Override elf_nacl.xr linker script so that libc_pic.os links correctly
[glibc/nacl-glibc.git] / sysdeps / s390 / ffs.c
blobaa17233dbe02cdad49c356c776fe5da6c4aaf47d
1 /* ffs -- find first set bit in a word, counted from least significant end.
2 S/390 version.
3 Copyright (C) 2000, 2001, 2004 Free Software Foundation, Inc.
4 Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
5 This file is part of the GNU C Library.
7 The GNU C Library is free software; you can redistribute it and/or
8 modify it under the terms of the GNU Lesser General Public
9 License as published by the Free Software Foundation; either
10 version 2.1 of the License, or (at your option) any later version.
12 The GNU C Library is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Lesser General Public License for more details.
17 You should have received a copy of the GNU Lesser General Public
18 License along with the GNU C Library; if not, write to the Free
19 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
20 02111-1307 USA. */
22 #include <limits.h>
23 #define ffsl __something_else
24 #include <string.h>
26 #undef ffs
28 /* ffs: find first bit set. This is defined the same way as
29 the libc and compiler builtin ffs routines, therefore
30 differs in spirit from the above ffz (man ffs). */
32 int
33 __ffs (x)
34 int x;
36 int r;
38 if (x == 0)
39 return 0;
40 __asm__(" lr %%r1,%1\n"
41 " sr %0,%0\n"
42 " tml %%r1,0xFFFF\n"
43 " jnz 0f\n"
44 " ahi %0,16\n"
45 " srl %%r1,16\n"
46 "0: tml %%r1,0x00FF\n"
47 " jnz 1f\n"
48 " ahi %0,8\n"
49 " srl %%r1,8\n"
50 "1: tml %%r1,0x000F\n"
51 " jnz 2f\n"
52 " ahi %0,4\n"
53 " srl %%r1,4\n"
54 "2: tml %%r1,0x0003\n"
55 " jnz 3f\n"
56 " ahi %0,2\n"
57 " srl %%r1,2\n"
58 "3: tml %%r1,0x0001\n"
59 " jnz 4f\n"
60 " ahi %0,1\n"
61 "4:"
62 : "=&d" (r) : "d" (x) : "cc", "1" );
63 return r+1;
66 weak_alias (__ffs, ffs)
67 libc_hidden_builtin_def (ffs)
68 #if ULONG_MAX == UINT_MAX
69 #undef ffsl
70 weak_alias (__ffs, ffsl)
71 #endif