My Project: address.hh File Reference

Classes for specifying addresses and other low-level constants. More...

#include "space.hh"

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Classes
class	Address
	A low-level machine address for labelling bytes and data. More...

class	SeqNum
	A class for uniquely labelling and comparing PcodeOps. More...

class	Range
	A contiguous range of bytes in some address space. More...

class	RangeList
	A disjoint set of Ranges, possibly across multiple address spaces. More...

Functions
uintb	calc_mask (int4 size)
	Calculate a mask for a given byte size. More...

uintb	pcode_right (uintb val, int4 sa)

uintb	pcode_left (uintb val, int4 sa)

uintb	minimalmask (uintb val)
	Calculate smallest mask that covers the given value. More...

bool	signbit_negative (uintb val, int4 size)
	Return true if the sign-bit is set. More...

uintb	uintb_negate (uintb in, int4 size)
	Negate the sized value. More...

uintb	sign_extend (uintb in, int4 sizein, int4 sizeout)
	Sign-extend a value between two byte sizes. More...

void	sign_extend (intb &val, int4 bit)
	Sign extend above given bit. More...

void	zero_extend (intb &val, int4 bit)
	Clear all bits above given bit. More...

void	byte_swap (intb &val, int4 size)
	Swap bytes in the given value. More...

uintb	byte_swap (uintb val, int4 size)
	Return the given value with bytes swapped. More...

int4	leastsigbit_set (uintb val)
	Return index of least significant bit set in given value. More...

int4	mostsigbit_set (uintb val)
	Return index of most significant bit set in given value. More...

int4	popcount (uintb val)
	Return the number of one bits in the given value. More...

int4	count_leading_zeros (uintb val)
	Return the number of leading zero bits in the given value. More...

uintb	coveringmask (uintb val)
	Return a mask that covers the given value. More...

int4	bit_transitions (uintb val, int4 sz)
	Calculate the number of bit transitions in the sized value. More...

void	mult64to128 (uint8 *res, uint8 x, uint8 y)
	Multiply 2 unsigned 64-bit values, producing a 128-bit value. More...

void	unsignedSubtract128 (uint8 a, uint8 b)
	Subtract (in-place) a 128-bit value from a base 128-value. More...

int4	unsignedCompare128 (uint8 a, uint8 b)
	Compare two unsigned 128-bit values. More...

int4	power2Divide (int4 n, uint8 divisor, uint8 &q, uint8 &r)
	Unsigned division of a power of 2 (upto 2^127) by a 64-bit divisor. More...

Variables
uintb	uintbmasks []
	Precalculated masks indexed by size.

Detailed Description

Classes for specifying addresses and other low-level constants.

All addresses are absolute and there are are no registers in CPUI. However, all addresses are prefixed with an "immutable" pointer, which can specify a separate RAM space, a register space, an i/o space etc. Thus a translation from a real machine language will typically simulate registers by placing them in their own space, separate from RAM. Indirection (i.e. pointers) must be simulated through the LOAD and STORE ops.

Function Documentation

◆ bit_transitions()

int4 bit_transitions	(	uintb	val,
		int4	sz
	)

Calculate the number of bit transitions in the sized value.

Treat val as a constant of size sz. Scanning across the bits of val return the number of transitions (from 0->1 or 1->0) If there are 2 or less transitions, this is an indication of a bit flag or a mask

Parameters

val	is the given value
sz	is the size to treat the value as

Returns: the number of transitions

◆ byte_swap() [1/2]

void byte_swap	(	intb &	val,
		int4	size
	)

Swap bytes in the given value.

Swap the least significant size bytes in val

Parameters

val	is a reference to the value to swap
size	is the number of bytes to swap

◆ byte_swap() [2/2]

uintb byte_swap	(	uintb	val,
		int4	size
	)

Return the given value with bytes swapped.

Swap the least significant size bytes in val

Parameters

val	is the value to swap
size	is the number of bytes to swap

Returns: the swapped value

◆ calc_mask()

uintb calc_mask ( int4 size )

inline

Calculate a mask for a given byte size.

Parameters

size	is the desired size in bytes

Returns: a value appropriate for masking off the first size bytes

◆ count_leading_zeros()

int4 count_leading_zeros ( uintb val )

Return the number of leading zero bits in the given value.

Count the number of more significant zero bits before the most significant one bit in the representation of the given value;

Parameters

val	is the given value

Returns: the number of zero bits

◆ coveringmask()

uintb coveringmask ( uintb val )

Return a mask that covers the given value.

Return smallest number of form 2^n-1, bigger or equal to the given value

Parameters

val	is the given value

Returns: the mask

◆ leastsigbit_set()

int4 leastsigbit_set ( uintb val )

Return index of least significant bit set in given value.

The least significant bit is index 0.

Parameters

val	is the given value

Returns: the index of the least significant set bit, or -1 if none are set

◆ minimalmask()

uintb minimalmask ( uintb val )

inline

Calculate smallest mask that covers the given value.

Calculcate a mask that covers either the least significant byte, uint2, uint4, or uint8, whatever is smallest.

Parameters

val	is the given value

Returns: the minimal mask

◆ mostsigbit_set()

int4 mostsigbit_set ( uintb val )

Return index of most significant bit set in given value.

The least significant bit is index 0.

Parameters

val	is the given value

Returns: the index of the most significant set bit, or -1 if none are set

◆ mult64to128()

void mult64to128	(	uint8 *	res,
		uint8	x,
		uint8	y
	)

Multiply 2 unsigned 64-bit values, producing a 128-bit value.

TODO: Remove once we import a full multiprecision library.

Parameters

res	points to the result array (2 uint8 pieces)
x	is the first 64-bit value
y	is the second 64-bit value

◆ pcode_left()

uintb pcode_left	(	uintb	val,
		int4	sa
	)

inline

Perform a CPUI_INT_LEFT on the given val

Parameters

val	is the value to shift
sa	is the number of bits to shift

Returns: the shifted value

◆ pcode_right()

uintb pcode_right	(	uintb	val,
		int4	sa
	)

inline

Perform a CPUI_INT_RIGHT on the given val

Parameters

val	is the value to shift
sa	is the number of bits to shift

Returns: the shifted value

◆ popcount()

int4 popcount ( uintb val )

Return the number of one bits in the given value.

Count the number (population) bits set.

Parameters

val	is the given value

Returns: the number of one bits

◆ power2Divide()

int4 power2Divide	(	int4	n,
		uint8	divisor,
		uint8 &	q,
		uint8 &	r
	)

Unsigned division of a power of 2 (upto 2^127) by a 64-bit divisor.

The result must be less than 2^64. The remainder is calculated.

Parameters

n	is the power of 2 for the numerand
divisor	is the 64-bit divisor
q	is the passed back 64-bit quotient
r	is the passed back 64-bit remainder

Returns: 0 if successful, 1 if result is too big, 2 if divide by 0

◆ sign_extend() [1/2]

uintb sign_extend	(	uintb	in,
		int4	sizein,
		int4	sizeout
	)

Sign-extend a value between two byte sizes.

Take the first sizein bytes of the given in and sign-extend this to sizeout bytes, keeping any more significant bytes zero

Parameters

in	is the given value
sizein	is the size to treat that value as an input
sizeout	is the size to sign-extend the value to

Returns: the sign-extended value

◆ sign_extend() [2/2]

void sign_extend	(	intb &	val,
		int4	bit
	)

Sign extend above given bit.

Sign extend val starting at bit

Parameters

val	is a reference to the value to be sign-extended
bit	is the index of the bit to extend from (0=least significant bit)

◆ signbit_negative()

bool signbit_negative	(	uintb	val,
		int4	size
	)

Return true if the sign-bit is set.

Treat the given val as a constant of size bytes

Parameters

val	is the given value
size	is the size in bytes

Returns: true if the constant (as sized) has its sign bit set

◆ uintb_negate()

uintb uintb_negate	(	uintb	in,
		int4	size
	)

Negate the sized value.

Treat the given in as a constant of size bytes. Negate this constant keeping the upper bytes zero.

Parameters

in	is the given value
size	is the size in bytes

Returns: the negation of the sized constant

◆ unsignedCompare128()

int4 unsignedCompare128	(	uint8 *	a,
		uint8 *	b
	)

Compare two unsigned 128-bit values.

TODO: Remove once we import a full multiprecision library. Given a first and second value, return -1, 0, or 1 depending on whether the first value is less, equal, or greater than the second value.

Parameters

a	is the first 128-bit value (as an array of 2 uint8 elements)
b	is the second 128-bit value

Returns: the comparison code

◆ unsignedSubtract128()

void unsignedSubtract128	(	uint8 *	a,
		uint8 *	b
	)

Subtract (in-place) a 128-bit value from a base 128-value.

The base value is altered in place. TODO: Remove once we import a full multiprecision library.

Parameters

a	is the base 128-bit value being subtracted from in-place
b	is the other 128-bit value being subtracted

◆ zero_extend()

void zero_extend	(	intb &	val,
		int4	bit
	)

Clear all bits above given bit.

Zero extend val starting at bit

Parameters

val	is a reference to the value to be zero extended
bit	is the index of the bit to extend from (0=least significant bit)

Classes

Functions

Variables

Detailed Description

Function Documentation

◆ bit_transitions()

◆ byte_swap() [1/2]

◆ byte_swap() [2/2]

◆ calc_mask()

◆ count_leading_zeros()

◆ coveringmask()

◆ leastsigbit_set()

◆ minimalmask()

◆ mostsigbit_set()

◆ mult64to128()

◆ pcode_left()

◆ pcode_right()

◆ popcount()

◆ power2Divide()

◆ sign_extend() [1/2]

◆ sign_extend() [2/2]

◆ signbit_negative()

◆ uintb_negate()

◆ unsignedCompare128()

◆ unsignedSubtract128()

◆ zero_extend()