xref: /openbmc/linux/arch/mips/math-emu/ieee754sp.h (revision 2c684d89)
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 
43 static 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 SPXSRSXn(rs)							\
50 	(xe += rs,							\
51 	 xm = (rs > (SP_FBITS+3))?1:((xm) >> (rs)) | ((xm) << (32-(rs)) != 0))
52 
53 #define SPXSRSX1() \
54 	(xe++, (xm = (xm >> 1) | (xm & 1)))
55 
56 #define SPXSRSYn(rs)								\
57 	(ye+=rs,								\
58 	 ym = (rs > (SP_FBITS+3))?1:((ym) >> (rs)) | ((ym) << (32-(rs)) != 0))
59 
60 #define SPXSRSY1() \
61 	(ye++, (ym = (ym >> 1) | (ym & 1)))
62 
63 /* convert denormal to normalized with extended exponent */
64 #define SPDNORMx(m,e) \
65 	while ((m >> SP_FBITS) == 0) { m <<= 1; e--; }
66 #define SPDNORMX	SPDNORMx(xm, xe)
67 #define SPDNORMY	SPDNORMx(ym, ye)
68 
69 static inline union ieee754sp buildsp(int s, int bx, unsigned m)
70 {
71 	union ieee754sp r;
72 
73 	assert((s) == 0 || (s) == 1);
74 	assert((bx) >= SP_EMIN - 1 + SP_EBIAS
75 	       && (bx) <= SP_EMAX + 1 + SP_EBIAS);
76 	assert(((m) >> SP_FBITS) == 0);
77 
78 	r.sign = s;
79 	r.bexp = bx;
80 	r.mant = m;
81 
82 	return r;
83 }
84 
85 extern union ieee754sp __cold ieee754sp_nanxcpt(union ieee754sp);
86 extern union ieee754sp ieee754sp_format(int, int, unsigned);
87