1 /*
2 +----------------------------------------------------------------------+
3 | Zend OPcache |
4 +----------------------------------------------------------------------+
5 | Copyright (c) The PHP Group |
6 +----------------------------------------------------------------------+
7 | This source file is subject to version 3.01 of the PHP license, |
8 | that is bundled with this package in the file LICENSE, and is |
9 | available through the world-wide-web at the following url: |
10 | http://www.php.net/license/3_01.txt |
11 | If you did not receive a copy of the PHP license and are unable to |
12 | obtain it through the world-wide-web, please send a note to |
13 | license@php.net so we can mail you a copy immediately. |
14 +----------------------------------------------------------------------+
15 | Authors: Dmitry Stogov <dmitry@php.net> |
16 +----------------------------------------------------------------------+
17 */
18
19 #include "php.h"
20 #include "Optimizer/zend_optimizer.h"
21 #include "Optimizer/zend_optimizer_internal.h"
22 #include "zend_API.h"
23 #include "zend_constants.h"
24 #include "zend_execute.h"
25 #include "zend_vm.h"
26 #include "zend_bitset.h"
27 #include "zend_cfg.h"
28 #include "zend_ssa.h"
29 #include "zend_func_info.h"
30 #include "zend_call_graph.h"
31 #include "zend_inference.h"
32 #include "zend_dump.h"
33
34 #ifndef ZEND_DEBUG_DFA
35 # define ZEND_DEBUG_DFA ZEND_DEBUG
36 #endif
37
38 #if ZEND_DEBUG_DFA
39 # include "ssa_integrity.c"
40 #endif
41
zend_dfa_analyze_op_array(zend_op_array * op_array,zend_optimizer_ctx * ctx,zend_ssa * ssa)42 int zend_dfa_analyze_op_array(zend_op_array *op_array, zend_optimizer_ctx *ctx, zend_ssa *ssa)
43 {
44 uint32_t build_flags;
45
46 if (op_array->last_try_catch) {
47 /* TODO: we can't analyze functions with try/catch/finally ??? */
48 return FAILURE;
49 }
50
51 /* Build SSA */
52 memset(ssa, 0, sizeof(zend_ssa));
53
54 if (zend_build_cfg(&ctx->arena, op_array, ZEND_CFG_NO_ENTRY_PREDECESSORS, &ssa->cfg) != SUCCESS) {
55 return FAILURE;
56 }
57
58 if ((ssa->cfg.flags & ZEND_FUNC_INDIRECT_VAR_ACCESS)) {
59 /* TODO: we can't analyze functions with indirect variable access ??? */
60 return FAILURE;
61 }
62
63 if (zend_cfg_build_predecessors(&ctx->arena, &ssa->cfg) != SUCCESS) {
64 return FAILURE;
65 }
66
67 if (ctx->debug_level & ZEND_DUMP_DFA_CFG) {
68 zend_dump_op_array(op_array, ZEND_DUMP_CFG, "dfa cfg", &ssa->cfg);
69 }
70
71 /* Compute Dominators Tree */
72 if (zend_cfg_compute_dominators_tree(op_array, &ssa->cfg) != SUCCESS) {
73 return FAILURE;
74 }
75
76 /* Identify reducible and irreducible loops */
77 if (zend_cfg_identify_loops(op_array, &ssa->cfg) != SUCCESS) {
78 return FAILURE;
79 }
80
81 if (ctx->debug_level & ZEND_DUMP_DFA_DOMINATORS) {
82 zend_dump_dominators(op_array, &ssa->cfg);
83 }
84
85 build_flags = 0;
86 if (ctx->debug_level & ZEND_DUMP_DFA_LIVENESS) {
87 build_flags |= ZEND_SSA_DEBUG_LIVENESS;
88 }
89 if (ctx->debug_level & ZEND_DUMP_DFA_PHI) {
90 build_flags |= ZEND_SSA_DEBUG_PHI_PLACEMENT;
91 }
92 if (zend_build_ssa(&ctx->arena, ctx->script, op_array, build_flags, ssa) != SUCCESS) {
93 return FAILURE;
94 }
95
96 if (ctx->debug_level & ZEND_DUMP_DFA_SSA) {
97 zend_dump_op_array(op_array, ZEND_DUMP_SSA, "dfa ssa", ssa);
98 }
99
100
101 if (zend_ssa_compute_use_def_chains(&ctx->arena, op_array, ssa) != SUCCESS){
102 return FAILURE;
103 }
104
105 if (zend_ssa_find_false_dependencies(op_array, ssa) != SUCCESS) {
106 return FAILURE;
107 }
108
109 if (zend_ssa_find_sccs(op_array, ssa) != SUCCESS){
110 return FAILURE;
111 }
112
113 if (zend_ssa_inference(&ctx->arena, op_array, ctx->script, ssa, ctx->optimization_level) != SUCCESS) {
114 return FAILURE;
115 }
116
117 if (zend_ssa_escape_analysis(ctx->script, op_array, ssa) != SUCCESS) {
118 return FAILURE;
119 }
120
121 if (ctx->debug_level & ZEND_DUMP_DFA_SSA_VARS) {
122 zend_dump_ssa_variables(op_array, ssa, 0);
123 }
124
125 return SUCCESS;
126 }
127
is_smart_branch_inhibiting_nop(zend_op_array * op_array,uint32_t target,uint32_t current,zend_basic_block * b,zend_basic_block * blocks_end)128 static zend_bool is_smart_branch_inhibiting_nop(
129 zend_op_array *op_array, uint32_t target, uint32_t current,
130 zend_basic_block *b, zend_basic_block *blocks_end)
131 {
132 uint32_t next;
133 /* Target points one past the last non-nop instruction. Make sure there is one. */
134 if (target == 0) {
135 return 0;
136 }
137
138 /* Find the next instruction, skipping unreachable or empty blocks. */
139 next = current + 1;
140 if (next >= b->start + b->len) {
141 do {
142 b++;
143 if (b == blocks_end) {
144 return 0;
145 }
146 } while (!(b->flags & ZEND_BB_REACHABLE) || b->len == 0);
147 next = b->start;
148 }
149
150 return (op_array->opcodes[next].opcode == ZEND_JMPZ ||
151 op_array->opcodes[next].opcode == ZEND_JMPNZ) &&
152 zend_is_smart_branch(op_array->opcodes + target - 1);
153 }
154
zend_ssa_remove_nops(zend_op_array * op_array,zend_ssa * ssa,zend_optimizer_ctx * ctx)155 static void zend_ssa_remove_nops(zend_op_array *op_array, zend_ssa *ssa, zend_optimizer_ctx *ctx)
156 {
157 zend_basic_block *blocks = ssa->cfg.blocks;
158 zend_basic_block *blocks_end = blocks + ssa->cfg.blocks_count;
159 zend_basic_block *b;
160 zend_func_info *func_info;
161 int j;
162 uint32_t i = 0;
163 uint32_t target = 0;
164 uint32_t *shiftlist;
165 ALLOCA_FLAG(use_heap);
166
167 shiftlist = (uint32_t *)do_alloca(sizeof(uint32_t) * op_array->last, use_heap);
168 memset(shiftlist, 0, sizeof(uint32_t) * op_array->last);
169 /* remove empty callee_info */
170 func_info = ZEND_FUNC_INFO(op_array);
171 if (func_info) {
172 zend_call_info **call_info = &func_info->callee_info;
173 while ((*call_info)) {
174 if ((*call_info)->caller_init_opline->opcode == ZEND_NOP) {
175 *call_info = (*call_info)->next_callee;
176 } else {
177 call_info = &(*call_info)->next_callee;
178 }
179 }
180 }
181
182 for (b = blocks; b < blocks_end; b++) {
183 if (b->flags & (ZEND_BB_REACHABLE|ZEND_BB_UNREACHABLE_FREE)) {
184 if (b->len) {
185 uint32_t new_start, old_end;
186 while (i < b->start) {
187 shiftlist[i] = i - target;
188 i++;
189 }
190
191 if (b->flags & ZEND_BB_UNREACHABLE_FREE) {
192 /* Only keep the FREE for the loop var */
193 ZEND_ASSERT(op_array->opcodes[b->start].opcode == ZEND_FREE
194 || op_array->opcodes[b->start].opcode == ZEND_FE_FREE);
195 b->len = 1;
196 }
197
198 new_start = target;
199 old_end = b->start + b->len;
200 while (i < old_end) {
201 shiftlist[i] = i - target;
202 if (EXPECTED(op_array->opcodes[i].opcode != ZEND_NOP) ||
203 is_smart_branch_inhibiting_nop(op_array, target, i, b, blocks_end)) {
204 if (i != target) {
205 op_array->opcodes[target] = op_array->opcodes[i];
206 ssa->ops[target] = ssa->ops[i];
207 ssa->cfg.map[target] = b - blocks;
208 }
209 target++;
210 }
211 i++;
212 }
213 b->start = new_start;
214 if (target != old_end) {
215 zend_op *opline;
216 zend_op *new_opline;
217
218 b->len = target - b->start;
219 opline = op_array->opcodes + old_end - 1;
220 if (opline->opcode == ZEND_NOP) {
221 continue;
222 }
223
224 new_opline = op_array->opcodes + target - 1;
225 zend_optimizer_migrate_jump(op_array, new_opline, opline);
226 }
227 } else {
228 b->start = target;
229 }
230 } else {
231 b->start = target;
232 b->len = 0;
233 }
234 }
235
236 if (target != op_array->last) {
237 /* reset rest opcodes */
238 for (i = target; i < op_array->last; i++) {
239 MAKE_NOP(op_array->opcodes + i);
240 }
241
242 /* update SSA variables */
243 for (j = 0; j < ssa->vars_count; j++) {
244 if (ssa->vars[j].definition >= 0) {
245 ssa->vars[j].definition -= shiftlist[ssa->vars[j].definition];
246 }
247 if (ssa->vars[j].use_chain >= 0) {
248 ssa->vars[j].use_chain -= shiftlist[ssa->vars[j].use_chain];
249 }
250 }
251 for (i = 0; i < op_array->last; i++) {
252 if (ssa->ops[i].op1_use_chain >= 0) {
253 ssa->ops[i].op1_use_chain -= shiftlist[ssa->ops[i].op1_use_chain];
254 }
255 if (ssa->ops[i].op2_use_chain >= 0) {
256 ssa->ops[i].op2_use_chain -= shiftlist[ssa->ops[i].op2_use_chain];
257 }
258 if (ssa->ops[i].res_use_chain >= 0) {
259 ssa->ops[i].res_use_chain -= shiftlist[ssa->ops[i].res_use_chain];
260 }
261 }
262
263 /* update branch targets */
264 for (b = blocks; b < blocks_end; b++) {
265 if ((b->flags & ZEND_BB_REACHABLE) && b->len != 0) {
266 zend_op *opline = op_array->opcodes + b->start + b->len - 1;
267 zend_optimizer_shift_jump(op_array, opline, shiftlist);
268 }
269 }
270
271 /* update try/catch array */
272 for (j = 0; j < op_array->last_try_catch; j++) {
273 op_array->try_catch_array[j].try_op -= shiftlist[op_array->try_catch_array[j].try_op];
274 op_array->try_catch_array[j].catch_op -= shiftlist[op_array->try_catch_array[j].catch_op];
275 if (op_array->try_catch_array[j].finally_op) {
276 op_array->try_catch_array[j].finally_op -= shiftlist[op_array->try_catch_array[j].finally_op];
277 op_array->try_catch_array[j].finally_end -= shiftlist[op_array->try_catch_array[j].finally_end];
278 }
279 }
280
281 /* update early binding list */
282 if (op_array->fn_flags & ZEND_ACC_EARLY_BINDING) {
283 uint32_t *opline_num = &ctx->script->first_early_binding_opline;
284
285 ZEND_ASSERT(op_array == &ctx->script->main_op_array);
286 do {
287 *opline_num -= shiftlist[*opline_num];
288 opline_num = &op_array->opcodes[*opline_num].result.opline_num;
289 } while (*opline_num != (uint32_t)-1);
290 }
291
292 /* update call graph */
293 if (func_info) {
294 zend_call_info *call_info = func_info->callee_info;
295 while (call_info) {
296 call_info->caller_init_opline -=
297 shiftlist[call_info->caller_init_opline - op_array->opcodes];
298 if (call_info->caller_call_opline) {
299 call_info->caller_call_opline -=
300 shiftlist[call_info->caller_call_opline - op_array->opcodes];
301 }
302 call_info = call_info->next_callee;
303 }
304 }
305
306 op_array->last = target;
307 }
308 free_alloca(shiftlist, use_heap);
309 }
310
safe_instanceof(zend_class_entry * ce1,zend_class_entry * ce2)311 static zend_bool safe_instanceof(zend_class_entry *ce1, zend_class_entry *ce2) {
312 if (ce1 == ce2) {
313 return 1;
314 }
315 if (!(ce1->ce_flags & ZEND_ACC_LINKED)) {
316 /* This case could be generalized, similarly to unlinked_instanceof */
317 return 0;
318 }
319 return instanceof_function(ce1, ce2);
320 }
321
can_elide_return_type_check(zend_op_array * op_array,zend_ssa * ssa,zend_ssa_op * ssa_op)322 static inline zend_bool can_elide_return_type_check(
323 zend_op_array *op_array, zend_ssa *ssa, zend_ssa_op *ssa_op) {
324 zend_arg_info *info = &op_array->arg_info[-1];
325 zend_ssa_var_info *use_info = &ssa->var_info[ssa_op->op1_use];
326 zend_ssa_var_info *def_info = &ssa->var_info[ssa_op->op1_def];
327
328 if (use_info->type & MAY_BE_REF) {
329 return 0;
330 }
331
332 /* A type is possible that is not in the allowed types */
333 if ((use_info->type & (MAY_BE_ANY|MAY_BE_UNDEF)) & ~(def_info->type & MAY_BE_ANY)) {
334 return 0;
335 }
336
337 /* These types are not represented exactly */
338 if (ZEND_TYPE_CODE(info->type) == IS_CALLABLE || ZEND_TYPE_CODE(info->type) == IS_ITERABLE) {
339 return 0;
340 }
341
342 if (ZEND_TYPE_IS_CLASS(info->type)) {
343 if (!use_info->ce || !def_info->ce || !safe_instanceof(use_info->ce, def_info->ce)) {
344 return 0;
345 }
346 }
347
348 return 1;
349 }
350
opline_supports_assign_contraction(zend_ssa * ssa,zend_op * opline,int src_var,uint32_t cv_var)351 static zend_bool opline_supports_assign_contraction(
352 zend_ssa *ssa, zend_op *opline, int src_var, uint32_t cv_var) {
353 if (opline->opcode == ZEND_NEW) {
354 /* see Zend/tests/generators/aborted_yield_during_new.phpt */
355 return 0;
356 }
357
358 if (opline->opcode == ZEND_DO_ICALL || opline->opcode == ZEND_DO_UCALL
359 || opline->opcode == ZEND_DO_FCALL || opline->opcode == ZEND_DO_FCALL_BY_NAME) {
360 /* Function calls may dtor the return value after it has already been written -- allow
361 * direct assignment only for types where a double-dtor does not matter. */
362 uint32_t type = ssa->var_info[src_var].type;
363 uint32_t simple = MAY_BE_NULL|MAY_BE_FALSE|MAY_BE_TRUE|MAY_BE_LONG|MAY_BE_DOUBLE;
364 return !((type & MAY_BE_ANY) & ~simple);
365 }
366
367 if (opline->opcode == ZEND_POST_INC || opline->opcode == ZEND_POST_DEC) {
368 /* POST_INC/DEC write the result variable before performing the inc/dec. For $i = $i++
369 * eliding the temporary variable would thus yield an incorrect result. */
370 return opline->op1_type != IS_CV || opline->op1.var != cv_var;
371 }
372
373 if (opline->opcode == ZEND_INIT_ARRAY) {
374 /* INIT_ARRAY initializes the result array before reading key/value. */
375 return (opline->op1_type != IS_CV || opline->op1.var != cv_var)
376 && (opline->op2_type != IS_CV || opline->op2.var != cv_var);
377 }
378
379 if (opline->opcode == ZEND_CAST
380 && (opline->extended_value == IS_ARRAY || opline->extended_value == IS_OBJECT)) {
381 /* CAST to array/object may initialize the result to an empty array/object before
382 * reading the expression. */
383 return opline->op1_type != IS_CV || opline->op1.var != cv_var;
384 }
385
386 return 1;
387 }
388
zend_dfa_optimize_calls(zend_op_array * op_array,zend_ssa * ssa)389 int zend_dfa_optimize_calls(zend_op_array *op_array, zend_ssa *ssa)
390 {
391 zend_func_info *func_info = ZEND_FUNC_INFO(op_array);
392 int removed_ops = 0;
393
394 if (func_info->callee_info) {
395 zend_call_info *call_info = func_info->callee_info;
396
397 do {
398 if (call_info->caller_call_opline
399 && call_info->caller_call_opline->opcode == ZEND_DO_ICALL
400 && call_info->callee_func
401 && ZSTR_LEN(call_info->callee_func->common.function_name) == sizeof("in_array")-1
402 && memcmp(ZSTR_VAL(call_info->callee_func->common.function_name), "in_array", sizeof("in_array")-1) == 0
403 && (call_info->caller_init_opline->extended_value == 2
404 || (call_info->caller_init_opline->extended_value == 3
405 && (call_info->caller_call_opline - 1)->opcode == ZEND_SEND_VAL
406 && (call_info->caller_call_opline - 1)->op1_type == IS_CONST))) {
407
408 zend_op *send_array;
409 zend_op *send_needly;
410 zend_bool strict = 0;
411
412 if (call_info->caller_init_opline->extended_value == 2) {
413 send_array = call_info->caller_call_opline - 1;
414 send_needly = call_info->caller_call_opline - 2;
415 } else {
416 if (zend_is_true(CT_CONSTANT_EX(op_array, (call_info->caller_call_opline - 1)->op1.constant))) {
417 strict = 1;
418 }
419 send_array = call_info->caller_call_opline - 2;
420 send_needly = call_info->caller_call_opline - 3;
421 }
422
423 if (send_array->opcode == ZEND_SEND_VAL
424 && send_array->op1_type == IS_CONST
425 && Z_TYPE_P(CT_CONSTANT_EX(op_array, send_array->op1.constant)) == IS_ARRAY
426 && (send_needly->opcode == ZEND_SEND_VAL
427 || send_needly->opcode == ZEND_SEND_VAR)
428 ) {
429 int ok = 1;
430
431 HashTable *src = Z_ARRVAL_P(CT_CONSTANT_EX(op_array, send_array->op1.constant));
432 HashTable *dst;
433 zval *val, tmp;
434 zend_ulong idx;
435
436 ZVAL_TRUE(&tmp);
437 dst = zend_new_array(zend_hash_num_elements(src));
438 if (strict) {
439 ZEND_HASH_FOREACH_VAL(src, val) {
440 if (Z_TYPE_P(val) == IS_STRING) {
441 zend_hash_add(dst, Z_STR_P(val), &tmp);
442 } else if (Z_TYPE_P(val) == IS_LONG) {
443 zend_hash_index_add(dst, Z_LVAL_P(val), &tmp);
444 } else {
445 zend_array_destroy(dst);
446 ok = 0;
447 break;
448 }
449 } ZEND_HASH_FOREACH_END();
450 } else {
451 ZEND_HASH_FOREACH_VAL(src, val) {
452 if (Z_TYPE_P(val) != IS_STRING || ZEND_HANDLE_NUMERIC(Z_STR_P(val), idx)) {
453 zend_array_destroy(dst);
454 ok = 0;
455 break;
456 }
457 zend_hash_add(dst, Z_STR_P(val), &tmp);
458 } ZEND_HASH_FOREACH_END();
459 }
460
461 if (ok) {
462 uint32_t op_num = send_needly - op_array->opcodes;
463 zend_ssa_op *ssa_op = ssa->ops + op_num;
464
465 if (ssa_op->op1_use >= 0) {
466 /* Reconstruct SSA */
467 int var_num = ssa_op->op1_use;
468 zend_ssa_var *var = ssa->vars + var_num;
469
470 ZEND_ASSERT(ssa_op->op1_def < 0);
471 zend_ssa_unlink_use_chain(ssa, op_num, ssa_op->op1_use);
472 ssa_op->op1_use = -1;
473 ssa_op->op1_use_chain = -1;
474 op_num = call_info->caller_call_opline - op_array->opcodes;
475 ssa_op = ssa->ops + op_num;
476 ssa_op->op1_use = var_num;
477 ssa_op->op1_use_chain = var->use_chain;
478 var->use_chain = op_num;
479 }
480
481 ZVAL_ARR(&tmp, dst);
482
483 /* Update opcode */
484 call_info->caller_call_opline->opcode = ZEND_IN_ARRAY;
485 call_info->caller_call_opline->extended_value = strict;
486 call_info->caller_call_opline->op1_type = send_needly->op1_type;
487 call_info->caller_call_opline->op1.num = send_needly->op1.num;
488 call_info->caller_call_opline->op2_type = IS_CONST;
489 call_info->caller_call_opline->op2.constant = zend_optimizer_add_literal(op_array, &tmp);
490 if (call_info->caller_init_opline->extended_value == 3) {
491 MAKE_NOP(call_info->caller_call_opline - 1);
492 }
493 MAKE_NOP(call_info->caller_init_opline);
494 MAKE_NOP(send_needly);
495 MAKE_NOP(send_array);
496 removed_ops++;
497
498 }
499 }
500 }
501 call_info = call_info->next_callee;
502 } while (call_info);
503 }
504
505 return removed_ops;
506 }
507
take_successor_0(zend_ssa * ssa,int block_num,zend_basic_block * block)508 static zend_always_inline void take_successor_0(zend_ssa *ssa, int block_num, zend_basic_block *block)
509 {
510 if (block->successors_count == 2) {
511 if (block->successors[1] != block->successors[0]) {
512 zend_ssa_remove_predecessor(ssa, block_num, block->successors[1]);
513 }
514 block->successors_count = 1;
515 }
516 }
517
take_successor_1(zend_ssa * ssa,int block_num,zend_basic_block * block)518 static zend_always_inline void take_successor_1(zend_ssa *ssa, int block_num, zend_basic_block *block)
519 {
520 if (block->successors_count == 2) {
521 if (block->successors[1] != block->successors[0]) {
522 zend_ssa_remove_predecessor(ssa, block_num, block->successors[0]);
523 block->successors[0] = block->successors[1];
524 }
525 block->successors_count = 1;
526 }
527 }
528
take_successor_ex(zend_ssa * ssa,int block_num,zend_basic_block * block,int target_block)529 static zend_always_inline void take_successor_ex(zend_ssa *ssa, int block_num, zend_basic_block *block, int target_block)
530 {
531 int i;
532
533 for (i = 0; i < block->successors_count; i++) {
534 if (block->successors[i] != target_block) {
535 zend_ssa_remove_predecessor(ssa, block_num, block->successors[i]);
536 }
537 }
538 block->successors[0] = target_block;
539 block->successors_count = 1;
540 }
541
compress_block(zend_op_array * op_array,zend_basic_block * block)542 static void compress_block(zend_op_array *op_array, zend_basic_block *block)
543 {
544 while (block->len > 0) {
545 zend_op *opline = &op_array->opcodes[block->start + block->len - 1];
546
547 if (opline->opcode == ZEND_NOP
548 && (block->len == 1 || !zend_is_smart_branch(opline - 1))) {
549 block->len--;
550 } else {
551 break;
552 }
553 }
554 }
555
replace_predecessor(zend_ssa * ssa,int block_id,int old_pred,int new_pred)556 static void replace_predecessor(zend_ssa *ssa, int block_id, int old_pred, int new_pred) {
557 zend_basic_block *block = &ssa->cfg.blocks[block_id];
558 int *predecessors = &ssa->cfg.predecessors[block->predecessor_offset];
559 zend_ssa_phi *phi;
560
561 int i;
562 int old_pred_idx = -1;
563 int new_pred_idx = -1;
564 for (i = 0; i < block->predecessors_count; i++) {
565 if (predecessors[i] == old_pred) {
566 old_pred_idx = i;
567 }
568 if (predecessors[i] == new_pred) {
569 new_pred_idx = i;
570 }
571 }
572
573 ZEND_ASSERT(old_pred_idx != -1);
574 if (new_pred_idx == -1) {
575 /* If the new predecessor doesn't exist yet, simply rewire the old one */
576 predecessors[old_pred_idx] = new_pred;
577 } else {
578 /* Otherwise, rewiring the old predecessor would make the new predecessor appear
579 * twice, which violates our CFG invariants. Remove the old predecessor instead. */
580 memmove(
581 predecessors + old_pred_idx,
582 predecessors + old_pred_idx + 1,
583 sizeof(int) * (block->predecessors_count - old_pred_idx - 1)
584 );
585
586 /* Also remove the corresponding phi node entries */
587 for (phi = ssa->blocks[block_id].phis; phi; phi = phi->next) {
588 memmove(
589 phi->sources + old_pred_idx,
590 phi->sources + old_pred_idx + 1,
591 sizeof(int) * (block->predecessors_count - old_pred_idx - 1)
592 );
593 }
594
595 block->predecessors_count--;
596 }
597 }
598
zend_ssa_replace_control_link(zend_op_array * op_array,zend_ssa * ssa,int from,int to,int new_to)599 static void zend_ssa_replace_control_link(zend_op_array *op_array, zend_ssa *ssa, int from, int to, int new_to)
600 {
601 zend_basic_block *src = &ssa->cfg.blocks[from];
602 zend_basic_block *old = &ssa->cfg.blocks[to];
603 zend_basic_block *dst = &ssa->cfg.blocks[new_to];
604 int i;
605 zend_op *opline;
606
607 for (i = 0; i < src->successors_count; i++) {
608 if (src->successors[i] == to) {
609 src->successors[i] = new_to;
610 }
611 }
612
613 if (src->len > 0) {
614 opline = op_array->opcodes + src->start + src->len - 1;
615 switch (opline->opcode) {
616 case ZEND_JMP:
617 case ZEND_FAST_CALL:
618 ZEND_ASSERT(ZEND_OP1_JMP_ADDR(opline) == op_array->opcodes + old->start);
619 ZEND_SET_OP_JMP_ADDR(opline, opline->op1, op_array->opcodes + dst->start);
620 break;
621 case ZEND_JMPZNZ:
622 if (ZEND_OFFSET_TO_OPLINE_NUM(op_array, opline, opline->extended_value) == old->start) {
623 opline->extended_value = ZEND_OPLINE_NUM_TO_OFFSET(op_array, opline, dst->start);
624 }
625 /* break missing intentionally */
626 case ZEND_JMPZ:
627 case ZEND_JMPNZ:
628 case ZEND_JMPZ_EX:
629 case ZEND_JMPNZ_EX:
630 case ZEND_FE_RESET_R:
631 case ZEND_FE_RESET_RW:
632 case ZEND_JMP_SET:
633 case ZEND_COALESCE:
634 case ZEND_ASSERT_CHECK:
635 if (ZEND_OP2_JMP_ADDR(opline) == op_array->opcodes + old->start) {
636 ZEND_SET_OP_JMP_ADDR(opline, opline->op2, op_array->opcodes + dst->start);
637 }
638 break;
639 case ZEND_CATCH:
640 if (!(opline->extended_value & ZEND_LAST_CATCH)) {
641 if (ZEND_OP2_JMP_ADDR(opline) == op_array->opcodes + old->start) {
642 ZEND_SET_OP_JMP_ADDR(opline, opline->op2, op_array->opcodes + dst->start);
643 }
644 }
645 break;
646 case ZEND_FE_FETCH_R:
647 case ZEND_FE_FETCH_RW:
648 if (ZEND_OFFSET_TO_OPLINE_NUM(op_array, opline, opline->extended_value) == old->start) {
649 opline->extended_value = ZEND_OPLINE_NUM_TO_OFFSET(op_array, opline, dst->start);
650 }
651 break;
652 case ZEND_SWITCH_LONG:
653 case ZEND_SWITCH_STRING:
654 {
655 HashTable *jumptable = Z_ARRVAL(ZEND_OP2_LITERAL(opline));
656 zval *zv;
657 ZEND_HASH_FOREACH_VAL(jumptable, zv) {
658 if (ZEND_OFFSET_TO_OPLINE_NUM(op_array, opline, Z_LVAL_P(zv)) == old->start) {
659 Z_LVAL_P(zv) = ZEND_OPLINE_NUM_TO_OFFSET(op_array, opline, dst->start);
660 }
661 } ZEND_HASH_FOREACH_END();
662 if (ZEND_OFFSET_TO_OPLINE_NUM(op_array, opline, opline->extended_value) == old->start) {
663 opline->extended_value = ZEND_OPLINE_NUM_TO_OFFSET(op_array, opline, dst->start);
664 }
665 break;
666 }
667 }
668 }
669
670 replace_predecessor(ssa, new_to, to, from);
671 }
672
zend_ssa_unlink_block(zend_op_array * op_array,zend_ssa * ssa,zend_basic_block * block,int block_num)673 static void zend_ssa_unlink_block(zend_op_array *op_array, zend_ssa *ssa, zend_basic_block *block, int block_num)
674 {
675 if (block->predecessors_count == 1 && ssa->blocks[block_num].phis == NULL) {
676 int *predecessors, i;
677
678 ZEND_ASSERT(block->successors_count == 1);
679 predecessors = &ssa->cfg.predecessors[block->predecessor_offset];
680 for (i = 0; i < block->predecessors_count; i++) {
681 zend_ssa_replace_control_link(op_array, ssa, predecessors[i], block_num, block->successors[0]);
682 }
683 zend_ssa_remove_block(op_array, ssa, block_num);
684 }
685 }
686
zend_dfa_optimize_jmps(zend_op_array * op_array,zend_ssa * ssa)687 static int zend_dfa_optimize_jmps(zend_op_array *op_array, zend_ssa *ssa)
688 {
689 int removed_ops = 0;
690 int block_num = 0;
691
692 for (block_num = 1; block_num < ssa->cfg.blocks_count; block_num++) {
693 zend_basic_block *block = &ssa->cfg.blocks[block_num];
694
695 if (!(block->flags & ZEND_BB_REACHABLE)) {
696 continue;
697 }
698 compress_block(op_array, block);
699 if (block->len == 0) {
700 zend_ssa_unlink_block(op_array, ssa, block, block_num);
701 }
702 }
703
704 block_num = 0;
705 while (block_num < ssa->cfg.blocks_count
706 && !(ssa->cfg.blocks[block_num].flags & ZEND_BB_REACHABLE)) {
707 block_num++;
708 }
709 while (block_num < ssa->cfg.blocks_count) {
710 int next_block_num = block_num + 1;
711 zend_basic_block *block = &ssa->cfg.blocks[block_num];
712 uint32_t op_num;
713 zend_op *opline;
714 zend_ssa_op *ssa_op;
715
716 while (next_block_num < ssa->cfg.blocks_count
717 && !(ssa->cfg.blocks[next_block_num].flags & ZEND_BB_REACHABLE)) {
718 next_block_num++;
719 }
720
721 if (block->len) {
722 op_num = block->start + block->len - 1;
723 opline = op_array->opcodes + op_num;
724 ssa_op = ssa->ops + op_num;
725
726 switch (opline->opcode) {
727 case ZEND_JMP:
728 optimize_jmp:
729 if (block->successors[0] == next_block_num) {
730 MAKE_NOP(opline);
731 removed_ops++;
732 goto optimize_nop;
733 }
734 break;
735 case ZEND_JMPZ:
736 optimize_jmpz:
737 if (opline->op1_type == IS_CONST) {
738 if (zend_is_true(CT_CONSTANT_EX(op_array, opline->op1.constant))) {
739 MAKE_NOP(opline);
740 removed_ops++;
741 take_successor_1(ssa, block_num, block);
742 goto optimize_nop;
743 } else {
744 opline->opcode = ZEND_JMP;
745 COPY_NODE(opline->op1, opline->op2);
746 take_successor_0(ssa, block_num, block);
747 goto optimize_jmp;
748 }
749 } else {
750 if (block->successors[0] == next_block_num) {
751 take_successor_0(ssa, block_num, block);
752 if (opline->op1_type == IS_CV && (OP1_INFO() & MAY_BE_UNDEF)) {
753 opline->opcode = ZEND_CHECK_VAR;
754 opline->op2.num = 0;
755 } else if (opline->op1_type == IS_CV || !(OP1_INFO() & (MAY_BE_STRING|MAY_BE_ARRAY|MAY_BE_OBJECT|MAY_BE_RESOURCE|MAY_BE_REF))) {
756 zend_ssa_remove_instr(ssa, opline, ssa_op);
757 removed_ops++;
758 goto optimize_nop;
759 } else {
760 opline->opcode = ZEND_FREE;
761 opline->op2.num = 0;
762 }
763 }
764 }
765 break;
766 case ZEND_JMPNZ:
767 optimize_jmpnz:
768 if (opline->op1_type == IS_CONST) {
769 if (zend_is_true(CT_CONSTANT_EX(op_array, opline->op1.constant))) {
770 opline->opcode = ZEND_JMP;
771 COPY_NODE(opline->op1, opline->op2);
772 take_successor_0(ssa, block_num, block);
773 goto optimize_jmp;
774 } else {
775 MAKE_NOP(opline);
776 removed_ops++;
777 take_successor_1(ssa, block_num, block);
778 goto optimize_nop;
779 }
780 } else if (block->successors_count == 2) {
781 if (block->successors[0] == next_block_num) {
782 take_successor_0(ssa, block_num, block);
783 if (opline->op1_type == IS_CV && (OP1_INFO() & MAY_BE_UNDEF)) {
784 opline->opcode = ZEND_CHECK_VAR;
785 opline->op2.num = 0;
786 } else if (opline->op1_type == IS_CV || !(OP1_INFO() & (MAY_BE_STRING|MAY_BE_ARRAY|MAY_BE_OBJECT|MAY_BE_RESOURCE|MAY_BE_REF))) {
787 zend_ssa_remove_instr(ssa, opline, ssa_op);
788 removed_ops++;
789 goto optimize_nop;
790 } else {
791 opline->opcode = ZEND_FREE;
792 opline->op2.num = 0;
793 }
794 }
795 }
796 break;
797 case ZEND_JMPZNZ:
798 if (opline->op1_type == IS_CONST) {
799 if (zend_is_true(CT_CONSTANT_EX(op_array, opline->op1.constant))) {
800 zend_op *target_opline = ZEND_OFFSET_TO_OPLINE(opline, opline->extended_value);
801 ZEND_SET_OP_JMP_ADDR(opline, opline->op1, target_opline);
802 take_successor_1(ssa, block_num, block);
803 } else {
804 zend_op *target_opline = ZEND_OP2_JMP_ADDR(opline);
805 ZEND_SET_OP_JMP_ADDR(opline, opline->op1, target_opline);
806 take_successor_0(ssa, block_num, block);
807 }
808 opline->op1_type = IS_UNUSED;
809 opline->extended_value = 0;
810 opline->opcode = ZEND_JMP;
811 goto optimize_jmp;
812 } else if (block->successors_count == 2) {
813 if (block->successors[0] == block->successors[1]) {
814 take_successor_0(ssa, block_num, block);
815 if (block->successors[0] == next_block_num) {
816 if (opline->op1_type == IS_CV && (OP1_INFO() & MAY_BE_UNDEF)) {
817 opline->opcode = ZEND_CHECK_VAR;
818 opline->op2.num = 0;
819 } else if (opline->op1_type == IS_CV || !(OP1_INFO() & (MAY_BE_STRING|MAY_BE_ARRAY|MAY_BE_OBJECT|MAY_BE_RESOURCE|MAY_BE_REF))) {
820 zend_ssa_remove_instr(ssa, opline, ssa_op);
821 removed_ops++;
822 goto optimize_nop;
823 } else {
824 opline->opcode = ZEND_FREE;
825 opline->op2.num = 0;
826 }
827 } else if ((opline->op1_type == IS_CV && !(OP1_INFO() & MAY_BE_UNDEF)) || !(OP1_INFO() & (MAY_BE_STRING|MAY_BE_ARRAY|MAY_BE_OBJECT|MAY_BE_RESOURCE|MAY_BE_REF))) {
828 ZEND_ASSERT(ssa_op->op1_use >= 0);
829 zend_ssa_unlink_use_chain(ssa, op_num, ssa_op->op1_use);
830 ssa_op->op1_use = -1;
831 ssa_op->op1_use_chain = -1;
832 opline->opcode = ZEND_JMP;
833 opline->op1_type = IS_UNUSED;
834 opline->op1.num = opline->op2.num;
835 goto optimize_jmp;
836 }
837 }
838 }
839 break;
840 case ZEND_JMPZ_EX:
841 if (ssa->vars[ssa_op->result_def].use_chain < 0
842 && ssa->vars[ssa_op->result_def].phi_use_chain == NULL) {
843 opline->opcode = ZEND_JMPZ;
844 opline->result_type = IS_UNUSED;
845 zend_ssa_remove_result_def(ssa, ssa_op);
846 goto optimize_jmpz;
847 } else if (opline->op1_type == IS_CONST) {
848 if (zend_is_true(CT_CONSTANT_EX(op_array, opline->op1.constant))) {
849 opline->opcode = ZEND_QM_ASSIGN;
850 take_successor_1(ssa, block_num, block);
851 }
852 }
853 break;
854 case ZEND_JMPNZ_EX:
855 if (ssa->vars[ssa_op->result_def].use_chain < 0
856 && ssa->vars[ssa_op->result_def].phi_use_chain == NULL) {
857 opline->opcode = ZEND_JMPNZ;
858 opline->result_type = IS_UNUSED;
859 zend_ssa_remove_result_def(ssa, ssa_op);
860 goto optimize_jmpnz;
861 } else if (opline->op1_type == IS_CONST) {
862 if (!zend_is_true(CT_CONSTANT_EX(op_array, opline->op1.constant))) {
863 opline->opcode = ZEND_QM_ASSIGN;
864 take_successor_1(ssa, block_num, block);
865 }
866 }
867 break;
868 case ZEND_JMP_SET:
869 if (ssa->vars[ssa_op->result_def].use_chain < 0
870 && ssa->vars[ssa_op->result_def].phi_use_chain == NULL) {
871 opline->opcode = ZEND_JMPNZ;
872 opline->result_type = IS_UNUSED;
873 zend_ssa_remove_result_def(ssa, ssa_op);
874 goto optimize_jmpnz;
875 } else if (opline->op1_type == IS_CONST) {
876 if (!zend_is_true(CT_CONSTANT_EX(op_array, opline->op1.constant))) {
877 MAKE_NOP(opline);
878 removed_ops++;
879 take_successor_1(ssa, block_num, block);
880 zend_ssa_remove_result_def(ssa, ssa_op);
881 goto optimize_nop;
882 }
883 }
884 break;
885 case ZEND_COALESCE:
886 {
887 zend_ssa_var *var = &ssa->vars[ssa_op->result_def];
888 if (opline->op1_type == IS_CONST
889 && var->use_chain < 0 && var->phi_use_chain == NULL) {
890 if (Z_TYPE_P(CT_CONSTANT_EX(op_array, opline->op1.constant)) == IS_NULL) {
891 zend_ssa_remove_result_def(ssa, ssa_op);
892 MAKE_NOP(opline);
893 removed_ops++;
894 take_successor_1(ssa, block_num, block);
895 goto optimize_nop;
896 } else {
897 opline->opcode = ZEND_JMP;
898 opline->result_type = IS_UNUSED;
899 zend_ssa_remove_result_def(ssa, ssa_op);
900 COPY_NODE(opline->op1, opline->op2);
901 take_successor_0(ssa, block_num, block);
902 goto optimize_jmp;
903 }
904 }
905 break;
906 }
907 case ZEND_SWITCH_LONG:
908 if (opline->op1_type == IS_CONST) {
909 zval *zv = CT_CONSTANT_EX(op_array, opline->op1.constant);
910 if (Z_TYPE_P(zv) != IS_LONG) {
911 removed_ops++;
912 MAKE_NOP(opline);
913 opline->extended_value = 0;
914 take_successor_ex(ssa, block_num, block, block->successors[0]);
915 goto optimize_nop;
916 } else {
917 HashTable *jmptable = Z_ARRVAL_P(CT_CONSTANT_EX(op_array, opline->op2.constant));
918 zval *jmp_zv = zend_hash_index_find(jmptable, Z_LVAL_P(zv));
919 uint32_t target;
920
921 if (jmp_zv) {
922 target = ZEND_OFFSET_TO_OPLINE_NUM(op_array, opline, Z_LVAL_P(jmp_zv));
923 } else {
924 target = ZEND_OFFSET_TO_OPLINE_NUM(op_array, opline, opline->extended_value);
925 }
926 opline->opcode = ZEND_JMP;
927 opline->extended_value = 0;
928 SET_UNUSED(opline->op1);
929 ZEND_SET_OP_JMP_ADDR(opline, opline->op1, op_array->opcodes + target);
930 SET_UNUSED(opline->op2);
931 take_successor_ex(ssa, block_num, block, ssa->cfg.map[target]);
932 goto optimize_jmp;
933 }
934 }
935 break;
936 case ZEND_SWITCH_STRING:
937 if (opline->op1_type == IS_CONST) {
938 zval *zv = CT_CONSTANT_EX(op_array, opline->op1.constant);
939 if (Z_TYPE_P(zv) != IS_STRING) {
940 removed_ops++;
941 MAKE_NOP(opline);
942 opline->extended_value = 0;
943 take_successor_ex(ssa, block_num, block, block->successors[0]);
944 goto optimize_nop;
945 } else {
946 HashTable *jmptable = Z_ARRVAL_P(CT_CONSTANT_EX(op_array, opline->op2.constant));
947 zval *jmp_zv = zend_hash_find(jmptable, Z_STR_P(zv));
948 uint32_t target;
949
950 if (jmp_zv) {
951 target = ZEND_OFFSET_TO_OPLINE_NUM(op_array, opline, Z_LVAL_P(jmp_zv));
952 } else {
953 target = ZEND_OFFSET_TO_OPLINE_NUM(op_array, opline, opline->extended_value);
954 }
955 opline->opcode = ZEND_JMP;
956 opline->extended_value = 0;
957 SET_UNUSED(opline->op1);
958 ZEND_SET_OP_JMP_ADDR(opline, opline->op1, op_array->opcodes + target);
959 SET_UNUSED(opline->op2);
960 take_successor_ex(ssa, block_num, block, ssa->cfg.map[target]);
961 goto optimize_jmp;
962 }
963 }
964 break;
965 case ZEND_NOP:
966 optimize_nop:
967 compress_block(op_array, block);
968 if (block->len == 0) {
969 if (block_num > 0) {
970 zend_ssa_unlink_block(op_array, ssa, block, block_num);
971 /* backtrack to previous basic block */
972 do {
973 block_num--;
974 } while (block_num >= 0
975 && !(ssa->cfg.blocks[block_num].flags & ZEND_BB_REACHABLE));
976 if (block_num >= 0) {
977 continue;
978 }
979 }
980 }
981 break;
982 default:
983 break;
984 }
985 }
986
987 block_num = next_block_num;
988 }
989
990 return removed_ops;
991 }
992
zend_dfa_optimize_op_array(zend_op_array * op_array,zend_optimizer_ctx * ctx,zend_ssa * ssa,zend_call_info ** call_map)993 void zend_dfa_optimize_op_array(zend_op_array *op_array, zend_optimizer_ctx *ctx, zend_ssa *ssa, zend_call_info **call_map)
994 {
995 if (ctx->debug_level & ZEND_DUMP_BEFORE_DFA_PASS) {
996 zend_dump_op_array(op_array, ZEND_DUMP_SSA, "before dfa pass", ssa);
997 }
998
999 if (ssa->var_info) {
1000 int op_1;
1001 int v;
1002 int remove_nops = 0;
1003 zend_op *opline;
1004 zval tmp;
1005
1006 #if ZEND_DEBUG_DFA
1007 ssa_verify_integrity(op_array, ssa, "before dfa");
1008 #endif
1009
1010 if (ZEND_OPTIMIZER_PASS_8 & ctx->optimization_level) {
1011 if (sccp_optimize_op_array(ctx, op_array, ssa, call_map)) {
1012 remove_nops = 1;
1013 }
1014
1015 if (zend_dfa_optimize_jmps(op_array, ssa)) {
1016 remove_nops = 1;
1017 }
1018
1019 #if ZEND_DEBUG_DFA
1020 ssa_verify_integrity(op_array, ssa, "after sccp");
1021 #endif
1022 if (ZEND_FUNC_INFO(op_array)) {
1023 if (zend_dfa_optimize_calls(op_array, ssa)) {
1024 remove_nops = 1;
1025 }
1026 }
1027 if (ctx->debug_level & ZEND_DUMP_AFTER_PASS_8) {
1028 zend_dump_op_array(op_array, ZEND_DUMP_SSA, "after sccp pass", ssa);
1029 }
1030 #if ZEND_DEBUG_DFA
1031 ssa_verify_integrity(op_array, ssa, "after calls");
1032 #endif
1033 }
1034
1035 if (ZEND_OPTIMIZER_PASS_14 & ctx->optimization_level) {
1036 if (dce_optimize_op_array(op_array, ssa, 0)) {
1037 remove_nops = 1;
1038 }
1039 if (zend_dfa_optimize_jmps(op_array, ssa)) {
1040 remove_nops = 1;
1041 }
1042 if (ctx->debug_level & ZEND_DUMP_AFTER_PASS_14) {
1043 zend_dump_op_array(op_array, ZEND_DUMP_SSA, "after dce pass", ssa);
1044 }
1045 #if ZEND_DEBUG_DFA
1046 ssa_verify_integrity(op_array, ssa, "after dce");
1047 #endif
1048 }
1049
1050 for (v = op_array->last_var; v < ssa->vars_count; v++) {
1051
1052 op_1 = ssa->vars[v].definition;
1053
1054 if (op_1 < 0) {
1055 continue;
1056 }
1057
1058 opline = op_array->opcodes + op_1;
1059
1060 /* Convert LONG constants to DOUBLE */
1061 if (ssa->var_info[v].use_as_double) {
1062 if (opline->opcode == ZEND_ASSIGN
1063 && opline->op2_type == IS_CONST
1064 && ssa->ops[op_1].op1_def == v
1065 && !RETURN_VALUE_USED(opline)
1066 ) {
1067
1068 // op_1: ASSIGN ? -> #v [use_as_double], long(?) => ASSIGN ? -> #v, double(?)
1069
1070 zval *zv = CT_CONSTANT_EX(op_array, opline->op2.constant);
1071 ZEND_ASSERT(Z_TYPE_INFO_P(zv) == IS_LONG);
1072 ZVAL_DOUBLE(&tmp, zval_get_double(zv));
1073 opline->op2.constant = zend_optimizer_add_literal(op_array, &tmp);
1074
1075 } else if (opline->opcode == ZEND_QM_ASSIGN
1076 && opline->op1_type == IS_CONST
1077 ) {
1078
1079 // op_1: QM_ASSIGN #v [use_as_double], long(?) => QM_ASSIGN #v, double(?)
1080
1081 zval *zv = CT_CONSTANT_EX(op_array, opline->op1.constant);
1082 ZEND_ASSERT(Z_TYPE_INFO_P(zv) == IS_LONG);
1083 ZVAL_DOUBLE(&tmp, zval_get_double(zv));
1084 opline->op1.constant = zend_optimizer_add_literal(op_array, &tmp);
1085 }
1086
1087 } else {
1088 if (opline->opcode == ZEND_ADD
1089 || opline->opcode == ZEND_SUB
1090 || opline->opcode == ZEND_MUL
1091 || opline->opcode == ZEND_IS_EQUAL
1092 || opline->opcode == ZEND_IS_NOT_EQUAL
1093 || opline->opcode == ZEND_IS_SMALLER
1094 || opline->opcode == ZEND_IS_SMALLER_OR_EQUAL
1095 ) {
1096
1097 if (opline->op1_type == IS_CONST
1098 && opline->op2_type != IS_CONST
1099 && (OP2_INFO() & MAY_BE_ANY) == MAY_BE_DOUBLE
1100 && Z_TYPE_INFO_P(CT_CONSTANT_EX(op_array, opline->op1.constant)) == IS_LONG
1101 ) {
1102
1103 // op_1: #v.? = ADD long(?), #?.? [double] => #v.? = ADD double(?), #?.? [double]
1104
1105 zval *zv = CT_CONSTANT_EX(op_array, opline->op1.constant);
1106 ZVAL_DOUBLE(&tmp, zval_get_double(zv));
1107 opline->op1.constant = zend_optimizer_add_literal(op_array, &tmp);
1108
1109 } else if (opline->op1_type != IS_CONST
1110 && opline->op2_type == IS_CONST
1111 && (OP1_INFO() & MAY_BE_ANY) == MAY_BE_DOUBLE
1112 && Z_TYPE_INFO_P(CT_CONSTANT_EX(op_array, opline->op2.constant)) == IS_LONG
1113 ) {
1114
1115 // op_1: #v.? = ADD #?.? [double], long(?) => #v.? = ADD #?.? [double], double(?)
1116
1117 zval *zv = CT_CONSTANT_EX(op_array, opline->op2.constant);
1118 ZVAL_DOUBLE(&tmp, zval_get_double(zv));
1119 opline->op2.constant = zend_optimizer_add_literal(op_array, &tmp);
1120 }
1121 } else if (opline->opcode == ZEND_CONCAT) {
1122 if (!(OP1_INFO() & MAY_BE_OBJECT)
1123 && !(OP2_INFO() & MAY_BE_OBJECT)) {
1124 opline->opcode = ZEND_FAST_CONCAT;
1125 }
1126 } else if (opline->opcode == ZEND_VERIFY_RETURN_TYPE
1127 && opline->op1_type != IS_CONST
1128 && ssa->ops[op_1].op1_def == v
1129 && ssa->ops[op_1].op1_use >= 0
1130 && ssa->ops[op_1].op1_use_chain == -1
1131 && ssa->vars[v].use_chain >= 0
1132 && can_elide_return_type_check(op_array, ssa, &ssa->ops[op_1])) {
1133
1134 // op_1: VERIFY_RETURN_TYPE #orig_var.? [T] -> #v.? [T] => NOP
1135
1136 int orig_var = ssa->ops[op_1].op1_use;
1137 if (zend_ssa_unlink_use_chain(ssa, op_1, orig_var)) {
1138
1139 int ret = ssa->vars[v].use_chain;
1140
1141 ssa->ops[ret].op1_use = orig_var;
1142 ssa->ops[ret].op1_use_chain = ssa->vars[orig_var].use_chain;
1143 ssa->vars[orig_var].use_chain = ret;
1144
1145 ssa->vars[v].definition = -1;
1146 ssa->vars[v].use_chain = -1;
1147
1148 ssa->ops[op_1].op1_def = -1;
1149 ssa->ops[op_1].op1_use = -1;
1150
1151 MAKE_NOP(opline);
1152 remove_nops = 1;
1153 }
1154 }
1155 }
1156
1157 if (ssa->vars[v].var >= op_array->last_var) {
1158 /* skip TMP and VAR */
1159 continue;
1160 }
1161
1162 if (opline->opcode == ZEND_ASSIGN
1163 && ssa->ops[op_1].op1_def == v
1164 && !RETURN_VALUE_USED(opline)
1165 ) {
1166 int orig_var = ssa->ops[op_1].op1_use;
1167
1168 if (orig_var >= 0
1169 && !(ssa->var_info[orig_var].type & (MAY_BE_STRING|MAY_BE_ARRAY|MAY_BE_OBJECT|MAY_BE_RESOURCE|MAY_BE_REF))
1170 ) {
1171
1172 int src_var = ssa->ops[op_1].op2_use;
1173
1174 if ((opline->op2_type & (IS_TMP_VAR|IS_VAR))
1175 && src_var >= 0
1176 && !(ssa->var_info[src_var].type & MAY_BE_REF)
1177 && ssa->vars[src_var].definition >= 0
1178 && ssa->ops[ssa->vars[src_var].definition].result_def == src_var
1179 && ssa->ops[ssa->vars[src_var].definition].result_use < 0
1180 && ssa->vars[src_var].use_chain == op_1
1181 && ssa->ops[op_1].op2_use_chain < 0
1182 && !ssa->vars[src_var].phi_use_chain
1183 && !ssa->vars[src_var].sym_use_chain
1184 && opline_supports_assign_contraction(
1185 ssa, &op_array->opcodes[ssa->vars[src_var].definition],
1186 src_var, opline->op1.var)
1187 ) {
1188
1189 int op_2 = ssa->vars[src_var].definition;
1190
1191 // op_2: #src_var.T = OP ... => #v.CV = OP ...
1192 // op_1: ASSIGN #orig_var.CV [undef,scalar] -> #v.CV, #src_var.T NOP
1193
1194 if (zend_ssa_unlink_use_chain(ssa, op_1, orig_var)) {
1195 /* Reconstruct SSA */
1196 ssa->vars[v].definition = op_2;
1197 ssa->ops[op_2].result_def = v;
1198
1199 ssa->vars[src_var].definition = -1;
1200 ssa->vars[src_var].use_chain = -1;
1201
1202 ssa->ops[op_1].op1_use = -1;
1203 ssa->ops[op_1].op2_use = -1;
1204 ssa->ops[op_1].op1_def = -1;
1205 ssa->ops[op_1].op1_use_chain = -1;
1206
1207 /* Update opcodes */
1208 op_array->opcodes[op_2].result_type = opline->op1_type;
1209 op_array->opcodes[op_2].result.var = opline->op1.var;
1210 MAKE_NOP(opline);
1211 remove_nops = 1;
1212 }
1213 } else if (opline->op2_type == IS_CONST
1214 || ((opline->op2_type & (IS_TMP_VAR|IS_VAR|IS_CV))
1215 && ssa->ops[op_1].op2_use >= 0
1216 && ssa->ops[op_1].op2_def < 0)
1217 ) {
1218
1219 // op_1: ASSIGN #orig_var.CV [undef,scalar] -> #v.CV, CONST|TMPVAR => QM_ASSIGN v.CV, CONST|TMPVAR
1220
1221 if (ssa->ops[op_1].op1_use != ssa->ops[op_1].op2_use) {
1222 zend_ssa_unlink_use_chain(ssa, op_1, orig_var);
1223 } else {
1224 ssa->ops[op_1].op2_use_chain = ssa->ops[op_1].op1_use_chain;
1225 }
1226
1227 /* Reconstruct SSA */
1228 ssa->ops[op_1].result_def = v;
1229 ssa->ops[op_1].op1_def = -1;
1230 ssa->ops[op_1].op1_use = ssa->ops[op_1].op2_use;
1231 ssa->ops[op_1].op1_use_chain = ssa->ops[op_1].op2_use_chain;
1232 ssa->ops[op_1].op2_use = -1;
1233 ssa->ops[op_1].op2_use_chain = -1;
1234
1235 /* Update opcode */
1236 opline->result_type = opline->op1_type;
1237 opline->result.var = opline->op1.var;
1238 opline->op1_type = opline->op2_type;
1239 opline->op1.var = opline->op2.var;
1240 opline->op2_type = IS_UNUSED;
1241 opline->op2.var = 0;
1242 opline->opcode = ZEND_QM_ASSIGN;
1243 }
1244 }
1245
1246 } else if (opline->opcode == ZEND_ASSIGN_OP
1247 && opline->extended_value == ZEND_ADD
1248 && ssa->ops[op_1].op1_def == v
1249 && opline->op2_type == IS_CONST
1250 && Z_TYPE_P(CT_CONSTANT_EX(op_array, opline->op2.constant)) == IS_LONG
1251 && Z_LVAL_P(CT_CONSTANT_EX(op_array, opline->op2.constant)) == 1
1252 && ssa->ops[op_1].op1_use >= 0
1253 && !(ssa->var_info[ssa->ops[op_1].op1_use].type & (MAY_BE_FALSE|MAY_BE_TRUE|MAY_BE_STRING|MAY_BE_ARRAY|MAY_BE_OBJECT|MAY_BE_RESOURCE|MAY_BE_REF))) {
1254
1255 // op_1: ASSIGN_ADD #?.CV [undef,null,int,foat] ->#v.CV, int(1) => PRE_INC #?.CV ->#v.CV
1256
1257 opline->opcode = ZEND_PRE_INC;
1258 opline->extended_value = 0;
1259 SET_UNUSED(opline->op2);
1260
1261 } else if (opline->opcode == ZEND_ASSIGN_OP
1262 && opline->extended_value == ZEND_SUB
1263 && ssa->ops[op_1].op1_def == v
1264 && opline->op2_type == IS_CONST
1265 && Z_TYPE_P(CT_CONSTANT_EX(op_array, opline->op2.constant)) == IS_LONG
1266 && Z_LVAL_P(CT_CONSTANT_EX(op_array, opline->op2.constant)) == 1
1267 && ssa->ops[op_1].op1_use >= 0
1268 && !(ssa->var_info[ssa->ops[op_1].op1_use].type & (MAY_BE_FALSE|MAY_BE_TRUE|MAY_BE_STRING|MAY_BE_ARRAY|MAY_BE_OBJECT|MAY_BE_RESOURCE|MAY_BE_REF))) {
1269
1270 // op_1: ASSIGN_SUB #?.CV [undef,null,int,foat] -> #v.CV, int(1) => PRE_DEC #?.CV ->#v.CV
1271
1272 opline->opcode = ZEND_PRE_DEC;
1273 opline->extended_value = 0;
1274 SET_UNUSED(opline->op2);
1275
1276 } else if (ssa->ops[op_1].op1_def == v
1277 && !RETURN_VALUE_USED(opline)
1278 && ssa->ops[op_1].op1_use >= 0
1279 && !(ssa->var_info[ssa->ops[op_1].op1_use].type & (MAY_BE_STRING|MAY_BE_ARRAY|MAY_BE_OBJECT|MAY_BE_RESOURCE|MAY_BE_REF))
1280 && opline->opcode == ZEND_ASSIGN_OP
1281 && opline->extended_value != ZEND_CONCAT) {
1282
1283 // op_1: ASSIGN_OP #orig_var.CV [undef,null,bool,int,double] -> #v.CV, ? => #v.CV = ADD #orig_var.CV, ?
1284
1285 /* Reconstruct SSA */
1286 ssa->ops[op_1].result_def = ssa->ops[op_1].op1_def;
1287 ssa->ops[op_1].op1_def = -1;
1288
1289 /* Update opcode */
1290 opline->opcode = opline->extended_value;
1291 opline->extended_value = 0;
1292 opline->result_type = opline->op1_type;
1293 opline->result.var = opline->op1.var;
1294
1295 }
1296 }
1297
1298 #if ZEND_DEBUG_DFA
1299 ssa_verify_integrity(op_array, ssa, "after dfa");
1300 #endif
1301
1302 if (remove_nops) {
1303 zend_ssa_remove_nops(op_array, ssa, ctx);
1304 #if ZEND_DEBUG_DFA
1305 ssa_verify_integrity(op_array, ssa, "after nop");
1306 #endif
1307 }
1308 }
1309
1310 if (ctx->debug_level & ZEND_DUMP_AFTER_DFA_PASS) {
1311 zend_dump_op_array(op_array, ZEND_DUMP_SSA, "after dfa pass", ssa);
1312 }
1313 }
1314
zend_optimize_dfa(zend_op_array * op_array,zend_optimizer_ctx * ctx)1315 void zend_optimize_dfa(zend_op_array *op_array, zend_optimizer_ctx *ctx)
1316 {
1317 void *checkpoint = zend_arena_checkpoint(ctx->arena);
1318 zend_ssa ssa;
1319
1320 if (zend_dfa_analyze_op_array(op_array, ctx, &ssa) != SUCCESS) {
1321 zend_arena_release(&ctx->arena, checkpoint);
1322 return;
1323 }
1324
1325 zend_dfa_optimize_op_array(op_array, ctx, &ssa, NULL);
1326
1327 /* Destroy SSA */
1328 zend_arena_release(&ctx->arena, checkpoint);
1329 }
1330
