# Conversion Instructions

## Convert Byte to Word (cbtw)

cbtw

##### Operation

sign-extend AL -> AX

##### Description

`cbtw` converts the signed byte in AL to a signed word in AX by extending the most-significant bit (sign bit) of AL into all bits of AH.

##### Example

cbtw

## Convert Word to Long (cwtl)

cwtl

##### Operation

sign-extend AX -> EAX

##### Description

`cwtl` converts the signed word in AX to a signed long in EAX by extending the most-significant bit (sign bit) of AX into two most-significant bytes of EAX.

##### Example

cwtl

## Convert Signed Word to Signed Double Word (cwtd)

cwtd

##### Operation

sign-extend AX -> DX:AX

##### Description

`cwt`d converts the signed word in AX to a signed double word in DX:AX by extending the most-significant bit (sign bit) of AX into all bits of DX.

##### Example

cwtd

## Convert Signed Long to Signed Double Long (cltd)

cltd

##### Operation

sign-extend EAX -> EDX:EAX

##### Description

`cltd` converts the signed long in EAX to a signed double long in EDX:EAX by extending the most-significant bit (sign bit) of EAX into all bits of EDX.

##### Example

cltd