1 files changed, 41 insertions, 0 deletions
diff --git a/sysdeps/generic/memswap.h b/sysdeps/generic/memswap.h
new file mode 100644
index 0000000..f09dae1
--- /dev/null
+++ b/sysdeps/generic/memswap.h
@@ -0,0 +1,41 @@
+/* Swap the content of two memory blocks, overlap is NOT handled.
+   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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <string.h>
+
+static inline void
+__memswap (void *__restrict p1, void *__restrict p2, size_t n)
+{
+  /* Use multiple small memcpys with constant size to enable inlining on most
+     targets.  */
+  enum { SWAP_GENERIC_SIZE = 32 };
+  unsigned char tmp[SWAP_GENERIC_SIZE];
+  while (n > SWAP_GENERIC_SIZE)
+    {
+      memcpy (tmp, p1, SWAP_GENERIC_SIZE);
+      p1 = __mempcpy (p1, p2, SWAP_GENERIC_SIZE);
+      p2 = __mempcpy (p2, tmp, SWAP_GENERIC_SIZE);
+      n -= SWAP_GENERIC_SIZE;
+    }
+  while (n > 0)
+    {
+      unsigned char t = ((unsigned char *)p1)[--n];
+      ((unsigned char *)p1)[n] = ((unsigned char *)p2)[n];
+      ((unsigned char *)p2)[n] = t;
+    }
+}