projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 4acf9396 GCI |
1 | /* @(#)s_finite.c 5.1 93/09/24 */ |
| 2 | /* | |
| 3 | * ==================================================== | |
| 4 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. | |
| 5 | * | |
| 6 | * Developed at SunPro, a Sun Microsystems, Inc. business. | |
| 7 | * Permission to use, copy, modify, and distribute this | |
| 8 | * software is freely granted, provided that this notice | |
| 9 | * is preserved. | |
| 10 | * ==================================================== | |
| 11 | */ | |
| 12 | ||
| 13 | #ifndef lint | |
| 14 | static char rcsid[] = "$Id: s_finite.c,v 1.4 1994/03/03 17:04:34 jtc Exp $"; | |
| 15 | #endif | |
| 16 | ||
| 17 | /* | |
| 18 | * finite(x) returns 1 is x is finite, else 0; | |
| 19 | * no branching! | |
| 20 | */ | |
| 21 | ||
| 22 | #include "math.h" | |
| 23 | #include <machine/endian.h> | |
| 24 | ||
| 25 | #if BYTE_ORDER == LITTLE_ENDIAN | |
| 26 | #define n0 1 | |
| 27 | #else | |
| 28 | #define n0 0 | |
| 29 | #endif | |
| 30 | ||
| 31 | #ifdef __STDC__ | |
| 32 | int finite(double x) | |
| 33 | #else | |
| 34 | int finite(x) | |
| 35 | double x; | |
| 36 | #endif | |
| 37 | { | |
| 38 | int hx; | |
| 39 | hx = *(n0+(int*)&x); | |
| 40 | return (unsigned)((hx&0x7fffffff)-0x7ff00000)>>31; | |
| 41 | } |