diff options
Diffstat (limited to 'sysdeps/arm/armv6t2/ffsll.S')
| -rw-r--r-- | sysdeps/arm/armv6t2/ffsll.S | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/sysdeps/arm/armv6t2/ffsll.S b/sysdeps/arm/armv6t2/ffsll.S new file mode 100644 index 0000000000..204ff80092 --- /dev/null +++ b/sysdeps/arm/armv6t2/ffsll.S @@ -0,0 +1,50 @@ +/* ffsll -- find first set bit in a long long, from least significant end. + Copyright (C) 2013-2014 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library. If not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> + + .syntax unified + .text + +ENTRY (ffsll) + @ If low part is 0, operate on the high part. Ensure that the + @ word on which we operate is in r0. Set r2 to the bit offset + @ of the word being considered. Set the flags for the word + @ being operated on. +#ifdef __ARMEL__ + cmp r0, #0 + itee ne + movne r2, #0 + moveq r2, #32 + movseq r0, r1 +#else + cmp r1, #0 + ittee ne + movne r2, #0 + movne r0, r1 + moveq r2, #32 + cmpeq r0, #0 +#endif + @ Perform the ffs on r0. + rbit r0, r0 + ittt ne + clzne r0, r0 + addne r2, r2, #1 + addne r0, r0, r2 + bx lr +END (ffsll) |