ENABLE_IEEE_INTERRUPT(3I) Last changed: 1-6-98
NAME
ENABLE_IEEE_INTERRUPT - Enables floating-point interrupt
SYNOPSIS
ENABLE_IEEE_INTERRUPT ([INTERRUPT=]interrupt)
IMPLEMENTATION
UNICOS/mk and IRIX systems
CRAY T90 systems that support IEEE floating-point arithmetic
STANDARDS
CF90 and MIPSpro 7 Fortran 90 compiler extension to Fortran 90
IEEE Standard for Binary Floating-point Arithmetic
DESCRIPTION
The ENABLE_IEEE_INTERRUPT intrinsic subroutine enables the specified
floating-point interrupt. It accepts the following argument:
interrupt Must be of an integer type that occupies a full word.
If interrupt is an array, it must be 1-dimensional.
The single value in the scalar argument case, or each
element in the array argument case, must be set to one
of the values represented by one of the following named
constants:
* IEEE_NTPT_CRI_INVALID_OPND (accepted only on CRAY T90
systems that support IEEE floating-point arithmetic)
* IEEE_NTPT_INEXACT_RESULT
* IEEE_NTPT_UNDERFLOW
* IEEE_NTPT_OVERFLOW
* IEEE_NTPT_DIV_BY_ZERO
* IEEE_NTPT_INVALID_OPR
* IEEE_NTPT_ALL
The IEEE_INEXACT_RESULT and IEEE_UNDERFLOW interrupts should be
disabled before the execution of any I/O statement that involves
conversion to prevent arithmetic exceptions during the execution of
those I/O statements.
The name of this intrinsic cannot be passed as an argument.
NOTES
The IEEE intrinsic procedures use the named constants contained in a
system module, so you must include one of the following statements in
your program:
* On UNICOS and UNICOS/mk systems: USE CRI_IEEE_DEFINITIONS
* On UNICOS, UNICOS/mk, and IRIX systems: USE FTN_IEEE_DEFINITIONS
The CRI_IEEE_DEFINITIONS module is obsolescent. It will be removed
for the CF90 4.0 release.
On UNICOS/mk systems, you cannot use ENABLE_IEEE_INTERRUPT to set the
following bits:
* Bit 49, invalid operation disable
* Bit 50, division by zero disable
* Bit 51, overflow disable
The hardware ignores attempts to set these bits.
CAUTIONS
Care should be taken before enabling interrupts on inexact results
because inexact results are so prevalent. In particular, inexact
results will occur while performing operations which are not generally
regarded as floating-point operations. These include, but are not
limited to, Fortran I/O statements, memory allocations and DO loop
iteration count computations.
RETURN VALUES
Upon return, the interrupt, or each element of interrupt, is enabled.
If interrupt, or any element of interrupt, has the value
IEEE_NTPT_ALL, all interrupts are enabled.
EXAMPLES
See DISABLE_IEEE_INTERRUPT(3I) for an example that uses this intrinsic
subroutine.
SEE ALSODISABLE_IEEE_INTERRUPT(3I)
Intrinsic Procedures Reference Manual, publication SR-2138, for the
printed version of this man page.
