Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 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 | |
| 35 | #define DP_EBIAS 1023 |
| 36 | #define DP_EMIN (-1022) |
| 37 | #define DP_EMAX 1023 |
| 38 | |
| 39 | #define SP_EBIAS 127 |
| 40 | #define SP_EMIN (-126) |
| 41 | #define SP_EMAX 127 |
| 42 | |
| 43 | /* indexed by class */ |
| 44 | const char *const ieee754_cname[] = { |
| 45 | "Normal", |
| 46 | "Zero", |
| 47 | "Denormal", |
| 48 | "Infinity", |
| 49 | "QNaN", |
| 50 | "SNaN", |
| 51 | }; |
| 52 | |
| 53 | /* the control status register |
| 54 | */ |
| 55 | struct ieee754_csr ieee754_csr; |
| 56 | |
| 57 | /* special constants |
| 58 | */ |
| 59 | |
| 60 | |
| 61 | #if (defined(BYTE_ORDER) && BYTE_ORDER == LITTLE_ENDIAN) || defined(__MIPSEL__) |
| 62 | #define SPSTR(s,b,m) {m,b,s} |
| 63 | #define DPSTR(s,b,mh,ml) {ml,mh,b,s} |
| 64 | #endif |
| 65 | |
| 66 | #ifdef __MIPSEB__ |
| 67 | #define SPSTR(s,b,m) {s,b,m} |
| 68 | #define DPSTR(s,b,mh,ml) {s,b,mh,ml} |
| 69 | #endif |
| 70 | |
| 71 | const struct ieee754dp_konst __ieee754dp_spcvals[] = { |
| 72 | DPSTR(0, DP_EMIN - 1 + DP_EBIAS, 0, 0), /* + zero */ |
| 73 | DPSTR(1, DP_EMIN - 1 + DP_EBIAS, 0, 0), /* - zero */ |
| 74 | DPSTR(0, DP_EBIAS, 0, 0), /* + 1.0 */ |
| 75 | DPSTR(1, DP_EBIAS, 0, 0), /* - 1.0 */ |
| 76 | DPSTR(0, 3 + DP_EBIAS, 0x40000, 0), /* + 10.0 */ |
| 77 | DPSTR(1, 3 + DP_EBIAS, 0x40000, 0), /* - 10.0 */ |
| 78 | DPSTR(0, DP_EMAX + 1 + DP_EBIAS, 0, 0), /* + infinity */ |
| 79 | DPSTR(1, DP_EMAX + 1 + DP_EBIAS, 0, 0), /* - infinity */ |
| 80 | DPSTR(0,DP_EMAX+1+DP_EBIAS,0x7FFFF,0xFFFFFFFF), /* + indef quiet Nan */ |
| 81 | DPSTR(0, DP_EMAX + DP_EBIAS, 0xFFFFF, 0xFFFFFFFF), /* + max */ |
| 82 | DPSTR(1, DP_EMAX + DP_EBIAS, 0xFFFFF, 0xFFFFFFFF), /* - max */ |
| 83 | DPSTR(0, DP_EMIN + DP_EBIAS, 0, 0), /* + min normal */ |
| 84 | DPSTR(1, DP_EMIN + DP_EBIAS, 0, 0), /* - min normal */ |
| 85 | DPSTR(0, DP_EMIN - 1 + DP_EBIAS, 0, 1), /* + min denormal */ |
| 86 | DPSTR(1, DP_EMIN - 1 + DP_EBIAS, 0, 1), /* - min denormal */ |
| 87 | DPSTR(0, 31 + DP_EBIAS, 0, 0), /* + 1.0e31 */ |
| 88 | DPSTR(0, 63 + DP_EBIAS, 0, 0), /* + 1.0e63 */ |
| 89 | }; |
| 90 | |
| 91 | const struct ieee754sp_konst __ieee754sp_spcvals[] = { |
| 92 | SPSTR(0, SP_EMIN - 1 + SP_EBIAS, 0), /* + zero */ |
| 93 | SPSTR(1, SP_EMIN - 1 + SP_EBIAS, 0), /* - zero */ |
| 94 | SPSTR(0, SP_EBIAS, 0), /* + 1.0 */ |
| 95 | SPSTR(1, SP_EBIAS, 0), /* - 1.0 */ |
| 96 | SPSTR(0, 3 + SP_EBIAS, 0x200000), /* + 10.0 */ |
| 97 | SPSTR(1, 3 + SP_EBIAS, 0x200000), /* - 10.0 */ |
| 98 | SPSTR(0, SP_EMAX + 1 + SP_EBIAS, 0), /* + infinity */ |
| 99 | SPSTR(1, SP_EMAX + 1 + SP_EBIAS, 0), /* - infinity */ |
| 100 | SPSTR(0,SP_EMAX+1+SP_EBIAS,0x3FFFFF), /* + indef quiet Nan */ |
| 101 | SPSTR(0, SP_EMAX + SP_EBIAS, 0x7FFFFF), /* + max normal */ |
| 102 | SPSTR(1, SP_EMAX + SP_EBIAS, 0x7FFFFF), /* - max normal */ |
| 103 | SPSTR(0, SP_EMIN + SP_EBIAS, 0), /* + min normal */ |
| 104 | SPSTR(1, SP_EMIN + SP_EBIAS, 0), /* - min normal */ |
| 105 | SPSTR(0, SP_EMIN - 1 + SP_EBIAS, 1), /* + min denormal */ |
| 106 | SPSTR(1, SP_EMIN - 1 + SP_EBIAS, 1), /* - min denormal */ |
| 107 | SPSTR(0, 31 + SP_EBIAS, 0), /* + 1.0e31 */ |
| 108 | SPSTR(0, 63 + SP_EBIAS, 0), /* + 1.0e63 */ |
| 109 | }; |
| 110 | |
| 111 | |
| 112 | int ieee754si_xcpt(int r, const char *op, ...) |
| 113 | { |
| 114 | struct ieee754xctx ax; |
| 115 | |
| 116 | if (!TSTX()) |
| 117 | return r; |
| 118 | ax.op = op; |
| 119 | ax.rt = IEEE754_RT_SI; |
| 120 | ax.rv.si = r; |
| 121 | va_start(ax.ap, op); |
| 122 | ieee754_xcpt(&ax); |
| 123 | return ax.rv.si; |
| 124 | } |
| 125 | |
| 126 | s64 ieee754di_xcpt(s64 r, const char *op, ...) |
| 127 | { |
| 128 | struct ieee754xctx ax; |
| 129 | |
| 130 | if (!TSTX()) |
| 131 | return r; |
| 132 | ax.op = op; |
| 133 | ax.rt = IEEE754_RT_DI; |
| 134 | ax.rv.di = r; |
| 135 | va_start(ax.ap, op); |
| 136 | ieee754_xcpt(&ax); |
| 137 | return ax.rv.di; |
| 138 | } |