re PR rtl-optimization/45966 (Incorrect combiner transformation.)

	PR rtl-optimization/45966
	* combine.c (try_combine): If added_sets_2, deal with the case
	where i0 feeds i1 and i1 feeds i2.

From-SVN: r165674

gcc/ChangeLog

+2010-10-18  Bernd Schmidt  <bernds@codesourcery.com>
+
+	PR rtl-optimization/45966
+	* combine.c (try_combine): If added_sets_2, deal with the case
+	where i0 feeds i1 and i1 feeds i2.
+
 2010-10-18  Jan Hubicka  <jh@suse.cz>
 
 	* ipa.c (cgraph_externally_visible_p): Handle externally visible and

gcc/combine.c

@@ -3192,6 +3192,8 @@ try_combine (rtx i3, rtx i2, rtx i1, rtx i0, int *new_direct_jump_p)
 	    t = subst (t, i0dest, i0src, 0, 0);
 	  if (i1_feeds_i2_n)
 	    t = subst (t, i1dest, i1src, 0, 0);
+	  if (i0_feeds_i1_n && i1_feeds_i2_n)
+	    t = subst (t, i0dest, i0src, 0, 0);
 
 	  XVECEXP (newpat, 0, --total_sets) = t;
 	}