root/ext/opcache/Optimizer/pass1_5.c

/* [<][>][^][v][top][bottom][index][help] */
/* pass 1
 * - substitute persistent constants (true, false, null, etc)
 * - perform compile-time evaluation of constant binary and unary operations
 * - optimize series of ADD_STRING and/or ADD_CHAR
 * - convert CAST(IS_BOOL,x) into BOOL(x)
 * - convert INTI_FCALL_BY_NAME, DO_FCALL_BY_NAME into DO_FCALL
 */

if (ZEND_OPTIMIZER_PASS_1 & OPTIMIZATION_LEVEL) {
        int i = 0;
        zend_op *opline = op_array->opcodes;
        zend_op *end = opline + op_array->last;

        while (opline < end) {
                switch (opline->opcode) {
                case ZEND_ADD:
                case ZEND_SUB:
                case ZEND_MUL:
                case ZEND_DIV:
                case ZEND_MOD:
                case ZEND_SL:
                case ZEND_SR:
                case ZEND_CONCAT:
                case ZEND_IS_EQUAL:
                case ZEND_IS_NOT_EQUAL:
                case ZEND_IS_SMALLER:
                case ZEND_IS_SMALLER_OR_EQUAL:
                case ZEND_IS_IDENTICAL:
                case ZEND_IS_NOT_IDENTICAL:
                case ZEND_BW_OR:
                case ZEND_BW_AND:
                case ZEND_BW_XOR:
                case ZEND_BOOL_XOR:
                        if (ZEND_OP1_TYPE(opline) == IS_CONST &&
                                ZEND_OP2_TYPE(opline) == IS_CONST) {
                                /* binary operation with constant operands */
                                int (*binary_op)(zval *result, zval *op1, zval *op2 TSRMLS_DC) = get_binary_op(opline->opcode);
                                zend_uint tv = ZEND_RESULT(opline).var;         /* temporary variable */
                                zval result;
                                int er;

                                if (opline->opcode == ZEND_DIV &&
                                        Z_TYPE(ZEND_OP2_LITERAL(opline)) == IS_LONG &&
                                        Z_LVAL(ZEND_OP2_LITERAL(opline)) == 0) {
                                        /* div by 0 */
                                        break;
                                }
                                er = EG(error_reporting);
                                EG(error_reporting) = 0;
                                /* evaluate constant expression */
                                if (binary_op(&result, &ZEND_OP1_LITERAL(opline), &ZEND_OP2_LITERAL(opline) TSRMLS_CC) != SUCCESS) {
                                        EG(error_reporting) = er;
                                        break;
                                }
                                EG(error_reporting) = er;
                                PZ_SET_REFCOUNT_P(&result, 1);
                                PZ_UNSET_ISREF_P(&result);

                                literal_dtor(&ZEND_OP1_LITERAL(opline));
                                literal_dtor(&ZEND_OP2_LITERAL(opline));
                                MAKE_NOP(opline);

                                replace_tmp_by_const(op_array, opline + 1, tv, &result TSRMLS_CC);
                        }
                        break;

                case ZEND_CAST:
                        if (ZEND_OP1_TYPE(opline) == IS_CONST &&
                                opline->extended_value != IS_ARRAY &&
                                opline->extended_value != IS_OBJECT &&
                                opline->extended_value != IS_RESOURCE) {
                                /* cast of constant operand */
                                zend_uint tv = ZEND_RESULT(opline).var;         /* temporary variable */
                                zval res;
                                res = ZEND_OP1_LITERAL(opline);
                                zval_copy_ctor(&res);
                                switch (opline->extended_value) {
                                        case IS_NULL:
                                                convert_to_null(&res);
                                                break;
                                        case IS_BOOL:
                                                convert_to_boolean(&res);
                                                break;
                                        case IS_LONG:
                                                convert_to_long(&res);
                                                break;
                                        case IS_DOUBLE:
                                                convert_to_double(&res);
                                                break;
                                        case IS_STRING:
                                                convert_to_string(&res);
                                                break;
                                }

                                literal_dtor(&ZEND_OP1_LITERAL(opline));
                                MAKE_NOP(opline);

                                replace_tmp_by_const(op_array, opline + 1, tv, &res TSRMLS_CC);
                        } else if (opline->extended_value == IS_BOOL) {
                                /* T = CAST(X, IS_BOOL) => T = BOOL(X) */
                                opline->opcode = ZEND_BOOL;
                                opline->extended_value = 0;
                        }
                        break;

                case ZEND_BW_NOT:
                case ZEND_BOOL_NOT:
                        if (ZEND_OP1_TYPE(opline) == IS_CONST) {
                                /* unary operation on constant operand */
                                unary_op_type unary_op = get_unary_op(opline->opcode);
                                zval result;
                                zend_uint tv = ZEND_RESULT(opline).var;         /* temporary variable */
                                int er;

                                er = EG(error_reporting);
                                EG(error_reporting) = 0;
#if ZEND_EXTENSION_API_NO < PHP_5_3_X_API_NO
                                if (unary_op(&result, &ZEND_OP1_LITERAL(opline)) != SUCCESS) {
#else
                                if (unary_op(&result, &ZEND_OP1_LITERAL(opline) TSRMLS_CC) != SUCCESS) {
#endif
                                        EG(error_reporting) = er;
                                        break;
                                }
                                EG(error_reporting) = er;
                                PZ_SET_REFCOUNT_P(&result, 1);
                                PZ_UNSET_ISREF_P(&result);

                                literal_dtor(&ZEND_OP1_LITERAL(opline));
                                MAKE_NOP(opline);

                                replace_tmp_by_const(op_array, opline + 1, tv, &result TSRMLS_CC);
                        }
                        break;

                case ZEND_ADD_STRING:
                case ZEND_ADD_CHAR:
                        {
                                zend_op *next_op = opline + 1;
                                int requires_conversion = (opline->opcode == ZEND_ADD_CHAR? 1 : 0);
                                size_t final_length = 0;
                                char *ptr;
                                zend_op *last_op;

                                /* There is always a ZEND_RETURN at the end
                                if (next_op>=end) {
                                        break;
                                }
                                */
                                while (next_op->opcode == ZEND_ADD_STRING || next_op->opcode == ZEND_ADD_CHAR) {
                                        if (ZEND_RESULT(opline).var != ZEND_RESULT(next_op).var) {
                                                break;
                                        }
                                        if (next_op->opcode == ZEND_ADD_CHAR) {
                                                final_length += 1;
                                        } else { /* ZEND_ADD_STRING */
                                                final_length += ZEND_OP2_LITERAL(next_op).value.str.len;
                                        }
                                        next_op++;
                                }
                                if (final_length == 0) {
                                        break;
                                }
                                last_op = next_op;
                                final_length += (requires_conversion? 1 : ZEND_OP2_LITERAL(opline).value.str.len);
                                ptr = (char *)emalloc(final_length + 1);
                                ptr[final_length] = '\0';
                                if (requires_conversion) { /* ZEND_ADD_CHAR */
                                        char chval = (char)ZEND_OP2_LITERAL(opline).value.lval;

                                        ZEND_OP2_LITERAL(opline).value.str.val = ptr;
                                        ptr[0] = chval;
                                        ZEND_OP2_LITERAL(opline).type = IS_STRING;
                                        opline->opcode = ZEND_ADD_STRING;
                                        ptr++;
                                } else { /* ZEND_ADD_STRING */
                                        memcpy(ptr, Z_STRVAL(ZEND_OP2_LITERAL(opline)), Z_STRLEN(ZEND_OP2_LITERAL(opline)));
                                        if (!IS_INTERNED(Z_STRVAL(ZEND_OP2_LITERAL(opline)))) {
                                                efree(Z_STRVAL(ZEND_OP2_LITERAL(opline)));
                                        }
                                        Z_STRVAL(ZEND_OP2_LITERAL(opline)) = ptr;
                                        ptr += Z_STRLEN(ZEND_OP2_LITERAL(opline));
                                }
                                ZEND_OP2_LITERAL(opline).value.str.len = final_length;
                                next_op = opline + 1;
                                while (next_op < last_op) {
                                        if (next_op->opcode == ZEND_ADD_STRING) {
                                                memcpy(ptr, ZEND_OP2_LITERAL(next_op).value.str.val, ZEND_OP2_LITERAL(next_op).value.str.len);
                                                ptr += ZEND_OP2_LITERAL(next_op).value.str.len;
                                                literal_dtor(&ZEND_OP2_LITERAL(next_op));
                                        } else { /* ZEND_ADD_CHAR */
                                                *ptr = (char)ZEND_OP2_LITERAL(next_op).value.lval;
                                                ptr++;
                                        }
                                        MAKE_NOP(next_op);
                                        next_op++;
                                }
                                if (!((ZEND_OPTIMIZER_PASS_5|ZEND_OPTIMIZER_PASS_10) & OPTIMIZATION_LEVEL)) {
                                        /* NOP removal is disabled => insert JMP over NOPs */
                                        if (last_op-opline >= 3) { /* If we have more than 2 NOPS then JMP over them */
                                                (opline + 1)->opcode = ZEND_JMP;
                                                ZEND_OP1(opline + 1).opline_num = last_op - op_array->opcodes; /* that's OK even for ZE2, since opline_num's are resolved in pass 2 later */
                                        }
                                }
                        }
                        break;

                case ZEND_FETCH_CONSTANT:
                        if (ZEND_OP1_TYPE(opline) == IS_UNUSED &&
                                ZEND_OP2_TYPE(opline) == IS_CONST &&
                                Z_TYPE(ZEND_OP2_LITERAL(opline)) == IS_STRING &&
                                Z_STRLEN(ZEND_OP2_LITERAL(opline)) == sizeof("__COMPILER_HALT_OFFSET__") - 1 &&
                                memcmp(Z_STRVAL(ZEND_OP2_LITERAL(opline)), "__COMPILER_HALT_OFFSET__", sizeof("__COMPILER_HALT_OFFSET__") - 1) == 0) {
                                /* substitute __COMPILER_HALT_OFFSET__ constant */
                                zend_bool orig_in_execution = EG(in_execution);
                                zend_op_array *orig_op_array = EG(active_op_array);
                                zval offset;

                                EG(in_execution) = 1;
                                EG(active_op_array) = op_array;
                                if (zend_get_constant("__COMPILER_HALT_OFFSET__", sizeof("__COMPILER_HALT_OFFSET__") - 1, &offset TSRMLS_CC)) {
                                        zend_uint tv = ZEND_RESULT(opline).var;

                                        literal_dtor(&ZEND_OP2_LITERAL(opline));
                                        MAKE_NOP(opline);
                                        replace_tmp_by_const(op_array, opline, tv, &offset TSRMLS_CC);
                                }
                                EG(active_op_array) = orig_op_array;
                                EG(in_execution) = orig_in_execution;
                                break;
                        }

                        if (ZEND_OP1_TYPE(opline) == IS_UNUSED &&
                                ZEND_OP2_TYPE(opline) == IS_CONST &&
                                ZEND_OP2_LITERAL(opline).type == IS_STRING) {
                                /* substitute persistent constants */
                                zend_uint tv = ZEND_RESULT(opline).var;
                                zval c;

                                if (!zend_get_persistent_constant(Z_STRVAL(ZEND_OP2_LITERAL(opline)), Z_STRLEN(ZEND_OP2_LITERAL(opline)), &c, 1 TSRMLS_CC)) {
                                        break;
                                }
                                literal_dtor(&ZEND_OP2_LITERAL(opline));
                                MAKE_NOP(opline);
                                replace_tmp_by_const(op_array, opline, tv, &c TSRMLS_CC);
                        }
                        break;

                case ZEND_INIT_FCALL_BY_NAME:
                        if (opline->extended_value == 0 /* not method */ &&
                                ZEND_OP1_TYPE(opline) == IS_UNUSED &&
                                ZEND_OP2_TYPE(opline) == IS_CONST) {
                                if ((opline + 1)->opcode == ZEND_DO_FCALL_BY_NAME &&
                                        (opline + 1)->extended_value == 0) {
                                        (opline + 1)->opcode = ZEND_DO_FCALL;
                                        COPY_NODE((opline + 1)->op1, opline->op2);
                                        zend_str_tolower(Z_STRVAL(ZEND_OP1_LITERAL(opline + 1)), Z_STRLEN(ZEND_OP1_LITERAL(opline + 1)));
#if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
                                        Z_HASH_P(&ZEND_OP1_LITERAL(opline + 1)) = zend_hash_func(Z_STRVAL(ZEND_OP1_LITERAL(opline + 1)), Z_STRLEN(ZEND_OP1_LITERAL(opline + 1)) + 1);
                                        op_array->literals[(opline + 1)->op1.constant].cache_slot = op_array->last_cache_slot++;
#endif
                                        MAKE_NOP(opline);
                                }
                        }
                        break;

#if ZEND_EXTENSION_API_NO >= PHP_5_5_X_API_NO
                case ZEND_FETCH_R:
                case ZEND_FETCH_W:
                case ZEND_FETCH_RW:
                case ZEND_FETCH_FUNC_ARG:
                case ZEND_FETCH_IS:
                case ZEND_FETCH_UNSET:
                        if (opline != op_array->opcodes &&
                            (opline-1)->opcode == ZEND_BEGIN_SILENCE &&
                            (opline->extended_value & ZEND_FETCH_TYPE_MASK) == ZEND_FETCH_LOCAL &&
                                opline->op1_type == IS_CONST &&
                            opline->op2_type == IS_UNUSED &&
                            Z_TYPE(ZEND_OP1_LITERAL(opline)) == IS_STRING &&
                            (Z_STRLEN(ZEND_OP1_LITERAL(opline)) != sizeof("this")-1 ||
                             memcmp(Z_STRVAL(ZEND_OP1_LITERAL(opline)), "this", sizeof("this")) != 0)) {

                            int var = opline->result.var;
                            int level = 0;
                                zend_op *op = opline + 1;
                                zend_op *use = NULL;

                                while (op < end) {
                                        if (op->opcode == ZEND_BEGIN_SILENCE) {
                                                level++;
                                        } else if (op->opcode == ZEND_END_SILENCE) {
                                                if (level == 0) {
                                                        break;
                                                } else {
                                                        level--;
                                                }
                                        }
                                        if (op->op1_type == IS_VAR && op->op1.var == var) {
                                                if (use) {
                                                        /* used more than once */
                                                        use = NULL;
                                                        break;
                                                }
                                                use = op;
                                        } else if (op->op2_type == IS_VAR && op->op2.var == var) {
                                                if (use) {
                                                        /* used more than once */
                                                        use = NULL;
                                                        break;
                                                }
                                                use = op;
                                        }
                                        op++;
                                }
                                if (use) {
                                        if (use->op1_type == IS_VAR && use->op1.var == var) {
                                                use->op1_type = IS_CV;
                                                use->op1.var = zend_optimizer_lookup_cv(op_array,
                                                        Z_STRVAL(ZEND_OP1_LITERAL(opline)),
                                                        Z_STRLEN(ZEND_OP1_LITERAL(opline)));
                                                MAKE_NOP(opline);
                                        } else if (use->op2_type == IS_VAR && use->op2.var == var) {
                                                use->op2_type = IS_CV;
                                                use->op2.var = zend_optimizer_lookup_cv(op_array,
                                                        Z_STRVAL(ZEND_OP1_LITERAL(opline)),
                                                        Z_STRLEN(ZEND_OP1_LITERAL(opline)));
                                                MAKE_NOP(opline);
                                        }
                                }
                        }
                        break;
#endif
                
                }
                opline++;
                i++;
        }
}

/* [<][>][^][v][top][bottom][index][help] */