opencv/3rdparty/lapack/dlaisnan.c

/* dlaisnan.f -- translated by f2c (version 20061008).
   You must link the resulting object file with libf2c:
	on Microsoft Windows system, link with libf2c.lib;
	on Linux or Unix systems, link with .../path/to/libf2c.a -lm
	or, if you install libf2c.a in a standard place, with -lf2c -lm
	-- in that order, at the end of the command line, as in
		cc *.o -lf2c -lm
	Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,

		http://www.netlib.org/f2c/libf2c.zip
*/

#include "clapack.h"


logical dlaisnan_(doublereal *din1, doublereal *din2)
{
    /* System generated locals */
    logical ret_val;


/*  -- LAPACK auxiliary routine (version 3.2) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */

/*  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. */

/*  Arguments */
/*  ========= */

/*  DIN1     (input) DOUBLE PRECISION */
/*  DIN2     (input) DOUBLE PRECISION */
/*          Two numbers to compare for inequality. */

/*  ===================================================================== */

/*  .. Executable Statements .. */
    ret_val = *din1 != *din2;
    return ret_val;
} /* dlaisnan_ */