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|
/*
+----------------------------------------------------------------------+
| Zend OPcache |
+----------------------------------------------------------------------+
| Copyright (c) 1998-2016 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 "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_cfg.h"
#include "zend_ssa.h"
#include "zend_func_info.h"
#include "zend_inference.h"
#include "zend_dump.h"
int zend_dfa_analyze_op_array(zend_op_array *op_array, zend_optimizer_ctx *ctx, zend_ssa *ssa, uint32_t *flags)
{
uint32_t build_flags;
if (op_array->last_try_catch) {
/* TODO: we can't analyze functions with try/catch/finally ??? */
return FAILURE;
}
/* Build SSA */
memset(ssa, 0, sizeof(zend_ssa));
if (zend_build_cfg(&ctx->arena, op_array, 0, &ssa->cfg, flags) != SUCCESS) {
return FAILURE;
}
if (*flags & ZEND_FUNC_INDIRECT_VAR_ACCESS) {
/* TODO: we can't analyze functions with indirect variable access ??? */
return FAILURE;
}
if (zend_cfg_build_predecessors(&ctx->arena, &ssa->cfg) != SUCCESS) {
return FAILURE;
}
if (ctx->debug_level & ZEND_DUMP_DFA_CFG) {
zend_dump_op_array(op_array, ZEND_DUMP_CFG | ZEND_DUMP_HIDE_UNUSED_VARS, "dfa cfg", &ssa->cfg);
}
/* Compute Dominators Tree */
if (zend_cfg_compute_dominators_tree(op_array, &ssa->cfg) != SUCCESS) {
return FAILURE;
}
/* Identify reducible and irreducible loops */
if (zend_cfg_identify_loops(op_array, &ssa->cfg, flags) != SUCCESS) {
return FAILURE;
}
if (ctx->debug_level & ZEND_DUMP_DFA_DOMINATORS) {
zend_dump_dominators(op_array, &ssa->cfg);
}
build_flags = 0;
if (ctx->debug_level & ZEND_DUMP_DFA_LIVENESS) {
build_flags |= ZEND_SSA_DEBUG_LIVENESS;
}
if (ctx->debug_level & ZEND_DUMP_DFA_PHI) {
build_flags |= ZEND_SSA_DEBUG_PHI_PLACEMENT;
}
if (zend_build_ssa(&ctx->arena, op_array, build_flags, ssa, flags) != SUCCESS) {
return FAILURE;
}
if (ctx->debug_level & ZEND_DUMP_DFA_SSA) {
zend_dump_op_array(op_array, ZEND_DUMP_SSA | ZEND_DUMP_HIDE_UNUSED_VARS, "before dfa pass", ssa);
}
if (zend_ssa_compute_use_def_chains(&ctx->arena, op_array, ssa) != SUCCESS){
return FAILURE;
}
if (zend_ssa_find_false_dependencies(op_array, ssa) != SUCCESS) {
return FAILURE;
}
if (zend_ssa_find_sccs(op_array, ssa) != SUCCESS){
return FAILURE;
}
if (zend_ssa_inference(&ctx->arena, op_array, ctx->script, ssa) != SUCCESS) {
return FAILURE;
}
if (ctx->debug_level & ZEND_DUMP_DFA_SSA_VARS) {
zend_dump_ssa_variables(op_array, ssa);
}
return SUCCESS;
}
void zend_dfa_optimize_op_array(zend_op_array *op_array, zend_optimizer_ctx *ctx, zend_ssa *ssa)
{
if (ctx->debug_level & ZEND_DUMP_BEFORE_DFA_PASS) {
zend_dump_op_array(op_array, ZEND_DUMP_SSA | ZEND_DUMP_HIDE_UNUSED_VARS, "before dfa pass", ssa);
}
if (ssa->var_info) {
int i;
int remove_nops = 0;
// 1: #1.T = OP_Y | #3.CV = OP_Y
// 2: ASSIGN #2.CV [undef,scalar] -> #3.CV, #1.T | NOP
// --
// 2: ASSIGN #2.CV [undef,scalar] -> #3.CV, C | 3.CV = QM_ASSIGN C
// --
// 2: ASSIGN #2.CV [undef,scalar] -> #3.CV, #1.CV | 3.CV = QM_ASSIGN #1.CV
for (i = 0; i < ssa->vars_count; i++) {
int op2 = ssa->vars[i].definition;
if (op2 >= 0
&& op_array->opcodes[op2].opcode == ZEND_ASSIGN
&& op_array->opcodes[op2].op1_type == IS_CV
&& !RETURN_VALUE_USED(&op_array->opcodes[op2])
) {
int var2 = ssa->ops[op2].op1_use;
if (var2 >= 0
&& !(ssa->var_info[var2].type & (MAY_BE_STRING|MAY_BE_ARRAY|MAY_BE_OBJECT|MAY_BE_RESOURCE|MAY_BE_REF))
) {
if (op_array->opcodes[op2].op2_type & (IS_TMP_VAR|IS_VAR)) {
int var1 = ssa->ops[op2].op2_use;
if (var1 >= 0
&& !(ssa->var_info[var1].type & MAY_BE_REF)
&& ssa->vars[var1].definition >= 0
&& ssa->ops[ssa->vars[var1].definition].result_def == var1
&& ssa->ops[ssa->vars[var1].definition].result_use < 0
&& ssa->vars[var1].use_chain == op2
&& ssa->ops[op2].op2_use_chain < 0
&& !ssa->vars[var1].phi_use_chain
&& !ssa->vars[var1].sym_use_chain
/* see Zend/tests/generators/aborted_yield_during_new.phpt */
&& op_array->opcodes[ssa->vars[var1].definition].opcode != ZEND_NEW
) {
int op1 = ssa->vars[var1].definition;
int var3 = i;
if (zend_ssa_unlink_use_chain(ssa, op2, var2)) {
/* Reconstruct SSA */
ssa->vars[var3].definition = op1;
ssa->ops[op1].result_def = var3;
ssa->vars[var1].definition = -1;
ssa->vars[var1].use_chain = -1;
ssa->ops[op2].op1_use = -1;
ssa->ops[op2].op2_use = -1;
ssa->ops[op2].op1_def = -1;
ssa->ops[op2].op1_use_chain = -1;
/* Update opcodes */
op_array->opcodes[op1].result_type = op_array->opcodes[op2].op1_type;
op_array->opcodes[op1].result.var = op_array->opcodes[op2].op1.var;
MAKE_NOP(&op_array->opcodes[op2]);
remove_nops = 1;
}
}
} else if (op_array->opcodes[op2].op2_type == IS_CONST
|| (op_array->opcodes[op2].op2_type == IS_CV
&& ssa->ops[op2].op2_use >= 0
&& ssa->ops[op2].op2_def < 0
&& !(ssa->var_info[ssa->ops[op2].op2_use].type & MAY_BE_REF))
) {
int var3 = i;
if (zend_ssa_unlink_use_chain(ssa, op2, var2)) {
/* Reconstruct SSA */
ssa->ops[op2].result_def = var3;
ssa->ops[op2].op1_def = -1;
ssa->ops[op2].op1_use = ssa->ops[op2].op2_use;
ssa->ops[op2].op1_use_chain = ssa->ops[op2].op2_use_chain;
ssa->ops[op2].op2_use = -1;
ssa->ops[op2].op2_use_chain = -1;
/* Update opcode */
op_array->opcodes[op2].result_type = op_array->opcodes[op2].op1_type;
op_array->opcodes[op2].result.var = op_array->opcodes[op2].op1.var;
op_array->opcodes[op2].op1_type = op_array->opcodes[op2].op2_type;
op_array->opcodes[op2].op1.var = op_array->opcodes[op2].op2.var;
op_array->opcodes[op2].op2_type = IS_UNUSED;
op_array->opcodes[op2].op2.var = 0;
op_array->opcodes[op2].opcode = ZEND_QM_ASSIGN;
}
}
}
}
}
if (remove_nops) {
// TODO: remove nop???
}
}
if (ctx->debug_level & ZEND_DUMP_AFTER_DFA_PASS) {
zend_dump_op_array(op_array, ZEND_DUMP_SSA | ZEND_DUMP_HIDE_UNUSED_VARS, "after dfa pass", ssa);
}
}
void optimize_dfa(zend_op_array *op_array, zend_optimizer_ctx *ctx)
{
void *checkpoint = zend_arena_checkpoint(ctx->arena);
uint32_t flags = 0;
zend_ssa ssa;
if (zend_dfa_analyze_op_array(op_array, ctx, &ssa, &flags) != SUCCESS) {
zend_arena_release(&ctx->arena, checkpoint);
return;
}
zend_dfa_optimize_op_array(op_array, ctx, &ssa);
/* Destroy SSA */
zend_arena_release(&ctx->arena, checkpoint);
}
/*
* Local variables:
* tab-width: 4
* c-basic-offset: 4
* indent-tabs-mode: t
* End:
*/
|
