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