ieee_get_underflow_mode

Date:: 10-12-2011

NAME

IEEE_GET_UNDERFLOW_MODE - Determines if floating-point underflow mode is gradual underflow

SYNOPSIS

CALL IEEE_GET_UNDERFLOW_MODE ([GRADUAL=]gradual)
   LOGICAL :: gradual

IMPLEMENTATION

Cray Linux Environment (CLE)

STANDARDS

Fortran

IEEE Standard for Binary Floating-point Arithmetic

DESCRIPTION

The IEEE_GET_UNDERFLOW_MODE intrinsic subroutine is typically called upon entry to a procedure to determine if the current floating-point underflow mode is gradual underflow. It accepts the following argument:

gradual: Must be of type default logical. It is an INTENT(OUT) argument.

The name of this intrinsic cannot be passed as an argument.

The IEEE_GET_UNDERFLOW_MODE shall not be invoked unless the IEEE_SUPPORT_UNDERFLOW_CONTROL(X) is true for some X.

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.

The value of gradual is true if the current underflow mode is gradual underflow. Otherwise, the value is false to indicate abrupt underflow.

EXAMPLES

Example 1:

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

x_unflo_supported = IEEE_SUPPORT_UNDERFLOW_CONTROL(xdef)

IF (.NOT. x_unflo_supported) STOP "UNFL_UNSUP"

CALL IEEE_GET_UNDERFLOW_MODE(unflo_gradual)