| The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 1 | /*- |
| 2 | * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG> |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * |
| 14 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| 15 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 16 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 17 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| 18 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 19 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 20 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 21 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 22 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 23 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 24 | * SUCH DAMAGE. |
| 25 | * |
| 26 | * $FreeBSD: src/lib/msun/src/s_frexpl.c,v 1.1 2005/03/07 04:54:51 das Exp $ |
| 27 | */ |
| 28 | |
| 29 | #include <float.h> |
| 30 | #include <math.h> |
| 31 | |
| 32 | #include "fpmath.h" |
| 33 | |
| 34 | #if LDBL_MAX_EXP != 0x4000 |
| 35 | #error "Unsupported long double format" |
| 36 | #endif |
| 37 | |
| 38 | long double |
| 39 | frexpl(long double x, int *ex) |
| 40 | { |
| 41 | union IEEEl2bits u; |
| 42 | |
| 43 | u.e = x; |
| 44 | switch (u.bits.exp) { |
| 45 | case 0: /* 0 or subnormal */ |
| 46 | if ((u.bits.manl | u.bits.manh) == 0) { |
| 47 | *ex = 0; |
| 48 | } else { |
| 49 | u.e *= 0x1.0p514; |
| 50 | *ex = u.bits.exp - 0x4200; |
| 51 | u.bits.exp = 0x3ffe; |
| 52 | } |
| 53 | break; |
| 54 | case 0x7fff: /* infinity or NaN; value of *ex is unspecified */ |
| 55 | break; |
| 56 | default: /* normal */ |
| 57 | *ex = u.bits.exp - 0x3ffe; |
| 58 | u.bits.exp = 0x3ffe; |
| 59 | break; |
| 60 | } |
| 61 | return (u.e); |
| 62 | } |