opencv/3rdparty/lapack/ieeeck.c

167 lines
3.3 KiB
C

/* ieeeck.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"
integer ieeeck_(integer *ispec, real *zero, real *one)
{
/* System generated locals */
integer ret_val;
/* Local variables */
real nan1, nan2, nan3, nan4, nan5, nan6, neginf, posinf, negzro, newzro;
/* -- LAPACK auxiliary routine (version 3.2) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* IEEECK is called from the ILAENV to verify that Infinity and */
/* possibly NaN arithmetic is safe (i.e. will not trap). */
/* Arguments */
/* ========= */
/* ISPEC (input) INTEGER */
/* Specifies whether to test just for inifinity arithmetic */
/* or whether to test for infinity and NaN arithmetic. */
/* = 0: Verify infinity arithmetic only. */
/* = 1: Verify infinity and NaN arithmetic. */
/* ZERO (input) REAL */
/* Must contain the value 0.0 */
/* This is passed to prevent the compiler from optimizing */
/* away this code. */
/* ONE (input) REAL */
/* Must contain the value 1.0 */
/* This is passed to prevent the compiler from optimizing */
/* away this code. */
/* RETURN VALUE: INTEGER */
/* = 0: Arithmetic failed to produce the correct answers */
/* = 1: Arithmetic produced the correct answers */
/* .. Local Scalars .. */
/* .. */
/* .. Executable Statements .. */
ret_val = 1;
posinf = *one / *zero;
if (posinf <= *one) {
ret_val = 0;
return ret_val;
}
neginf = -(*one) / *zero;
if (neginf >= *zero) {
ret_val = 0;
return ret_val;
}
negzro = *one / (neginf + *one);
if (negzro != *zero) {
ret_val = 0;
return ret_val;
}
neginf = *one / negzro;
if (neginf >= *zero) {
ret_val = 0;
return ret_val;
}
newzro = negzro + *zero;
if (newzro != *zero) {
ret_val = 0;
return ret_val;
}
posinf = *one / newzro;
if (posinf <= *one) {
ret_val = 0;
return ret_val;
}
neginf *= posinf;
if (neginf >= *zero) {
ret_val = 0;
return ret_val;
}
posinf *= posinf;
if (posinf <= *one) {
ret_val = 0;
return ret_val;
}
/* Return if we were only asked to check infinity arithmetic */
if (*ispec == 0) {
return ret_val;
}
nan1 = posinf + neginf;
nan2 = posinf / neginf;
nan3 = posinf / posinf;
nan4 = posinf * *zero;
nan5 = neginf * negzro;
nan6 = nan5 * 0.f;
if (nan1 == nan1) {
ret_val = 0;
return ret_val;
}
if (nan2 == nan2) {
ret_val = 0;
return ret_val;
}
if (nan3 == nan3) {
ret_val = 0;
return ret_val;
}
if (nan4 == nan4) {
ret_val = 0;
return ret_val;
}
if (nan5 == nan5) {
ret_val = 0;
return ret_val;
}
if (nan6 == nan6) {
ret_val = 0;
return ret_val;
}
return ret_val;
} /* ieeeck_ */