projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 15637ed4 RG |
1 | /* |
| 2 | Copyright (C) 1990 Free Software Foundation | |
| 3 | written by Doug Lea (dl@rocky.oswego.edu) | |
| 4 | ||
| 78ed81a3 | 5 | This file is part of the GNU C++ Library. This library is free |
| 6 | software; you can redistribute it and/or modify it under the terms of | |
| 7 | the GNU Library General Public License as published by the Free | |
| 8 | Software Foundation; either version 2 of the License, or (at your | |
| 9 | option) any later version. This library is distributed in the hope | |
| 10 | that it will be useful, but WITHOUT ANY WARRANTY; without even the | |
| 11 | implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR | |
| 12 | PURPOSE. See the GNU Library General Public License for more details. | |
| 13 | You should have received a copy of the GNU Library General Public | |
| 14 | License along with this library; if not, write to the Free Software | |
| 15 | Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. | |
| 15637ed4 RG |
16 | */ |
| 17 | ||
| 18 | #ifdef __GNUG__ | |
| 19 | #pragma implementation | |
| 20 | #endif | |
| 21 | #include <builtin.h> | |
| 22 | #include <math.h> | |
| 23 | ||
| 24 | long sqrt(long x) | |
| 25 | { | |
| 26 | if (x <= 0) | |
| 27 | return 0; // no int error handler, so ... | |
| 28 | else if (x == 1) | |
| 29 | return 1; | |
| 30 | else | |
| 31 | { | |
| 32 | long r = x >> 1; | |
| 33 | long q; | |
| 34 | for(;;) | |
| 35 | { | |
| 36 | q = x / r; | |
| 37 | if (q >= r) | |
| 38 | return r; | |
| 39 | else | |
| 40 | r = (r + q) >> 1; | |
| 41 | } | |
| 42 | } | |
| 43 | } |