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Annotation of rpl/lapack/lapack/dlaisnan.f, revision 1.16

1.12      bertrand    1: *> \brief \b DLAISNAN tests input for NaN by comparing two arguments for inequality.
1.9       bertrand    2: *
                      3: *  =========== DOCUMENTATION ===========
                      4: *
1.16    ! bertrand    5: * Online html documentation available at
        !             6: *            http://www.netlib.org/lapack/explore-html/
1.9       bertrand    7: *
                      8: *> \htmlonly
1.16    ! bertrand    9: *> Download DLAISNAN + dependencies
        !            10: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlaisnan.f">
        !            11: *> [TGZ]</a>
        !            12: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlaisnan.f">
        !            13: *> [ZIP]</a>
        !            14: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlaisnan.f">
1.9       bertrand   15: *> [TXT]</a>
1.16    ! bertrand   16: *> \endhtmlonly
1.9       bertrand   17: *
                     18: *  Definition:
                     19: *  ===========
                     20: *
                     21: *       LOGICAL FUNCTION DLAISNAN( DIN1, DIN2 )
1.16    ! bertrand   22: *
1.9       bertrand   23: *       .. Scalar Arguments ..
                     24: *       DOUBLE PRECISION   DIN1, DIN2
                     25: *       ..
1.16    ! bertrand   26: *
1.9       bertrand   27: *
                     28: *> \par Purpose:
                     29: *  =============
                     30: *>
                     31: *> \verbatim
                     32: *>
                     33: *> This routine is not for general use.  It exists solely to avoid
                     34: *> over-optimization in DISNAN.
                     35: *>
                     36: *> DLAISNAN checks for NaNs by comparing its two arguments for
                     37: *> inequality.  NaN is the only floating-point value where NaN != NaN
                     38: *> returns .TRUE.  To check for NaNs, pass the same variable as both
                     39: *> arguments.
                     40: *>
                     41: *> A compiler must assume that the two arguments are
                     42: *> not the same variable, and the test will not be optimized away.
                     43: *> Interprocedural or whole-program optimization may delete this
                     44: *> test.  The ISNAN functions will be replaced by the correct
                     45: *> Fortran 03 intrinsic once the intrinsic is widely available.
                     46: *> \endverbatim
                     47: *
                     48: *  Arguments:
                     49: *  ==========
                     50: *
                     51: *> \param[in] DIN1
                     52: *> \verbatim
                     53: *>          DIN1 is DOUBLE PRECISION
                     54: *> \endverbatim
                     55: *>
                     56: *> \param[in] DIN2
                     57: *> \verbatim
                     58: *>          DIN2 is DOUBLE PRECISION
                     59: *>          Two numbers to compare for inequality.
                     60: *> \endverbatim
                     61: *
                     62: *  Authors:
                     63: *  ========
                     64: *
1.16    ! bertrand   65: *> \author Univ. of Tennessee
        !            66: *> \author Univ. of California Berkeley
        !            67: *> \author Univ. of Colorado Denver
        !            68: *> \author NAG Ltd.
1.9       bertrand   69: *
1.16    ! bertrand   70: *> \date December 2016
1.9       bertrand   71: *
1.16    ! bertrand   72: *> \ingroup OTHERauxiliary
1.9       bertrand   73: *
                     74: *  =====================================================================
1.5       bertrand   75:       LOGICAL FUNCTION DLAISNAN( DIN1, DIN2 )
1.1       bertrand   76: *
1.16    ! bertrand   77: *  -- LAPACK auxiliary routine (version 3.7.0) --
1.1       bertrand   78: *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
                     79: *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
1.16    ! bertrand   80: *     December 2016
1.1       bertrand   81: *
                     82: *     .. Scalar Arguments ..
1.5       bertrand   83:       DOUBLE PRECISION   DIN1, DIN2
1.1       bertrand   84: *     ..
                     85: *
                     86: *  =====================================================================
                     87: *
                     88: *  .. Executable Statements ..
                     89:       DLAISNAN = (DIN1.NE.DIN2)
                     90:       RETURN
                     91:       END