ieee_support_underflow_control

Date:

10-12-2011

NAME

IEEE_SUPPORT_UNDERFLOW_CONTROL - Determines if the system supports the ability to control the underflow mode during program execution

SYNOPSIS

IEEE_SUPPORT_UNDERFLOW_CONTROL ([[X=]x])

IMPLEMENTATION

Cray Linux Environment (CLE)

STANDARDS

Fortran

IEEE Standard for Binary Floating-point Arithmetic

DESCRIPTION

The function IEEE_SUPPORT_UNDERFLOW_CONTROL(0 can be used to determine if a system supports the ability to control the underflow mode for floating-point calculations for a particular kind of real or for all reals.

This function accepts the following argument:

x

Must be of type real. It may be a scalar or an array.

IEEE_SUPPORT_UNDERFLOW_CONTROL is an inquiry function. 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 the following statement in your program:

USE, INTRINSIC :: IEEE_ARITHMETIC

RETURN VALUES

The result type and type parameter is default logical.

If x is present, the result is true if the system supports control of the underflow mode for floating-point calculations for real variables of the same kind type as x; otherwise, the result is false.

If x is not present, the result is true if the system supports control of the underflow mode for floating-point calculations for all real variables variables supported on this system; otherwise, the result is false.

EXAMPLES

Example 1:

USE, INTRINSIC :: IEEE_ARITHMETIC
REAL xdef
REAL(8) x8
LOGICAL x_unflo_supported, allx_unflo_supported

x_unflo_supported = IEEE_SUPPORT_UNDERFLOW_CONTROL(xdef)

allx_unflo_supported = IEEE_SUPPORT_UNDERFLOW_CONTROL()