dlaisnan: Dlaisnan.f -

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.

dlaisnan (3)

SYNOPSIS

Functions/Subroutines

Function/Subroutine Documentation

logical function dlaisnan (double precisionDIN1, double precisionDIN2)

Author