mixal::Register2 Struct Reference

#include <registers.h>

Public Member Functions
	Register2 ()
	Register2 (int16_t value)
	Register2 (bool _negative, uint8_t _byte1, uint8_t _byte2)
	Register2 (char sign, uint8_t _byte1, uint8_t _byte2)
void	reset ()
uint8_t	operator[] (int index) const
uint16_t	bytes12 () const
int16_t	value () const
void	set (int16_t value)
void	set (int index, int8_t val)
void	set (bool negative, uint8_t byte1, uint8_t byte2)
void	set (char sign, uint8_t byte1, uint8_t byte2)

Public Attributes
bool	negative
uint8_t	byte1
uint8_t	byte2

Detailed Description

The register with 2 bytes (rI, rJ).

The 2 bytes registers are used to represent locations and offsets. It contains a sign indicator (+ or -) and 2 bytes. Each byte can represent at least [0, 64) integers.

Definition at line 23 of file registers.h.

Constructor & Destructor Documentation

Register2() [1/4]

mixal::Register2::Register2

(

)

Initialize the register with zeros.

Definition at line 7 of file registers.cpp.

                     : negative(), byte1(), byte2() {
}

Register2() [2/4]

mixal::Register2::Register2 ( int16_t  value )

explicit

Initialize the register with an integer value.

See also

set(int16_t)

Definition at line 10 of file registers.cpp.

                                  : negative(), byte1(), byte2() {
    set(value);
}

References set(), and value().

Register2() [3/4]

mixal::Register2::Register2	(	bool	_negative,
		uint8_t	_byte1,
		uint8_t	_byte2
	)

Initialize the register with all the specific values.

Definition at line 14 of file registers.cpp.

                                                                   :
    negative(_negative), byte1(_byte1), byte2(_byte2) {
}

Register2() [4/4]

mixal::Register2::Register2	(	char	sign,
		uint8_t	_byte1,
		uint8_t	_byte2
	)

Initialize the register with all the specific values.

Exceptions

std::runtime_error

when the sign is neither '+' nor '-'.

Definition at line 18 of file registers.cpp.

                                                              :
    negative(sign == '-'), byte1(_byte1), byte2(_byte2) {
    if (sign != '+' && sign != '-') {
        throw std::runtime_error("Invalid sign: " + std::string(1, sign));
    }
}

Member Function Documentation

bytes12()

uint16_t mixal::Register2::bytes12

(

)

const

Get the absolution value of the register.

Definition at line 35 of file registers.cpp.

                                  {
    int16_t high = static_cast<int16_t>(static_cast<uint8_t>(byte1));
    int16_t low = static_cast<int16_t>(static_cast<uint8_t>(byte2));
    return high * 64 + low;
}

Referenced by value().

operator[]()

uint8_t mixal::Register2::operator[]

(

int

index

)

const

Get the value with index in [1, 2].

Exceptions

std::runtime_error

when the index is not in [1, 2].

Definition at line 25 of file registers.cpp.

                                             {
    if (index == 1) {
        return byte1;
    }
    if (index == 2) {
        return byte2;
    }
    throw std::runtime_error("Invalid index for a two bytes register: " + std::to_string(index));
}

reset()

void mixal::Register2::reset ( )

inline

Reset the values in the register to 0.

Definition at line 44 of file registers.h.

                        {
        negative = false;
        byte1 = byte2 = 0;
    }

Referenced by mixal::Computer::reset().

set() [1/4]

void mixal::Register2::set	(	bool	negative,
		uint8_t	byte1,
		uint8_t	byte2
	)

Set all the values.

Definition at line 67 of file registers.cpp.

                                                               {
    this->negative = negative;
    this->byte1 = byte1;
    this->byte2 = byte2;
}

set() [2/4]

void mixal::Register2::set	(	char	sign,
		uint8_t	byte1,
		uint8_t	byte2
	)

Set all the values.

Exceptions

std::runtime_error

when the sign is neither '+' nor '-'.

Definition at line 73 of file registers.cpp.

                                                           {
    if (sign != '+' && sign != '-') {
        throw std::runtime_error("Invalid sign: " + std::string(1, sign));
    }
    this->negative = sign == '-';
    this->byte1 = byte1;
    this->byte2 = byte2;
}

set() [3/4]

void mixal::Register2::set	(	int	index,
		int8_t	val
	)

Set specific byte with the given index in [1, 2].

Parameters

val	The behavior is undefined if it is greater than 63.

Exceptions

std::runtime_error

when the index is not in [1, 2].

Definition at line 57 of file registers.cpp.

                                         {
    if (index == 1) {
        byte1 = val;
    } else if (index == 2) {
        byte2 = val;
    } else {
        throw std::runtime_error("Invalid index for a two bytes register: " + std::to_string(index));
    }
}

set() [4/4]

void mixal::Register2::set

(

int16_t

value

)

Set the register with an integer.

The sign will be set only when the input is non-zero. Therefore to set the word to -0 with this function, one can set it with a negative value first, then set it to 0.

The least significant 12 bits will be saved to the word. Each byte contains 6 bits. The byte2 will contain the least significant 6 bits.

Definition at line 46 of file registers.cpp.

                                 {
    if (value > 0) {
        negative = false;
    } else if (value < 0) {
        negative = true;
        value = -value;
    }
    byte1 = static_cast<uint8_t>(value / (1 << 6));
    byte2 = static_cast<uint8_t>(value % (1 << 6));
}

References value().

Referenced by Register2().

value()

int16_t mixal::Register2::value

(

)

const

Get the value represented by the register.

Definition at line 41 of file registers.cpp.

                               {
    int16_t val = static_cast<int16_t>(bytes12());
    return negative ? -val : val;
}

References bytes12().

Referenced by Register2(), and set().

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The documentation for this struct was generated from the following files:

• include/registers.h
• src/registers.cpp