diff options
Diffstat (limited to 'Zend/Optimizer/escape_analysis.c')
| -rw-r--r-- | Zend/Optimizer/escape_analysis.c | 539 |
1 files changed, 539 insertions, 0 deletions
diff --git a/Zend/Optimizer/escape_analysis.c b/Zend/Optimizer/escape_analysis.c new file mode 100644 index 0000000000..c0d5081c1f --- /dev/null +++ b/Zend/Optimizer/escape_analysis.c @@ -0,0 +1,539 @@ +/* + +----------------------------------------------------------------------+ + | Zend OPcache, Escape Analysis | + +----------------------------------------------------------------------+ + | 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: | + | 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@php.net> | + +----------------------------------------------------------------------+ +*/ + +#include "php.h" +#include "Optimizer/zend_optimizer.h" +#include "Optimizer/zend_optimizer_internal.h" +#include "zend_bitset.h" +#include "zend_cfg.h" +#include "zend_ssa.h" +#include "zend_inference.h" +#include "zend_dump.h" + +/* + * T. Kotzmann and H. Mossenbock. Escape analysis in the context of dynamic + * compilation and deoptimization. In Proceedings of the International + * Conference on Virtual Execution Environments, pages 111-120, Chicago, + * June 2005 + */ + +static zend_always_inline void union_find_init(int *parent, int *size, int count) /* {{{ */ +{ + int i; + + for (i = 0; i < count; i++) { + parent[i] = i; + size[i] = 1; + } +} +/* }}} */ + +static zend_always_inline int union_find_root(int *parent, int i) /* {{{ */ +{ + int p = parent[i]; + + while (i != p) { + p = parent[p]; + parent[i] = p; + i = p; + p = parent[i]; + } + return i; +} +/* }}} */ + +static zend_always_inline void union_find_unite(int *parent, int *size, int i, int j) /* {{{ */ +{ + int r1 = union_find_root(parent, i); + int r2 = union_find_root(parent, j); + + if (r1 != r2) { + if (size[r1] < size[r2]) { + parent[r1] = r2; + size[r2] += size[r1]; + } else { + parent[r2] = r1; + size[r1] += size[r2]; + } + } +} +/* }}} */ + +static int zend_build_equi_escape_sets(int *parent, zend_op_array *op_array, zend_ssa *ssa) /* {{{ */ +{ + zend_ssa_var *ssa_vars = ssa->vars; + int ssa_vars_count = ssa->vars_count; + zend_ssa_phi *p; + int i, j; + int *size; + ALLOCA_FLAG(use_heap) + + size = do_alloca(sizeof(int) * ssa_vars_count, use_heap); + if (!size) { + return FAILURE; + } + union_find_init(parent, size, ssa_vars_count); + + for (i = 0; i < ssa_vars_count; i++) { + if (ssa_vars[i].definition_phi) { + p = ssa_vars[i].definition_phi; + if (p->pi >= 0) { + union_find_unite(parent, size, i, p->sources[0]); + } else { + for (j = 0; j < ssa->cfg.blocks[p->block].predecessors_count; j++) { + union_find_unite(parent, size, i, p->sources[j]); + } + } + } else if (ssa_vars[i].definition >= 0) { + int def = ssa_vars[i].definition; + zend_ssa_op *op = ssa->ops + def; + zend_op *opline = op_array->opcodes + def; + + if (op->op1_def >= 0) { + if (op->op1_use >= 0) { + if (opline->opcode != ZEND_ASSIGN) { + union_find_unite(parent, size, op->op1_def, op->op1_use); + } + } + if (opline->opcode == ZEND_ASSIGN && op->op2_use >= 0) { + union_find_unite(parent, size, op->op1_def, op->op2_use); + } + } + if (op->op2_def >= 0) { + if (op->op2_use >= 0) { + union_find_unite(parent, size, op->op2_def, op->op2_use); + } + } + if (op->result_def >= 0) { + if (op->result_use >= 0) { + if (opline->opcode != ZEND_QM_ASSIGN) { + union_find_unite(parent, size, op->result_def, op->result_use); + } + } + if (opline->opcode == ZEND_QM_ASSIGN && op->op1_use >= 0) { + union_find_unite(parent, size, op->result_def, op->op1_use); + } + if (opline->opcode == ZEND_ASSIGN && op->op2_use >= 0) { + union_find_unite(parent, size, op->result_def, op->op2_use); + } + if (opline->opcode == ZEND_ASSIGN && op->op1_def >= 0) { + union_find_unite(parent, size, op->result_def, op->op1_def); + } + } + } + } + + for (i = 0; i < ssa_vars_count; i++) { + parent[i] = union_find_root(parent, i); + } + + free_alloca(size, use_heap); + + return SUCCESS; +} +/* }}} */ + +static inline zend_class_entry *get_class_entry(const zend_script *script, zend_string *lcname) /* {{{ */ +{ + zend_class_entry *ce = script ? zend_hash_find_ptr(&script->class_table, lcname) : NULL; + if (ce) { + return ce; + } + + ce = zend_hash_find_ptr(CG(class_table), lcname); + if (ce && ce->type == ZEND_INTERNAL_CLASS) { + return ce; + } + + return NULL; +} +/* }}} */ + +static int is_allocation_def(zend_op_array *op_array, zend_ssa *ssa, int def, int var, const zend_script *script) /* {{{ */ +{ + zend_ssa_op *ssa_op = ssa->ops + def; + zend_op *opline = op_array->opcodes + def; + + if (ssa_op->result_def == var) { + switch (opline->opcode) { + case ZEND_INIT_ARRAY: + return 1; + case ZEND_NEW: + /* objects with destructors should escape */ + if (opline->op1_type == IS_CONST) { + zend_class_entry *ce = get_class_entry(script, Z_STR_P(CRT_CONSTANT(opline->op1)+1)); + uint32_t forbidden_flags = + /* These flags will always cause an exception */ + ZEND_ACC_IMPLICIT_ABSTRACT_CLASS | ZEND_ACC_EXPLICIT_ABSTRACT_CLASS + | ZEND_ACC_INTERFACE | ZEND_ACC_TRAIT; + if (ce && !ce->parent && !ce->create_object && !ce->constructor && + !ce->destructor && !ce->__get && !ce->__set && + !(ce->ce_flags & forbidden_flags) && + (ce->ce_flags & ZEND_ACC_CONSTANTS_UPDATED)) { + return 1; + } + } + break; + case ZEND_QM_ASSIGN: + if (opline->op1_type == IS_CONST + && Z_TYPE_P(CRT_CONSTANT(opline->op1)) == IS_ARRAY) { + return 1; + } + if (opline->op1_type == IS_CV && (OP1_INFO() & MAY_BE_ARRAY)) { + return 1; + } + break; + case ZEND_ASSIGN: + if (opline->op1_type == IS_CV && (OP1_INFO() & MAY_BE_ARRAY)) { + return 1; + } + break; + } + } else if (ssa_op->op1_def == var) { + switch (opline->opcode) { + case ZEND_ASSIGN: + if (opline->op2_type == IS_CONST + && Z_TYPE_P(CRT_CONSTANT(opline->op2)) == IS_ARRAY) { + return 1; + } + if (opline->op2_type == IS_CV && (OP2_INFO() & MAY_BE_ARRAY)) { + return 1; + } + break; + case ZEND_ASSIGN_DIM: + if (OP1_INFO() & (MAY_BE_UNDEF | MAY_BE_NULL | MAY_BE_FALSE)) { + /* implicit object/array allocation */ + return 1; + } + break; + } + } + + return 0; +} +/* }}} */ + +static int is_local_def(zend_op_array *op_array, zend_ssa *ssa, int def, int var, const zend_script *script) /* {{{ */ +{ + zend_ssa_op *op = ssa->ops + def; + zend_op *opline = op_array->opcodes + def; + + if (op->result_def == var) { + switch (opline->opcode) { + case ZEND_INIT_ARRAY: + case ZEND_ADD_ARRAY_ELEMENT: + case ZEND_QM_ASSIGN: + case ZEND_ASSIGN: + return 1; + case ZEND_NEW: + /* objects with destructors should escape */ + if (opline->op1_type == IS_CONST) { + zend_class_entry *ce = get_class_entry(script, Z_STR_P(CRT_CONSTANT(opline->op1)+1)); + if (ce && !ce->create_object && !ce->constructor && + !ce->destructor && !ce->__get && !ce->__set && !ce->parent) { + return 1; + } + } + break; + } + } else if (op->op1_def == var) { + switch (opline->opcode) { + case ZEND_ASSIGN: + case ZEND_ASSIGN_DIM: + case ZEND_ASSIGN_OBJ: + case ZEND_ASSIGN_OBJ_REF: + case ZEND_ASSIGN_DIM_OP: + case ZEND_ASSIGN_OBJ_OP: + case ZEND_PRE_INC_OBJ: + case ZEND_PRE_DEC_OBJ: + case ZEND_POST_INC_OBJ: + case ZEND_POST_DEC_OBJ: + return 1; + } + } + + return 0; +} +/* }}} */ + +static int is_escape_use(zend_op_array *op_array, zend_ssa *ssa, int use, int var) /* {{{ */ +{ + zend_ssa_op *ssa_op = ssa->ops + use; + zend_op *opline = op_array->opcodes + use; + + if (ssa_op->op1_use == var) { + switch (opline->opcode) { + case ZEND_ASSIGN: + /* no_val */ + break; + case ZEND_QM_ASSIGN: + if (opline->op1_type == IS_CV) { + if (OP1_INFO() & MAY_BE_OBJECT) { + /* object aliasing */ + return 1; + } + } + break; + case ZEND_ISSET_ISEMPTY_DIM_OBJ: + case ZEND_ISSET_ISEMPTY_PROP_OBJ: + case ZEND_FETCH_DIM_R: + case ZEND_FETCH_OBJ_R: + case ZEND_FETCH_DIM_IS: + case ZEND_FETCH_OBJ_IS: + break; + case ZEND_ASSIGN_OP: + return 1; + case ZEND_ASSIGN_DIM_OP: + case ZEND_ASSIGN_OBJ_OP: + case ZEND_ASSIGN_STATIC_PROP_OP: + case ZEND_ASSIGN_DIM: + case ZEND_ASSIGN_OBJ: + case ZEND_ASSIGN_OBJ_REF: + break; + case ZEND_PRE_INC_OBJ: + case ZEND_PRE_DEC_OBJ: + case ZEND_POST_INC_OBJ: + case ZEND_POST_DEC_OBJ: + break; + case ZEND_INIT_ARRAY: + case ZEND_ADD_ARRAY_ELEMENT: + if (opline->extended_value & ZEND_ARRAY_ELEMENT_REF) { + return 1; + } + if (OP1_INFO() & MAY_BE_OBJECT) { + /* object aliasing */ + return 1; + } + /* reference dependencies processed separately */ + break; + case ZEND_OP_DATA: + if ((opline-1)->opcode != ZEND_ASSIGN_DIM + && (opline-1)->opcode != ZEND_ASSIGN_OBJ) { + return 1; + } + if (OP1_INFO() & MAY_BE_OBJECT) { + /* object aliasing */ + return 1; + } + opline--; + ssa_op--; + if (opline->op1_type != IS_CV + || (OP1_INFO() & MAY_BE_REF) + || (ssa_op->op1_def >= 0 && ssa->vars[ssa_op->op1_def].alias)) { + /* assignment into escaping structure */ + return 1; + } + /* reference dependencies processed separately */ + break; + default: + return 1; + } + } + + if (ssa_op->op2_use == var) { + switch (opline->opcode) { + case ZEND_ASSIGN: + if (opline->op1_type != IS_CV + || (OP1_INFO() & MAY_BE_REF) + || (ssa_op->op1_def >= 0 && ssa->vars[ssa_op->op1_def].alias)) { + /* assignment into escaping variable */ + return 1; + } + if (opline->op2_type == IS_CV || opline->result_type != IS_UNUSED) { + if (OP2_INFO() & MAY_BE_OBJECT) { + /* object aliasing */ + return 1; + } + } + break; + default: + return 1; + } + } + + if (ssa_op->result_use == var) { + switch (opline->opcode) { + case ZEND_ASSIGN: + case ZEND_QM_ASSIGN: + case ZEND_INIT_ARRAY: + case ZEND_ADD_ARRAY_ELEMENT: + break; + default: + return 1; + } + } + + return 0; +} +/* }}} */ + +int zend_ssa_escape_analysis(const zend_script *script, zend_op_array *op_array, zend_ssa *ssa) /* {{{ */ +{ + zend_ssa_var *ssa_vars = ssa->vars; + int ssa_vars_count = ssa->vars_count; + int i, root, use; + int *ees; + bool has_allocations; + int num_non_escaped; + ALLOCA_FLAG(use_heap) + + if (!ssa_vars) { + return SUCCESS; + } + + has_allocations = 0; + for (i = op_array->last_var; i < ssa_vars_count; i++) { + if (ssa_vars[i].definition >= 0 + && (ssa->var_info[i].type & (MAY_BE_ARRAY|MAY_BE_OBJECT)) + && is_allocation_def(op_array, ssa, ssa_vars[i].definition, i, script)) { + has_allocations = 1; + break; + } + } + if (!has_allocations) { + return SUCCESS; + } + + + /* 1. Build EES (Equi-Escape Sets) */ + ees = do_alloca(sizeof(int) * ssa_vars_count, use_heap); + if (!ees) { + return FAILURE; + } + + if (zend_build_equi_escape_sets(ees, op_array, ssa) != SUCCESS) { + return FAILURE; + } + + /* 2. Identify Allocations */ + num_non_escaped = 0; + for (i = op_array->last_var; i < ssa_vars_count; i++) { + root = ees[i]; + if (ssa_vars[root].escape_state > ESCAPE_STATE_NO_ESCAPE) { + /* already escape. skip */ + } else if (ssa_vars[i].alias && (ssa->var_info[i].type & MAY_BE_REF)) { + if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) { + num_non_escaped--; + } + ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE; + } else if (ssa_vars[i].definition >= 0 + && (ssa->var_info[i].type & (MAY_BE_ARRAY|MAY_BE_OBJECT))) { + if (!is_local_def(op_array, ssa, ssa_vars[i].definition, i, script)) { + if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) { + num_non_escaped--; + } + ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE; + } else if (ssa_vars[root].escape_state == ESCAPE_STATE_UNKNOWN + && is_allocation_def(op_array, ssa, ssa_vars[i].definition, i, script)) { + ssa_vars[root].escape_state = ESCAPE_STATE_NO_ESCAPE; + num_non_escaped++; + } + } + } + + /* 3. Mark escaped EES */ + if (num_non_escaped) { + for (i = 0; i < ssa_vars_count; i++) { + if (ssa_vars[i].use_chain >= 0) { + root = ees[i]; + if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) { + FOREACH_USE(ssa_vars + i, use) { + if (is_escape_use(op_array, ssa, use, i)) { + ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE; + num_non_escaped--; + if (num_non_escaped == 0) { + i = ssa_vars_count; + } + break; + } + } FOREACH_USE_END(); + } + } + } + } + + /* 4. Process referential dependencies */ + if (num_non_escaped) { + bool changed; + + do { + changed = 0; + for (i = 0; i < ssa_vars_count; i++) { + if (ssa_vars[i].use_chain >= 0) { + root = ees[i]; + if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) { + FOREACH_USE(ssa_vars + i, use) { + zend_ssa_op *op = ssa->ops + use; + zend_op *opline = op_array->opcodes + use; + int enclosing_root; + + if (opline->opcode == ZEND_OP_DATA && + ((opline-1)->opcode == ZEND_ASSIGN_DIM || + (opline-1)->opcode == ZEND_ASSIGN_OBJ || + (opline-1)->opcode == ZEND_ASSIGN_OBJ_REF) && + op->op1_use == i && + (op-1)->op1_use >= 0) { + enclosing_root = ees[(op-1)->op1_use]; + } else if ((opline->opcode == ZEND_INIT_ARRAY || + opline->opcode == ZEND_ADD_ARRAY_ELEMENT) && + op->op1_use == i && + op->result_def >= 0) { + enclosing_root = ees[op->result_def]; + } else { + continue; + } + + if (ssa_vars[enclosing_root].escape_state == ESCAPE_STATE_UNKNOWN || + ssa_vars[enclosing_root].escape_state > ssa_vars[root].escape_state) { + if (ssa_vars[enclosing_root].escape_state == ESCAPE_STATE_UNKNOWN) { + ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE; + } else { + ssa_vars[root].escape_state = ssa_vars[enclosing_root].escape_state; + } + if (ssa_vars[root].escape_state == ESCAPE_STATE_GLOBAL_ESCAPE) { + num_non_escaped--; + if (num_non_escaped == 0) { + changed = 0; + } else { + changed = 1; + } + break; + } else { + changed = 1; + } + } + } FOREACH_USE_END(); + } + } + } + } while (changed); + } + + /* 5. Propagate values of escape sets to variables */ + for (i = 0; i < ssa_vars_count; i++) { + root = ees[i]; + if (i != root) { + ssa_vars[i].escape_state = ssa_vars[root].escape_state; + } + } + + free_alloca(ees, use_heap); + + return SUCCESS; +} +/* }}} */ |