OVERFL - test and reset overflow indicators.

Alternate Entry Name: .OFLOW

Usage:

B:
   status = overfl([type]);

C:
   int overfl( [int type] );

Where:

status

is one if the selected overflow indicator is on and zero if it is not.

type

selects which overflow indicator is to be tested.

0

tests the fixed point overflow indicator (default).

1

tests the exponent overflow indicator.

2

tests the exponent underflow indicator.

Description:

OVERFL executes one of the "transfer on overflow" instructions ("tov", "teo", or "teu") to check one of the overflow bits in the indicator register. This will determine if the bit is on or off. Executing any of these instructions will turn off the bit if it was on.

B programs start with the overflow faults masked, so that overflows do not cause faults.

See Also:

expl b lib .indic

for another method to examine the overflow bits, and to change the overflow mask.

Copyright © 1996, Thinkage Ltd.