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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> |
+----------------------------------------------------------------------+
*/
/* pass 10:
* - remove NOPs
*/
#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"
void zend_optimizer_nop_removal(zend_op_array *op_array, zend_optimizer_ctx *ctx)
{
zend_op *end, *opline;
uint32_t new_count, i, shift;
int j;
uint32_t *shiftlist;
ALLOCA_FLAG(use_heap);
shiftlist = (uint32_t *)do_alloca(sizeof(uint32_t) * op_array->last, use_heap);
i = new_count = shift = 0;
end = op_array->opcodes + op_array->last;
for (opline = op_array->opcodes; opline < end; opline++) {
/* Kill JMP-over-NOP-s */
if (opline->opcode == ZEND_JMP && ZEND_OP1_JMP_ADDR(opline) > op_array->opcodes + i) {
/* check if there are only NOPs under the branch */
zend_op *target = ZEND_OP1_JMP_ADDR(opline) - 1;
while (target->opcode == ZEND_NOP) {
target--;
}
if (target == opline) {
/* only NOPs */
opline->opcode = ZEND_NOP;
}
}
shiftlist[i++] = shift;
if (opline->opcode == ZEND_NOP) {
shift++;
} else {
if (shift) {
zend_op *new_opline = op_array->opcodes + new_count;
*new_opline = *opline;
zend_optimizer_migrate_jump(op_array, new_opline, opline);
}
new_count++;
}
}
if (shift) {
op_array->last = new_count;
end = op_array->opcodes + op_array->last;
/* update JMPs */
for (opline = op_array->opcodes; opline<end; opline++) {
zend_optimizer_shift_jump(op_array, opline, shiftlist);
}
/* update try/catch array */
for (j = 0; j < op_array->last_try_catch; j++) {
op_array->try_catch_array[j].try_op -= shiftlist[op_array->try_catch_array[j].try_op];
op_array->try_catch_array[j].catch_op -= shiftlist[op_array->try_catch_array[j].catch_op];
if (op_array->try_catch_array[j].finally_op) {
op_array->try_catch_array[j].finally_op -= shiftlist[op_array->try_catch_array[j].finally_op];
op_array->try_catch_array[j].finally_end -= shiftlist[op_array->try_catch_array[j].finally_end];
}
}
}
free_alloca(shiftlist, use_heap);
}
|
