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 SP_EBIAS 127
30#define SP_EMIN (-126)
31#define SP_EMAX 127
32#define SP_FBITS 23
33#define SP_MBITS 23
34
35#define SP_MBIT(x) ((u32)1 << (x))
36#define SP_HIDDEN_BIT SP_MBIT(SP_FBITS)
37#define SP_SIGN_BIT SP_MBIT(31)
38
39#define SPSIGN(sp) (sp.sign)
40#define SPBEXP(sp) (sp.bexp)
41#define SPMANT(sp) (sp.mant)
42
43static inline int ieee754sp_finite(union ieee754sp x)
44{
45 return SPBEXP(x) != SP_EMAX + 1 + SP_EBIAS;
46}
47
48/* 3bit extended single precision sticky right shift */
49#define XSPSRS(v, rs) \
50 ((rs > (SP_FBITS+3))?1:((v) >> (rs)) | ((v) << (32-(rs)) != 0))
51
52#define XSPSRS1(m) \
53 ((m >> 1) | (m & 1))
54
55#define SPXSRSX1() \
56 (xe++, (xm = XSPSRS1(xm)))
57
58#define SPXSRSY1() \
59 (ye++, (ym = XSPSRS1(ym)))
60
61/* convert denormal to normalized with extended exponent */
62#define SPDNORMx(m,e) \
63 while ((m >> SP_FBITS) == 0) { m <<= 1; e--; }
64#define SPDNORMX SPDNORMx(xm, xe)
65#define SPDNORMY SPDNORMx(ym, ye)
66#define SPDNORMZ SPDNORMx(zm, ze)
67
68static inline union ieee754sp buildsp(int s, int bx, unsigned m)
69{
70 union ieee754sp r;
71
72 assert((s) == 0 || (s) == 1);
73 assert((bx) >= SP_EMIN - 1 + SP_EBIAS
74 && (bx) <= SP_EMAX + 1 + SP_EBIAS);
75 assert(((m) >> SP_FBITS) == 0);
76
77 r.sign = s;
78 r.bexp = bx;
79 r.mant = m;
80
81 return r;
82}
83
84extern union ieee754sp __cold ieee754sp_nanxcpt(union ieee754sp);
85extern union ieee754sp ieee754sp_format(int, int, unsigned);