contur::ALU Class Reference

Arithmetic Logic Unit — performs all computational operations. More...

#include <alu.h>

Public Member Functions
	ALU ()=default
	~ALU ()=default
	ALU (const ALU &)=default
ALU &	operator= (const ALU &)=default
	ALU (ALU &&) noexcept=default
ALU &	operator= (ALU &&) noexcept=default
Result< RegisterValue >	add (RegisterValue a, RegisterValue b) const noexcept
	Addition: a + b.
Result< RegisterValue >	sub (RegisterValue a, RegisterValue b) const noexcept
	Subtraction: a - b.
Result< RegisterValue >	mul (RegisterValue a, RegisterValue b) const noexcept
	Multiplication: a * b.
Result< RegisterValue >	div (RegisterValue a, RegisterValue b) const noexcept
	Division: a / b.
Result< RegisterValue >	bitwiseAnd (RegisterValue a, RegisterValue b) const noexcept
	Bitwise AND: a & b.
Result< RegisterValue >	bitwiseOr (RegisterValue a, RegisterValue b) const noexcept
	Bitwise OR: a | b.
Result< RegisterValue >	bitwiseXor (RegisterValue a, RegisterValue b) const noexcept
	Bitwise XOR: a ^ b.
Result< RegisterValue >	shiftLeft (RegisterValue a, RegisterValue b) const noexcept
	Left shift: a << b.
Result< RegisterValue >	shiftRight (RegisterValue a, RegisterValue b) const noexcept
	Right shift: a >> b (arithmetic shift).
RegisterValue	compare (RegisterValue a, RegisterValue b) const noexcept
	Compares two values and returns a flags word.

Static Public Attributes
static constexpr RegisterValue	ZERO_FLAG = 1
	a == b
static constexpr RegisterValue	SIGN_FLAG = 2
	a < b

Detailed Description

Arithmetic Logic Unit — performs all computational operations.

The ALU is owned by the CPU and invoked during the execute phase of the fetch-decode-execute cycle. All methods are pure functions: they take operands and return results without side effects.

Definition at line 20 of file alu.h.

Constructor & Destructor Documentation

ALU() [1/3]

contur::ALU::ALU ( )

default

~ALU()

contur::ALU::~ALU ( )

default

ALU() [2/3]

contur::ALU::ALU ( const ALU & )

default

ALU() [3/3]

contur::ALU::ALU ( ALU && )

defaultnoexcept

Member Function Documentation

add()

Result< RegisterValue > contur::ALU::add ( RegisterValue a, RegisterValue b ) const

nodiscardnoexcept

Addition: a + b.

bitwiseAnd()

Result< RegisterValue > contur::ALU::bitwiseAnd ( RegisterValue a, RegisterValue b ) const

nodiscardnoexcept

Bitwise AND: a & b.

bitwiseOr()

Result< RegisterValue > contur::ALU::bitwiseOr ( RegisterValue a, RegisterValue b ) const

nodiscardnoexcept

Bitwise OR: a | b.

bitwiseXor()

Result< RegisterValue > contur::ALU::bitwiseXor ( RegisterValue a, RegisterValue b ) const

nodiscardnoexcept

Bitwise XOR: a ^ b.

compare()

RegisterValue contur::ALU::compare ( RegisterValue a, RegisterValue b ) const

nodiscardnoexcept

Compares two values and returns a flags word.

The returned value encodes comparison flags:

• Bit 0 (ZERO_FLAG): set if a == b
• Bit 1 (SIGN_FLAG): set if a < b (signed comparison)

Returns

A flags word (never fails).

div()

Result< RegisterValue > contur::ALU::div ( RegisterValue a, RegisterValue b ) const

nodiscardnoexcept

Division: a / b.

Returns

DivisionByZero error if b == 0.

mul()

Result< RegisterValue > contur::ALU::mul ( RegisterValue a, RegisterValue b ) const

nodiscardnoexcept

Multiplication: a * b.

operator=() [1/2]

ALU & contur::ALU::operator= ( ALU && )

defaultnoexcept

operator=() [2/2]

ALU & contur::ALU::operator= ( const ALU & )

default

shiftLeft()

Result< RegisterValue > contur::ALU::shiftLeft ( RegisterValue a, RegisterValue b ) const

nodiscardnoexcept

Left shift: a << b.

shiftRight()

Result< RegisterValue > contur::ALU::shiftRight ( RegisterValue a, RegisterValue b ) const

nodiscardnoexcept

Right shift: a >> b (arithmetic shift).

sub()

Result< RegisterValue > contur::ALU::sub ( RegisterValue a, RegisterValue b ) const

nodiscardnoexcept

Subtraction: a - b.

Member Data Documentation

SIGN_FLAG

RegisterValue contur::ALU::SIGN_FLAG = 2

staticconstexpr

a < b

Definition at line 78 of file alu.h.

ZERO_FLAG

RegisterValue contur::ALU::ZERO_FLAG = 1

staticconstexpr

a == b

Definition at line 77 of file alu.h.

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The documentation for this class was generated from the following file:

• include/contur/cpu/alu.h