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-rw-r--r--kernel/arch/tile/lib/strlen_32.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/kernel/arch/tile/lib/strlen_32.c b/kernel/arch/tile/lib/strlen_32.c
new file mode 100644
index 000000000..f26f88e11
--- /dev/null
+++ b/kernel/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 <linux/types.h>
+#include <linux/string.h>
+#include <linux/module.h>
+
+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);