re PR target/39386 ([avr] different computation results for O1 and O0 executables)

	
	PR target/39386
	* config/avr/avr.c (out_shift_with_cnt): Use tmp_reg as
	shift counter for x << x and x >> x shifts.

From-SVN: r176756

gcc/ChangeLog

+2011-07-25  Georg-Johann Lay  <avr@gjlay.de>
+	
+	PR target/39386
+	* config/avr/avr.c (out_shift_with_cnt): Use tmp_reg as
+	shift counter for x << x and x >> x shifts.
+
 2011-07-25  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	PR target/47124

gcc/config/avr/avr.c

@@ -3147,8 +3147,11 @@ out_shift_with_cnt (const char *templ, rtx insn, rtx operands[],
     }
   else if (register_operand (operands[2], QImode))
     {
-      if (reg_unused_after (insn, operands[2]))
-	op[3] = op[2];
+      if (reg_unused_after (insn, operands[2])
+          && !reg_overlap_mentioned_p (operands[0], operands[2]))
+        {
+          op[3] = op[2];
+        }
       else
 	{
 	  op[3] = tmp_reg_rtx;