LAPACK 3.12.0
LAPACK: Linear Algebra PACKage
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dlaisnan.f
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1*> \brief \b DLAISNAN tests input for NaN by comparing two arguments for inequality.
2*
3* =========== DOCUMENTATION ===========
4*
5* Online html documentation available at
6* http://www.netlib.org/lapack/explore-html/
7*
8*> \htmlonly
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">
15*> [TXT]</a>
16*> \endhtmlonly
17*
18* Definition:
19* ===========
20*
21* LOGICAL FUNCTION DLAISNAN( DIN1, DIN2 )
22*
23* .. Scalar Arguments ..
24* DOUBLE PRECISION, INTENT(IN) :: DIN1, DIN2
25* ..
26*
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*
65*> \author Univ. of Tennessee
66*> \author Univ. of California Berkeley
67*> \author Univ. of Colorado Denver
68*> \author NAG Ltd.
69*
70*> \ingroup laisnan
71*
72* =====================================================================
73 LOGICAL FUNCTION dlaisnan( DIN1, DIN2 )
74*
75* -- LAPACK auxiliary routine --
76* -- LAPACK is a software package provided by Univ. of Tennessee, --
77* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
78*
79* .. Scalar Arguments ..
80 DOUBLE PRECISION, INTENT(IN) :: din1, din2
81* ..
82*
83* =====================================================================
84*
85* .. Executable Statements ..
86 dlaisnan = (din1.NE.din2)
87 RETURN
88 END
logical function dlaisnan(din1, din2)
DLAISNAN tests input for NaN by comparing two arguments for inequality.
Definition dlaisnan.f:74