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-rw-r--r--sysdeps/arm/memset.S78
1 files changed, 78 insertions, 0 deletions
diff --git a/sysdeps/arm/memset.S b/sysdeps/arm/memset.S
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+/* 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)