LXR linux/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
  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/* 32bit * 32bit => 64bit unsigned integer multiplication */
  59#define DPXMULT(x, y)   ((u64)(x) * (u64)y)
  60
  61/* convert denormal to normalized with extended exponent */
  62#define DPDNORMx(m,e) \
  63        while ((m >> DP_FBITS) == 0) { m <<= 1; e--; }
  64#define DPDNORMX        DPDNORMx(xm, xe)
  65#define DPDNORMY        DPDNORMx(ym, ye)
  66#define DPDNORMZ        DPDNORMx(zm, ze)
  67
  68static inline union ieee754dp builddp(int s, int bx, u64 m)
  69{
  70        union ieee754dp r;
  71
  72        assert((s) == 0 || (s) == 1);
  73        assert((bx) >= DP_EMIN - 1 + DP_EBIAS
  74               && (bx) <= DP_EMAX + 1 + DP_EBIAS);
  75        assert(((m) >> DP_FBITS) == 0);
  76
  77        r.sign = s;
  78        r.bexp = bx;
  79        r.mant = m;
  80
  81        return r;
  82}
  83
  84extern union ieee754dp __cold ieee754dp_nanxcpt(union ieee754dp);
  85extern union ieee754dp ieee754dp_format(int, int, u64);
  86