LAPACK  3.4.1
LAPACK: Linear Algebra PACKage
dlaisnan.f
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00001 *> \brief \b DLAISNAN
00002 *
00003 *  =========== DOCUMENTATION ===========
00004 *
00005 * Online html documentation available at 
00006 *            http://www.netlib.org/lapack/explore-html/ 
00007 *
00008 *> \htmlonly
00009 *> Download DLAISNAN + dependencies 
00010 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlaisnan.f"> 
00011 *> [TGZ]</a> 
00012 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlaisnan.f"> 
00013 *> [ZIP]</a> 
00014 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlaisnan.f"> 
00015 *> [TXT]</a>
00016 *> \endhtmlonly 
00017 *
00018 *  Definition:
00019 *  ===========
00020 *
00021 *       LOGICAL FUNCTION DLAISNAN( DIN1, DIN2 )
00022 * 
00023 *       .. Scalar Arguments ..
00024 *       DOUBLE PRECISION   DIN1, DIN2
00025 *       ..
00026 *  
00027 *
00028 *> \par Purpose:
00029 *  =============
00030 *>
00031 *> \verbatim
00032 *>
00033 *> This routine is not for general use.  It exists solely to avoid
00034 *> over-optimization in DISNAN.
00035 *>
00036 *> DLAISNAN checks for NaNs by comparing its two arguments for
00037 *> inequality.  NaN is the only floating-point value where NaN != NaN
00038 *> returns .TRUE.  To check for NaNs, pass the same variable as both
00039 *> arguments.
00040 *>
00041 *> A compiler must assume that the two arguments are
00042 *> not the same variable, and the test will not be optimized away.
00043 *> Interprocedural or whole-program optimization may delete this
00044 *> test.  The ISNAN functions will be replaced by the correct
00045 *> Fortran 03 intrinsic once the intrinsic is widely available.
00046 *> \endverbatim
00047 *
00048 *  Arguments:
00049 *  ==========
00050 *
00051 *> \param[in] DIN1
00052 *> \verbatim
00053 *>          DIN1 is DOUBLE PRECISION
00054 *> \endverbatim
00055 *>
00056 *> \param[in] DIN2
00057 *> \verbatim
00058 *>          DIN2 is DOUBLE PRECISION
00059 *>          Two numbers to compare for inequality.
00060 *> \endverbatim
00061 *
00062 *  Authors:
00063 *  ========
00064 *
00065 *> \author Univ. of Tennessee 
00066 *> \author Univ. of California Berkeley 
00067 *> \author Univ. of Colorado Denver 
00068 *> \author NAG Ltd. 
00069 *
00070 *> \date November 2011
00071 *
00072 *> \ingroup auxOTHERauxiliary
00073 *
00074 *  =====================================================================
00075       LOGICAL FUNCTION DLAISNAN( DIN1, DIN2 )
00076 *
00077 *  -- LAPACK auxiliary routine (version 3.4.0) --
00078 *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
00079 *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
00080 *     November 2011
00081 *
00082 *     .. Scalar Arguments ..
00083       DOUBLE PRECISION   DIN1, DIN2
00084 *     ..
00085 *
00086 *  =====================================================================
00087 *
00088 *  .. Executable Statements ..
00089       DLAISNAN = (DIN1.NE.DIN2)
00090       RETURN
00091       END
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