org.jikesrvm.util

Class Bits

java.lang.Object

org.jikesrvm.util.Bits

public class Bits
extends Object

Utilities for manipulating values at the bit-level.

Constructor Summary

Constructors

Constructor and Description
Bits()

Method Summary

Modifier and Type	Method and Description
static boolean	fits(Address val, int bits) Find out whether a given signed value can be represented in a given number of bits.
static boolean	fits(int val, int bits) Finds out whether a given signed value can be represented in a given number of bits.
static boolean	fits(long val, int bits) Finds out whether a given signed value can be represented in a given number of bits.
static boolean	fits(Offset val, int bits) Finds out whether a given signed value can be represented in a given number of bits.
static boolean	fits(Word val, int bits) Finds out whether a given signed value can be represented in a given number of bits.
static int	lower16(int value)
static int	lower32(long value)
static int	lower8(int value)
static int	PPCMaskLower16(int value)
static int	PPCMaskLower16(Offset value)
static int	PPCMaskUpper16(int value)
static int	PPCMaskUpper16(Offset value)
static int	upper16(int value)
static int	upper24(int value)
static int	upper32(long value)

Methods inherited from class java.lang.Object

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

Constructor Detail

Bits

public Bits()

Method Detail

PPCMaskLower16

public static int PPCMaskLower16(int value)

Parameters:

value - the value to mask

Returns:

the lower 16 bits to be used in a PPC immediate field

PPCMaskLower16

public static int PPCMaskLower16(Offset value)

Parameters:

value - the value to mask

Returns:

the lower 16 bits to be used in a PPC immediate field

PPCMaskUpper16

public static int PPCMaskUpper16(int value)

Parameters:

value - the value to mask

Returns:

the upper 16 bits to be used in a PPC immediate field

PPCMaskUpper16

public static int PPCMaskUpper16(Offset value)

Parameters:

value - the value to mask

Returns:

the upper 16 bits to be used in a PPC immediate field, make sure fits in 32 bits

lower8

public static int lower8(int value)

Parameters:

value - the value to mask

Returns:

the lower 8 bits (as an int) of an int

lower16

public static int lower16(int value)

Parameters:

value - the value to mask

Returns:

the lower 16 bits (as an int) of an int

upper16

public static int upper16(int value)

Parameters:

value - the value to mask

Returns:

the upper 16 bits (as an int) of an int

upper24

public static int upper24(int value)

Parameters:

value - the value to mask

Returns:

the upper 24 bits (as an int) of an int

lower32

public static int lower32(long value)

Parameters:

value - the value to mask

Returns:

the lower 32 bits (as an int) of a long

upper32

public static int upper32(long value)

Parameters:

value - the value to mask

Returns:

the upper 32 bits (as an int) of a long

fits

public static boolean fits(long val,
                           int bits)

Finds out whether a given signed value can be represented in a given number of bits.

Parameters:

val - the value to be represented

bits - the number of bits to use.

Returns:

true if val can be encoded in bits.

fits

public static boolean fits(Offset val,
                           int bits)

Finds out whether a given signed value can be represented in a given number of bits.

Parameters:

val - the value to be represented

bits - the number of bits to use.

Returns:

true if val can be encoded in bits.

fits

public static boolean fits(Address val,
                           int bits)

Find out whether a given signed value can be represented in a given number of bits.

Parameters:

val - the value to be represented

bits - the number of bits to use.

Returns:

true if val can be encoded in bits.

fits

public static boolean fits(int val,
                           int bits)

Finds out whether a given signed value can be represented in a given number of bits.

Parameters:

val - the value to be represented

bits - the number of bits to use.

Returns:

true if val can be encoded in bits.

fits

public static boolean fits(Word val,
                           int bits)

Finds out whether a given signed value can be represented in a given number of bits.

Parameters:

val - the value to be represented

bits - the number of bits to use.

Returns:

true if val can be encoded in bits.