diff options
Diffstat (limited to 'sysdeps/arm/memset.S')
-rw-r--r-- | sysdeps/arm/memset.S | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/sysdeps/arm/memset.S b/sysdeps/arm/memset.S new file mode 100644 index 0000000000..cf04db4634 --- /dev/null +++ b/sysdeps/arm/memset.S @@ -0,0 +1,78 @@ +/* Copyright (C) 1998-2014 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Philip Blundell <philb@gnu.org> + + 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/>. */ + +/* Thumb requires excessive IT insns here. */ +#define NO_THUMB +#include <sysdep.h> + + .text + .syntax unified + +/* void *memset (dstpp, c, len) */ + +ENTRY(memset) + mov r3, r0 + cmp r2, #8 + bcc 2f @ less than 8 bytes to move + +1: + tst r3, #3 @ aligned yet? + sfi_breg r3, \ + strbne r1, [\B], #1 + subne r2, r2, #1 + bne 1b + + and r1, r1, #255 @ clear any sign bits + orr r1, r1, r1, lsl $8 + orr r1, r1, r1, lsl $16 + mov ip, r1 + +1: + subs r2, r2, #8 + sfi_breg r3, \ + stmiacs \B!, {r1, ip} @ store up to 32 bytes per loop iteration + subscs r2, r2, #8 + sfi_breg r3, \ + stmiacs \B!, {r1, ip} + subscs r2, r2, #8 + sfi_breg r3, \ + stmiacs \B!, {r1, ip} + subscs r2, r2, #8 + sfi_breg r3, \ + stmiacs \B!, {r1, ip} + bcs 1b + + and r2, r2, #7 +2: + subs r2, r2, #1 @ store up to 4 bytes per loop iteration + sfi_breg r3, \ + strbcs r1, [\B], #1 + subscs r2, r2, #1 + sfi_breg r3, \ + strbcs r1, [\B], #1 + subscs r2, r2, #1 + sfi_breg r3, \ + strbcs r1, [\B], #1 + subscs r2, r2, #1 + sfi_breg r3, \ + strbcs r1, [\B], #1 + bcs 2b + + DO_RET(lr) +END(memset) +libc_hidden_builtin_def (memset) |