4.10.1 Copy Sign

Format:

CPYSyFa.rq,Fb.rq,Fc.wq!Floating-point Operate format

Operation:

CASE

CPYS: Fc Fav<63> Fbv<62:0>

CPYSN: Fc NOT(Fav<63>) Fbv<62:0>

CPYSE: Fc Fav<63:52> Fbv<51:0>

ENDCASE

Exceptions:

 

None

 

Instruction mnemonics:

 

CPYS

Copy Sign

CPYSE

Copy Sign and Exponent

CPYSN

Copy Sign Negate

Qualifiers:

 

None

 

Description:

For CPYS and CPYSN, the sign bit of Fa is fetched (and complemented in the case of CPYSN) and concatenated with the exponent and fraction bits from Fb; the result is stored in Fc.

For CPYSE, the sign and exponent bits from Fa are fetched and concatenated with the fraction bits from Fb; the result is stored in Fc.

No checking of the operands is performed.

Notes:

Register moves can be performed using CPYS Fx,Fx,Fy. Floating-point absolute value can be done using CPYS F31,Fx,Fy. Floating-point negation can be done using CPYSN Fx,Fx,Fy. Floating values can be scaled to a known range by using CPYSE.

Instruction Descriptions 4–105

Page 161
Image 161
Compaq ECQD2KCTE manual Copy Sign, Format