projects / apple / libc.git / blame
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|---|---|---|
| e9ce8d39 A |
1 | /* |
| 2 | * Copyright (c) 1999 Apple Computer, Inc. All rights reserved. | |
| 3 | * | |
| 4 | * @APPLE_LICENSE_HEADER_START@ | |
| 5 | * | |
| 734aad71 | 6 | * Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved. |
| e9ce8d39 | 7 | * |
| 734aad71 A |
8 | * This file contains Original Code and/or Modifications of Original Code |
| 9 | * as defined in and that are subject to the Apple Public Source License | |
| 10 | * Version 2.0 (the 'License'). You may not use this file except in | |
| 11 | * compliance with the License. Please obtain a copy of the License at | |
| 12 | * http://www.opensource.apple.com/apsl/ and read it before using this | |
| 13 | * file. | |
| 14 | * | |
| 15 | * The Original Code and all software distributed under the License are | |
| 16 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER | |
| e9ce8d39 A |
17 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
| 18 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, | |
| 734aad71 A |
19 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
| 20 | * Please see the License for the specific language governing rights and | |
| 21 | * limitations under the License. | |
| e9ce8d39 A |
22 | * |
| 23 | * @APPLE_LICENSE_HEADER_END@ | |
| 24 | */ | |
| 25 | /* Copyright (c) 1992, 1997 NeXT Software, Inc. All rights reserved. | |
| 26 | * | |
| 27 | * File: libc/gen/ppc/isinf.c | |
| 28 | * Author: Derek B Clegg, NeXT Software, Inc. | |
| 29 | * | |
| 30 | * HISTORY | |
| 31 | * 24-Jan-1997 Umesh Vaishampayan (umeshv@NeXT.com) | |
| 32 | * Ported to PPC. | |
| 33 | * 11-Nov-92 Derek B Clegg (dclegg@next.com) | |
| 34 | * Created. | |
| 35 | * | |
| 36 | * int isinf(double value); | |
| 37 | * | |
| 38 | * Returns 1 if `value' is equal to positive IEEE infinity, -1 if `value' | |
| 39 | * is equal to negative IEEE infinity, 0 otherwise. | |
| 40 | * | |
| 41 | * An IEEE infinity is a double value with the maximum biased exponent value | |
| 42 | * (2047) and a zero fraction value. | |
| 43 | */ | |
| 44 | #import "fp.h" | |
| 45 | ||
| 46 | int | |
| 47 | isinf(double value) | |
| 48 | { | |
| 49 | union dbl d; | |
| 50 | ||
| 51 | d.value = value; | |
| 52 | if (d.u[0] == 0x7FF00000 && d.u[1] == 0) | |
| 53 | return 1; | |
| 54 | if (d.u[0] == 0xFFF00000 && d.u[1] == 0) | |
| 55 | return -1; | |
| 56 | return 0; | |
| 57 | } |