tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1/*
2 * IEEE754 floating point
3 * double precision internal header file
4 */
5/*
6 * MIPS floating point support
7 * Copyright (C) 1994-2000 Algorithmics Ltd.
8 *
9 * This program is free software; you can distribute it and/or modify it
10 * under the terms of the GNU General Public License (Version 2) as
11 * published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope it will be useful, but WITHOUT
14 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 * for more details.
17 *
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21 */
22
23#include <linux/compiler.h>
24
25#include "ieee754int.h"
26
27#define assert(expr) ((void)0)
28
29#define DP_EBIAS 1023
30#define DP_EMIN (-1022)
31#define DP_EMAX 1023
32#define DP_FBITS 52
33#define DP_MBITS 52
34
35#define DP_MBIT(x) ((u64)1 << (x))
36#define DP_HIDDEN_BIT DP_MBIT(DP_FBITS)
37#define DP_SIGN_BIT DP_MBIT(63)
38
39#define DPSIGN(dp) (dp.sign)
40#define DPBEXP(dp) (dp.bexp)
41#define DPMANT(dp) (dp.mant)
42
43static inline int ieee754dp_finite(union ieee754dp x)
44{
45 return DPBEXP(x) != DP_EMAX + 1 + DP_EBIAS;
46}
47
48/* 3bit extended double precision sticky right shift */
49#define XDPSRS(v,rs) \
50 ((rs > (DP_FBITS+3))?1:((v) >> (rs)) | ((v) << (64-(rs)) != 0))
51
52#define XDPSRSX1() \
53 (xe++, (xm = (xm >> 1) | (xm & 1)))
54
55#define XDPSRS1(v) \
56 (((v) >> 1) | ((v) & 1))
57
58/* convert denormal to normalized with extended exponent */
59#define DPDNORMx(m,e) \
60 while ((m >> DP_FBITS) == 0) { m <<= 1; e--; }
61#define DPDNORMX DPDNORMx(xm, xe)
62#define DPDNORMY DPDNORMx(ym, ye)
63
64static inline union ieee754dp builddp(int s, int bx, u64 m)
65{
66 union ieee754dp r;
67
68 assert((s) == 0 || (s) == 1);
69 assert((bx) >= DP_EMIN - 1 + DP_EBIAS
70 && (bx) <= DP_EMAX + 1 + DP_EBIAS);
71 assert(((m) >> DP_FBITS) == 0);
72
73 r.sign = s;
74 r.bexp = bx;
75 r.mant = m;
76
77 return r;
78}
79
80extern union ieee754dp __cold ieee754dp_nanxcpt(union ieee754dp);
81extern union ieee754dp ieee754dp_format(int, int, u64);