1/*
2 * Copyright © 2012 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 *    Eric Anholt <eric@anholt.net>
25 *
26 */
27
28#ifndef BRW_CFG_H
29#define BRW_CFG_H
30
31#include "brw_ir.h"
32#ifdef __cplusplus
33#include "brw_ir_analysis.h"
34#endif
35
36struct bblock_t;
37
38/**
39 * CFG edge types.
40 *
41 * A logical edge represents a potential control flow path of the original
42 * scalar program, while a physical edge represents a control flow path that
43 * may not have existed in the original program but was introduced during
44 * vectorization in order to implement divergent control flow of different
45 * shader invocations within the same SIMD thread.
46 *
47 * All logical edges in the CFG are considered to be physical edges but not
48 * the other way around -- I.e. the logical CFG is a subset of the physical
49 * one.
50 */
51enum bblock_link_kind {
52   bblock_link_logical = 0,
53   bblock_link_physical
54};
55
56struct bblock_link {
57#ifdef __cplusplus
58   DECLARE_RALLOC_CXX_OPERATORS(bblock_link)
59
60   bblock_link(bblock_t *block, enum bblock_link_kind kind)
61      : block(block), kind(kind)
62   {
63   }
64#endif
65
66   struct exec_node link;
67   struct bblock_t *block;
68
69   /* Type of this CFG edge.  Because bblock_link_logical also implies
70    * bblock_link_physical, the proper way to test for membership of edge 'l'
71    * in CFG kind 'k' is 'l.kind <= k'.
72    */
73   enum bblock_link_kind kind;
74};
75
76struct backend_shader;
77struct cfg_t;
78
79struct bblock_t {
80#ifdef __cplusplus
81   DECLARE_RALLOC_CXX_OPERATORS(bblock_t)
82
83   explicit bblock_t(cfg_t *cfg);
84
85   void add_successor(void *mem_ctx, bblock_t *successor,
86                      enum bblock_link_kind kind);
87   bool is_predecessor_of(const bblock_t *block,
88                          enum bblock_link_kind kind) const;
89   bool is_successor_of(const bblock_t *block,
90                        enum bblock_link_kind kind) const;
91   bool can_combine_with(const bblock_t *that) const;
92   void combine_with(bblock_t *that);
93   void dump() const;
94
95   backend_instruction *start();
96   const backend_instruction *start() const;
97   backend_instruction *end();
98   const backend_instruction *end() const;
99
100   bblock_t *next();
101   const bblock_t *next() const;
102   bblock_t *prev();
103   const bblock_t *prev() const;
104
105   bool starts_with_control_flow() const;
106   bool ends_with_control_flow() const;
107
108   backend_instruction *first_non_control_flow_inst();
109   backend_instruction *last_non_control_flow_inst();
110#endif
111
112   struct exec_node link;
113   struct cfg_t *cfg;
114
115   int start_ip;
116   int end_ip;
117
118   /**
119    * Change in end_ip since the last time IPs of later blocks were updated.
120    */
121   int end_ip_delta;
122
123   struct exec_list instructions;
124   struct exec_list parents;
125   struct exec_list children;
126   int num;
127};
128
129static inline struct backend_instruction *
130bblock_start(struct bblock_t *block)
131{
132   return (struct backend_instruction *)exec_list_get_head(&block->instructions);
133}
134
135static inline const struct backend_instruction *
136bblock_start_const(const struct bblock_t *block)
137{
138   return (const struct backend_instruction *)exec_list_get_head_const(&block->instructions);
139}
140
141static inline struct backend_instruction *
142bblock_end(struct bblock_t *block)
143{
144   return (struct backend_instruction *)exec_list_get_tail(&block->instructions);
145}
146
147static inline const struct backend_instruction *
148bblock_end_const(const struct bblock_t *block)
149{
150   return (const struct backend_instruction *)exec_list_get_tail_const(&block->instructions);
151}
152
153static inline struct bblock_t *
154bblock_next(struct bblock_t *block)
155{
156   if (exec_node_is_tail_sentinel(block->link.next))
157      return NULL;
158
159   return (struct bblock_t *)block->link.next;
160}
161
162static inline const struct bblock_t *
163bblock_next_const(const struct bblock_t *block)
164{
165   if (exec_node_is_tail_sentinel(block->link.next))
166      return NULL;
167
168   return (const struct bblock_t *)block->link.next;
169}
170
171static inline struct bblock_t *
172bblock_prev(struct bblock_t *block)
173{
174   if (exec_node_is_head_sentinel(block->link.prev))
175      return NULL;
176
177   return (struct bblock_t *)block->link.prev;
178}
179
180static inline const struct bblock_t *
181bblock_prev_const(const struct bblock_t *block)
182{
183   if (exec_node_is_head_sentinel(block->link.prev))
184      return NULL;
185
186   return (const struct bblock_t *)block->link.prev;
187}
188
189static inline bool
190bblock_starts_with_control_flow(const struct bblock_t *block)
191{
192   enum opcode op = bblock_start_const(block)->opcode;
193   return op == BRW_OPCODE_DO || op == BRW_OPCODE_ENDIF;
194}
195
196static inline bool
197bblock_ends_with_control_flow(const struct bblock_t *block)
198{
199   enum opcode op = bblock_end_const(block)->opcode;
200   return op == BRW_OPCODE_IF ||
201          op == BRW_OPCODE_ELSE ||
202          op == BRW_OPCODE_WHILE ||
203          op == BRW_OPCODE_BREAK ||
204          op == BRW_OPCODE_CONTINUE;
205}
206
207static inline struct backend_instruction *
208bblock_first_non_control_flow_inst(struct bblock_t *block)
209{
210   struct backend_instruction *inst = bblock_start(block);
211   if (bblock_starts_with_control_flow(block))
212#ifdef __cplusplus
213      inst = (struct backend_instruction *)inst->next;
214#else
215      inst = (struct backend_instruction *)inst->link.next;
216#endif
217   return inst;
218}
219
220static inline struct backend_instruction *
221bblock_last_non_control_flow_inst(struct bblock_t *block)
222{
223   struct backend_instruction *inst = bblock_end(block);
224   if (bblock_ends_with_control_flow(block))
225#ifdef __cplusplus
226      inst = (struct backend_instruction *)inst->prev;
227#else
228      inst = (struct backend_instruction *)inst->link.prev;
229#endif
230   return inst;
231}
232
233#ifdef __cplusplus
234inline backend_instruction *
235bblock_t::start()
236{
237   return bblock_start(this);
238}
239
240inline const backend_instruction *
241bblock_t::start() const
242{
243   return bblock_start_const(this);
244}
245
246inline backend_instruction *
247bblock_t::end()
248{
249   return bblock_end(this);
250}
251
252inline const backend_instruction *
253bblock_t::end() const
254{
255   return bblock_end_const(this);
256}
257
258inline bblock_t *
259bblock_t::next()
260{
261   return bblock_next(this);
262}
263
264inline const bblock_t *
265bblock_t::next() const
266{
267   return bblock_next_const(this);
268}
269
270inline bblock_t *
271bblock_t::prev()
272{
273   return bblock_prev(this);
274}
275
276inline const bblock_t *
277bblock_t::prev() const
278{
279   return bblock_prev_const(this);
280}
281
282inline bool
283bblock_t::starts_with_control_flow() const
284{
285   return bblock_starts_with_control_flow(this);
286}
287
288inline bool
289bblock_t::ends_with_control_flow() const
290{
291   return bblock_ends_with_control_flow(this);
292}
293
294inline backend_instruction *
295bblock_t::first_non_control_flow_inst()
296{
297   return bblock_first_non_control_flow_inst(this);
298}
299
300inline backend_instruction *
301bblock_t::last_non_control_flow_inst()
302{
303   return bblock_last_non_control_flow_inst(this);
304}
305#endif
306
307struct cfg_t {
308#ifdef __cplusplus
309   DECLARE_RALLOC_CXX_OPERATORS(cfg_t)
310
311   cfg_t(const backend_shader *s, exec_list *instructions);
312   ~cfg_t();
313
314   void remove_block(bblock_t *block);
315
316   bblock_t *first_block();
317   const bblock_t *first_block() const;
318   bblock_t *last_block();
319   const bblock_t *last_block() const;
320
321   bblock_t *new_block();
322   void set_next_block(bblock_t **cur, bblock_t *block, int ip);
323   void make_block_array();
324
325   void dump();
326   void dump_cfg();
327
328   /**
329    * Propagate bblock_t::end_ip_delta data through the CFG.
330    */
331   inline void adjust_block_ips();
332
333#endif
334   const struct backend_shader *s;
335   void *mem_ctx;
336
337   /** Ordered list (by ip) of basic blocks */
338   struct exec_list block_list;
339   struct bblock_t **blocks;
340   int num_blocks;
341};
342
343static inline struct bblock_t *
344cfg_first_block(struct cfg_t *cfg)
345{
346   return (struct bblock_t *)exec_list_get_head(&cfg->block_list);
347}
348
349static inline const struct bblock_t *
350cfg_first_block_const(const struct cfg_t *cfg)
351{
352   return (const struct bblock_t *)exec_list_get_head_const(&cfg->block_list);
353}
354
355static inline struct bblock_t *
356cfg_last_block(struct cfg_t *cfg)
357{
358   return (struct bblock_t *)exec_list_get_tail(&cfg->block_list);
359}
360
361static inline const struct bblock_t *
362cfg_last_block_const(const struct cfg_t *cfg)
363{
364   return (const struct bblock_t *)exec_list_get_tail_const(&cfg->block_list);
365}
366
367#ifdef __cplusplus
368inline bblock_t *
369cfg_t::first_block()
370{
371   return cfg_first_block(this);
372}
373
374const inline bblock_t *
375cfg_t::first_block() const
376{
377   return cfg_first_block_const(this);
378}
379
380inline bblock_t *
381cfg_t::last_block()
382{
383   return cfg_last_block(this);
384}
385
386const inline bblock_t *
387cfg_t::last_block() const
388{
389   return cfg_last_block_const(this);
390}
391#endif
392
393/* Note that this is implemented with a double for loop -- break will
394 * break from the inner loop only!
395 */
396#define foreach_block_and_inst(__block, __type, __inst, __cfg) \
397   foreach_block (__block, __cfg)                              \
398      foreach_inst_in_block (__type, __inst, __block)
399
400/* Note that this is implemented with a double for loop -- break will
401 * break from the inner loop only!
402 */
403#define foreach_block_and_inst_safe(__block, __type, __inst, __cfg) \
404   foreach_block_safe (__block, __cfg)                              \
405      foreach_inst_in_block_safe (__type, __inst, __block)
406
407#define foreach_block(__block, __cfg)                          \
408   foreach_list_typed (bblock_t, __block, link, &(__cfg)->block_list)
409
410#define foreach_block_reverse(__block, __cfg)                  \
411   foreach_list_typed_reverse (bblock_t, __block, link, &(__cfg)->block_list)
412
413#define foreach_block_safe(__block, __cfg)                     \
414   foreach_list_typed_safe (bblock_t, __block, link, &(__cfg)->block_list)
415
416#define foreach_block_reverse_safe(__block, __cfg)             \
417   foreach_list_typed_reverse_safe (bblock_t, __block, link, &(__cfg)->block_list)
418
419#define foreach_inst_in_block(__type, __inst, __block)         \
420   foreach_in_list(__type, __inst, &(__block)->instructions)
421
422#define foreach_inst_in_block_safe(__type, __inst, __block)    \
423   for (__type *__inst = (__type *)__block->instructions.head_sentinel.next, \
424               *__next = (__type *)__inst->next;               \
425        __next != NULL;                                        \
426        __inst = __next,                                       \
427        __next = (__type *)__next->next)
428
429#define foreach_inst_in_block_reverse(__type, __inst, __block) \
430   foreach_in_list_reverse(__type, __inst, &(__block)->instructions)
431
432#define foreach_inst_in_block_reverse_safe(__type, __inst, __block) \
433   foreach_in_list_reverse_safe(__type, __inst, &(__block)->instructions)
434
435#define foreach_inst_in_block_starting_from(__type, __scan_inst, __inst) \
436   for (__type *__scan_inst = (__type *)__inst->next;          \
437        !__scan_inst->is_tail_sentinel();                      \
438        __scan_inst = (__type *)__scan_inst->next)
439
440#define foreach_inst_in_block_reverse_starting_from(__type, __scan_inst, __inst) \
441   for (__type *__scan_inst = (__type *)__inst->prev;          \
442        !__scan_inst->is_head_sentinel();                      \
443        __scan_inst = (__type *)__scan_inst->prev)
444
445#ifdef __cplusplus
446inline void
447cfg_t::adjust_block_ips()
448{
449   int delta = 0;
450
451   foreach_block(block, this) {
452      block->start_ip += delta;
453      block->end_ip += delta;
454
455      delta += block->end_ip_delta;
456
457      block->end_ip_delta = 0;
458   }
459}
460
461namespace brw {
462   /**
463    * Immediate dominator tree analysis of a shader.
464    */
465   struct idom_tree {
466      idom_tree(const backend_shader *s);
467      ~idom_tree();
468
469      bool
470      validate(const backend_shader *) const
471      {
472         /* FINISHME */
473         return true;
474      }
475
476      analysis_dependency_class
477      dependency_class() const
478      {
479         return DEPENDENCY_BLOCKS;
480      }
481
482      const bblock_t *
483      parent(const bblock_t *b) const
484      {
485         assert(unsigned(b->num) < num_parents);
486         return parents[b->num];
487      }
488
489      bblock_t *
490      parent(bblock_t *b) const
491      {
492         assert(unsigned(b->num) < num_parents);
493         return parents[b->num];
494      }
495
496      bblock_t *
497      intersect(bblock_t *b1, bblock_t *b2) const;
498
499      void
500      dump() const;
501
502   private:
503      unsigned num_parents;
504      bblock_t **parents;
505   };
506}
507#endif
508
509#endif /* BRW_CFG_H */
510