bionic/x86: Optimization for string routines

Optimized strcpy, strcat,
strncpy, strncat, strlcpy, strlcat,
memchr, memrchr, strchr, strrchr, index,
strnlen, strlen, wcslen, wmemcmp, wcscmp,
wcschr, wcsrchr, wcscpy, wcscat

Change-Id: I82b29132edf9a2e144e0bb3ee4ff5217df8d2a6d
Signed-off-by: Liubov Dmitrieva <liubov.dmitrieva@intel.com>

libc/bionic/__strchr_chk.cpp

@@ -0,0 +1,46 @@
+/*-
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <string.h>
+#include "libc_logging.h"
+
+extern "C" char* __strchr_chk(const char* p, int ch, size_t s_len) {
+  for (;; ++p, s_len--) {
+    if (__predict_false(s_len == 0)) {
+      __fortify_chk_fail("read beyond buffer", 0);
+    }
+    if (*p == static_cast<char>(ch)) {
+      return const_cast<char*>(p);
+    }
+    if (*p == '\0') {
+      return NULL;
+    }
+  }
+  /* NOTREACHED */
+}