1 /*
2  * Copyright © 2020 Valve 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 /*
26  * Replaces make availability/visible semantics on barriers with
27  * ACCESS_COHERENT on memory loads/stores
28  */
29 
30 #include "nir/nir.h"
31 #include "shader_enums.h"
32 
33 static bool
get_intrinsic_info(nir_intrinsic_instr * intrin,nir_variable_mode * modes,bool * reads,bool * writes)34 get_intrinsic_info(nir_intrinsic_instr *intrin, nir_variable_mode *modes,
35                    bool *reads, bool *writes)
36 {
37    switch (intrin->intrinsic) {
38    case nir_intrinsic_image_deref_load:
39       *modes = nir_src_as_deref(intrin->src[0])->modes;
40       *reads = true;
41       break;
42    case nir_intrinsic_image_deref_store:
43       *modes = nir_src_as_deref(intrin->src[0])->modes;
44       *writes = true;
45       break;
46    case nir_intrinsic_image_deref_atomic_add:
47    case nir_intrinsic_image_deref_atomic_umin:
48    case nir_intrinsic_image_deref_atomic_imin:
49    case nir_intrinsic_image_deref_atomic_umax:
50    case nir_intrinsic_image_deref_atomic_imax:
51    case nir_intrinsic_image_deref_atomic_and:
52    case nir_intrinsic_image_deref_atomic_or:
53    case nir_intrinsic_image_deref_atomic_xor:
54    case nir_intrinsic_image_deref_atomic_exchange:
55    case nir_intrinsic_image_deref_atomic_comp_swap:
56       *modes = nir_src_as_deref(intrin->src[0])->modes;
57       *reads = true;
58       *writes = true;
59       break;
60    case nir_intrinsic_load_ssbo:
61       *modes = nir_var_mem_ssbo;
62       *reads = true;
63       break;
64    case nir_intrinsic_store_ssbo:
65       *modes = nir_var_mem_ssbo;
66       *writes = true;
67       break;
68    case nir_intrinsic_ssbo_atomic_add:
69    case nir_intrinsic_ssbo_atomic_imin:
70    case nir_intrinsic_ssbo_atomic_umin:
71    case nir_intrinsic_ssbo_atomic_imax:
72    case nir_intrinsic_ssbo_atomic_umax:
73    case nir_intrinsic_ssbo_atomic_and:
74    case nir_intrinsic_ssbo_atomic_or:
75    case nir_intrinsic_ssbo_atomic_xor:
76    case nir_intrinsic_ssbo_atomic_exchange:
77    case nir_intrinsic_ssbo_atomic_comp_swap:
78       *modes = nir_var_mem_ssbo;
79       *reads = true;
80       *writes = true;
81       break;
82    case nir_intrinsic_load_global:
83       *modes = nir_var_mem_global;
84       *reads = true;
85       break;
86    case nir_intrinsic_store_global:
87       *modes = nir_var_mem_global;
88       *writes = true;
89       break;
90    case nir_intrinsic_global_atomic_add:
91    case nir_intrinsic_global_atomic_imin:
92    case nir_intrinsic_global_atomic_umin:
93    case nir_intrinsic_global_atomic_imax:
94    case nir_intrinsic_global_atomic_umax:
95    case nir_intrinsic_global_atomic_and:
96    case nir_intrinsic_global_atomic_or:
97    case nir_intrinsic_global_atomic_xor:
98    case nir_intrinsic_global_atomic_exchange:
99    case nir_intrinsic_global_atomic_comp_swap:
100       *modes = nir_var_mem_global;
101       *reads = true;
102       *writes = true;
103       break;
104    case nir_intrinsic_load_deref:
105       *modes = nir_src_as_deref(intrin->src[0])->modes;
106       *reads = true;
107       break;
108    case nir_intrinsic_store_deref:
109       *modes = nir_src_as_deref(intrin->src[0])->modes;
110       *writes = true;
111       break;
112    case nir_intrinsic_deref_atomic_add:
113    case nir_intrinsic_deref_atomic_imin:
114    case nir_intrinsic_deref_atomic_umin:
115    case nir_intrinsic_deref_atomic_imax:
116    case nir_intrinsic_deref_atomic_umax:
117    case nir_intrinsic_deref_atomic_and:
118    case nir_intrinsic_deref_atomic_or:
119    case nir_intrinsic_deref_atomic_xor:
120    case nir_intrinsic_deref_atomic_exchange:
121    case nir_intrinsic_deref_atomic_comp_swap:
122       *modes = nir_src_as_deref(intrin->src[0])->modes;
123       *reads = true;
124       *writes = true;
125       break;
126    default:
127       return false;
128    }
129    return true;
130 }
131 
132 static bool
visit_instr(nir_instr * instr,uint32_t * cur_modes,unsigned vis_avail_sem)133 visit_instr(nir_instr *instr, uint32_t *cur_modes, unsigned vis_avail_sem)
134 {
135    if (instr->type != nir_instr_type_intrinsic)
136       return false;
137    nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
138 
139    if (intrin->intrinsic == nir_intrinsic_scoped_barrier &&
140        (nir_intrinsic_memory_semantics(intrin) & vis_avail_sem)) {
141       *cur_modes |= nir_intrinsic_memory_modes(intrin);
142 
143       unsigned semantics = nir_intrinsic_memory_semantics(intrin);
144       nir_intrinsic_set_memory_semantics(
145          intrin, semantics & ~vis_avail_sem);
146       return true;
147    }
148 
149    if (!*cur_modes)
150       return false; /* early exit */
151 
152    nir_variable_mode modes;
153    bool reads = false, writes = false;
154    if (!get_intrinsic_info(intrin, &modes, &reads, &writes))
155       return false;
156 
157    if (!reads && vis_avail_sem == NIR_MEMORY_MAKE_VISIBLE)
158       return false;
159    if (!writes && vis_avail_sem == NIR_MEMORY_MAKE_AVAILABLE)
160       return false;
161 
162    if (!nir_intrinsic_has_access(intrin))
163       return false;
164 
165    unsigned access = nir_intrinsic_access(intrin);
166 
167    if (access & (ACCESS_NON_READABLE | ACCESS_NON_WRITEABLE | ACCESS_CAN_REORDER | ACCESS_COHERENT))
168       return false;
169 
170    if (*cur_modes & modes) {
171       nir_intrinsic_set_access(intrin, access | ACCESS_COHERENT);
172       return true;
173    }
174 
175    return false;
176 }
177 
178 static bool
lower_make_visible(nir_cf_node * cf_node,uint32_t * cur_modes)179 lower_make_visible(nir_cf_node *cf_node, uint32_t *cur_modes)
180 {
181    bool progress = false;
182    switch (cf_node->type) {
183    case nir_cf_node_block: {
184       nir_block *block = nir_cf_node_as_block(cf_node);
185       nir_foreach_instr(instr, block)
186          progress |= visit_instr(instr, cur_modes, NIR_MEMORY_MAKE_VISIBLE);
187       break;
188    }
189    case nir_cf_node_if: {
190       nir_if *nif = nir_cf_node_as_if(cf_node);
191       uint32_t cur_modes_then = *cur_modes;
192       uint32_t cur_modes_else = *cur_modes;
193       foreach_list_typed(nir_cf_node, if_node, node, &nif->then_list)
194          progress |= lower_make_visible(if_node, &cur_modes_then);
195       foreach_list_typed(nir_cf_node, if_node, node, &nif->else_list)
196          progress |= lower_make_visible(if_node, &cur_modes_else);
197       *cur_modes |= cur_modes_then | cur_modes_else;
198       break;
199    }
200    case nir_cf_node_loop: {
201       nir_loop *loop = nir_cf_node_as_loop(cf_node);
202       bool loop_progress;
203       do {
204          loop_progress = false;
205          foreach_list_typed(nir_cf_node, loop_node, node, &loop->body)
206             loop_progress |= lower_make_visible(loop_node, cur_modes);
207          progress |= loop_progress;
208       } while (loop_progress);
209       break;
210    }
211    case nir_cf_node_function:
212       unreachable("Invalid cf type");
213    }
214    return progress;
215 }
216 
217 static bool
lower_make_available(nir_cf_node * cf_node,uint32_t * cur_modes)218 lower_make_available(nir_cf_node *cf_node, uint32_t *cur_modes)
219 {
220    bool progress = false;
221    switch (cf_node->type) {
222    case nir_cf_node_block: {
223       nir_block *block = nir_cf_node_as_block(cf_node);
224       nir_foreach_instr_reverse(instr, block)
225          progress |= visit_instr(instr, cur_modes, NIR_MEMORY_MAKE_AVAILABLE);
226       break;
227    }
228    case nir_cf_node_if: {
229       nir_if *nif = nir_cf_node_as_if(cf_node);
230       uint32_t cur_modes_then = *cur_modes;
231       uint32_t cur_modes_else = *cur_modes;
232       foreach_list_typed_reverse(nir_cf_node, if_node, node, &nif->then_list)
233          progress |= lower_make_available(if_node, &cur_modes_then);
234       foreach_list_typed_reverse(nir_cf_node, if_node, node, &nif->else_list)
235          progress |= lower_make_available(if_node, &cur_modes_else);
236       *cur_modes |= cur_modes_then | cur_modes_else;
237       break;
238    }
239    case nir_cf_node_loop: {
240       nir_loop *loop = nir_cf_node_as_loop(cf_node);
241       bool loop_progress;
242       do {
243          loop_progress = false;
244          foreach_list_typed_reverse(nir_cf_node, loop_node, node, &loop->body)
245             loop_progress |= lower_make_available(loop_node, cur_modes);
246          progress |= loop_progress;
247       } while (loop_progress);
248       break;
249    }
250    case nir_cf_node_function:
251       unreachable("Invalid cf type");
252    }
253    return progress;
254 }
255 
256 bool
nir_lower_memory_model(nir_shader * shader)257 nir_lower_memory_model(nir_shader *shader)
258 {
259    bool progress = false;
260 
261    struct exec_list *cf_list = &nir_shader_get_entrypoint(shader)->body;
262 
263    uint32_t modes = 0;
264    foreach_list_typed(nir_cf_node, cf_node, node, cf_list)
265       progress |= lower_make_visible(cf_node, &modes);
266 
267    modes = 0;
268    foreach_list_typed_reverse(nir_cf_node, cf_node, node, cf_list)
269       progress |= lower_make_available(cf_node, &modes);
270 
271    return progress;
272 }
273