re PR rtl-optimization/30807 (postreload bug (might be generic in trunk))

	PR rtl-optimization/30807
	* postreload.c (reload_combine): For every new use of REG_SUM,
	record the use of BASE.


Co-Authored-By: Kaz Kojima <kkojima@gcc.gnu.org>

From-SVN: r149282

gcc/ChangeLog

+2009-07-06  J"orn Rennecke  <joern.rennecke@arc.com>
+	    Kaz Kojima  <kkojima@gcc.gnu.org>
+
+	PR rtl-optimization/30807
+	* postreload.c (reload_combine): For every new use of REG_SUM,
+	record the use of BASE.
+
 2009-07-06  Jan Hubicka  <jh@suse.cz>
 
 	* params.def: Revert my accidental commit at 2009-06-30.

gcc/postreload.c

@@ -886,6 +886,19 @@ reload_combine (void)
 
 	      if (apply_change_group ())
 		{
+		  /* For every new use of REG_SUM, we have to record the use
+		     of BASE therein, i.e. operand 1.  */
+		  for (i = reg_state[regno].use_index;
+		       i < RELOAD_COMBINE_MAX_USES; i++)
+		    reload_combine_note_use
+		      (&XEXP (*reg_state[regno].reg_use[i].usep, 1),
+		       reg_state[regno].reg_use[i].insn);
+
+		  if (reg_state[REGNO (base)].use_ruid
+		      > reg_state[regno].use_ruid)
+		    reg_state[REGNO (base)].use_ruid
+		      = reg_state[regno].use_ruid;
+
 		  /* Delete the reg-reg addition.  */
 		  delete_insn (insn);