zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/build/uClibc/libc/string/arm/strlen.S b/ap/build/uClibc/libc/string/arm/strlen.S
new file mode 100644
index 0000000..949e918
--- /dev/null
+++ b/ap/build/uClibc/libc/string/arm/strlen.S
@@ -0,0 +1,111 @@
+/* Copyright (C) 1998 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Code contributed by Matthew Wilcox <willy@odie.barnet.ac.uk>
+
+ 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <features.h>
+#include <endian.h>
+#include <sys/syscall.h>
+#include <bits/arm_asm.h>
+
+/* size_t strlen(const char *S)
+ * entry: r0 -> string
+ * exit: r0 = len
+ */
+
+.text
+.global strlen
+.type strlen,%function
+.align 4
+
+#if defined(THUMB1_ONLY)
+/* A simple implementation for when the ARM implementation can't be used. */
+.thumb_func
+strlen:
+ mov r2, #0
+1:
+ ldrb r1, [r0, r2]
+ add r2, r2, #1
+ cmp r1, #0
+ bne 1b
+ sub r0, r2, #1
+ bx lr
+#else
+strlen:
+ bic r1, r0, $3 @ addr of word containing first byte
+ ldr r2, [r1], $4 @ get the first word
+ ands r3, r0, $3 @ how many bytes are duff?
+ rsb r0, r3, $0 @ get - that number into counter.
+ beq Laligned @ skip into main check routine if no
+ @ more
+#if __BYTE_ORDER == __BIG_ENDIAN
+ orr r2, r2, $0xff000000 @ set this byte to non-zero
+ subs r3, r3, $1 @ any more to do?
+ IT(t, gt)
+ orrgt r2, r2, $0x00ff0000 @ if so, set this byte
+ subs r3, r3, $1 @ more?
+ IT(t, gt)
+ orrgt r2, r2, $0x0000ff00 @ then set.
+#else
+ orr r2, r2, $0x000000ff @ set this byte to non-zero
+ subs r3, r3, $1 @ any more to do?
+ IT(t, gt)
+ orrgt r2, r2, $0x0000ff00 @ if so, set this byte
+ subs r3, r3, $1 @ more?
+ IT(t, gt)
+ orrgt r2, r2, $0x00ff0000 @ then set.
+#endif
+Laligned: @ here, we have a word in r2. Does it
+ tst r2, $0x000000ff @ contain any zeroes?
+ IT(tttt, ne)
+ tstne r2, $0x0000ff00 @
+ tstne r2, $0x00ff0000 @
+ tstne r2, $0xff000000 @
+ addne r0, r0, $4 @ if not, the string is 4 bytes longer
+ IT(t, ne)
+ ldrne r2, [r1], $4 @ and we continue to the next word
+ bne Laligned @
+Llastword: @ drop through to here once we find a
+#if __BYTE_ORDER == __BIG_ENDIAN
+ tst r2, $0xff000000 @ word that has a zero byte in it
+ IT(tttt, ne)
+ addne r0, r0, $1 @
+ tstne r2, $0x00ff0000 @ and add up to 3 bytes on to it
+ addne r0, r0, $1 @
+ tstne r2, $0x0000ff00 @ (if first three all non-zero, 4th
+ IT(t, ne)
+ addne r0, r0, $1 @ must be zero)
+#else
+ tst r2, $0x000000ff @
+ IT(tttt, ne)
+ addne r0, r0, $1 @
+ tstne r2, $0x0000ff00 @ and add up to 3 bytes on to it
+ addne r0, r0, $1 @
+ tstne r2, $0x00ff0000 @ (if first three all non-zero, 4th
+ IT(t, ne)
+ addne r0, r0, $1 @ must be zero)
+#endif
+#if defined(__USE_BX__)
+ bx lr
+#else
+ mov pc,lr
+#endif
+#endif
+
+.size strlen,.-strlen
+
+libc_hidden_def(strlen)