1 files changed, 71 insertions, 0 deletions
diff --git a/sysdeps/generic/string-fzi.h b/sysdeps/generic/string-fzi.h
new file mode 100644
index 0000000000..2deecefc23
--- /dev/null
+++ b/sysdeps/generic/string-fzi.h
@@ -0,0 +1,71 @@
+/* Zero byte detection; indexes.  Generic C version.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#ifndef _STRING_FZI_H
+#define _STRING_FZI_H 1
+
+#include <limits.h>
+#include <endian.h>
+#include <string-fza.h>
+
+static __always_inline int
+clz (find_t c)
+{
+  if (sizeof (find_t) == sizeof (unsigned long))
+    return __builtin_clzl (c);
+  else
+    return __builtin_clzll (c);
+}
+
+static __always_inline int
+ctz (find_t c)
+{
+  if (sizeof (find_t) == sizeof (unsigned long))
+    return __builtin_ctzl (c);
+  else
+    return __builtin_ctzll (c);
+}
+
+/* A subroutine for the index_zero functions.  Given a test word C, return
+   the (memory order) index of the first byte (in memory order) that is
+   non-zero.  */
+static __always_inline unsigned int
+index_first (find_t c)
+{
+  int r;
+  if (__BYTE_ORDER == __LITTLE_ENDIAN)
+    r = ctz (c);
+  else
+    r = clz (c);
+  return r / CHAR_BIT;
+}
+
+/* Similarly, but return the (memory order) index of the last byte that is
+   non-zero.  */
+static __always_inline unsigned int
+index_last (find_t c)
+{
+  int r;
+  if (__BYTE_ORDER == __LITTLE_ENDIAN)
+    r = clz (c);
+  else
+    r = ctz (c);
+  return sizeof (find_t) - 1 - (r / CHAR_BIT);
+}
+
+#endif /* STRING_FZI_H */