*> \brief \b DLAISNAN tests input for NaN by comparing two arguments for inequality. * * =========== DOCUMENTATION =========== * * Online html documentation available at * http://www.netlib.org/lapack/explore-html/ * *> \htmlonly *> Download DLAISNAN + dependencies *> *> [TGZ] *> *> [ZIP] *> *> [TXT] *> \endhtmlonly * * Definition: * =========== * * LOGICAL FUNCTION DLAISNAN( DIN1, DIN2 ) * * .. Scalar Arguments .. * DOUBLE PRECISION, INTENT(IN) :: DIN1, DIN2 * .. * * *> \par Purpose: * ============= *> *> \verbatim *> *> 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. *> \endverbatim * * Arguments: * ========== * *> \param[in] DIN1 *> \verbatim *> DIN1 is DOUBLE PRECISION *> \endverbatim *> *> \param[in] DIN2 *> \verbatim *> DIN2 is DOUBLE PRECISION *> Two numbers to compare for inequality. *> \endverbatim * * Authors: * ======== * *> \author Univ. of Tennessee *> \author Univ. of California Berkeley *> \author Univ. of Colorado Denver *> \author NAG Ltd. * *> \date June 2017 * *> \ingroup OTHERauxiliary * * ===================================================================== LOGICAL FUNCTION DLAISNAN( DIN1, DIN2 ) * * -- LAPACK auxiliary routine (version 3.7.1) -- * -- LAPACK is a software package provided by Univ. of Tennessee, -- * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- * June 2017 * * .. Scalar Arguments .. DOUBLE PRECISION, INTENT(IN) :: DIN1, DIN2 * .. * * ===================================================================== * * .. Executable Statements .. DLAISNAN = (DIN1.NE.DIN2) RETURN END