/src/php-src/Zend/Optimizer/pass3.c

Source
/*
   +----------------------------------------------------------------------+
   | Zend OPcache                                                         |
   +----------------------------------------------------------------------+
   | Copyright © The PHP Group and Contributors.                          |
   +----------------------------------------------------------------------+
   | This source file is subject to the Modified BSD License that is      |
   | bundled with this package in the file LICENSE, and is available      |
   | through the World Wide Web at <https://www.php.net/license/>.        |
   |                                                                      |
   | SPDX-License-Identifier: BSD-3-Clause                                |
   +----------------------------------------------------------------------+
   | Authors: Andi Gutmans <andi@php.net>                                 |
   |          Zeev Suraski <zeev@php.net>                                 |
   |          Stanislav Malyshev <stas@zend.com>                          |
   |          Dmitry Stogov <dmitry@php.net>                              |
   +----------------------------------------------------------------------+
*/

/* pass 3: (Jump optimization)
 * - optimize series of JMPs
 */

#include "Optimizer/zend_optimizer.h"
#include "Optimizer/zend_optimizer_internal.h"
#include "zend_API.h"
#include "zend_constants.h"
#include "zend_execute.h"
#include "zend_vm.h"

/* we use "jmp_hitlist" to avoid infinity loops during jmp optimization */
static zend_always_inline bool in_hitlist(const zend_op *target, zend_op **jmp_hitlist, int jmp_hitlist_count)
{
  int i;

  for (i = 0; i < jmp_hitlist_count; i++) {
    if (jmp_hitlist[i] == target) {
      return true;
    }
  }
  return false;
}

#define CHECK_LOOP(target) \
  if (EXPECTED(!in_hitlist(target, jmp_hitlist, jmp_hitlist_count))) { \
    jmp_hitlist[jmp_hitlist_count++] = target;  \
  } else { \
    break; \
  }

void zend_optimizer_pass3(zend_op_array *op_array, zend_optimizer_ctx *ctx)
{
  zend_op *opline;
  zend_op *target;
  zend_op **jmp_hitlist;
  int jmp_hitlist_count;
  ALLOCA_FLAG(use_heap);

  jmp_hitlist = (zend_op**)do_alloca(sizeof(zend_op*)*op_array->last, use_heap);
  opline = op_array->opcodes;
  const zend_op *end =  opline + op_array->last;

  while (opline < end) {

    switch (opline->opcode) {
      case ZEND_JMP:
        jmp_hitlist_count = 0;

        target = ZEND_OP1_JMP_ADDR(opline);
        while (1) {
          if (target->opcode == ZEND_JMP) {
            /* convert JMP L1 ... L1: JMP L2 to JMP L2 .. L1: JMP L2 */
            target = ZEND_OP1_JMP_ADDR(target);
            CHECK_LOOP(target);
          } else if (target->opcode == ZEND_NOP) {
            target = target + 1;
          } else {
            break;
          }
          ZEND_SET_OP_JMP_ADDR(opline, opline->op1, target);
        }

        if (target == opline + 1) {
          /* convert L: JMP L+1 to NOP */
          MAKE_NOP(opline);
        } else if ((target->opcode == ZEND_RETURN ||
                    target->opcode == ZEND_RETURN_BY_REF ||
                    target->opcode == ZEND_GENERATOR_RETURN) &&
                   !(op_array->fn_flags & ZEND_ACC_HAS_FINALLY_BLOCK)) {
          /* JMP L, L: RETURN to immediate RETURN */
          *opline = *target;
          if (opline->op1_type == IS_CONST) {
            zval zv;
            ZVAL_COPY(&zv, &ZEND_OP1_LITERAL(opline));
            opline->op1.constant = zend_optimizer_add_literal(op_array, &zv);
          }
        } else if (opline > op_array->opcodes &&
                   ((opline-1)->opcode == ZEND_JMPZ ||
                    (opline-1)->opcode == ZEND_JMPNZ)) {
            if (ZEND_OP2_JMP_ADDR(opline-1) == target) {
            /* JMPZ(X,L1), JMP(L1) -> NOP, JMP(L1) */
            zend_optimizer_convert_to_free_op1(op_array, opline - 1);
            }
        }
        break;

      case ZEND_JMP_SET:
      case ZEND_COALESCE:
        jmp_hitlist_count = 0;

        target = ZEND_OP2_JMP_ADDR(opline);
        while (1) {
          if (target->opcode == ZEND_JMP) {
            target = ZEND_OP1_JMP_ADDR(target);
            CHECK_LOOP(target);
          } else if (target->opcode == ZEND_NOP) {
            target = target + 1;
          } else {
            break;
          }
          ZEND_SET_OP_JMP_ADDR(opline, opline->op2, target);
        }
        break;

      case ZEND_JMPZ:
      case ZEND_JMPNZ:
        jmp_hitlist_count = 0;

        target = ZEND_OP2_JMP_ADDR(opline);
        while (1) {
          if (target->opcode == ZEND_JMP) {
            /* plain JMP */
            /* JMPZ(X,L1), L1: JMP(L2) => JMPZ(X,L2), L1: JMP(L2) */
            target = ZEND_OP1_JMP_ADDR(target);
            CHECK_LOOP(target);
          } else if (target->opcode == opline->opcode &&
                     SAME_VAR(opline->op1, target->op1)) {
            /* same opcode and same var as this opcode */
            /* JMPZ(X,L1), L1: JMPZ(X,L2) => JMPZ(X,L2), L1: JMPZ(X,L2) */
            target = ZEND_OP2_JMP_ADDR(target);
            CHECK_LOOP(target);
          } else if (target->opcode == INV_COND(opline->opcode) &&
                     SAME_VAR(opline->op1, target->op1)) {
            /* convert JMPZ(X,L1), L1: JMPNZ(X,L2) to
               JMPZ(X,L1+1) */
            target = target + 1;
          } else if (target->opcode == ZEND_NOP) {
            target = target + 1;
          } else {
            break;
          }
          ZEND_SET_OP_JMP_ADDR(opline, opline->op2, target);
        }

        /* convert L: JMPZ L+1 to NOP */
        if (target == opline + 1) {
          zend_optimizer_convert_to_free_op1(op_array, opline);
        }
        break;

      case ZEND_JMPZ_EX:
      case ZEND_JMPNZ_EX:
        jmp_hitlist_count = 0;

        target = ZEND_OP2_JMP_ADDR(opline);
        while (1) {
          if (target->opcode == ZEND_JMP) {
            /* plain JMP */
            /* JMPZ_EX(X,L1), L1: JMP(L2) => JMPZ_EX(X,L2), L1: JMP(L2) */
            target = ZEND_OP1_JMP_ADDR(target);
            CHECK_LOOP(target);
          } else if (target->opcode == opline->opcode-3 &&
                     (SAME_VAR(target->op1, opline->result) ||
                      SAME_VAR(target->op1, opline->op1))) {
            /* convert T=JMPZ_EX(X,L1), L1: JMPZ(T,L2) to
               JMPZ_EX(X,L2) */
            target = ZEND_OP2_JMP_ADDR(target);
            CHECK_LOOP(target);
          } else if (target->opcode == opline->opcode &&
                     target->result.var == opline->result.var &&
                     (SAME_VAR(target->op1, opline->result) ||
                      SAME_VAR(target->op1, opline->op1))) {
            /* convert T=JMPZ_EX(X,L1), L1: T=JMPZ_EX(T,L2) to
               JMPZ_EX(X,L2) */
            target = ZEND_OP2_JMP_ADDR(target);
            CHECK_LOOP(target);
          } else if (target->opcode == INV_EX_COND(opline->opcode) &&
                     (SAME_VAR(target->op1, opline->result) ||
                      SAME_VAR(target->op1, opline->op1))) {
             /* convert T=JMPZ_EX(X,L1), L1: JMPNZ(T,L2) to
              JMPZ_EX(X,L1+1) */
            target = target + 1;
          } else if (target->opcode == INV_EX_COND_EX(opline->opcode) &&
                     target->result.var == opline->result.var &&
                     (SAME_VAR(target->op1, opline->result) ||
                      SAME_VAR(target->op1, opline->op1))) {
             /* convert T=JMPZ_EX(X,L1), L1: T=JMPNZ_EX(T,L2) to
              JMPZ_EX(X,L1+1) */
            target = target + 1;
          } else if (target->opcode == ZEND_BOOL &&
                     (SAME_VAR(target->op1, opline->result) ||
                      SAME_VAR(target->op1, opline->op1))) {
            /* convert Y = JMPZ_EX(X,L1), L1: Z = BOOL(Y) to
               Z = JMPZ_EX(X,L1+1) */

            /* NOTE: This optimization pattern is not safe, but works, */
            /*       because result of JMPZ_EX instruction             */
            /*       is not used on the following path and             */
            /*       should be used once on the branch path.           */
            /*                                                         */
            /*       The pattern works well only if jumps processed in */
            /*       direct order, otherwise it breaks JMPZ_EX         */
            /*       sequences too early.                              */
            opline->result.var = target->result.var;
            target = target + 1;
            CHECK_LOOP(target);
          } else if (target->opcode == ZEND_NOP) {
            target = target + 1;
          } else {
            break;
          }
          ZEND_SET_OP_JMP_ADDR(opline, opline->op2, target);
        }

        /* convert L: T = JMPZ_EX X,L+1 to T = BOOL(X) */
        if (target == opline + 1) {
          opline->opcode = ZEND_BOOL;
          opline->op2.num = 0;
        }
        break;
    }
    opline++;
  }
  free_alloca(jmp_hitlist, use_heap);
}

Coverage Report

Created: 2026-10-28 06:20

Line	Count	Source
1		/*
2		+----------------------------------------------------------------------+
3		\| Zend OPcache \|
4		+----------------------------------------------------------------------+
5		\| Copyright © The PHP Group and Contributors. \|
6		+----------------------------------------------------------------------+
7		\| This source file is subject to the Modified BSD License that is \|
8		\| bundled with this package in the file LICENSE, and is available \|
9		\| through the World Wide Web at <https://www.php.net/license/>. \|
10		\| \|
11		\| SPDX-License-Identifier: BSD-3-Clause \|
12		+----------------------------------------------------------------------+
13		\| Authors: Andi Gutmans <andi@php.net> \|
14		\| Zeev Suraski <zeev@php.net> \|
15		\| Stanislav Malyshev <stas@zend.com> \|
16		\| Dmitry Stogov <dmitry@php.net> \|
17		+----------------------------------------------------------------------+
18		*/
19
20		/* pass 3: (Jump optimization)
21		* - optimize series of JMPs
22		*/
23
24		#include "Optimizer/zend_optimizer.h"
25		#include "Optimizer/zend_optimizer_internal.h"
26		#include "zend_API.h"
27		#include "zend_constants.h"
28		#include "zend_execute.h"
29		#include "zend_vm.h"
30
31		/* we use "jmp_hitlist" to avoid infinity loops during jmp optimization */
32		static zend_always_inline bool in_hitlist(const zend_op target, zend_op *jmp_hitlist, int jmp_hitlist_count)
33	2.79k	{
34	2.79k	int i;
35
36	3.75k	for (i = 0; i < jmp_hitlist_count; i++) {
37	1.72k	if (jmp_hitlist[i] == target) {
38	765	return true;
39	765	}
40	1.72k	}
41	2.02k	return false;
42	2.79k	}
43
44		#define CHECK_LOOP(target) \
45	2.79k	if (EXPECTED(!in_hitlist(target, jmp_hitlist, jmp_hitlist_count))) { \
46	2.02k	jmp_hitlist[jmp_hitlist_count++] = target; \
47	2.02k	} else { \
48	765	break; \
49	765	}
50
51		void zend_optimizer_pass3(zend_op_array op_array, zend_optimizer_ctx ctx)
52	25.9k	{
53	25.9k	zend_op *opline;
54	25.9k	zend_op *target;
55	25.9k	zend_op **jmp_hitlist;
56	25.9k	int jmp_hitlist_count;
57	25.9k	ALLOCA_FLAG(use_heap);
58
59	25.9k	jmp_hitlist = (zend_op*)do_alloca(sizeof(zend_op)*op_array->last, use_heap);
60	25.9k	opline = op_array->opcodes;
61	25.9k	const zend_op *end = opline + op_array->last;
62
63	191k	while (opline < end) {
64
65	165k	switch (opline->opcode) {
66	2.95k	case ZEND_JMP:
67	2.95k	jmp_hitlist_count = 0;
68
69	2.95k	target = ZEND_OP1_JMP_ADDR(opline);
70	4.13k	while (1) {
71	4.13k	if (target->opcode == ZEND_JMP) {
72		/* convert JMP L1 ... L1: JMP L2 to JMP L2 .. L1: JMP L2 */
73	1.90k	target = ZEND_OP1_JMP_ADDR(target);
74	1.90k	CHECK_LOOP(target);
75	2.23k	} else if (target->opcode == ZEND_NOP) {
76	17	target = target + 1;
77	2.21k	} else {
78	2.21k	break;
79	2.21k	}
80	1.18k	ZEND_SET_OP_JMP_ADDR(opline, opline->op1, target);
81	1.18k	}
82
83	2.95k	if (target == opline + 1) {
84		/* convert L: JMP L+1 to NOP */
85	1.33k	MAKE_NOP(opline);
86	1.61k	} else if ((target->opcode == ZEND_RETURN \|\|
87	1.59k	target->opcode == ZEND_RETURN_BY_REF \|\|
88	1.59k	target->opcode == ZEND_GENERATOR_RETURN) &&
89	24	!(op_array->fn_flags & ZEND_ACC_HAS_FINALLY_BLOCK)) {
90		/* JMP L, L: RETURN to immediate RETURN */
91	24	opline = target;
92	24	if (opline->op1_type == IS_CONST) {
93	24	zval zv;
94	24	ZVAL_COPY(&zv, &ZEND_OP1_LITERAL(opline));
95	24	opline->op1.constant = zend_optimizer_add_literal(op_array, &zv);
96	24	}
97	1.59k	} else if (opline > op_array->opcodes &&
98	1.39k	((opline-1)->opcode == ZEND_JMPZ \|\|
99	1.38k	(opline-1)->opcode == ZEND_JMPNZ)) {
100	20	if (ZEND_OP2_JMP_ADDR(opline-1) == target) {
101		/* JMPZ(X,L1), JMP(L1) -> NOP, JMP(L1) */
102	0	zend_optimizer_convert_to_free_op1(op_array, opline - 1);
103	0	}
104	20	}
105	2.95k	break;
106
107	249	case ZEND_JMP_SET:
108	957	case ZEND_COALESCE:
109	957	jmp_hitlist_count = 0;
110
111	957	target = ZEND_OP2_JMP_ADDR(opline);
112	957	while (1) {
113	957	if (target->opcode == ZEND_JMP) {
114	0	target = ZEND_OP1_JMP_ADDR(target);
115	0	CHECK_LOOP(target);
116	957	} else if (target->opcode == ZEND_NOP) {
117	0	target = target + 1;
118	957	} else {
119	957	break;
120	957	}
121	0	ZEND_SET_OP_JMP_ADDR(opline, opline->op2, target);
122	0	}
123	957	break;
124
125	243	case ZEND_JMPZ:
126	908	case ZEND_JMPNZ:
127	908	jmp_hitlist_count = 0;
128
129	908	target = ZEND_OP2_JMP_ADDR(opline);
130	933	while (1) {
131	933	if (target->opcode == ZEND_JMP) {
132		/* plain JMP */
133		/* JMPZ(X,L1), L1: JMP(L2) => JMPZ(X,L2), L1: JMP(L2) */
134	4	target = ZEND_OP1_JMP_ADDR(target);
135	4	CHECK_LOOP(target);
136	929	} else if (target->opcode == opline->opcode &&
137	24	SAME_VAR(opline->op1, target->op1)) {
138		/* same opcode and same var as this opcode */
139		/* JMPZ(X,L1), L1: JMPZ(X,L2) => JMPZ(X,L2), L1: JMPZ(X,L2) */
140	24	target = ZEND_OP2_JMP_ADDR(target);
141	24	CHECK_LOOP(target);
142	905	} else if (target->opcode == INV_COND(opline->opcode) &&
143	1	SAME_VAR(opline->op1, target->op1)) {
144		/* convert JMPZ(X,L1), L1: JMPNZ(X,L2) to
145		JMPZ(X,L1+1) */
146	0	target = target + 1;
147	905	} else if (target->opcode == ZEND_NOP) {
148	9	target = target + 1;
149	896	} else {
150	896	break;
151	896	}
152	25	ZEND_SET_OP_JMP_ADDR(opline, opline->op2, target);
153	25	}
154
155		/* convert L: JMPZ L+1 to NOP */
156	908	if (target == opline + 1) {
157	2	zend_optimizer_convert_to_free_op1(op_array, opline);
158	2	}
159	908	break;
160
161	675	case ZEND_JMPZ_EX:
162	797	case ZEND_JMPNZ_EX:
163	797	jmp_hitlist_count = 0;
164
165	797	target = ZEND_OP2_JMP_ADDR(opline);
166	1.66k	while (1) {
167	1.66k	if (target->opcode == ZEND_JMP) {
168		/* plain JMP */
169		/* JMPZ_EX(X,L1), L1: JMP(L2) => JMPZ_EX(X,L2), L1: JMP(L2) */
170	49	target = ZEND_OP1_JMP_ADDR(target);
171	49	CHECK_LOOP(target);
172	1.61k	} else if (target->opcode == opline->opcode-3 &&
173	2	(SAME_VAR(target->op1, opline->result) \|\|
174	2	SAME_VAR(target->op1, opline->op1))) {
175		/* convert T=JMPZ_EX(X,L1), L1: JMPZ(T,L2) to
176		JMPZ_EX(X,L2) */
177	2	target = ZEND_OP2_JMP_ADDR(target);
178	2	CHECK_LOOP(target);
179	1.61k	} else if (target->opcode == opline->opcode &&
180	810	target->result.var == opline->result.var &&
181	810	(SAME_VAR(target->op1, opline->result) \|\|
182	806	SAME_VAR(target->op1, opline->op1))) {
183		/* convert T=JMPZ_EX(X,L1), L1: T=JMPZ_EX(T,L2) to
184		JMPZ_EX(X,L2) */
185	806	target = ZEND_OP2_JMP_ADDR(target);
186	806	CHECK_LOOP(target);
187	807	} else if (target->opcode == INV_EX_COND(opline->opcode) &&
188	4	(SAME_VAR(target->op1, opline->result) \|\|
189	4	SAME_VAR(target->op1, opline->op1))) {
190		/* convert T=JMPZ_EX(X,L1), L1: JMPNZ(T,L2) to
191		JMPZ_EX(X,L1+1) */
192	4	target = target + 1;
193	803	} else if (target->opcode == INV_EX_COND_EX(opline->opcode) &&
194	20	target->result.var == opline->result.var &&
195	20	(SAME_VAR(target->op1, opline->result) \|\|
196	20	SAME_VAR(target->op1, opline->op1))) {
197		/* convert T=JMPZ_EX(X,L1), L1: T=JMPNZ_EX(T,L2) to
198		JMPZ_EX(X,L1+1) */
199	20	target = target + 1;
200	783	} else if (target->opcode == ZEND_BOOL &&
201	18	(SAME_VAR(target->op1, opline->result) \|\|
202	16	SAME_VAR(target->op1, opline->op1))) {
203		/* convert Y = JMPZ_EX(X,L1), L1: Z = BOOL(Y) to
204		Z = JMPZ_EX(X,L1+1) */
205
206		/* NOTE: This optimization pattern is not safe, but works, */
207		/* because result of JMPZ_EX instruction */
208		/* is not used on the following path and */
209		/* should be used once on the branch path. */
210		/* */
211		/* The pattern works well only if jumps processed in */
212		/* direct order, otherwise it breaks JMPZ_EX */
213		/* sequences too early. */
214	2	opline->result.var = target->result.var;
215	2	target = target + 1;
216	2	CHECK_LOOP(target);
217	781	} else if (target->opcode == ZEND_NOP) {
218	0	target = target + 1;
219	781	} else {
220	781	break;
221	781	}
222	867	ZEND_SET_OP_JMP_ADDR(opline, opline->op2, target);
223	867	}
224
225		/* convert L: T = JMPZ_EX X,L+1 to T = BOOL(X) */
226	797	if (target == opline + 1) {
227	0	opline->opcode = ZEND_BOOL;
228	0	opline->op2.num = 0;
229	0	}
230	797	break;
231	165k	}
232	165k	opline++;
233	165k	}
234	25.9k	free_alloca(jmp_hitlist, use_heap);
235	25.9k	}