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| Rev | Author | Line No. | Line |
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| 2 | pj | 1 | /*- |
| 2 | * Copyright (c) 1992, 1993 |
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| 3 | * The Regents of the University of California. All rights reserved. |
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| 4 | * |
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| 5 | * This software was developed by the Computer Systems Engineering group |
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| 6 | * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and |
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| 7 | * contributed to Berkeley. |
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| 8 | * |
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| 9 | * Redistribution and use in source and binary forms, with or without |
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| 10 | * modification, are permitted provided that the following conditions |
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| 11 | * are met: |
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| 12 | * 1. Redistributions of source code must retain the above copyright |
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| 13 | * notice, this list of conditions and the following disclaimer. |
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| 14 | * 2. Redistributions in binary form must reproduce the above copyright |
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| 15 | * notice, this list of conditions and the following disclaimer in the |
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| 16 | * documentation and/or other materials provided with the distribution. |
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| 17 | * 3. All advertising materials mentioning features or use of this software |
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| 18 | * must display the following acknowledgement: |
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| 19 | * This product includes software developed by the University of |
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| 20 | * California, Berkeley and its contributors. |
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| 21 | * 4. Neither the name of the University nor the names of its contributors |
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| 22 | * may be used to endorse or promote products derived from this software |
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| 23 | * without specific prior written permission. |
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| 24 | * |
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| 25 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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| 26 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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| 27 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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| 28 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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| 29 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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| 30 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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| 31 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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| 32 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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| 33 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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| 34 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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| 35 | * SUCH DAMAGE. |
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| 36 | */ |
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| 37 | |||
| 38 | #if defined(LIBC_SCCS) && !defined(lint) |
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| 39 | static char sccsid[] = "@(#)floatdidf.c 8.1 (Berkeley) 6/4/93"; |
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| 40 | #endif /* LIBC_SCCS and not lint */ |
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| 41 | |||
| 42 | #include "quad.h" |
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| 43 | |||
| 44 | /* |
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| 45 | * Convert (signed) quad to double. |
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| 46 | */ |
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| 47 | double |
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| 48 | __floatdidf(x) |
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| 49 | quad_t x; |
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| 50 | { |
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| 51 | double d; |
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| 52 | union uu u; |
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| 53 | int neg; |
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| 54 | |||
| 55 | /* |
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| 56 | * Get an unsigned number first, by negating if necessary. |
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| 57 | */ |
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| 58 | if (x < 0) |
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| 59 | u.q = -x, neg = 1; |
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| 60 | else |
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| 61 | u.q = x, neg = 0; |
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| 62 | |||
| 63 | /* |
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| 64 | * Now u.ul[H] has the factor of 2^32 (or whatever) and u.ul[L] |
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| 65 | * has the units. Ideally we could just set d, add LONG_BITS to |
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| 66 | * its exponent, and then add the units, but this is portable |
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| 67 | * code and does not know how to get at an exponent. Machine- |
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| 68 | * specific code may be able to do this more efficiently. |
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| 69 | */ |
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| 70 | d = (double)u.ul[H] * ((1 << (LONG_BITS - 2)) * 4.0); |
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| 71 | d += u.ul[L]; |
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| 72 | |||
| 73 | return (neg ? -d : d); |
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| 74 | } |