Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* IEEE754 floating point arithmetic |
| 2 | * single precision |
| 3 | */ |
| 4 | /* |
| 5 | * MIPS floating point support |
| 6 | * Copyright (C) 1994-2000 Algorithmics Ltd. |
| 7 | * http://www.algor.co.uk |
| 8 | * |
| 9 | * ######################################################################## |
| 10 | * |
| 11 | * This program is free software; you can distribute it and/or modify it |
| 12 | * under the terms of the GNU General Public License (Version 2) as |
| 13 | * published by the Free Software Foundation. |
| 14 | * |
| 15 | * This program is distributed in the hope it will be useful, but WITHOUT |
| 16 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 17 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 18 | * for more details. |
| 19 | * |
| 20 | * You should have received a copy of the GNU General Public License along |
| 21 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 22 | * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. |
| 23 | * |
| 24 | * ######################################################################## |
| 25 | */ |
| 26 | |
| 27 | |
| 28 | #include "ieee754sp.h" |
| 29 | |
| 30 | ieee754sp ieee754sp_fint(int x) |
| 31 | { |
Atsushi Nemoto | ecf52d3 | 2006-06-01 01:00:03 +0900 | [diff] [blame^] | 32 | unsigned xm; |
| 33 | int xe; |
| 34 | int xs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | |
| 36 | CLEARCX; |
| 37 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | if (x == 0) |
| 39 | return ieee754sp_zero(0); |
| 40 | if (x == 1 || x == -1) |
| 41 | return ieee754sp_one(x < 0); |
| 42 | if (x == 10 || x == -10) |
| 43 | return ieee754sp_ten(x < 0); |
| 44 | |
| 45 | xs = (x < 0); |
| 46 | if (xs) { |
| 47 | if (x == (1 << 31)) |
| 48 | xm = ((unsigned) 1 << 31); /* max neg can't be safely negated */ |
| 49 | else |
| 50 | xm = -x; |
| 51 | } else { |
| 52 | xm = x; |
| 53 | } |
| 54 | xe = SP_MBITS + 3; |
| 55 | |
| 56 | if (xm >> (SP_MBITS + 1 + 3)) { |
| 57 | /* shunt out overflow bits |
| 58 | */ |
| 59 | while (xm >> (SP_MBITS + 1 + 3)) { |
| 60 | SPXSRSX1(); |
| 61 | } |
| 62 | } else { |
| 63 | /* normalize in grs extended single precision |
| 64 | */ |
| 65 | while ((xm >> (SP_MBITS + 3)) == 0) { |
| 66 | xm <<= 1; |
| 67 | xe--; |
| 68 | } |
| 69 | } |
| 70 | SPNORMRET1(xs, xe, xm, "fint", x); |
| 71 | } |
| 72 | |
| 73 | |
| 74 | ieee754sp ieee754sp_funs(unsigned int u) |
| 75 | { |
| 76 | if ((int) u < 0) |
| 77 | return ieee754sp_add(ieee754sp_1e31(), |
| 78 | ieee754sp_fint(u & ~(1 << 31))); |
| 79 | return ieee754sp_fint(u); |
| 80 | } |