php版本 PHP 5.3.14
1. ==(调用is_equal_function->compare_function ),!=(调用is_not_equal_function->compare_function)
<?php $i = 1; $j = 1.0; echo $i == $j;
//opcode
line # * op fetch ext return operands --------------------------------------------------------------------------------- 3 0 > ASSIGN !0, 1 4 1 ASSIGN !1, 1 6 2 IS_EQUAL ~2 !0, !1 3 ECHO ~2 7 4 > RETURN 1
调用Zend/zend_operators.c is_equal_function
if (compare_function(result, op1, op2 TSRMLS_CC) == FAILURE) { return FAILURE; } ZVAL_BOOL(result, (Z_LVAL_P(result) == 0)); return SUCCESS;
//compare_function,比较两个zval,op1,op2,结果记录到result,
switch (TYPE_PAIR(Z_TYPE_P(op1), Z_TYPE_P(op2))) { case TYPE_PAIR(IS_LONG, IS_LONG)://两个整形比较 ZVAL_LONG(result, Z_LVAL_P(op1)>Z_LVAL_P(op2)?1:(Z_LVAL_P(op1)<Z_LVAL_P(op2)?-1:0)); return SUCCESS; case TYPE_PAIR(IS_DOUBLE, IS_LONG)://一个double,一个整形,会将整形转化为double,相减, Z_DVAL_P(result) = Z_DVAL_P(op1) - (double)Z_LVAL_P(op2); ZVAL_LONG(result, ZEND_NORMALIZE_BOOL(Z_DVAL_P(result))); return SUCCESS; case TYPE_PAIR(IS_LONG, IS_DOUBLE)://同上, Z_DVAL_P(result) = (double)Z_LVAL_P(op1) - Z_DVAL_P(op2); ZVAL_LONG(result, ZEND_NORMALIZE_BOOL(Z_DVAL_P(result))); return SUCCESS; case TYPE_PAIR(IS_DOUBLE, IS_DOUBLE)://同上 Z_DVAL_P(result) = Z_DVAL_P(op1) - Z_DVAL_P(op2); ZVAL_LONG(result, ZEND_NORMALIZE_BOOL(Z_DVAL_P(result))); return SUCCESS; case TYPE_PAIR(IS_ARRAY, IS_ARRAY)://数组比较,todo zend_compare_arrays(result, op1, op2 TSRMLS_CC); return SUCCESS; case TYPE_PAIR(IS_NULL, IS_NULL)://null ZVAL_LONG(result, 0); return SUCCESS; case TYPE_PAIR(IS_NULL, IS_BOOL)://null bool ZVAL_LONG(result, Z_LVAL_P(op2) ? -1 : 0); return SUCCESS; case TYPE_PAIR(IS_BOOL, IS_NULL)://同上 ZVAL_LONG(result, Z_LVAL_P(op1) ? 1 : 0); return SUCCESS; case TYPE_PAIR(IS_BOOL, IS_BOOL)://bool,相减 ZVAL_LONG(result, ZEND_NORMALIZE_BOOL(Z_LVAL_P(op1) - Z_LVAL_P(op2))); return SUCCESS; case TYPE_PAIR(IS_STRING, IS_STRING)://两个字符串 todo zendi_smart_strcmp(result, op1, op2); return SUCCESS; case TYPE_PAIR(IS_NULL, IS_STRING)://字符串 null ZVAL_LONG(result, zend_binary_strcmp("", 0, Z_STRVAL_P(op2), Z_STRLEN_P(op2))); return SUCCESS; case TYPE_PAIR(IS_STRING, IS_NULL)://同上 ZVAL_LONG(result, zend_binary_strcmp(Z_STRVAL_P(op1), Z_STRLEN_P(op1), "", 0)); return SUCCESS; case TYPE_PAIR(IS_OBJECT, IS_NULL)://object null, ZVAL_LONG(result, 1); return SUCCESS; case TYPE_PAIR(IS_NULL, IS_OBJECT)://同上 ZVAL_LONG(result, -1); return SUCCESS; case TYPE_PAIR(IS_OBJECT, IS_OBJECT)://object todo /* If both are objects sharing the same comparision handler then use is */ if (Z_OBJ_HANDLER_P(op1,compare_objects) == Z_OBJ_HANDLER_P(op2,compare_objects)) { if (Z_OBJ_HANDLE_P(op1) == Z_OBJ_HANDLE_P(op2)) { /* object handles are identical, apprently this is the same object */ ZVAL_LONG(result, 0); return SUCCESS; } ZVAL_LONG(result, Z_OBJ_HT_P(op1)->compare_objects(op1, op2 TSRMLS_CC)); return SUCCESS; } /* break missing intentionally */ default: if (Z_TYPE_P(op1) == IS_OBJECT) { if (Z_OBJ_HT_P(op1)->get) { op_free = Z_OBJ_HT_P(op1)->get(op1 TSRMLS_CC); ret = compare_function(result, op_free, op2 TSRMLS_CC); zend_free_obj_get_result(op_free TSRMLS_CC); return ret; } else if (Z_TYPE_P(op2) != IS_OBJECT && Z_OBJ_HT_P(op1)->cast_object) { ALLOC_INIT_ZVAL(op_free); if (Z_OBJ_HT_P(op1)->cast_object(op1, op_free, Z_TYPE_P(op2) TSRMLS_CC) == FAILURE) { ZVAL_LONG(result, 1); zend_free_obj_get_result(op_free TSRMLS_CC); return SUCCESS; } ret = compare_function(result, op_free, op2 TSRMLS_CC); zend_free_obj_get_result(op_free TSRMLS_CC); return ret; } } if (Z_TYPE_P(op2) == IS_OBJECT) { if (Z_OBJ_HT_P(op2)->get) { op_free = Z_OBJ_HT_P(op2)->get(op2 TSRMLS_CC); ret = compare_function(result, op1, op_free TSRMLS_CC); zend_free_obj_get_result(op_free TSRMLS_CC); return ret; } else if (Z_TYPE_P(op1) != IS_OBJECT && Z_OBJ_HT_P(op2)->cast_object) { ALLOC_INIT_ZVAL(op_free); if (Z_OBJ_HT_P(op2)->cast_object(op2, op_free, Z_TYPE_P(op1) TSRMLS_CC) == FAILURE) { ZVAL_LONG(result, -1); zend_free_obj_get_result(op_free TSRMLS_CC); return SUCCESS; } ret = compare_function(result, op1, op_free TSRMLS_CC); zend_free_obj_get_result(op_free TSRMLS_CC); return ret; } else if (Z_TYPE_P(op1) == IS_OBJECT) { ZVAL_LONG(result, 1); return SUCCESS; } } if (!converted) { if (Z_TYPE_P(op1) == IS_NULL) { zendi_convert_to_boolean(op2, op2_copy, result); ZVAL_LONG(result, Z_LVAL_P(op2) ? -1 : 0); return SUCCESS; } else if (Z_TYPE_P(op2) == IS_NULL) { zendi_convert_to_boolean(op1, op1_copy, result); ZVAL_LONG(result, Z_LVAL_P(op1) ? 1 : 0); return SUCCESS; } else if (Z_TYPE_P(op1) == IS_BOOL) { zendi_convert_to_boolean(op2, op2_copy, result); ZVAL_LONG(result, ZEND_NORMALIZE_BOOL(Z_LVAL_P(op1) - Z_LVAL_P(op2))); return SUCCESS; } else if (Z_TYPE_P(op2) == IS_BOOL) { zendi_convert_to_boolean(op1, op1_copy, result); ZVAL_LONG(result, ZEND_NORMALIZE_BOOL(Z_LVAL_P(op1) - Z_LVAL_P(op2))); return SUCCESS; } else { zendi_convert_scalar_to_number(op1, op1_copy, result); zendi_convert_scalar_to_number(op2, op2_copy, result); converted = 1; } } else if (Z_TYPE_P(op1)==IS_ARRAY) { ZVAL_LONG(result, 1); return SUCCESS; } else if (Z_TYPE_P(op2)==IS_ARRAY) { ZVAL_LONG(result, -1); return SUCCESS; } else if (Z_TYPE_P(op1)==IS_OBJECT) { ZVAL_LONG(result, 1); return SUCCESS; } else if (Z_TYPE_P(op2)==IS_OBJECT) { ZVAL_LONG(result, -1); return SUCCESS; } else { ZVAL_LONG(result, 0); return FAILURE; } }