pTAL Reference Manual (H06.08+)

Built-In Routines

HP pTAL Reference Manual—523746-006

15-82

$SCALE

$SCALE moves the position of the implied fixed-point (decimal point) by changing a

FIXED(fpoint ) value.

fixed-expression

is the FIXED expression whose implied decimal point is to be changed.

scale

is an INT constant in the range -19 to +19 that specifies the number of positions to

move the implied decimal point with respect to the least significant digit. If scale

is negative, the implied decimal point moves to the left; if scale is positive, the

implied decimal point moves to the right.

$SCALE adjusts the implied decimal point of the stored FIXED value by multiplying or

dividing the value by 10 to the scale power. Some precision might be lost with

negative scale values.

If the result of the scale operation exceeds the range of a FIXED expression, $SCALE

traps if overflow traps are enabled (see Section 13, Hardware Indicators); otherwise,

$SCALE ignores the problem.

To retain precision when you divide operands that have nonzero fpoint settings, use

the $SCALE built-in routine to scale up the fpoint of the dividend by a factor equal

to the fpoint of the divisor, as in Example 15-80 on page 15-83.

pTAL privileged procedure No

Can be executed only by privileged procedures No

Sets condition code No

Sets $CARRY No

Sets $OVERFLOW Yes

Example 15-79. $SCALE Routine

FIXED(3) a := 9.123F;

FIXED(7) result;

result := $SCALE (a, 4); ! Return FIXED(7) value from

! FIXED(3) value

( )

VST110.vsd

$SCALE ,

fixed-expression scale