combine.c (combinable_i3pat): Don't forbid occurrences of i2dest or i1dest in…

combine.c (combinable_i3pat): Don't forbid occurrences of i2dest or i1dest in inner_dest if inner_dest is a mem.

* combine.c (combinable_i3pat): Don't forbid occurrences of
i2dest or i1dest in inner_dest if inner_dest is a mem.

From-SVN: r69566

gcc/ChangeLog

+Fri Jul 18 15:22:28 2003  Alexandre Oliva  <aoliva@redhat.com>
+
+	* combine.c (combinable_i3pat): Don't forbid occurrences of
+	i2dest or i1dest in inner_dest if inner_dest is a mem.
+
 Fri Jul 18 17:05:57 CEST 2003  Jan Hubicka  <jh@suse.cz>
 
 	* cgraph.c (cgraph_remove_node): Clear the hash table slot.

gcc/combine.c

@@ -1301,9 +1301,14 @@ combinable_i3pat (rtx i3, rtx *loc, rtx i2dest, rtx i1dest,
 	     || GET_CODE (inner_dest) == ZERO_EXTRACT)
 	inner_dest = XEXP (inner_dest, 0);
 
-      /* Check for the case where I3 modifies its output, as
-	 discussed above.  */
-      if ((inner_dest != dest
+      /* Check for the case where I3 modifies its output, as discussed
+	 above.  We don't want to prevent pseudos from being combined
+	 into the address of a MEM, so only prevent the combination if
+	 i1 or i2 set the same MEM.  */
+      if ((inner_dest != dest &&
+	   (GET_CODE (inner_dest) != MEM
+	    || rtx_equal_p (i2dest, inner_dest)
+	    || (i1dest && rtx_equal_p (i1dest, inner_dest)))
 	   && (reg_overlap_mentioned_p (i2dest, inner_dest)
 	       || (i1dest && reg_overlap_mentioned_p (i1dest, inner_dest))))