LXR linux/arch/mips/math-emu/ieee754sp.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 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/* 64 bit right shift with rounding */
  49#define XSPSRS64(v, rs)                                         \
  50        (((rs) >= 64) ? ((v) != 0) : ((v) >> (rs)) | ((v) << (64-(rs)) != 0))
  51
  52/* 3bit extended single precision sticky right shift */
  53#define XSPSRS(v, rs)                                           \
  54        ((rs > (SP_FBITS+3))?1:((v) >> (rs)) | ((v) << (32-(rs)) != 0))
  55
  56#define XSPSRS1(m) \
  57        ((m >> 1) | (m & 1))
  58
  59#define SPXSRSX1() \
  60        (xe++, (xm = XSPSRS1(xm)))
  61
  62#define SPXSRSY1() \
  63        (ye++, (ym = XSPSRS1(ym)))
  64
  65/* convert denormal to normalized with extended exponent */
  66#define SPDNORMx(m,e) \
  67        while ((m >> SP_FBITS) == 0) { m <<= 1; e--; }
  68#define SPDNORMX        SPDNORMx(xm, xe)
  69#define SPDNORMY        SPDNORMx(ym, ye)
  70#define SPDNORMZ        SPDNORMx(zm, ze)
  71
  72static inline union ieee754sp buildsp(int s, int bx, unsigned int m)
  73{
  74        union ieee754sp r;
  75
  76        assert((s) == 0 || (s) == 1);
  77        assert((bx) >= SP_EMIN - 1 + SP_EBIAS
  78               && (bx) <= SP_EMAX + 1 + SP_EBIAS);
  79        assert(((m) >> SP_FBITS) == 0);
  80
  81        r.sign = s;
  82        r.bexp = bx;
  83        r.mant = m;
  84
  85        return r;
  86}
  87
  88extern union ieee754sp __cold ieee754sp_nanxcpt(union ieee754sp);
  89extern union ieee754sp ieee754sp_format(int, int, unsigned);
  90