arch/mips/math-emu/ieee754dp.h

   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
  43 static 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 #define DPDNORMZ        DPDNORMx(zm, ze)
  64
  65 static inline union ieee754dp builddp(int s, int bx, u64 m)
  66 {
  67         union ieee754dp r;
  68
  69         assert((s) == 0 || (s) == 1);
  70         assert((bx) >= DP_EMIN - 1 + DP_EBIAS
  71                && (bx) <= DP_EMAX + 1 + DP_EBIAS);
  72         assert(((m) >> DP_FBITS) == 0);
  73
  74         r.sign = s;
  75         r.bexp = bx;
  76         r.mant = m;
  77
  78         return r;
  79 }
  80
  81 extern union ieee754dp __cold ieee754dp_nanxcpt(union ieee754dp);
  82 extern union ieee754dp ieee754dp_format(int, int, u64);