==== 7.5.65 isub ====

Subtract int 

Format 

isub 

Forms 

isub = 68 (0x44) 

Stack 

..., value1.word1, value1.word2, value2.word1, value2.word2 -> ..., result.word1, result.word2 

Description 

Both value1 and value2 must be of type int. The values are popped from the operand stack. The int result is value1 - value2. The result is pushed onto the operand stack. 

For int subtraction, a - b produces the same result as a + (-b). For int values, subtraction from zeros is the same as negation. 

Despite the fact that overflow or underflow may occur, in which case the result may have a different sign than the true mathematical result, execution of an isub instruction never throws a runtime exception. 

Notes 

If a virtual machine does not support the int data type, the isub instruction will not be available.