xref: /minix3/lib/libm/src/s_isinff.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_isinff.c,v 1.6 2003/07/26 19:25:06 salo Exp $");
9*2fe8fb19SBen Gras #endif
10*2fe8fb19SBen Gras 
11*2fe8fb19SBen Gras /*
12*2fe8fb19SBen Gras  * isinff(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
isinff(float x)20*2fe8fb19SBen Gras isinff(float x)
21*2fe8fb19SBen Gras {
22*2fe8fb19SBen Gras 	int32_t ix;
23*2fe8fb19SBen Gras 	GET_FLOAT_WORD(ix,x);
24*2fe8fb19SBen Gras 	ix &= 0x7fffffff;
25*2fe8fb19SBen Gras 	ix ^= 0x7f800000;
26*2fe8fb19SBen Gras 	return (ix == 0);
27*2fe8fb19SBen Gras }
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