From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/tile/lib/strlen_32.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 arch/tile/lib/strlen_32.c (limited to 'arch/tile/lib/strlen_32.c') diff --git a/arch/tile/lib/strlen_32.c b/arch/tile/lib/strlen_32.c new file mode 100644 index 000000000..f26f88e11 --- /dev/null +++ b/arch/tile/lib/strlen_32.c @@ -0,0 +1,36 @@ +/* + * Copyright 2010 Tilera Corporation. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * This program 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, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + */ + +#include +#include +#include + +size_t strlen(const char *s) +{ + /* Get an aligned pointer. */ + const uintptr_t s_int = (uintptr_t) s; + const uint32_t *p = (const uint32_t *)(s_int & -4); + + /* Read the first word, but force bytes before the string to be nonzero. + * This expression works because we know shift counts are taken mod 32. + */ + uint32_t v = *p | ((1 << (s_int << 3)) - 1); + + uint32_t bits; + while ((bits = __insn_seqb(v, 0)) == 0) + v = *++p; + + return ((const char *)p) + (__insn_ctz(bits) >> 3) - s; +} +EXPORT_SYMBOL(strlen); -- cgit v1.2.3-54-g00ecf