xref: /minix3/lib/libm/src/s_isinf.c (revision 2fe8fb192fe7e8720e3e7a77f928da545e872a6a)
1*2fe8fb19SBen Gras /*
2*2fe8fb19SBen Gras  * Written by J.T. Conklin <jtc@NetBSD.org>.
3*2fe8fb19SBen Gras  * Public domain.
4*2fe8fb19SBen Gras  */
5*2fe8fb19SBen Gras 
6*2fe8fb19SBen Gras #include <sys/cdefs.h>
7*2fe8fb19SBen Gras #if defined(LIBM_SCCS) && !defined(lint)
8*2fe8fb19SBen Gras __RCSID("$NetBSD: s_isinf.c,v 1.6 2003/07/26 19:25:05 salo Exp $");
9*2fe8fb19SBen Gras #endif
10*2fe8fb19SBen Gras 
11*2fe8fb19SBen Gras /*
12*2fe8fb19SBen Gras  * isinf(x) returns 1 is x is inf, else 0;
13*2fe8fb19SBen Gras  * no branching!
14*2fe8fb19SBen Gras  */
15*2fe8fb19SBen Gras 
16*2fe8fb19SBen Gras #include "math.h"
17*2fe8fb19SBen Gras #include "math_private.h"
18*2fe8fb19SBen Gras 
19*2fe8fb19SBen Gras int
isinf(double x)20*2fe8fb19SBen Gras isinf(double x)
21*2fe8fb19SBen Gras {
22*2fe8fb19SBen Gras 	int32_t hx,lx;
23*2fe8fb19SBen Gras 	EXTRACT_WORDS(hx,lx,x);
24*2fe8fb19SBen Gras 	hx &= 0x7fffffff;
25*2fe8fb19SBen Gras 	hx ^= 0x7ff00000;
26*2fe8fb19SBen Gras 	hx |= lx;
27*2fe8fb19SBen Gras 	return (hx == 0);
28*2fe8fb19SBen Gras }
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