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/*
+----------------------------------------------------------------------+
| Zend OPcache |
+----------------------------------------------------------------------+
| Copyright (c) The PHP Group |
+----------------------------------------------------------------------+
| This source file is subject to version 3.01 of the PHP license, |
| that is bundled with this package in the file LICENSE, and is |
| available through the world-wide-web at the following url: |
| https://www.php.net/license/3_01.txt |
| If you did not receive a copy of the PHP license and are unable to |
| obtain it through the world-wide-web, please send a note to |
| license@php.net so we can mail you a copy immediately. |
+----------------------------------------------------------------------+
| Authors: Andi Gutmans <andi@php.net> |
| Zeev Suraski <zeev@php.net> |
| Stanislav Malyshev <stas@zend.com> |
| Dmitry Stogov <dmitry@php.net> |
+----------------------------------------------------------------------+
*/
#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"
#include "zend_bitset.h"
#include "zend_observer.h"
#define INVALID_VAR ((uint32_t)-1)
#define GET_AVAILABLE_T() \
for (i = 0; i < T; i++) { \
if (!zend_bitset_in(taken_T, i)) { \
break; \
} \
} \
zend_bitset_incl(taken_T, i); \
if (i > max) { \
max = i; \
}
void zend_optimize_temporary_variables(zend_op_array *op_array, zend_optimizer_ctx *ctx)
{
uint32_t T = op_array->T;
int offset = op_array->last_var;
uint32_t bitset_len;
zend_bitset taken_T; /* T index in use */
zend_op **start_of_T; /* opline where T is first used */
int *map_T; /* Map's the T to its new index */
zend_op *opline, *end;
int currT;
int i;
int max = -1;
void *checkpoint = zend_arena_checkpoint(ctx->arena);
bitset_len = zend_bitset_len(T);
taken_T = (zend_bitset) zend_arena_alloc(&ctx->arena, bitset_len * ZEND_BITSET_ELM_SIZE);
start_of_T = (zend_op **) zend_arena_alloc(&ctx->arena, T * sizeof(zend_op *));
map_T = (int *) zend_arena_alloc(&ctx->arena, T * sizeof(int));
memset(map_T, 0xff, T * sizeof(int));
end = op_array->opcodes;
opline = &op_array->opcodes[op_array->last - 1];
/* Find T definition points */
while (opline >= end) {
if (opline->result_type & (IS_VAR | IS_TMP_VAR)) {
start_of_T[VAR_NUM(opline->result.var) - offset] = opline;
}
opline--;
}
zend_bitset_clear(taken_T, bitset_len);
end = op_array->opcodes;
opline = &op_array->opcodes[op_array->last - 1];
while (opline >= end) {
if ((opline->op1_type & (IS_VAR | IS_TMP_VAR))) {
currT = VAR_NUM(opline->op1.var) - offset;
if (opline->opcode == ZEND_ROPE_END) {
int num = (((opline->extended_value + 1) * sizeof(zend_string*)) + (sizeof(zval) - 1)) / sizeof(zval);
int var;
var = max;
while (var >= 0 && !zend_bitset_in(taken_T, var)) {
var--;
}
max = MAX(max, var + num);
var = var + 1;
map_T[currT] = var;
zend_bitset_incl(taken_T, var);
opline->op1.var = NUM_VAR(var + offset);
while (num > 1) {
num--;
zend_bitset_incl(taken_T, var + num);
}
} else {
if (map_T[currT] == INVALID_VAR) {
int use_new_var = 0;
/* Code in "finally" blocks may modify temporary variables.
* We allocate new temporaries for values that need to
* relive FAST_CALLs.
*/
if ((op_array->fn_flags & ZEND_ACC_HAS_FINALLY_BLOCK) &&
(opline->opcode == ZEND_RETURN ||
opline->opcode == ZEND_GENERATOR_RETURN ||
opline->opcode == ZEND_RETURN_BY_REF ||
opline->opcode == ZEND_FREE ||
opline->opcode == ZEND_FE_FREE)) {
zend_op *curr = opline;
while (--curr >= end) {
if (curr->opcode == ZEND_FAST_CALL) {
use_new_var = 1;
break;
} else if (curr->opcode != ZEND_FREE &&
curr->opcode != ZEND_FE_FREE &&
curr->opcode != ZEND_VERIFY_RETURN_TYPE &&
curr->opcode != ZEND_DISCARD_EXCEPTION) {
break;
}
}
}
if (use_new_var) {
i = ++max;
zend_bitset_incl(taken_T, i);
} else {
GET_AVAILABLE_T();
}
map_T[currT] = i;
}
opline->op1.var = NUM_VAR(map_T[currT] + offset);
}
}
if ((opline->op2_type & (IS_VAR | IS_TMP_VAR))) {
currT = VAR_NUM(opline->op2.var) - offset;
if (map_T[currT] == INVALID_VAR) {
GET_AVAILABLE_T();
map_T[currT] = i;
}
opline->op2.var = NUM_VAR(map_T[currT] + offset);
}
if (opline->result_type & (IS_VAR | IS_TMP_VAR)) {
currT = VAR_NUM(opline->result.var) - offset;
if (map_T[currT] == INVALID_VAR) {
/* As a result of DCE, an opcode may have an unused result. */
GET_AVAILABLE_T();
map_T[currT] = i;
}
opline->result.var = NUM_VAR(map_T[currT] + offset);
if (start_of_T[currT] == opline) {
/* ZEND_FAST_CALL can not share temporary var with others
* since the fast_var could also be set by ZEND_HANDLE_EXCEPTION
* which could be ahead of it */
if (opline->opcode != ZEND_FAST_CALL) {
zend_bitset_excl(taken_T, map_T[currT]);
}
if (opline->opcode == ZEND_ROPE_INIT) {
uint32_t num = ((opline->extended_value * sizeof(zend_string*)) + (sizeof(zval) - 1)) / sizeof(zval);
while (num > 1) {
num--;
zend_bitset_excl(taken_T, map_T[currT]+num);
}
}
}
}
opline--;
}
zend_arena_release(&ctx->arena, checkpoint);
op_array->T = max + 1 + ZEND_OBSERVER_ENABLED; // reserve last temporary for observers if enabled
}
|