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|
/*
+----------------------------------------------------------------------+
| Zend Engine, DFG - Data Flow Graph |
+----------------------------------------------------------------------+
| Copyright (c) 1998-2018 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: |
| http://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: Dmitry Stogov <dmitry@zend.com> |
+----------------------------------------------------------------------+
*/
#include "php.h"
#include "zend_compile.h"
#include "zend_dfg.h"
int zend_build_dfg(const zend_op_array *op_array, const zend_cfg *cfg, zend_dfg *dfg, uint32_t build_flags) /* {{{ */
{
int set_size;
zend_basic_block *blocks = cfg->blocks;
int blocks_count = cfg->blocks_count;
zend_bitset tmp, def, use, in, out;
int k;
uint32_t var_num;
int j;
set_size = dfg->size;
tmp = dfg->tmp;
def = dfg->def;
use = dfg->use;
in = dfg->in;
out = dfg->out;
/* Collect "def" and "use" sets */
for (j = 0; j < blocks_count; j++) {
zend_op *opline, *end;
if ((blocks[j].flags & ZEND_BB_REACHABLE) == 0) {
continue;
}
opline = op_array->opcodes + blocks[j].start;
end = opline + blocks[j].len;
for (; opline < end; opline++) {
if (opline->opcode != ZEND_OP_DATA) {
zend_op *next = opline + 1;
if (next < end && next->opcode == ZEND_OP_DATA) {
if (next->op1_type & (IS_CV|IS_VAR|IS_TMP_VAR)) {
var_num = EX_VAR_TO_NUM(next->op1.var);
if (!DFG_ISSET(def, set_size, j, var_num)) {
DFG_SET(use, set_size, j, var_num);
}
}
if (next->op2_type & (IS_CV|IS_VAR|IS_TMP_VAR)) {
var_num = EX_VAR_TO_NUM(next->op2.var);
if (!DFG_ISSET(def, set_size, j, var_num)) {
DFG_SET(use, set_size, j, var_num);
}
}
}
if (opline->op1_type == IS_CV) {
var_num = EX_VAR_TO_NUM(opline->op1.var);
switch (opline->opcode) {
case ZEND_ADD_ARRAY_ELEMENT:
case ZEND_INIT_ARRAY:
if ((build_flags & ZEND_SSA_RC_INFERENCE)
|| (opline->extended_value & ZEND_ARRAY_ELEMENT_REF)) {
goto op1_def;
}
goto op1_use;
case ZEND_FE_RESET_R:
case ZEND_SEND_VAR:
case ZEND_CAST:
case ZEND_QM_ASSIGN:
case ZEND_JMP_SET:
case ZEND_COALESCE:
if (build_flags & ZEND_SSA_RC_INFERENCE) {
goto op1_def;
}
goto op1_use;
case ZEND_YIELD:
if ((build_flags & ZEND_SSA_RC_INFERENCE)
|| (op_array->fn_flags & ZEND_ACC_RETURN_REFERENCE)) {
goto op1_def;
}
goto op1_use;
case ZEND_UNSET_CV:
case ZEND_ASSIGN:
case ZEND_ASSIGN_REF:
case ZEND_BIND_GLOBAL:
case ZEND_BIND_STATIC:
case ZEND_SEND_VAR_EX:
case ZEND_SEND_REF:
case ZEND_SEND_VAR_NO_REF:
case ZEND_SEND_VAR_NO_REF_EX:
case ZEND_FE_RESET_RW:
case ZEND_ASSIGN_ADD:
case ZEND_ASSIGN_SUB:
case ZEND_ASSIGN_MUL:
case ZEND_ASSIGN_DIV:
case ZEND_ASSIGN_MOD:
case ZEND_ASSIGN_SL:
case ZEND_ASSIGN_SR:
case ZEND_ASSIGN_CONCAT:
case ZEND_ASSIGN_BW_OR:
case ZEND_ASSIGN_BW_AND:
case ZEND_ASSIGN_BW_XOR:
case ZEND_ASSIGN_POW:
case ZEND_PRE_INC:
case ZEND_PRE_DEC:
case ZEND_POST_INC:
case ZEND_POST_DEC:
case ZEND_ASSIGN_DIM:
case ZEND_ASSIGN_OBJ:
case ZEND_UNSET_DIM:
case ZEND_UNSET_OBJ:
case ZEND_FETCH_DIM_W:
case ZEND_FETCH_DIM_RW:
case ZEND_FETCH_DIM_FUNC_ARG:
case ZEND_FETCH_DIM_UNSET:
case ZEND_FETCH_OBJ_W:
case ZEND_FETCH_OBJ_RW:
case ZEND_FETCH_OBJ_FUNC_ARG:
case ZEND_FETCH_OBJ_UNSET:
case ZEND_VERIFY_RETURN_TYPE:
op1_def:
/* `def` always come along with dtor or separation,
* thus the origin var info might be also `use`d in the feature(CG) */
DFG_SET(use, set_size, j, var_num);
DFG_SET(def, set_size, j, var_num);
break;
default:
op1_use:
if (!DFG_ISSET(def, set_size, j, var_num)) {
DFG_SET(use, set_size, j, var_num);
}
}
} else if (opline->op1_type & (IS_VAR|IS_TMP_VAR)) {
var_num = EX_VAR_TO_NUM(opline->op1.var);
if (!DFG_ISSET(def, set_size, j, var_num)) {
DFG_SET(use, set_size, j, var_num);
}
if (opline->opcode == ZEND_VERIFY_RETURN_TYPE) {
DFG_SET(def, set_size, j, var_num);
}
}
if (opline->op2_type == IS_CV) {
var_num = EX_VAR_TO_NUM(opline->op2.var);
switch (opline->opcode) {
case ZEND_ASSIGN:
if (build_flags & ZEND_SSA_RC_INFERENCE) {
goto op2_def;
}
goto op2_use;
case ZEND_BIND_LEXICAL:
if ((build_flags & ZEND_SSA_RC_INFERENCE) || opline->extended_value) {
goto op2_def;
}
goto op2_use;
case ZEND_ASSIGN_REF:
case ZEND_FE_FETCH_R:
case ZEND_FE_FETCH_RW:
op2_def:
// FIXME: include into "use" too ...?
DFG_SET(use, set_size, j, var_num);
DFG_SET(def, set_size, j, var_num);
break;
default:
op2_use:
if (!DFG_ISSET(def, set_size, j, var_num)) {
DFG_SET(use, set_size, j, var_num);
}
break;
}
} else if (opline->op2_type & (IS_VAR|IS_TMP_VAR)) {
var_num = EX_VAR_TO_NUM(opline->op2.var);
if (opline->opcode == ZEND_FE_FETCH_R || opline->opcode == ZEND_FE_FETCH_RW) {
DFG_SET(def, set_size, j, var_num);
} else {
if (!DFG_ISSET(def, set_size, j, var_num)) {
DFG_SET(use, set_size, j, var_num);
}
}
}
if (opline->result_type & (IS_CV|IS_VAR|IS_TMP_VAR)) {
var_num = EX_VAR_TO_NUM(opline->result.var);
if ((build_flags & ZEND_SSA_USE_CV_RESULTS)
&& opline->result_type == IS_CV) {
DFG_SET(use, set_size, j, var_num);
}
DFG_SET(def, set_size, j, var_num);
}
}
}
}
/* Calculate "in" and "out" sets */
{
uint32_t worklist_len = zend_bitset_len(blocks_count);
zend_bitset worklist;
ALLOCA_FLAG(use_heap);
worklist = ZEND_BITSET_ALLOCA(worklist_len, use_heap);
memset(worklist, 0, worklist_len * ZEND_BITSET_ELM_SIZE);
for (j = 0; j < blocks_count; j++) {
zend_bitset_incl(worklist, j);
}
while (!zend_bitset_empty(worklist, worklist_len)) {
/* We use the last block on the worklist, because predecessors tend to be located
* before the succeeding block, so this converges faster. */
j = zend_bitset_last(worklist, worklist_len);
zend_bitset_excl(worklist, j);
if ((blocks[j].flags & ZEND_BB_REACHABLE) == 0) {
continue;
}
if (blocks[j].successors_count != 0) {
zend_bitset_copy(DFG_BITSET(out, set_size, j), DFG_BITSET(in, set_size, blocks[j].successors[0]), set_size);
for (k = 1; k < blocks[j].successors_count; k++) {
zend_bitset_union(DFG_BITSET(out, set_size, j), DFG_BITSET(in, set_size, blocks[j].successors[k]), set_size);
}
} else {
zend_bitset_clear(DFG_BITSET(out, set_size, j), set_size);
}
zend_bitset_union_with_difference(tmp, DFG_BITSET(use, set_size, j), DFG_BITSET(out, set_size, j), DFG_BITSET(def, set_size, j), set_size);
if (!zend_bitset_equal(DFG_BITSET(in, set_size, j), tmp, set_size)) {
zend_bitset_copy(DFG_BITSET(in, set_size, j), tmp, set_size);
/* Add predecessors of changed block to worklist */
{
int *predecessors = &cfg->predecessors[blocks[j].predecessor_offset];
for (k = 0; k < blocks[j].predecessors_count; k++) {
zend_bitset_incl(worklist, predecessors[k]);
}
}
}
}
free_alloca(worklist, use_heap);
}
return SUCCESS;
}
/* }}} */
/*
* Local variables:
* tab-width: 4
* c-basic-offset: 4
* indent-tabs-mode: t
* End:
*/
|
