hardware
Class Frame

java.lang.Object
  |
  +--hardware.Frame

public class Frame

extends java.lang.Object

Encapsulates a hardware-dependent subprogram frame. Makes assumptions about the wordsize of the machine as well as the procedure calling convention. Specifically, it assumes that the FP register is a pointer to the first procedure argument, with subsequent arguments at numerically greater offsets (toward the base of the stack). The local variables are located starting at FP minus the wordsize, and Frame initializes the offsetLocal variable in that way. The computed frame size (cbSize, in bytes) does not include space required for the parameters--they are assumed to be either in registers or added on to the caller's stack.

Field Summary

int	cbSize
int	offsetLocal
int	offsetParam
static int	wordsize

Constructor Summary

Frame()

Method Summary

int	addLocal() Create a new local in the frame.
int	addLocal(int size)
int	addParam() Create a new parameter in the frame.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

wordsize

public static final int wordsize

cbSize

public int cbSize

offsetLocal

public int offsetLocal

offsetParam

public int offsetParam

Constructor Detail

Frame

public Frame()

Method Detail

addLocal

public int addLocal()

Create a new local in the frame. Offsets grow more negative from FP.

addLocal

public int addLocal(int size)

addParam

public int addParam()

Create a new parameter in the frame. Offsets grow more positive from FP. Parameters do not contribute to the frame size, since they are allocated in the caller's frame.