xref: /OK3568_Linux_fs/kernel/arch/mips/math-emu/ieee754sp.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0-only */
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * IEEE754 floating point
4*4882a593Smuzhiyun  * double precision internal header file
5*4882a593Smuzhiyun  */
6*4882a593Smuzhiyun /*
7*4882a593Smuzhiyun  * MIPS floating point support
8*4882a593Smuzhiyun  * Copyright (C) 1994-2000 Algorithmics Ltd.
9*4882a593Smuzhiyun  */
10*4882a593Smuzhiyun 
11*4882a593Smuzhiyun #include <linux/compiler.h>
12*4882a593Smuzhiyun 
13*4882a593Smuzhiyun #include "ieee754int.h"
14*4882a593Smuzhiyun 
15*4882a593Smuzhiyun #define assert(expr) ((void)0)
16*4882a593Smuzhiyun 
17*4882a593Smuzhiyun #define SP_EBIAS	127
18*4882a593Smuzhiyun #define SP_EMIN		(-126)
19*4882a593Smuzhiyun #define SP_EMAX		127
20*4882a593Smuzhiyun #define SP_FBITS	23
21*4882a593Smuzhiyun #define SP_MBITS	23
22*4882a593Smuzhiyun 
23*4882a593Smuzhiyun #define SP_MBIT(x)	((u32)1 << (x))
24*4882a593Smuzhiyun #define SP_HIDDEN_BIT	SP_MBIT(SP_FBITS)
25*4882a593Smuzhiyun #define SP_SIGN_BIT	SP_MBIT(31)
26*4882a593Smuzhiyun 
27*4882a593Smuzhiyun #define SPSIGN(sp)	(sp.sign)
28*4882a593Smuzhiyun #define SPBEXP(sp)	(sp.bexp)
29*4882a593Smuzhiyun #define SPMANT(sp)	(sp.mant)
30*4882a593Smuzhiyun 
ieee754sp_finite(union ieee754sp x)31*4882a593Smuzhiyun static inline int ieee754sp_finite(union ieee754sp x)
32*4882a593Smuzhiyun {
33*4882a593Smuzhiyun 	return SPBEXP(x) != SP_EMAX + 1 + SP_EBIAS;
34*4882a593Smuzhiyun }
35*4882a593Smuzhiyun 
36*4882a593Smuzhiyun /* 64 bit right shift with rounding */
37*4882a593Smuzhiyun #define XSPSRS64(v, rs)						\
38*4882a593Smuzhiyun 	(((rs) >= 64) ? ((v) != 0) : ((v) >> (rs)) | ((v) << (64-(rs)) != 0))
39*4882a593Smuzhiyun 
40*4882a593Smuzhiyun /* 3bit extended single precision sticky right shift */
41*4882a593Smuzhiyun #define XSPSRS(v, rs)						\
42*4882a593Smuzhiyun 	((rs > (SP_FBITS+3))?1:((v) >> (rs)) | ((v) << (32-(rs)) != 0))
43*4882a593Smuzhiyun 
44*4882a593Smuzhiyun #define XSPSRS1(m) \
45*4882a593Smuzhiyun 	((m >> 1) | (m & 1))
46*4882a593Smuzhiyun 
47*4882a593Smuzhiyun #define SPXSRSX1() \
48*4882a593Smuzhiyun 	(xe++, (xm = XSPSRS1(xm)))
49*4882a593Smuzhiyun 
50*4882a593Smuzhiyun #define SPXSRSY1() \
51*4882a593Smuzhiyun 	(ye++, (ym = XSPSRS1(ym)))
52*4882a593Smuzhiyun 
53*4882a593Smuzhiyun /* convert denormal to normalized with extended exponent */
54*4882a593Smuzhiyun #define SPDNORMx(m,e) \
55*4882a593Smuzhiyun 	while ((m >> SP_FBITS) == 0) { m <<= 1; e--; }
56*4882a593Smuzhiyun #define SPDNORMX	SPDNORMx(xm, xe)
57*4882a593Smuzhiyun #define SPDNORMY	SPDNORMx(ym, ye)
58*4882a593Smuzhiyun #define SPDNORMZ	SPDNORMx(zm, ze)
59*4882a593Smuzhiyun 
buildsp(int s,int bx,unsigned int m)60*4882a593Smuzhiyun static inline union ieee754sp buildsp(int s, int bx, unsigned int m)
61*4882a593Smuzhiyun {
62*4882a593Smuzhiyun 	union ieee754sp r;
63*4882a593Smuzhiyun 
64*4882a593Smuzhiyun 	assert((s) == 0 || (s) == 1);
65*4882a593Smuzhiyun 	assert((bx) >= SP_EMIN - 1 + SP_EBIAS
66*4882a593Smuzhiyun 	       && (bx) <= SP_EMAX + 1 + SP_EBIAS);
67*4882a593Smuzhiyun 	assert(((m) >> SP_FBITS) == 0);
68*4882a593Smuzhiyun 
69*4882a593Smuzhiyun 	r.sign = s;
70*4882a593Smuzhiyun 	r.bexp = bx;
71*4882a593Smuzhiyun 	r.mant = m;
72*4882a593Smuzhiyun 
73*4882a593Smuzhiyun 	return r;
74*4882a593Smuzhiyun }
75*4882a593Smuzhiyun 
76*4882a593Smuzhiyun extern union ieee754sp __cold ieee754sp_nanxcpt(union ieee754sp);
77*4882a593Smuzhiyun extern union ieee754sp ieee754sp_format(int, int, unsigned);
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