xref: /PHP-5.6/ext/opcache/Optimizer/pass3.c (revision 3fff53fc) 
1 /* pass 3:
2  * - optimize $i = $i+expr to $i+=expr
3  * - optimize series of JMPs
4  * - change $i++ to ++$i where possible
5  */
6 
7 /* compares opcodes with allowing oc1 be _EX of oc2 */
8 #define SAME_OPCODE_EX(oc1, oc2) ((oc1 == oc2) || (oc1 == ZEND_JMPZ_EX && oc2 == ZEND_JMPZ) || (oc1 == ZEND_JMPNZ_EX && oc2 == ZEND_JMPNZ))
9 
10 /* we use "jmp_hitlist" to avoid infinity loops during jmp optimization */
11 #define CHECK_JMP(target, label) 			\
12 	for (i=0; i<jmp_hitlist_count; i++) {	\
13 		if (jmp_hitlist[i] == ZEND_OP1(&op_array->opcodes[target]).opline_num) {		\
14 			goto label;						\
15 		}									\
16 	}										\
17 	jmp_hitlist[jmp_hitlist_count++] = ZEND_OP1(&op_array->opcodes[target]).opline_num;
18 
19 #define CHECK_JMP2(target, label) 			\
20 	for (i=0; i<jmp_hitlist_count; i++) {	\
21 		if (jmp_hitlist[i] == ZEND_OP2(&op_array->opcodes[target]).opline_num) {		\
22 			goto label;						\
23 		}									\
24 	}										\
25 	jmp_hitlist[jmp_hitlist_count++] = ZEND_OP2(&op_array->opcodes[target]).opline_num;
26 
27 if (ZEND_OPTIMIZER_PASS_3 & OPTIMIZATION_LEVEL) {
28 	zend_op *opline;
29 	zend_op *end = op_array->opcodes + op_array->last;
30 	zend_uint *jmp_hitlist;
31 	int jmp_hitlist_count;
32 	int i;
33 	zend_uint opline_num = 0;
34 	ALLOCA_FLAG(use_heap);
35 
36 	jmp_hitlist = (zend_uint *)DO_ALLOCA(sizeof(zend_uint)*op_array->last);
37 	opline = op_array->opcodes;
38 
39 	while (opline < end) {
40 		jmp_hitlist_count = 0;
41 
42 		switch (opline->opcode) {
43 			case ZEND_ADD:
44 			case ZEND_SUB:
45 			case ZEND_MUL:
46 			case ZEND_DIV:
47 			case ZEND_MOD:
48 #if ZEND_EXTENSION_API_NO >= PHP_5_6_X_API_NO
49 			case ZEND_POW:
50 #endif
51 			case ZEND_CONCAT:
52 			case ZEND_SL:
53 			case ZEND_SR:
54 			case ZEND_BW_OR:
55 			case ZEND_BW_AND:
56 			case ZEND_BW_XOR:
57 				{
58 					zend_op *next_opline = opline + 1;
59 
60 					while (next_opline < end && next_opline->opcode == ZEND_NOP) {
61 						++next_opline;
62 					}
63 
64 					if (next_opline >= end || next_opline->opcode != ZEND_ASSIGN) {
65 						break;
66 					}
67 
68 					if ((ZEND_OP2_TYPE(opline) == IS_VAR || ZEND_OP2_TYPE(opline) == IS_CV)
69 						&& ZEND_OP2(opline).var == ZEND_OP1(next_opline).var &&
70 						(opline->opcode == ZEND_ADD ||
71 						 opline->opcode == ZEND_MUL ||
72 						 opline->opcode == ZEND_BW_OR ||
73 						 opline->opcode == ZEND_BW_AND ||
74 						 opline->opcode == ZEND_BW_XOR)) {
75 						/* change $i=expr+$i to $i=$i+expr so that the next
76 						* optimization works on it
77 						*/
78 #if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
79 						zend_uchar tmp_type = opline->op1_type;
80 						znode_op tmp = opline->op1;
81 #else
82 						znode tmp = opline->op1;
83 #endif
84 
85 						if (opline->opcode != ZEND_ADD || ZEND_OP1_TYPE(opline) == IS_CONST) {
86 							/* protection from array add: $a = array + $a is not commutative! */
87 							COPY_NODE(opline->op1, opline->op2);
88 							COPY_NODE(opline->op2, tmp);
89 						}
90 					}
91 					if ((ZEND_OP1_TYPE(opline) == IS_VAR || ZEND_OP1_TYPE(opline) == IS_CV)
92 						&& ZEND_OP1(opline).var == ZEND_OP1(next_opline).var
93 						&& ZEND_OP1_TYPE(opline) == ZEND_OP1_TYPE(next_opline)) {
94 						switch (opline->opcode) {
95 							case ZEND_ADD:
96 								opline->opcode = ZEND_ASSIGN_ADD;
97 								break;
98 							case ZEND_SUB:
99 								opline->opcode = ZEND_ASSIGN_SUB;
100 								break;
101 							case ZEND_MUL:
102 								opline->opcode = ZEND_ASSIGN_MUL;
103 								break;
104 							case ZEND_DIV:
105 								opline->opcode = ZEND_ASSIGN_DIV;
106 								break;
107 							case ZEND_MOD:
108 								opline->opcode = ZEND_ASSIGN_MOD;
109 								break;
110 #if ZEND_EXTENSION_API_NO >= PHP_5_6_X_API_NO
111 							case ZEND_POW:
112 								opline->opcode = ZEND_ASSIGN_POW;
113 								break;
114 #endif
115 							case ZEND_CONCAT:
116 								opline->opcode = ZEND_ASSIGN_CONCAT;
117 								break;
118 							case ZEND_SL:
119 								opline->opcode = ZEND_ASSIGN_SL;
120 								break;
121 							case ZEND_SR:
122 								opline->opcode = ZEND_ASSIGN_SR;
123 								break;
124 							case ZEND_BW_OR:
125 								opline->opcode = ZEND_ASSIGN_BW_OR;
126 								break;
127 							case ZEND_BW_AND:
128 								opline->opcode = ZEND_ASSIGN_BW_AND;
129 								break;
130 							case ZEND_BW_XOR:
131 								opline->opcode = ZEND_ASSIGN_BW_XOR;
132 								break;
133 						}
134 						COPY_NODE(opline->result, next_opline->result);
135 						MAKE_NOP(next_opline);
136 						opline++;
137 						opline_num++;
138 					}
139 				}
140 				break;
141 
142 			case ZEND_JMP:
143 #if ZEND_EXTENSION_API_NO > PHP_5_4_X_API_NO
144 				if (op_array->has_finally_block) {
145 					break;
146 				}
147 #endif
148 
149 				/* convert L: JMP L+1 to NOP */
150 				if (ZEND_OP1(opline).opline_num == opline_num + 1) {
151 					MAKE_NOP(opline);
152 					goto done_jmp_optimization;
153 				}
154 
155 				/* convert JMP L1 ... L1: JMP L2 to JMP L2 .. L1: JMP L2 */
156 				while (ZEND_OP1(opline).opline_num < op_array->last
157 						&& op_array->opcodes[ZEND_OP1(opline).opline_num].opcode == ZEND_JMP) {
158 					int target = ZEND_OP1(opline).opline_num;
159 					CHECK_JMP(target, done_jmp_optimization);
160 					ZEND_OP1(opline).opline_num = ZEND_OP1(&op_array->opcodes[target]).opline_num;
161 				}
162 				break;
163 
164 #if ZEND_EXTENSION_API_NO >= PHP_5_3_X_API_NO
165 			case ZEND_JMP_SET:
166 #if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
167 			case ZEND_JMP_SET_VAR:
168 #endif
169 
170 #if ZEND_EXTENSION_API_NO > PHP_5_4_X_API_NO
171 				if (op_array->has_finally_block) {
172 					break;
173 				}
174 #endif
175 
176 				while (ZEND_OP2(opline).opline_num < op_array->last) {
177 					int target = ZEND_OP2(opline).opline_num;
178 					if (op_array->opcodes[target].opcode == ZEND_JMP) {
179 						ZEND_OP2(opline).opline_num = ZEND_OP1(&op_array->opcodes[target]).opline_num;
180 					} else {
181 						break;
182 					}
183 				}
184 				break;
185 #endif
186 
187 			case ZEND_JMPZ:
188 			case ZEND_JMPNZ:
189 #if ZEND_EXTENSION_API_NO > PHP_5_4_X_API_NO
190 				if (op_array->has_finally_block) {
191 					break;
192 				}
193 #endif
194 
195 				/* convert L: JMPZ L+1 to NOP */
196 				if (ZEND_OP2(opline).opline_num == opline_num + 1) {
197 					MAKE_NOP(opline);
198 					goto done_jmp_optimization;
199 				}
200 
201 				while (ZEND_OP2(opline).opline_num < op_array->last) {
202 					int target = ZEND_OP2(opline).opline_num;
203 
204 					if (op_array->opcodes[target].opcode == ZEND_JMP) {
205 						/* plain JMP */
206 						/* JMPZ(X,L1), L1: JMP(L2) => JMPZ(X,L2), L1: JMP(L2) */
207 						CHECK_JMP(target, done_jmp_optimization);
208 						ZEND_OP2(opline).opline_num = ZEND_OP1(&op_array->opcodes[target]).opline_num;
209 					} else if (op_array->opcodes[target].opcode == opline->opcode &&
210 					           SAME_VAR(opline->op1, op_array->opcodes[target].op1)) {
211 						/* same opcode and same var as this opcode */
212 						/* JMPZ(X,L1), L1: JMPZ(X,L2) => JMPZ(X,L2), L1: JMPZ(X,L2) */
213 						CHECK_JMP2(target, done_jmp_optimization);
214 						ZEND_OP2(opline).opline_num = ZEND_OP2(&op_array->opcodes[target]).opline_num;
215 					} else if (op_array->opcodes[target].opcode == opline->opcode + 3 &&
216 					           SAME_VAR(opline->op1, op_array->opcodes[target].op1)) {
217 						/* convert JMPZ(X,L1), L1: T JMPZ_EX(X,L2) to
218 						   T = JMPZ_EX(X, L2) */
219 						ZEND_OP2(opline).opline_num = ZEND_OP2(&op_array->opcodes[target]).opline_num;opline->opcode += 3;
220 						COPY_NODE(opline->result, op_array->opcodes[target].result);
221 						break;
222 					} else if (op_array->opcodes[target].opcode == INV_COND(opline->opcode) &&
223 					           SAME_VAR(opline->op1, op_array->opcodes[target].op1)) {
224 						/* convert JMPZ(X,L1), L1: JMPNZ(X,L2) to
225 						   JMPZ(X,L1+1) */
226 						ZEND_OP2(opline).opline_num = target + 1;
227 						break;
228 					} else if (op_array->opcodes[target].opcode == INV_COND_EX(opline->opcode) &&
229 					           SAME_VAR(opline->op1, op_array->opcodes[target].op1)) {
230 						/* convert JMPZ(X,L1), L1: T = JMPNZ_EX(X,L2) to
231 						   T = JMPZ_EX(X,L1+1) */
232 						ZEND_OP2(opline).opline_num = target + 1;
233 						opline->opcode += 3;
234 						COPY_NODE(opline->result, op_array->opcodes[target].result);
235 						break;
236 					} else {
237 						break;
238 					}
239 				}
240 				break;
241 
242 			case ZEND_JMPZ_EX:
243 			case ZEND_JMPNZ_EX: {
244 #if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
245 					zend_uchar T_type = opline->result_type;
246 					znode_op T = opline->result;
247 #else
248 					znode T = opline->result;
249 #endif
250 #if ZEND_EXTENSION_API_NO > PHP_5_4_X_API_NO
251 					if (op_array->has_finally_block) {
252 						break;
253 					}
254 #endif
255 					/* convert L: T = JMPZ_EX X,L+1 to T = BOOL(X) */
256 					/* convert L: T = JMPZ_EX T,L+1 to NOP */
257 					if (ZEND_OP2(opline).opline_num == opline_num + 1) {
258 						if (ZEND_OP1(opline).var == ZEND_RESULT(opline).var) {
259 							MAKE_NOP(opline);
260 						} else {
261 							opline->opcode = ZEND_BOOL;
262 							SET_UNUSED(opline->op2);
263 						}
264 						goto done_jmp_optimization;
265 					}
266 
267 					while (ZEND_OP2(opline).opline_num < op_array->last) {
268 						int target = ZEND_OP2(opline).opline_num;
269 						if (SAME_OPCODE_EX(opline->opcode, op_array->opcodes[target].opcode) &&
270 							SAME_VAR(op_array->opcodes[target].op1, T)) {
271 							/* Check for JMPZ_EX to JMPZ[_EX] with the same condition, either with _EX or not */
272 							if (op_array->opcodes[target].opcode == opline->opcode) {
273 								/* change T only if we have _EX opcode there */
274 								COPY_NODE(T, op_array->opcodes[target].result);
275 							}
276 							CHECK_JMP2(target, continue_jmp_ex_optimization);
277 							ZEND_OP2(opline).opline_num = ZEND_OP2(&op_array->opcodes[target]).opline_num;
278 						} else if (op_array->opcodes[target].opcode == ZEND_JMPZNZ &&
279 								  SAME_VAR(op_array->opcodes[target].op1, T)) {
280 							/* Check for JMPZNZ with same cond variable */
281 							int new_target;
282 							CHECK_JMP2(target, continue_jmp_ex_optimization);
283 							if (opline->opcode == ZEND_JMPZ_EX) {
284 								new_target = ZEND_OP2(&op_array->opcodes[target]).opline_num;
285 							} else {
286 								/* JMPNZ_EX */
287 								new_target = op_array->opcodes[target].extended_value;
288 							}
289 							ZEND_OP2(opline).opline_num = new_target;
290 						} else if ((op_array->opcodes[target].opcode == INV_EX_COND_EX(opline->opcode) ||
291 									op_array->opcodes[target].opcode == INV_EX_COND(opline->opcode)) &&
292 									SAME_VAR(opline->op1, op_array->opcodes[target].op1)) {
293 						   /* convert JMPZ_EX(X,L1), L1: JMPNZ_EX(X,L2) to
294 							  JMPZ_EX(X,L1+1) */
295 						   ZEND_OP2(opline).opline_num = target + 1;
296 						   break;
297 						} else {
298 							break;
299 						}
300 					} /* while */
301 continue_jmp_ex_optimization:
302 					break;
303 #if 0
304 					/* If Ti = JMPZ_EX(X, L) and Ti is not used, convert to JMPZ(X, L) */
305 					{
306 						zend_op *op;
307 						for(op = opline+1; op<end; op++) {
308 							if(ZEND_RESULT_TYPE(op) == IS_TMP_VAR &&
309 							   ZEND_RESULT(op).var == ZEND_RESULT(opline).var) {
310 								break; /* can pass to part 2 */
311 							}
312 
313 							if(op->opcode == ZEND_JMP ||
314 							   op->opcode == ZEND_JMPZ ||
315 							   op->opcode == ZEND_JMPZ_EX ||
316 							   op->opcode == ZEND_JMPNZ ||
317 							   op->opcode == ZEND_JMPNZ_EX ||
318 							   op->opcode == ZEND_JMPZNZ ||
319 							   op->opcode == ZEND_BRK ||
320 							   op->opcode == ZEND_CONT ||
321 							   op->opcode == ZEND_CASE ||
322 							   op->opcode == ZEND_RETURN ||
323 #if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
324 							   op->opcode == ZEND_RETURN_BY_REF ||
325 #endif
326 #if ZEND_EXTENSION_API_NO > PHP_5_4_X_API_NO
327 							   op->opcode == ZEND_FAST_RET ||
328 #endif
329 							   op->opcode == ZEND_FE_FETCH ||
330 							   op->opcode == ZEND_EXIT) {
331 								break;
332 							}
333 
334 							if(ZEND_OP1_TYPE(op) == IS_TMP_VAR &&
335 							   ZEND_OP1(op).var == ZEND_RESULT(opline).var) {
336 								goto done_jmp_optimization;
337 							}
338 
339 							if(ZEND_OP2_TYPE(op) == IS_TMP_VAR &&
340 							   ZEND_OP2(op).var == ZEND_RESULT(opline).var) {
341 								goto done_jmp_optimization;
342 							}
343 						} /* for */
344 
345 						for(op = &op_array->opcodes[ZEND_OP2(opline).opline_num]; op<end; op++) {
346 
347 							if(ZEND_RESULT_TYPE(op) == IS_TMP_VAR &&
348 							   ZEND_RESULT(op).var == ZEND_RESULT(opline).var) {
349 								break; /* can pass to optimization */
350 							}
351 
352 							if(op->opcode == ZEND_JMP ||
353 							   op->opcode == ZEND_JMPZ ||
354 							   op->opcode == ZEND_JMPZ_EX ||
355 							   op->opcode == ZEND_JMPNZ ||
356 							   op->opcode == ZEND_JMPNZ_EX ||
357 							   op->opcode == ZEND_JMPZNZ ||
358 							   op->opcode == ZEND_BRK ||
359 							   op->opcode == ZEND_CONT ||
360 							   op->opcode == ZEND_CASE ||
361 							   op->opcode == ZEND_RETURN ||
362 #if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
363 							   op->opcode == ZEND_RETURN_BY_REF ||
364 #endif
365 #if ZEND_EXTENSION_API_NO > PHP_5_4_X_API_NO
366 							   op->opcode == ZEND_FAST_RET ||
367 #endif
368 							   op->opcode == ZEND_FE_FETCH ||
369 							   op->opcode == ZEND_EXIT) {
370 								break;
371 							}
372 
373 							if(ZEND_OP1_TYPE(op) == IS_TMP_VAR &&
374 							   ZEND_OP1(op).var == ZEND_RESULT(opline).var) {
375 								goto done_jmp_optimization;
376 							}
377 
378 							if(ZEND_OP2_TYPE(op) == IS_TMP_VAR &&
379 							   ZEND_OP2(op).var == ZEND_RESULT(opline).var) {
380 								goto done_jmp_optimization;
381 							}
382 						}
383 
384 						opline->opcode = opline->opcode-3; /* JMP_EX -> JMP */
385 						SET_UNUSED(opline->result);
386 						break;
387 					}
388 #endif
389 				}
390 				break;
391 
392 			case ZEND_JMPZNZ:
393 #if ZEND_EXTENSION_API_NO > PHP_5_4_X_API_NO
394 				if (op_array->has_finally_block) {
395 					break;
396 				}
397 #endif
398 				/* JMPZNZ(X,L1,L2), L1: JMP(L3) => JMPZNZ(X,L3,L2), L1: JMP(L3) */
399 				while (ZEND_OP2(opline).opline_num < op_array->last
400 						&& op_array->opcodes[ZEND_OP2(opline).opline_num].opcode == ZEND_JMP) {
401 					int target = ZEND_OP2(opline).opline_num;
402 					CHECK_JMP(target, continue_jmpznz_optimization);
403 					ZEND_OP2(opline).opline_num = ZEND_OP1(&op_array->opcodes[target]).opline_num;
404 				}
405 continue_jmpznz_optimization:
406 				/* JMPZNZ(X,L1,L2), L2: JMP(L3) => JMPZNZ(X,L1,L3), L2: JMP(L3) */
407 				while (opline->extended_value < op_array->last
408 						&& op_array->opcodes[opline->extended_value].opcode == ZEND_JMP) {
409 					int target = opline->extended_value;
410 					CHECK_JMP(target, done_jmp_optimization);
411 					opline->extended_value = ZEND_OP1(&op_array->opcodes[target]).opline_num;
412 				}
413 				break;
414 
415 			case ZEND_POST_INC:
416 			case ZEND_POST_DEC: {
417 					/* POST_INC, FREE => PRE_INC */
418 					zend_op *next_op = opline + 1;
419 
420 					if (next_op >= end) {
421 						break;
422 					}
423 					if (next_op->opcode == ZEND_FREE &&
424 						ZEND_OP1(next_op).var == ZEND_RESULT(opline).var) {
425 						MAKE_NOP(next_op);
426 						switch (opline->opcode) {
427 							case ZEND_POST_INC:
428 								opline->opcode = ZEND_PRE_INC;
429 								break;
430 							case ZEND_POST_DEC:
431 								opline->opcode = ZEND_PRE_DEC;
432 								break;
433 						}
434 #if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
435 						ZEND_RESULT_TYPE(opline) = IS_VAR | EXT_TYPE_UNUSED;
436 #else
437 						ZEND_RESULT_TYPE(opline) = IS_VAR;
438 						ZEND_RESULT(opline).EA.type = 0;
439 						ZEND_RESULT(opline).EA.type |= EXT_TYPE_UNUSED;
440 #endif
441 					}
442 				}
443 				break;
444 		}
445 done_jmp_optimization:
446 		opline++;
447 		opline_num++;
448 	}
449 	FREE_ALLOCA(jmp_hitlist);
450 }
451