1 /* Generic unsigned 32 bit division implementation.
2 Copyright (C) 2009, 2011 Free Software Foundation, Inc.
3 Contributed by Embecosm on behalf of Adapteva, Inc.
5 This file is part of GCC.
7 This file is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the
9 Free Software Foundation; either version 3, or (at your option) any
12 This file is distributed in the hope that it will be useful, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 General Public License for more details.
17 Under Section 7 of GPL version 3, you are granted additional
18 permissions described in the GCC Runtime Library Exception, version
19 3.1, as published by the Free Software Foundation.
21 You should have received a copy of the GNU General Public License and
22 a copy of the GCC Runtime Library Exception along with this program;
23 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24 <http://www.gnu.org/licenses/>. */
26 typedef union { unsigned int i; float f; } fu;
28 unsigned int __udivsi3 (unsigned int a, unsigned int b);
31 __udivsi3 (unsigned int a, unsigned int b)
33 unsigned int d, t, s0, s1, s2, r0, r1;
34 fu u0, u1, u2, u1b, u2b;
41 /* Assuming B is nonzero, compute S0 such that 0 <= S0,
42 (B << S0+1) does not overflow,
43 A < 4.01 * (B << S0), with S0 choosen as small as possible
44 without taking to much time calculating. */
45 #ifdef CONVERT_UNSIGNED
48 #else /* !CONVERT_UNSIGNED */
53 u0.i = (a >> 8) - 0x00800000 + 0x3f800000 + (31 << 23);
54 #else /* To use flag seting / cmove, this can be written as: */
56 unsigned c = 0xff800000 - 0x4f000000;
62 #endif /* !CONVERT_UNSIGNED */
63 s0 = u0.i + 1 /* Compensate for rounding errors. */
64 - 0x00800000 /* adjust by one */ ;
66 s0 = (int)s0 >= 0 ? s0 : 0;
87 #define STEP(n) case n: a += a; t = a - d; if (t <= a) a = t;
123 r0 = r1 | (r0-1 & a);