1 files changed, 105 insertions, 0 deletions
diff --git a/cpukit/libc/string/memcpy.c b/cpukit/libc/string/memcpy.c
new file mode 100644
index 0000000000..52f716b927
--- /dev/null
+++ b/cpukit/libc/string/memcpy.c
@@ -0,0 +1,105 @@
+/*
+FUNCTION
+        <<memcpy>>---copy memory regions
+
+SYNOPSIS
+        #include <string.h>
+        void* memcpy(void *restrict <[out]>, const void *restrict <[in]>,
+                     size_t <[n]>);
+
+DESCRIPTION
+        This function copies <[n]> bytes from the memory region
+        pointed to by <[in]> to the memory region pointed to by
+        <[out]>.
+
+        If the regions overlap, the behavior is undefined.
+
+RETURNS
+        <<memcpy>> returns a pointer to the first byte of the <[out]>
+        region.
+
+PORTABILITY
+<<memcpy>> is ANSI C.
+
+<<memcpy>> requires no supporting OS subroutines.
+
+QUICKREF
+        memcpy ansi pure
+	*/
+
+#include <_ansi.h>
+#include <string.h>
+#include "local.h"
+
+/* Nonzero if either X or Y is not aligned on a "long" boundary.  */
+#define UNALIGNED(X, Y) \
+  (((long)X & (sizeof (long) - 1)) | ((long)Y & (sizeof (long) - 1)))
+
+/* How many bytes are copied each iteration of the 4X unrolled loop.  */
+#define BIGBLOCKSIZE    (sizeof (long) << 2)
+
+/* How many bytes are copied each iteration of the word copy loop.  */
+#define LITTLEBLOCKSIZE (sizeof (long))
+
+/* Threshhold for punting to the byte copier.  */
+#define TOO_SMALL(LEN)  ((LEN) < BIGBLOCKSIZE)
+
+void *
+__inhibit_loop_to_libcall
+memcpy (void *__restrict dst0,
+	const void *__restrict src0,
+	size_t len0)
+{
+#if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__)
+  char *dst = (char *) dst0;
+  char *src = (char *) src0;
+
+  void *save = dst0;
+
+  while (len0--)
+    {
+      *dst++ = *src++;
+    }
+
+  return save;
+#else
+  char *dst = dst0;
+  const char *src = src0;
+  long *aligned_dst;
+  const long *aligned_src;
+
+  /* If the size is small, or either SRC or DST is unaligned,
+     then punt into the byte copy loop.  This should be rare.  */
+  if (!TOO_SMALL(len0) && !UNALIGNED (src, dst))
+    {
+      aligned_dst = (long*)dst;
+      aligned_src = (long*)src;
+
+      /* Copy 4X long words at a time if possible.  */
+      while (len0 >= BIGBLOCKSIZE)
+        {
+          *aligned_dst++ = *aligned_src++;
+          *aligned_dst++ = *aligned_src++;
+          *aligned_dst++ = *aligned_src++;
+          *aligned_dst++ = *aligned_src++;
+          len0 -= BIGBLOCKSIZE;
+        }
+
+      /* Copy one long word at a time if possible.  */
+      while (len0 >= LITTLEBLOCKSIZE)
+        {
+          *aligned_dst++ = *aligned_src++;
+          len0 -= LITTLEBLOCKSIZE;
+        }
+
+       /* Pick up any residual with a byte copier.  */
+      dst = (char*)aligned_dst;
+      src = (char*)aligned_src;
+    }
+
+  while (len0--)
+    *dst++ = *src++;
+
+  return dst0;
+#endif /* not PREFER_SIZE_OVER_SPEED */
+}