fppmask — Apollo

2.0;fppmask, revision 2.0, 81/07/02
FPPMASK (FLOATING_POINT_MASK) -- Set or display the floating-point error mask.
usage:  FPPMASK  [-D] [-E] [LOS] [UNDR]


FORMAT

  FPPMASK  [options]


  FPPMASK sets or displays the state of the floating-point package error mask
  for a process.  The error mask specifies some of the conditions that
  constitute a floating-point exception for the process.


OPTIONS

  If no options are specified, the current floating-point error mask condition
  is displayed.

  -D condition ...    Disable 'condition' (see below).  Both conditions may be
                      specified.

  -E condition ...    Enable 'condition' (see below).  Both conditions may be
                      specified.

  'condition' may be either of the following:

  LOS                 Loss of significance.  This condition occurs when
                      subtracting floating-point values that are exactly equal.

  UNDR                Underflow.  This condition occurs when a floating-point
                      result is too small to be represented.  For single-
                      precision values, this error occurs at about 0.118E-37.
                      For double-precision values, the error occurs at about
                      0.223E-307.

  Both conditions are initially disabled when a process is created.


EXAMPLES

  1. $ fppmask                                 Display current settings.
     LOS (loss of significance):   disabled
     UNDR (underflow):             disabled

  2. $ fppmask -e los undr                     Enable both LOS and UNDR
                                                conditions.

  3. $ fppmask -d undr                         Disable UNDR condition.
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