1 files changed, 104 insertions, 0 deletions
diff --git a/newlib/libc/string/strcat.c b/newlib/libc/string/strcat.c
new file mode 100644
index 00000000000..411eadb85a1
--- /dev/null
+++ b/newlib/libc/string/strcat.c
@@ -0,0 +1,104 @@
+/*
+FUNCTION
+	<<strcat>>---concatenate strings
+
+INDEX
+	strcat
+
+ANSI_SYNOPSIS
+	#include <string.h>
+	char *strcat(char *<[dst]>, const char *<[src]>);
+
+TRAD_SYNOPSIS
+	#include <string.h>
+	char *strcat(<[dst]>, <[src]>)
+	char *<[dst]>;
+	char *<[src]>;
+
+DESCRIPTION
+	<<strcat>> appends a copy of the string pointed to by <[src]>
+	(including the terminating null character) to the end of the
+	string pointed to by <[dst]>.  The initial character of
+	<[src]> overwrites the null character at the end of <[dst]>.
+
+RETURNS
+	This function returns the initial value of <[dst]>
+
+PORTABILITY
+<<strcat>> is ANSI C.
+
+<<strcat>> requires no supporting OS subroutines.
+
+QUICKREF
+	strcat ansi pure
+*/
+
+#include <string.h>
+#include <limits.h>
+
+/* Nonzero if X is aligned on a "long" boundary.  */
+#define ALIGNED(X) \
+  (((long)X & (sizeof (long) - 1)) == 0)
+
+#if LONG_MAX == 2147483647L
+#define DETECTNULL(X) (((X) - 0x01010101) & ~(X) & 0x80808080)
+#else
+#if LONG_MAX == 9223372036854775807L
+/* Nonzero if X (a long int) contains a NULL byte. */
+#define DETECTNULL(X) (((X) - 0x0101010101010101) & ~(X) & 0x8080808080808080)
+#else
+#error long int is not a 32bit or 64bit type.
+#endif
+#endif
+
+#ifndef DETECTNULL
+#error long int is not a 32bit or 64bit byte
+#endif
+
+
+/*SUPPRESS 560*/
+/*SUPPRESS 530*/
+
+char *
+_DEFUN (strcat, (s1, s2),
+	char *s1 _AND
+	_CONST char *s2)
+{
+#if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__)
+  char *s = s1;
+
+  while (*s1)
+    s1++;
+
+  while (*s1++ = *s2++)
+    ;
+  return s;
+#else
+  char *s = s1;
+
+
+  /* Skip over the data in s1 as quickly as possible.  */
+  if (ALIGNED (s1))
+    {
+      unsigned long *aligned_s1 = (unsigned long *)s1;
+      while (!DETECTNULL (*aligned_s1))
+	aligned_s1++;
+
+      s1 = (char *)aligned_s1;
+    }
+
+  while (*s1)
+    s1++;
+
+  /* s1 now points to the its trailing null character, we can
+     just use strcpy to do the work for us now.
+
+     ?!? We might want to just include strcpy here.
+     Also, this will cause many more unaligned string copies because
+     s1 is much less likely to be aligned.  I don't know if its worth
+     tweaking strcpy to handle this better.  */
+  strcpy (s1, s2);
+	
+  return s;
+#endif /* not PREFER_SIZE_OVER_SPEED */
+}