LAPACK  3.6.1
LAPACK: Linear Algebra PACKage
logical function dlaisnan ( double precision  DIN1,
double precision  DIN2 
)

DLAISNAN tests input for NaN by comparing two arguments for inequality.

Download DLAISNAN + dependencies [TGZ] [ZIP] [TXT]

Purpose:
 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.
Parameters
[in]DIN1
          DIN1 is DOUBLE PRECISION
[in]DIN2
          DIN2 is DOUBLE PRECISION
          Two numbers to compare for inequality.
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date
September 2012

Definition at line 76 of file dlaisnan.f.

76 *
77 * -- LAPACK auxiliary routine (version 3.4.2) --
78 * -- LAPACK is a software package provided by Univ. of Tennessee, --
79 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
80 * September 2012
81 *
82 * .. Scalar Arguments ..
83  DOUBLE PRECISION din1, din2
84 * ..
85 *
86 * =====================================================================
87 *
88 * .. Executable Statements ..
89  dlaisnan = (din1.NE.din2)
90  RETURN
logical function dlaisnan(DIN1, DIN2)
DLAISNAN tests input for NaN by comparing two arguments for inequality.
Definition: dlaisnan.f:76