NAME

trpfpe, fpecnt − trap and repair floating point faults

SYNOPSIS

subroutine trpfpe (numesg, rtnval)
double precision rtnval

integer function fpecnt ()

common /fpeflt/ fperr
logical fperr

DESCRIPTION

trpfpe sets up a signal handler to trap arithmetic exceptions. If the exception is due to a floating point arithmetic fault, the result of the operation is replaced with the rtnval specified.  rtnval must be a double precision value. For example, 0.0d0 or the return value of dflmax(). 

The first numesg occurrences of a floating point arithmetic error will cause a message to be written to the standard error file.  Any exception that cannot be repaired will result in the default action, typically an abort with core image. 

fpecnt returns the number of faults since the last call to trpfpe. 

The logical value in the common block labeled fpeflt will be set to .TRUE. each time a fault occurs. 

FILES

/usr/lib/libF77.a

SEE ALSO

signal(3F)

NOTES

When compiling source with the -Qocs option, an explicit underscore needs to be added to the end of the routine names.  When compiling source with the -Qocs option, two explicit underscores need to be added to the end of the name of the common block fpeflt.

BUGS

This handler just prints a message.  There are no arithmetic faults (only traps) around, so that no instruction is interrupted before it completes, and the program counter points to the next floating point instruction (not necessarily next executable instruction after the one that got the exception). 

If the operation involves changing the stack pointer, it cannot be repaired.  This seldom should be a problem with the f77 compiler, but such an operation might be produced by the optimizer. 

CX/UX Hf77 Fortran Reference Manual