Prepare for radical source tree reorganization. zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 77 insertions, 0 deletions

diff --git a/REORG.TODO/sysdeps/arm/strlen.S b/REORG.TODO/sysdeps/arm/strlen.S
new file mode 100644
index 0000000000..fb1589bbe6
--- /dev/null
+++ b/REORG.TODO/sysdeps/arm/strlen.S
@@ -0,0 +1,77 @@
+/* Copyright (C) 1998-2017 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, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* Thumb requires excessive IT insns here.  */
+#define NO_THUMB
+#include <sysdep.h>
+
+/* size_t strlen(const char *S)
+ * entry: r0 -> string
+ * exit: r0 = len
+ */
+
+	.syntax unified
+	.text
+
+ENTRY(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
+#ifdef __ARMEB__
+	orr     r2, r2, $0xff000000     @ set this byte to non-zero
+	subs    r3, r3, $1              @ any more to do?
+	orrgt   r2, r2, $0x00ff0000     @ if so, set this byte
+	subs    r3, r3, $1              @ more?
+	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?
+	orrgt   r2, r2, $0x0000ff00     @ if so, set this byte
+	subs    r3, r3, $1              @ more?
+	orrgt   r2, r2, $0x00ff0000     @ then set.
+#endif
+Laligned:				@ here, we have a word in r2.  Does it
+	tst     r2, $0x000000ff         @ contain any zeroes?
+	tstne   r2, $0x0000ff00         @
+	tstne   r2, $0x00ff0000         @
+	tstne   r2, $0xff000000         @
+	addne   r0, r0, $4              @ if not, the string is 4 bytes longer
+	ldrne   r2, [r1], $4            @ and we continue to the next word
+	bne     Laligned                @
+Llastword:				@ drop through to here once we find a
+#ifdef __ARMEB__
+	tst     r2, $0xff000000         @ word that has a zero byte in it
+	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
+	addne   r0, r0, $1              @  must be zero)
+#else
+	tst     r2, $0x000000ff         @ word that has a zero byte in it
+	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
+	addne   r0, r0, $1              @  must be zero)
+#endif
+	DO_RET(lr)
+END(strlen)
+libc_hidden_builtin_def (strlen)