1 /*
2 * University of Illinois/NCSA Open Source License
3 *
4 * Copyright (c) 2003-2012 University of Illinois at Urbana-Champaign.
5 * All rights reserved.
6 *
7 * Developed by:
8 *
9 * LLVM Team
10 *
11 * University of Illinois at Urbana-Champaign
12 *
13 * http://llvm.org
14 *
15 * Permission is hereby granted, free of charge, to any person obtaining a copy
16 * of this software and associated documentation files (the "Software"), to deal
17 * with the Software without restriction, including without limitation the
18 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
19 * sell copies of the Software, and to permit persons to whom the Software is
20 * furnished to do so, subject to the following conditions:
21 *
22 * * Redistributions of source code must retain the above copyright notice,
23 * this list of conditions and the following disclaimers.
24 *
25 * * Redistributions in binary form must reproduce the above copyright
26 * notice, this list of conditions and the following disclaimers in the
27 * documentation and/or other materials provided with the distribution.
28 *
29 * * Neither the names of the LLVM Team, University of Illinois at
30 * Urbana-Champaign, nor the names of its contributors may be used to
31 * endorse or promote products derived from this Software without specific
32 * prior written permission.
33 *
34 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
35 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
36 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
37 * CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
38 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
39 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH
40 * THE SOFTWARE.
41 */
42
43 /*
44 * C compiler runtime logic for __ctzdi2() related builtins taken from LLVM.
45 */
46
47 #include <sys/isa_defs.h>
48 #include <limits.h>
49
50 typedef union {
51 long long all;
52 struct {
53 #ifdef _LITTLE_ENDIAN
54 unsigned low;
55 int high;
56 #else
57 int high;
58 unsigned low;
59 #endif /* _LITTLE_ENDIAN */
60 } s;
61 } dwords;
62
63 int
__ctzdi2(unsigned long long val)64 __ctzdi2(unsigned long long val)
65 {
66 dwords x;
67 x.all = val;
68 const int f = -(x.s.low == 0);
69 return (__builtin_ctz((x.s.high & f) | (x.s.low & ~f)) +
70 (f & ((int)(sizeof (int) * CHAR_BIT))));
71 }
72