LXR linux/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
  59const 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
  79const 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
 100int 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        va_end(ax.ap);
 112        return ax.rv.si;
 113}
 114
 115s64 ieee754di_xcpt(s64 r, const char *op, ...)
 116{
 117        struct ieee754xctx ax;
 118
 119        if (!TSTX())
 120                return r;
 121        ax.op = op;
 122        ax.rt = IEEE754_RT_DI;
 123        ax.rv.di = r;
 124        va_start(ax.ap, op);
 125        ieee754_xcpt(&ax);
 126        va_end(ax.ap);
 127        return ax.rv.di;
 128}
 129