4.10.22 VAX Floating Square Root

Format:

SQRTxFb.rx,Fc.wx!Floating-point Operate format

Operation:

Fc Fb ** (1/2)

Exceptions:

Invalid operation

Instruction mnemonics:

SQRTF

Square root F_floating

SQRTG

Square root G_floating

Qualifiers:

Rounding:

Chopped (/C)

Trapping:

Exception Completion (/S)

 

Underflow Enable (/U) — See Notes below

Description:

The square root of the floating-point operand in register Fb is written to register Fc. (The Fa field of this instruction must be set to a value of F31.)

The result is rounded or chopped to the specified precision. The single-precision operation on a canonical single-precision value produces a canonical single-precision result.

An invalid operation is signaled if the operand has exp=0 and is not a true zero (that is, VAX reserved operands and dirty zeros trap). An invalid operation is signaled if the sign of the oper- and is negative.

The contents of the Fc are UNPREDICTABLE if an invalid operation is signaled.

Notes:

Floating-point overflow and underflow are not possible for square root operation. The underflow enable qualifier is ignored.

4–128Alpha Architecture Handbook

Page 184
Image 184
Compaq ECQD2KCTE manual VAX Floating Square Root, Sqrtf