1/*
2 * Copyright © 2014 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 * Authors:
24 *    Jason Ekstrand (jason@jlekstrand.net)
25 *
26 */
27
28
29#ifndef _NIR_WORKLIST_
30#define _NIR_WORKLIST_
31
32#include "nir.h"
33#include "util/set.h"
34#include "util/u_vector.h"
35
36#ifdef __cplusplus
37extern "C" {
38#endif
39
40/** Represents a double-ended queue of unique blocks
41 *
42 * The worklist datastructure guarantees that eacy block is in the queue at
43 * most once.  Pushing a block onto either end of the queue is a no-op if
44 * the block is already in the queue.  In order for this to work, the
45 * caller must ensure that the blocks are properly indexed.
46 */
47typedef struct {
48   /* The total size of the worklist */
49   unsigned size;
50
51   /* The number of blocks currently in the worklist */
52   unsigned count;
53
54   /* The offset in the array of blocks at which the list starts */
55   unsigned start;
56
57   /* A bitset of all of the blocks currently present in the worklist */
58   BITSET_WORD *blocks_present;
59
60   /* The actual worklist */
61   nir_block **blocks;
62} nir_block_worklist;
63
64void nir_block_worklist_init(nir_block_worklist *w, unsigned num_blocks,
65                             void *mem_ctx);
66void nir_block_worklist_fini(nir_block_worklist *w);
67
68void nir_block_worklist_add_all(nir_block_worklist *w, nir_function_impl *impl);
69
70static inline bool
71nir_block_worklist_is_empty(const nir_block_worklist *w)
72{
73   return w->count == 0;
74}
75
76void nir_block_worklist_push_head(nir_block_worklist *w, nir_block *block);
77
78nir_block *nir_block_worklist_peek_head(const nir_block_worklist *w);
79
80nir_block *nir_block_worklist_pop_head(nir_block_worklist *w);
81
82void nir_block_worklist_push_tail(nir_block_worklist *w, nir_block *block);
83
84nir_block *nir_block_worklist_peek_tail(const nir_block_worklist *w);
85
86nir_block *nir_block_worklist_pop_tail(nir_block_worklist *w);
87
88
89/*
90 * This worklist implementation, in contrast to the block worklist, does not
91 * have unique entries, meaning a nir_instr can be inserted more than once
92 * into the worklist. It uses u_vector to keep the overhead and memory
93 * footprint at a minimum.
94 *
95 * Making it unique by using a set was tested, but for the single usecase
96 * (nir_opt_dce) it did not improve speed. There we check the pass_flag bit
97 * and abort immediately if there's nothing to do, so the added overhead of
98 * the set was higher than just processing the few extra entries.
99 */
100
101typedef struct {
102   struct u_vector instr_vec;
103} nir_instr_worklist;
104
105static inline nir_instr_worklist *
106nir_instr_worklist_create() {
107   nir_instr_worklist *wl = malloc(sizeof(nir_instr_worklist));
108   if (!wl)
109      return NULL;
110
111   if (!u_vector_init_pow2(&wl->instr_vec, 8, sizeof(struct nir_instr *))) {
112      free(wl);
113      return NULL;
114   }
115
116   return wl;
117}
118
119static inline uint32_t
120nir_instr_worklist_length(nir_instr_worklist *wl)
121{
122   return u_vector_length(&wl->instr_vec);
123}
124
125static inline bool
126nir_instr_worklist_is_empty(nir_instr_worklist *wl)
127{
128   return nir_instr_worklist_length(wl) == 0;
129}
130
131static inline void
132nir_instr_worklist_destroy(nir_instr_worklist *wl)
133{
134   u_vector_finish(&wl->instr_vec);
135   free(wl);
136}
137
138static inline void
139nir_instr_worklist_push_tail(nir_instr_worklist *wl, nir_instr *instr)
140{
141   struct nir_instr **vec_instr = u_vector_add(&wl->instr_vec);
142   *vec_instr = instr;
143}
144
145static inline nir_instr *
146nir_instr_worklist_pop_head(nir_instr_worklist *wl)
147{
148   struct nir_instr **vec_instr = u_vector_remove(&wl->instr_vec);
149
150   if (vec_instr == NULL)
151      return NULL;
152
153   return *vec_instr;
154}
155
156void
157nir_instr_worklist_add_ssa_srcs(nir_instr_worklist *wl, nir_instr *instr);
158
159#define nir_foreach_instr_in_worklist(instr, wl) \
160   for (nir_instr *instr; (instr = nir_instr_worklist_pop_head(wl));)
161
162#ifdef __cplusplus
163} /* extern "C" */
164#endif
165
166#endif /* _NIR_WORKLIST_ */
167