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| author | Ulrich Drepper <drepper@redhat.com> | 2004-12-22 20:10:10 +0000 |
|---|---|---|
| committer | Ulrich Drepper <drepper@redhat.com> | 2004-12-22 20:10:10 +0000 |
| commit | a334319f6530564d22e775935d9c91663623a1b4 (patch) | |
| tree | b5877475619e4c938e98757d518bb1e9cbead751 /sysdeps/arm/strlen.S | |
| parent | 0ecb606cb6cf65de1d9fc8a919bceb4be476c602 (diff) | |
| download | glibc-a334319f6530564d22e775935d9c91663623a1b4.tar.gz glibc-a334319f6530564d22e775935d9c91663623a1b4.tar.xz glibc-a334319f6530564d22e775935d9c91663623a1b4.zip | |
(CFLAGS-tst-align.c): Add -mpreferred-stack-boundary=4.
Diffstat (limited to 'sysdeps/arm/strlen.S')
| -rw-r--r-- | sysdeps/arm/strlen.S | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/sysdeps/arm/strlen.S b/sysdeps/arm/strlen.S new file mode 100644 index 0000000000..86e16652e4 --- /dev/null +++ b/sysdeps/arm/strlen.S @@ -0,0 +1,73 @@ +/* Copyright (C) 1998, 2003 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 <sysdep.h> + +/* size_t strlen(const char *S) + * entry: r0 -> string + * exit: r0 = len + */ + +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) |