rtlanal.c (rtx_varies_p): Return 0 for NULL_RTX

	* rtlanal.c (rtx_varies_p): Return 0 for NULL_RTX
testsuite/
	* gcc.c-torture/compile/libcall-1.c: New test.

From-SVN: r78027

gcc/ChangeLog

 2004-02-18  Paul Brook  <paul@codesourcery.com>
 
+	* rtlanal.c (rtx_varies_p): Return 0 for NULL_RTX
+
+2004-02-18  Paul Brook  <paul@codesourcery.com>
+
 	PR debug/12934
 	* dwarf2out.c (loc_descriptor_from_tree): Handle
 	EXPR_WITH_FILE_LOCATION.

gcc/rtlanal.c

@@ -134,10 +134,14 @@ rtx_unstable_p (rtx x)
 int
 rtx_varies_p (rtx x, int for_alias)
 {
-  RTX_CODE code = GET_CODE (x);
+  RTX_CODE code;
   int i;
   const char *fmt;
 
+  if (!x)
+    return 0;
+
+  code = GET_CODE (x);
   switch (code)
     {
     case MEM:

gcc/testsuite/ChangeLog

 2004-02-18  Paul Brook  <paul@codesourcery.com>
 
+	* gcc.c-torture/compile/libcall-1.c: New test.
+
+2004-02-18  Paul Brook  <paul@codesourcery.com>
+
 	PR debug/12934
 	* gcc.dg/debug/debug-7.c: New test.
 

gcc/testsuite/gcc.c-torture/compile/libcall-1.c

+/* Failed on ARM because rtx_varies_p didn't like the REG_EQUAL notes
+   generated for libcalls.
+   http://gcc.gnu.org/ml/gcc-patches/2004-02/msg01518.html */
+static const char digs[] = "0123456789ABCDEF";
+int __attribute__((pure)) bar();
+
+int foo (int i)
+{
+  int len;
+  if (i)
+    return 0;
+  len = bar();
+  return digs[len];
+}