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dlaisnan-f(3)

dlaisnan.f –

Synopsis

Functions/Subroutines

LOGICAL function dlaisnan (DIN1, DIN2)
DLAISNAN tests input for NaN by comparing two arguments for inequality.

Function/Subroutine Documentation

LOGICAL function dlaisnan (double precisionDIN1, double precisionDIN2)

DLAISNAN tests input for NaN by comparing two arguments for inequality.

Purpose:

 This routine is not for general use. It exists solely to avoid
 over-optimization in DISNAN.
 DLAISNAN checks for NaNs by comparing its two arguments for
 inequality. NaN is the only floating-point value where NaN != NaN
 returns .TRUE. To check for NaNs, pass the same variable as both
 arguments.
 A compiler must assume that the two arguments are
 not the same variable, and the test will not be optimized away.
 Interprocedural or whole-program optimization may delete this
 test. The ISNAN functions will be replaced by the correct
 Fortran 03 intrinsic once the intrinsic is widely available.

 

Parameters:

DIN1

 DIN1 is DOUBLE PRECISION

DIN2

 DIN2 is DOUBLE PRECISION
 Two numbers to compare for inequality.

 

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

September 2012

Definition at line 75 of file dlaisnan.f.

Author

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