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Fgetman extract the mantissa fgetman – Motorola DSP96002 User Manual

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DSP96002 USER’S MANUAL

MOTOROLA

FGETMAN

Extract the Mantissa

FGETMAN

Operation:

Normalized mantissa of S

D

(parallel data bus move)

Assembler Syntax:

FGETMAN S,D (move syntax - see the MOVE in-

struction description.)

Description:

Extract the mantissa and sign of the floating-point operand S, normalizes the mantissa, forces the expo-

nent to "ebias" so the result is in the range 1-2, and stores the result as a floating-point value in the spec-

ified destination D regardless of whether the mantissa is denormalized or not.

As an example of the use of FGETMAN, GETEXP, and FSCALE; consider decomposing a floating-point

number into its mantissa and unbiased exponent and then recreating the original floating-point number.

FGETMAN

D0, D1

;extract normalized mantissa

GETEXP

D0,D2

;extract unbiased exponent

MOVE

D2.L, D2.H

;move unbiased exponent

FSCALE.X

D2.H, D1

;scale original mantissa

Input (SEP)

Output (SEP)

-infinity

NaN, signals OPERR

negative, non-zero

signed mantissa

-0.0

-0.0

+0.0

+0.0

positive, non-zero

signed mantissa

+infinity

NaN, signals OPERR

NaN

NaN

Input Operand(s) Precision: SEP Floating-Point.

Output Operand Precision: SEP Floating-Point.