 : 0;
20 bool lower_offset = !opts || !opts->native_offset;
21 nir_def *offset = nir_get_io_offset_src(intr)->ssa;
22 nir_def *addr =
23 nir_load_ssbo_address(b, 1, 64, intr->src[index_src].ssa,
24 lower_offset ? nir_imm_int(b, 0) : offset);
25
26 if (lower_offset)
27 addr = nir_iadd(b, addr, nir_u2u64(b, offset));
28
29 return addr;
30 }
31
32 static bool
pass(nir_builder * b,nir_intrinsic_instr * intr,void * data)33 pass(nir_builder *b, nir_intrinsic_instr *intr, void *data)
34 {
35 const nir_lower_ssbo_options *opts = data;
36
37 b->cursor = nir_before_instr(&intr->instr);
38
39 nir_def *def = NULL;
40 switch (intr->intrinsic) {
41 case nir_intrinsic_load_ssbo:
42 if (opts && opts->native_loads)
43 return false;
44
45 def = nir_build_load_global(b, intr->def.num_components,
46 intr->def.bit_size,
47 calc_address(b, intr, opts),
48 .align_mul = nir_intrinsic_align_mul(intr),
49 .align_offset = nir_intrinsic_align_offset(intr));
50 break;
51
52 case nir_intrinsic_store_ssbo:
53 nir_build_store_global(b, intr->src[0].ssa,
54 calc_address(b, intr, opts),
55 .align_mul = nir_intrinsic_align_mul(intr),
56 .align_offset = nir_intrinsic_align_offset(intr),
57 .write_mask = nir_intrinsic_write_mask(intr));
58 break;
59
60 case nir_intrinsic_ssbo_atomic:
61 def = nir_global_atomic(b, intr->def.bit_size,
62 calc_address(b, intr, opts),
63 intr->src[2].ssa,
64 .atomic_op = nir_intrinsic_atomic_op(intr));
65 break;
66
67 case nir_intrinsic_ssbo_atomic_swap:
68 def = nir_global_atomic_swap(b, intr->def.bit_size,
69 calc_address(b, intr, opts),
70 intr->src[2].ssa, intr->src[3].ssa,
71 .atomic_op = nir_intrinsic_atomic_op(intr));
72 break;
73
74 default:
75 return false;
76 }
77
78 if (def)
79 nir_def_rewrite_uses(&intr->def, def);
80
81 nir_instr_remove(&intr->instr);
82 return true;
83 }
84
85 bool
nir_lower_ssbo(nir_shader * shader,const nir_lower_ssbo_options * opts)86 nir_lower_ssbo(nir_shader *shader, const nir_lower_ssbo_options *opts)
87 {
88 return nir_shader_intrinsics_pass(shader, pass,
89 nir_metadata_control_flow,
90 (void *)opts);
91 }
92