/src/php-src/Zend/Optimizer/compact_vars.c
Line | Count | Source (jump to first uncovered line) |
1 | | /* |
2 | | +----------------------------------------------------------------------+ |
3 | | | Zend Engine, Removing unused variables | |
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 | | | https://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: Nikita Popov <nikic@php.net> | |
16 | | +----------------------------------------------------------------------+ |
17 | | */ |
18 | | |
19 | | #include "Optimizer/zend_optimizer_internal.h" |
20 | | #include "zend_bitset.h" |
21 | | #include "zend_observer.h" |
22 | | |
23 | | /* This pass removes all CVs and temporaries that are completely unused. It does *not* merge any CVs or TMPs. |
24 | | * This pass does not operate on SSA form anymore. */ |
25 | 109k | void zend_optimizer_compact_vars(zend_op_array *op_array) { |
26 | 109k | int i; |
27 | | |
28 | 109k | ALLOCA_FLAG(use_heap1); |
29 | 109k | ALLOCA_FLAG(use_heap2); |
30 | 109k | uint32_t used_vars_len = zend_bitset_len(op_array->last_var + op_array->T); |
31 | 109k | zend_bitset used_vars = ZEND_BITSET_ALLOCA(used_vars_len, use_heap1); |
32 | 109k | uint32_t *vars_map = do_alloca((op_array->last_var + op_array->T) * sizeof(uint32_t), use_heap2); |
33 | 109k | uint32_t num_cvs, num_tmps; |
34 | | |
35 | | /* Determine which CVs are used */ |
36 | 109k | zend_bitset_clear(used_vars, used_vars_len); |
37 | 2.61M | for (i = 0; i < op_array->last; i++) { |
38 | 2.50M | zend_op *opline = &op_array->opcodes[i]; |
39 | 2.50M | if (opline->op1_type & (IS_CV|IS_VAR|IS_TMP_VAR)) { |
40 | 1.46M | zend_bitset_incl(used_vars, VAR_NUM(opline->op1.var)); |
41 | 1.46M | } |
42 | 2.50M | if (opline->op2_type & (IS_CV|IS_VAR|IS_TMP_VAR)) { |
43 | 616k | zend_bitset_incl(used_vars, VAR_NUM(opline->op2.var)); |
44 | 616k | } |
45 | 2.50M | if (opline->result_type & (IS_CV|IS_VAR|IS_TMP_VAR)) { |
46 | 1.28M | zend_bitset_incl(used_vars, VAR_NUM(opline->result.var)); |
47 | 1.28M | if (opline->opcode == ZEND_ROPE_INIT) { |
48 | 26.0k | uint32_t num = ((opline->extended_value * sizeof(zend_string*)) + (sizeof(zval) - 1)) / sizeof(zval); |
49 | 214k | while (num > 1) { |
50 | 188k | num--; |
51 | 188k | zend_bitset_incl(used_vars, VAR_NUM(opline->result.var) + num); |
52 | 188k | } |
53 | 26.0k | } |
54 | 1.28M | } |
55 | 2.50M | } |
56 | | |
57 | 109k | num_cvs = 0; |
58 | 547k | for (i = 0; i < op_array->last_var; i++) { |
59 | 437k | if (zend_bitset_in(used_vars, i)) { |
60 | 434k | vars_map[i] = num_cvs++; |
61 | 434k | } else { |
62 | 3.93k | vars_map[i] = (uint32_t) -1; |
63 | 3.93k | } |
64 | 437k | } |
65 | | |
66 | 109k | num_tmps = 0; |
67 | 425k | for (i = op_array->last_var; i < op_array->last_var + op_array->T; i++) { |
68 | 316k | if (zend_bitset_in(used_vars, i)) { |
69 | 316k | vars_map[i] = num_cvs + num_tmps++; |
70 | 316k | } else { |
71 | 0 | vars_map[i] = (uint32_t) -1; |
72 | 0 | } |
73 | 316k | } |
74 | | |
75 | 109k | free_alloca(used_vars, use_heap1); |
76 | 109k | if (num_cvs == op_array->last_var && num_tmps == op_array->T) { |
77 | 106k | free_alloca(vars_map, use_heap2); |
78 | 106k | return; |
79 | 106k | } |
80 | | |
81 | 2.68k | ZEND_ASSERT(num_cvs <= op_array->last_var); |
82 | 2.68k | ZEND_ASSERT(num_tmps <= op_array->T); |
83 | | |
84 | | /* Update CV and TMP references in opcodes */ |
85 | 108k | for (i = 0; i < op_array->last; i++) { |
86 | 106k | zend_op *opline = &op_array->opcodes[i]; |
87 | 106k | if (opline->op1_type & (IS_CV|IS_VAR|IS_TMP_VAR)) { |
88 | 69.1k | opline->op1.var = NUM_VAR(vars_map[VAR_NUM(opline->op1.var)]); |
89 | 69.1k | } |
90 | 106k | if (opline->op2_type & (IS_CV|IS_VAR|IS_TMP_VAR)) { |
91 | 28.2k | opline->op2.var = NUM_VAR(vars_map[VAR_NUM(opline->op2.var)]); |
92 | 28.2k | } |
93 | 106k | if (opline->result_type & (IS_CV|IS_VAR|IS_TMP_VAR)) { |
94 | 61.4k | opline->result.var = NUM_VAR(vars_map[VAR_NUM(opline->result.var)]); |
95 | 61.4k | } |
96 | 106k | } |
97 | | |
98 | | /* Update CV name table */ |
99 | 2.68k | if (num_cvs != op_array->last_var) { |
100 | 2.68k | if (num_cvs) { |
101 | 2.26k | zend_string **names = safe_emalloc(sizeof(zend_string *), num_cvs, 0); |
102 | 18.4k | for (i = 0; i < op_array->last_var; i++) { |
103 | 16.1k | if (vars_map[i] != (uint32_t) -1) { |
104 | 12.8k | names[vars_map[i]] = op_array->vars[i]; |
105 | 12.8k | } else { |
106 | 3.32k | zend_string_release_ex(op_array->vars[i], 0); |
107 | 3.32k | } |
108 | 16.1k | } |
109 | 2.26k | efree(op_array->vars); |
110 | 2.26k | op_array->vars = names; |
111 | 2.26k | } else { |
112 | 1.02k | for (i = 0; i < op_array->last_var; i++) { |
113 | 607 | zend_string_release_ex(op_array->vars[i], 0); |
114 | 607 | } |
115 | 421 | efree(op_array->vars); |
116 | 421 | op_array->vars = NULL; |
117 | 421 | } |
118 | 2.68k | op_array->last_var = num_cvs; |
119 | 2.68k | } |
120 | | |
121 | 2.68k | op_array->T = num_tmps + ZEND_OBSERVER_ENABLED; // reserve last temporary for observers if enabled |
122 | | |
123 | 2.68k | free_alloca(vars_map, use_heap2); |
124 | 2.68k | } |