/src/php-src/Zend/Optimizer/pass3.c
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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 | | | 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: Andi Gutmans <andi@php.net> | |
16 | | | Zeev Suraski <zeev@php.net> | |
17 | | | Stanislav Malyshev <stas@zend.com> | |
18 | | | Dmitry Stogov <dmitry@php.net> | |
19 | | +----------------------------------------------------------------------+ |
20 | | */ |
21 | | |
22 | | /* pass 3: (Jump optimization) |
23 | | * - optimize series of JMPs |
24 | | */ |
25 | | |
26 | | #include "Optimizer/zend_optimizer.h" |
27 | | #include "Optimizer/zend_optimizer_internal.h" |
28 | | #include "zend_API.h" |
29 | | #include "zend_constants.h" |
30 | | #include "zend_execute.h" |
31 | | #include "zend_vm.h" |
32 | | |
33 | | /* we use "jmp_hitlist" to avoid infinity loops during jmp optimization */ |
34 | | static zend_always_inline bool in_hitlist(zend_op *target, zend_op **jmp_hitlist, int jmp_hitlist_count) |
35 | 13 | { |
36 | 13 | int i; |
37 | | |
38 | 13 | for (i = 0; i < jmp_hitlist_count; i++) { |
39 | 0 | if (jmp_hitlist[i] == target) { |
40 | 0 | return true; |
41 | 0 | } |
42 | 0 | } |
43 | 13 | return false; |
44 | 13 | } |
45 | | |
46 | | #define CHECK_LOOP(target) \ |
47 | 13 | if (EXPECTED(!in_hitlist(target, jmp_hitlist, jmp_hitlist_count))) { \ |
48 | 13 | jmp_hitlist[jmp_hitlist_count++] = target; \ |
49 | 13 | } else { \ |
50 | 0 | break; \ |
51 | 0 | } |
52 | | |
53 | | void zend_optimizer_pass3(zend_op_array *op_array, zend_optimizer_ctx *ctx) |
54 | 82 | { |
55 | 82 | zend_op *opline; |
56 | 82 | zend_op *end; |
57 | 82 | zend_op *target; |
58 | 82 | zend_op **jmp_hitlist; |
59 | 82 | int jmp_hitlist_count; |
60 | 82 | ALLOCA_FLAG(use_heap); |
61 | | |
62 | 82 | jmp_hitlist = (zend_op**)do_alloca(sizeof(zend_op*)*op_array->last, use_heap); |
63 | 82 | opline = op_array->opcodes; |
64 | 82 | end = opline + op_array->last; |
65 | | |
66 | 6.00k | while (opline < end) { |
67 | | |
68 | 5.91k | switch (opline->opcode) { |
69 | 161 | case ZEND_JMP: |
70 | 161 | jmp_hitlist_count = 0; |
71 | | |
72 | 161 | target = ZEND_OP1_JMP_ADDR(opline); |
73 | 175 | while (1) { |
74 | 175 | if (target->opcode == ZEND_JMP) { |
75 | | /* convert JMP L1 ... L1: JMP L2 to JMP L2 .. L1: JMP L2 */ |
76 | 4 | target = ZEND_OP1_JMP_ADDR(target); |
77 | 4 | CHECK_LOOP(target); |
78 | 171 | } else if (target->opcode == ZEND_NOP) { |
79 | 10 | target = target + 1; |
80 | 161 | } else { |
81 | 161 | break; |
82 | 161 | } |
83 | 14 | ZEND_SET_OP_JMP_ADDR(opline, opline->op1, target); |
84 | 14 | } |
85 | | |
86 | 161 | if (target == opline + 1) { |
87 | | /* convert L: JMP L+1 to NOP */ |
88 | 0 | MAKE_NOP(opline); |
89 | 161 | } else if ((target->opcode == ZEND_RETURN || |
90 | 151 | target->opcode == ZEND_RETURN_BY_REF || |
91 | 151 | target->opcode == ZEND_GENERATOR_RETURN) && |
92 | 10 | !(op_array->fn_flags & ZEND_ACC_HAS_FINALLY_BLOCK)) { |
93 | | /* JMP L, L: RETURN to immediate RETURN */ |
94 | 10 | *opline = *target; |
95 | 10 | if (opline->op1_type == IS_CONST) { |
96 | 10 | zval zv; |
97 | 10 | ZVAL_COPY(&zv, &ZEND_OP1_LITERAL(opline)); |
98 | 10 | opline->op1.constant = zend_optimizer_add_literal(op_array, &zv); |
99 | 10 | } |
100 | 151 | } else if (opline > op_array->opcodes && |
101 | 151 | ((opline-1)->opcode == ZEND_JMPZ || |
102 | 151 | (opline-1)->opcode == ZEND_JMPNZ)) { |
103 | 0 | if (ZEND_OP2_JMP_ADDR(opline-1) == target) { |
104 | | /* JMPZ(X,L1), JMP(L1) -> NOP, JMP(L1) */ |
105 | 0 | zend_optimizer_convert_to_free_op1(op_array, opline - 1); |
106 | 0 | } |
107 | 0 | } |
108 | 161 | break; |
109 | | |
110 | 12 | case ZEND_JMP_SET: |
111 | 44 | case ZEND_COALESCE: |
112 | 44 | jmp_hitlist_count = 0; |
113 | | |
114 | 44 | target = ZEND_OP2_JMP_ADDR(opline); |
115 | 44 | while (1) { |
116 | 44 | if (target->opcode == ZEND_JMP) { |
117 | 0 | target = ZEND_OP1_JMP_ADDR(target); |
118 | 0 | CHECK_LOOP(target); |
119 | 44 | } else if (target->opcode == ZEND_NOP) { |
120 | 0 | target = target + 1; |
121 | 44 | } else { |
122 | 44 | break; |
123 | 44 | } |
124 | 0 | ZEND_SET_OP_JMP_ADDR(opline, opline->op2, target); |
125 | 0 | } |
126 | 44 | break; |
127 | | |
128 | 4 | case ZEND_JMPZ: |
129 | 76 | case ZEND_JMPNZ: |
130 | 76 | jmp_hitlist_count = 0; |
131 | | |
132 | 76 | target = ZEND_OP2_JMP_ADDR(opline); |
133 | 80 | while (1) { |
134 | 80 | if (target->opcode == ZEND_JMP) { |
135 | | /* plain JMP */ |
136 | | /* JMPZ(X,L1), L1: JMP(L2) => JMPZ(X,L2), L1: JMP(L2) */ |
137 | 4 | target = ZEND_OP1_JMP_ADDR(target); |
138 | 4 | CHECK_LOOP(target); |
139 | 76 | } else if (target->opcode == opline->opcode && |
140 | 0 | SAME_VAR(opline->op1, target->op1)) { |
141 | | /* same opcode and same var as this opcode */ |
142 | | /* JMPZ(X,L1), L1: JMPZ(X,L2) => JMPZ(X,L2), L1: JMPZ(X,L2) */ |
143 | 0 | target = ZEND_OP2_JMP_ADDR(target); |
144 | 0 | CHECK_LOOP(target); |
145 | 76 | } else if (target->opcode == INV_COND(opline->opcode) && |
146 | 0 | SAME_VAR(opline->op1, target->op1)) { |
147 | | /* convert JMPZ(X,L1), L1: JMPNZ(X,L2) to |
148 | | JMPZ(X,L1+1) */ |
149 | 0 | target = target + 1; |
150 | 76 | } else if (target->opcode == ZEND_NOP) { |
151 | 0 | target = target + 1; |
152 | 76 | } else { |
153 | 76 | break; |
154 | 76 | } |
155 | 4 | ZEND_SET_OP_JMP_ADDR(opline, opline->op2, target); |
156 | 4 | } |
157 | | |
158 | | /* convert L: JMPZ L+1 to NOP */ |
159 | 76 | if (target == opline + 1) { |
160 | 0 | zend_optimizer_convert_to_free_op1(op_array, opline); |
161 | 0 | } |
162 | 76 | break; |
163 | | |
164 | 12 | case ZEND_JMPZ_EX: |
165 | 18 | case ZEND_JMPNZ_EX: |
166 | 18 | jmp_hitlist_count = 0; |
167 | | |
168 | 18 | target = ZEND_OP2_JMP_ADDR(opline); |
169 | 31 | while (1) { |
170 | 31 | if (target->opcode == ZEND_JMP) { |
171 | | /* plain JMP */ |
172 | | /* JMPZ_EX(X,L1), L1: JMP(L2) => JMPZ_EX(X,L2), L1: JMP(L2) */ |
173 | 0 | target = ZEND_OP1_JMP_ADDR(target); |
174 | 0 | CHECK_LOOP(target); |
175 | 31 | } else if (target->opcode == opline->opcode-3 && |
176 | 0 | (SAME_VAR(target->op1, opline->result) || |
177 | 0 | SAME_VAR(target->op1, opline->op1))) { |
178 | | /* convert T=JMPZ_EX(X,L1), L1: JMPZ(T,L2) to |
179 | | JMPZ_EX(X,L2) */ |
180 | 0 | target = ZEND_OP2_JMP_ADDR(target); |
181 | 0 | CHECK_LOOP(target); |
182 | 31 | } else if (target->opcode == opline->opcode && |
183 | 5 | target->result.var == opline->result.var && |
184 | 5 | (SAME_VAR(target->op1, opline->result) || |
185 | 5 | SAME_VAR(target->op1, opline->op1))) { |
186 | | /* convert T=JMPZ_EX(X,L1), L1: T=JMPZ_EX(T,L2) to |
187 | | JMPZ_EX(X,L2) */ |
188 | 5 | target = ZEND_OP2_JMP_ADDR(target); |
189 | 5 | CHECK_LOOP(target); |
190 | 26 | } else if (target->opcode == INV_EX_COND(opline->opcode) && |
191 | 0 | (SAME_VAR(target->op1, opline->result) || |
192 | 0 | SAME_VAR(target->op1, opline->op1))) { |
193 | | /* convert T=JMPZ_EX(X,L1), L1: JMPNZ(T,L2) to |
194 | | JMPZ_EX(X,L1+1) */ |
195 | 0 | target = target + 1; |
196 | 26 | } else if (target->opcode == INV_EX_COND_EX(opline->opcode) && |
197 | 8 | target->result.var == opline->result.var && |
198 | 8 | (SAME_VAR(target->op1, opline->result) || |
199 | 8 | SAME_VAR(target->op1, opline->op1))) { |
200 | | /* convert T=JMPZ_EX(X,L1), L1: T=JMPNZ_EX(T,L2) to |
201 | | JMPZ_EX(X,L1+1) */ |
202 | 8 | target = target + 1; |
203 | 18 | } else if (target->opcode == ZEND_BOOL && |
204 | 8 | (SAME_VAR(target->op1, opline->result) || |
205 | 8 | SAME_VAR(target->op1, opline->op1))) { |
206 | | /* convert Y = JMPZ_EX(X,L1), L1: Z = BOOL(Y) to |
207 | | Z = JMPZ_EX(X,L1+1) */ |
208 | | |
209 | | /* NOTE: This optimization pattern is not safe, but works, */ |
210 | | /* because result of JMPZ_EX instruction */ |
211 | | /* is not used on the following path and */ |
212 | | /* should be used once on the branch path. */ |
213 | | /* */ |
214 | | /* The pattern works well only if jumps processed in */ |
215 | | /* direct order, otherwise it breaks JMPZ_EX */ |
216 | | /* sequences too early. */ |
217 | 0 | opline->result.var = target->result.var; |
218 | 0 | target = target + 1; |
219 | 0 | CHECK_LOOP(target); |
220 | 18 | } else if (target->opcode == ZEND_NOP) { |
221 | 0 | target = target + 1; |
222 | 18 | } else { |
223 | 18 | break; |
224 | 18 | } |
225 | 13 | ZEND_SET_OP_JMP_ADDR(opline, opline->op2, target); |
226 | 13 | } |
227 | | |
228 | | /* convert L: T = JMPZ_EX X,L+1 to T = BOOL(X) */ |
229 | 18 | if (target == opline + 1) { |
230 | 0 | opline->opcode = ZEND_BOOL; |
231 | 0 | opline->op2.num = 0; |
232 | 0 | } |
233 | 18 | break; |
234 | 5.91k | } |
235 | 5.91k | opline++; |
236 | 5.91k | } |
237 | 82 | free_alloca(jmp_hitlist, use_heap); |
238 | 82 | } |