Introduction to Compiler Construction in a Java World

JVM Code Generation 191

Casting an int to an Integer is called boxing and requires an invocation of the Integer

.valueOf() method:

invoke s t atic java / lang / I n t e g e r . valueOf :(I ) Ljava / lang / Integer ;

Casting an Integer to an int is called unboxing and requires an invocation of the

Integer.intValue() method:

invok e v irtua l java / lang / Integer . intValue :() I

Certain casts, from one primitive type to another, require that a special instruction be

executed. For example, the i2c instruction converts an int to a char. There is a Converter

defined for each valid conversion in j--.

5.8 Further Readings

[Lindholm and Yellin, 1999] is the