arch/mips/math-emu/ieee754.c

   1 /* ieee754 floating point arithmetic
   2  * single and double precision
   3  *
   4  * BUGS
   5  * not much dp done
   6  * doesn't generate IEEE754_INEXACT
   7  *
   8  */
   9 /*
  10  * MIPS floating point support
  11  * Copyright (C) 1994-2000 Algorithmics Ltd.
  12  * http://www.algor.co.uk
  13  *
  14  * ########################################################################
  15  *
  16  *  This program is free software; you can distribute it and/or modify it
  17  *  under the terms of the GNU General Public License (Version 2) as
  18  *  published by the Free Software Foundation.
  19  *
  20  *  This program is distributed in the hope it will be useful, but WITHOUT
  21  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  22  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  23  *  for more details.
  24  *
  25  *  You should have received a copy of the GNU General Public License along
  26  *  with this program; if not, write to the Free Software Foundation, Inc.,
  27  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  28  *
  29  * ########################################################################
  30  */
  31
  32
  33 #include "ieee754int.h"
  34 #include "ieee754sp.h"
  35 #include "ieee754dp.h"
  36
  37 #define DP_EBIAS        1023
  38 #define DP_EMIN         (-1022)
  39 #define DP_EMAX         1023
  40
  41 #define SP_EBIAS        127
  42 #define SP_EMIN         (-126)
  43 #define SP_EMAX         127
  44
  45 /* special constants
  46 */
  47
  48
  49 #if (defined(BYTE_ORDER) && BYTE_ORDER == LITTLE_ENDIAN) || defined(__MIPSEL__)
  50 #define SPSTR(s,b,m) {m,b,s}
  51 #define DPSTR(s,b,mh,ml) {ml,mh,b,s}
  52 #endif
  53
  54 #ifdef __MIPSEB__
  55 #define SPSTR(s,b,m) {s,b,m}
  56 #define DPSTR(s,b,mh,ml) {s,b,mh,ml}
  57 #endif
  58
  59 const struct ieee754dp_konst __ieee754dp_spcvals[] = {
  60         DPSTR(0, DP_EMIN - 1 + DP_EBIAS, 0, 0), /* + zero   */
  61         DPSTR(1, DP_EMIN - 1 + DP_EBIAS, 0, 0), /* - zero   */
  62         DPSTR(0, DP_EBIAS, 0, 0),       /* + 1.0   */
  63         DPSTR(1, DP_EBIAS, 0, 0),       /* - 1.0   */
  64         DPSTR(0, 3 + DP_EBIAS, 0x40000, 0),     /* + 10.0   */
  65         DPSTR(1, 3 + DP_EBIAS, 0x40000, 0),     /* - 10.0   */
  66         DPSTR(0, DP_EMAX + 1 + DP_EBIAS, 0, 0), /* + infinity */
  67         DPSTR(1, DP_EMAX + 1 + DP_EBIAS, 0, 0), /* - infinity */
  68         DPSTR(0,DP_EMAX+1+DP_EBIAS,0x7FFFF,0xFFFFFFFF), /* + indef quiet Nan */
  69         DPSTR(0, DP_EMAX + DP_EBIAS, 0xFFFFF, 0xFFFFFFFF),      /* + max */
  70         DPSTR(1, DP_EMAX + DP_EBIAS, 0xFFFFF, 0xFFFFFFFF),      /* - max */
  71         DPSTR(0, DP_EMIN + DP_EBIAS, 0, 0),     /* + min normal */
  72         DPSTR(1, DP_EMIN + DP_EBIAS, 0, 0),     /* - min normal */
  73         DPSTR(0, DP_EMIN - 1 + DP_EBIAS, 0, 1), /* + min denormal */
  74         DPSTR(1, DP_EMIN - 1 + DP_EBIAS, 0, 1), /* - min denormal */
  75         DPSTR(0, 31 + DP_EBIAS, 0, 0),  /* + 1.0e31 */
  76         DPSTR(0, 63 + DP_EBIAS, 0, 0),  /* + 1.0e63 */
  77 };
  78
  79 const struct ieee754sp_konst __ieee754sp_spcvals[] = {
  80         SPSTR(0, SP_EMIN - 1 + SP_EBIAS, 0),    /* + zero   */
  81         SPSTR(1, SP_EMIN - 1 + SP_EBIAS, 0),    /* - zero   */
  82         SPSTR(0, SP_EBIAS, 0),  /* + 1.0   */
  83         SPSTR(1, SP_EBIAS, 0),  /* - 1.0   */
  84         SPSTR(0, 3 + SP_EBIAS, 0x200000),       /* + 10.0   */
  85         SPSTR(1, 3 + SP_EBIAS, 0x200000),       /* - 10.0   */
  86         SPSTR(0, SP_EMAX + 1 + SP_EBIAS, 0),    /* + infinity */
  87         SPSTR(1, SP_EMAX + 1 + SP_EBIAS, 0),    /* - infinity */
  88         SPSTR(0,SP_EMAX+1+SP_EBIAS,0x3FFFFF),     /* + indef quiet Nan  */
  89         SPSTR(0, SP_EMAX + SP_EBIAS, 0x7FFFFF), /* + max normal */
  90         SPSTR(1, SP_EMAX + SP_EBIAS, 0x7FFFFF), /* - max normal */
  91         SPSTR(0, SP_EMIN + SP_EBIAS, 0),        /* + min normal */
  92         SPSTR(1, SP_EMIN + SP_EBIAS, 0),        /* - min normal */
  93         SPSTR(0, SP_EMIN - 1 + SP_EBIAS, 1),    /* + min denormal */
  94         SPSTR(1, SP_EMIN - 1 + SP_EBIAS, 1),    /* - min denormal */
  95         SPSTR(0, 31 + SP_EBIAS, 0),     /* + 1.0e31 */
  96         SPSTR(0, 63 + SP_EBIAS, 0),     /* + 1.0e63 */
  97 };
  98
  99
 100 int ieee754si_xcpt(int r, const char *op, ...)
 101 {
 102         struct ieee754xctx ax;
 103
 104         if (!TSTX())
 105                 return r;
 106         ax.op = op;
 107         ax.rt = IEEE754_RT_SI;
 108         ax.rv.si = r;
 109         va_start(ax.ap, op);
 110         ieee754_xcpt(&ax);
 111         return ax.rv.si;
 112 }
 113
 114 s64 ieee754di_xcpt(s64 r, const char *op, ...)
 115 {
 116         struct ieee754xctx ax;
 117
 118         if (!TSTX())
 119                 return r;
 120         ax.op = op;
 121         ax.rt = IEEE754_RT_DI;
 122         ax.rv.di = r;
 123         va_start(ax.ap, op);
 124         ieee754_xcpt(&ax);
 125         return ax.rv.di;
 126 }