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Annotation of rpl/lapack/lapack/dlaisnan.f, revision 1.1

1.1     ! bertrand    1:       LOGICAL FUNCTION DLAISNAN(DIN1,DIN2)
        !             2: *
        !             3: *  -- LAPACK auxiliary routine (version 3.2) --
        !             4: *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
        !             5: *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
        !             6: *     November 2006
        !             7: *
        !             8: *     .. Scalar Arguments ..
        !             9:       DOUBLE PRECISION DIN1,DIN2
        !            10: *     ..
        !            11: *
        !            12: *  Purpose
        !            13: *  =======
        !            14: *
        !            15: *  This routine is not for general use.  It exists solely to avoid
        !            16: *  over-optimization in DISNAN.
        !            17: *
        !            18: *  DLAISNAN checks for NaNs by comparing its two arguments for
        !            19: *  inequality.  NaN is the only floating-point value where NaN != NaN
        !            20: *  returns .TRUE.  To check for NaNs, pass the same variable as both
        !            21: *  arguments.
        !            22: *
        !            23: *  A compiler must assume that the two arguments are
        !            24: *  not the same variable, and the test will not be optimized away.
        !            25: *  Interprocedural or whole-program optimization may delete this
        !            26: *  test.  The ISNAN functions will be replaced by the correct
        !            27: *  Fortran 03 intrinsic once the intrinsic is widely available.
        !            28: *
        !            29: *  Arguments
        !            30: *  =========
        !            31: *
        !            32: *  DIN1     (input) DOUBLE PRECISION
        !            33: *  DIN2     (input) DOUBLE PRECISION
        !            34: *          Two numbers to compare for inequality.
        !            35: *
        !            36: *  =====================================================================
        !            37: *
        !            38: *  .. Executable Statements ..
        !            39:       DLAISNAN = (DIN1.NE.DIN2)
        !            40:       RETURN
        !            41:       END