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