1 /*
2 +----------------------------------------------------------------------+
3 | Zend OPcache |
4 +----------------------------------------------------------------------+
5 | Copyright (c) 1998-2018 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: Andi Gutmans <andi@zend.com> |
16 | Zeev Suraski <zeev@zend.com> |
17 | Stanislav Malyshev <stas@zend.com> |
18 | Dmitry Stogov <dmitry@zend.com> |
19 +----------------------------------------------------------------------+
20 */
21
22 /* pass 10:
23 * - remove NOPs
24 */
25
26 #include "php.h"
27 #include "Optimizer/zend_optimizer.h"
28 #include "Optimizer/zend_optimizer_internal.h"
29 #include "zend_API.h"
30 #include "zend_constants.h"
31 #include "zend_execute.h"
32 #include "zend_vm.h"
33
zend_optimizer_nop_removal(zend_op_array * op_array)34 void zend_optimizer_nop_removal(zend_op_array *op_array)
35 {
36 zend_op *end, *opline;
37 uint32_t new_count, i, shift;
38 int j;
39 uint32_t *shiftlist;
40 ALLOCA_FLAG(use_heap);
41
42 shiftlist = (uint32_t *)do_alloca(sizeof(uint32_t) * op_array->last, use_heap);
43 i = new_count = shift = 0;
44 end = op_array->opcodes + op_array->last;
45 for (opline = op_array->opcodes; opline < end; opline++) {
46
47 /* Kill JMP-over-NOP-s */
48 if (opline->opcode == ZEND_JMP && ZEND_OP1_JMP_ADDR(opline) > op_array->opcodes + i) {
49 /* check if there are only NOPs under the branch */
50 zend_op *target = ZEND_OP1_JMP_ADDR(opline) - 1;
51
52 while (target->opcode == ZEND_NOP) {
53 target--;
54 }
55 if (target == opline) {
56 /* only NOPs */
57 opline->opcode = ZEND_NOP;
58 }
59 }
60
61 shiftlist[i++] = shift;
62 if (opline->opcode == ZEND_NOP) {
63 shift++;
64 } else {
65 if (shift) {
66 zend_op *new_opline = op_array->opcodes + new_count;
67
68 *new_opline = *opline;
69 switch (new_opline->opcode) {
70 case ZEND_JMP:
71 case ZEND_FAST_CALL:
72 ZEND_SET_OP_JMP_ADDR(new_opline, new_opline->op1, ZEND_OP1_JMP_ADDR(opline));
73 break;
74 case ZEND_JMPZNZ:
75 new_opline->extended_value = ZEND_OPLINE_NUM_TO_OFFSET(op_array, new_opline, ZEND_OFFSET_TO_OPLINE_NUM(op_array, opline, opline->extended_value));
76 /* break missing intentionally */
77 case ZEND_JMPZ:
78 case ZEND_JMPNZ:
79 case ZEND_JMPZ_EX:
80 case ZEND_JMPNZ_EX:
81 case ZEND_FE_RESET_R:
82 case ZEND_FE_RESET_RW:
83 case ZEND_JMP_SET:
84 case ZEND_COALESCE:
85 case ZEND_ASSERT_CHECK:
86 ZEND_SET_OP_JMP_ADDR(new_opline, new_opline->op2, ZEND_OP2_JMP_ADDR(opline));
87 break;
88 case ZEND_CATCH:
89 if (!opline->result.num) {
90 new_opline->extended_value = ZEND_OPLINE_NUM_TO_OFFSET(op_array, new_opline, ZEND_OFFSET_TO_OPLINE_NUM(op_array, opline, opline->extended_value));
91 }
92 break;
93 case ZEND_DECLARE_ANON_CLASS:
94 case ZEND_DECLARE_ANON_INHERITED_CLASS:
95 case ZEND_FE_FETCH_R:
96 case ZEND_FE_FETCH_RW:
97 new_opline->extended_value = ZEND_OPLINE_NUM_TO_OFFSET(op_array, new_opline, ZEND_OFFSET_TO_OPLINE_NUM(op_array, opline, opline->extended_value));
98 break;
99 }
100 }
101 new_count++;
102 }
103 }
104
105 if (shift) {
106 op_array->last = new_count;
107 end = op_array->opcodes + op_array->last;
108
109 /* update JMPs */
110 for (opline = op_array->opcodes; opline<end; opline++) {
111 switch (opline->opcode) {
112 case ZEND_JMP:
113 case ZEND_FAST_CALL:
114 ZEND_SET_OP_JMP_ADDR(opline, opline->op1, ZEND_OP1_JMP_ADDR(opline) - shiftlist[ZEND_OP1_JMP_ADDR(opline) - op_array->opcodes]);
115 break;
116 case ZEND_JMPZNZ:
117 opline->extended_value = ZEND_OPLINE_NUM_TO_OFFSET(op_array, opline, ZEND_OFFSET_TO_OPLINE_NUM(op_array, opline, opline->extended_value) - shiftlist[ZEND_OFFSET_TO_OPLINE_NUM(op_array, opline, opline->extended_value)]);
118 /* break missing intentionally */
119 case ZEND_JMPZ:
120 case ZEND_JMPNZ:
121 case ZEND_JMPZ_EX:
122 case ZEND_JMPNZ_EX:
123 case ZEND_FE_RESET_R:
124 case ZEND_FE_RESET_RW:
125 case ZEND_JMP_SET:
126 case ZEND_COALESCE:
127 case ZEND_ASSERT_CHECK:
128 ZEND_SET_OP_JMP_ADDR(opline, opline->op2, ZEND_OP2_JMP_ADDR(opline) - shiftlist[ZEND_OP2_JMP_ADDR(opline) - op_array->opcodes]);
129 break;
130 case ZEND_DECLARE_ANON_CLASS:
131 case ZEND_DECLARE_ANON_INHERITED_CLASS:
132 case ZEND_FE_FETCH_R:
133 case ZEND_FE_FETCH_RW:
134 case ZEND_CATCH:
135 opline->extended_value = ZEND_OPLINE_NUM_TO_OFFSET(op_array, opline, ZEND_OFFSET_TO_OPLINE_NUM(op_array, opline, opline->extended_value) - shiftlist[ZEND_OFFSET_TO_OPLINE_NUM(op_array, opline, opline->extended_value)]);
136 break;
137 }
138 }
139
140 /* update brk/cont array */
141 for (j = 0; j < op_array->last_live_range; j++) {
142 op_array->live_range[j].start -= shiftlist[op_array->live_range[j].start];
143 op_array->live_range[j].end -= shiftlist[op_array->live_range[j].end];
144 }
145
146 /* update try/catch array */
147 for (j = 0; j < op_array->last_try_catch; j++) {
148 op_array->try_catch_array[j].try_op -= shiftlist[op_array->try_catch_array[j].try_op];
149 op_array->try_catch_array[j].catch_op -= shiftlist[op_array->try_catch_array[j].catch_op];
150 if (op_array->try_catch_array[j].finally_op) {
151 op_array->try_catch_array[j].finally_op -= shiftlist[op_array->try_catch_array[j].finally_op];
152 op_array->try_catch_array[j].finally_end -= shiftlist[op_array->try_catch_array[j].finally_end];
153 }
154 }
155
156 /* update early binding list */
157 if (op_array->early_binding != (uint32_t)-1) {
158 uint32_t *opline_num = &op_array->early_binding;
159
160 do {
161 *opline_num -= shiftlist[*opline_num];
162 opline_num = &ZEND_RESULT(&op_array->opcodes[*opline_num]).opline_num;
163 } while (*opline_num != (uint32_t)-1);
164 }
165 }
166 free_alloca(shiftlist, use_heap);
167 }
168
