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-rw-r--r--sysdeps/tile/strrchr.c68
1 files changed, 68 insertions, 0 deletions
diff --git a/sysdeps/tile/strrchr.c b/sysdeps/tile/strrchr.c
new file mode 100644
index 0000000000..51a08b71bf
--- /dev/null
+++ b/sysdeps/tile/strrchr.c
@@ -0,0 +1,68 @@
+/* Copyright (C) 2011-2017 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
+
+ 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/>. */
+
+#include <string.h>
+#include <stdint.h>
+#include "string-endian.h"
+
+char *
+strrchr (const char *s, int c)
+{
+ /* Get an aligned pointer. */
+ const uintptr_t s_int = (uintptr_t) s;
+ const uint64_t *p = (const uint64_t *) (s_int & -8);
+
+ /* Create eight copies of the byte for which we are looking. */
+ const uint64_t goal = copy_byte(c);
+
+ /* Read the first aligned word, but force bytes before the string to
+ match neither zero nor goal (we make sure the high bit of each byte
+ is 1, and the low 7 bits are all the opposite of the goal byte). */
+ const uint64_t before_mask = MASK (s_int);
+ uint64_t v = (*p | before_mask) ^ (goal & v1shrui (before_mask, 1));
+ const char *found = NULL;
+ uint64_t zero_matches, goal_matches;
+ while (1)
+ {
+ /* Look for a terminating '\0'. */
+ zero_matches = v1cmpeqi (v, 0);
+
+ /* Look for the goal byte. */
+ goal_matches = v1cmpeq (v, goal);
+
+ /* If we found the goal, record the last offset. */
+ if (__builtin_expect (goal_matches != 0, 0))
+ {
+ if (__builtin_expect (zero_matches != 0, 0))
+ {
+ /* Clear any goal after the first zero. */
+ int first_nul = CFZ (zero_matches);
+ goal_matches &= NULMASK (first_nul);
+ }
+ if (__builtin_expect (goal_matches != 0, 1))
+ found = ((char *) p) + 7 - (REVCZ (goal_matches) >> 3);
+ }
+
+ if (__builtin_expect (zero_matches != 0, 0))
+ return (char *) found;
+
+ v = *++p;
+ }
+}
+weak_alias (strrchr, rindex)
+libc_hidden_builtin_def (strrchr)