[LIBIBERTY]: Expose tail calls in xmemdup and xstrdup

["Kaveh R. Ghazi" <ghazi at caip dot rutgers dot edu>]

This patch exposes tail calls in xmemdup and xstrdup to the optimizer.
It is similar to a patch to plain strdup way back here:
http://gcc.gnu.org/ml/gcc-patches/2003-04/msg00903.html

In order to guarantee that memcpy is declared, I prototype it
explicitly as is done in many other libiberty functions.  I also
removed the "register" keyword since we're allowing the compiler to
figure out the best allocation scheme now.

I verified by manually creating a .s file that the tail calls to
memcpy are turned into jmps in both functions.

Bootstrapped/regtest underway on x86_64-unknown-linux-gnu.
Okay for mainline if it passes?

		Thanks,
		--Kaveh


2005-03-24  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>

	* xmemdup.c, xstrdup.c: Expose the tail call.
	
diff -rup orig/egcc-CVS20050323/libiberty/xmemdup.c egcc-CVS20050323/libiberty/xmemdup.c
--- orig/egcc-CVS20050323/libiberty/xmemdup.c	2001-09-26 14:16:17.000000000 -0400
+++ egcc-CVS20050323/libiberty/xmemdup.c	2005-03-24 09:47:27.394415056 -0500
@@ -15,17 +15,15 @@ allocated, the remaining memory is zeroe
 
 */
 
-#ifdef HAVE_CONFIG_H
-#include "config.h"
-#endif
-#include "ansidecl.h"
 #include "libiberty.h"
-
-#include <sys/types.h> /* For size_t. */
-#ifdef HAVE_STRING_H
-#include <string.h>
+/* libiberty.h will have gotten size_t on an ANSI_PROTOTYPES platform,
+   otherwise... */
+#ifndef ANSI_PROTOTYPES
+#define size_t unsigned long
 #endif
 
+extern PTR	memcpy PARAMS ((PTR, const PTR, size_t));
+
 PTR
 xmemdup (input, copy_size, alloc_size)
   const PTR input;
@@ -33,6 +31,5 @@ xmemdup (input, copy_size, alloc_size)
   size_t alloc_size;
 {
   PTR output = xcalloc (1, alloc_size);
-  memcpy (output, input, copy_size);
-  return output;
+  return memcpy (output, input, copy_size);
 }
diff -rup orig/egcc-CVS20050323/libiberty/xstrdup.c egcc-CVS20050323/libiberty/xstrdup.c
--- orig/egcc-CVS20050323/libiberty/xstrdup.c	2001-09-26 14:16:17.000000000 -0400
+++ egcc-CVS20050323/libiberty/xstrdup.c	2005-03-24 09:47:40.558413824 -0500
@@ -13,22 +13,21 @@ obtain memory.
 
 */
 
-#include <sys/types.h>
-#ifdef HAVE_CONFIG_H
-#include "config.h"
-#endif
-#ifdef HAVE_STRING_H
-#include <string.h>
-#endif
-#include "ansidecl.h"
 #include "libiberty.h"
+/* libiberty.h will have gotten size_t on an ANSI_PROTOTYPES platform,
+   otherwise... */
+#ifndef ANSI_PROTOTYPES
+#define size_t unsigned long
+#endif
+
+extern size_t	strlen PARAMS ((const char*));
+extern PTR	memcpy PARAMS ((PTR, const PTR, size_t));
 
 char *
 xstrdup (s)
   const char *s;
 {
-  register size_t len = strlen (s) + 1;
-  register char *ret = xmalloc (len);
-  memcpy (ret, s, len);
-  return ret;
+  const size_t len = strlen (s) + 1;
+  char *const ret = xmalloc (len);
+  return memcpy (ret, s, len);
 }