Revert the revert:

	2013-10-26  Vladimir Makarov  <vmakarov@redhat.com>

	Revert:
	2013-10-25  Vladimir Makarov  <vmakarov@redhat.com>

	* lra-spills.c (lra_final_code_change): Remove useless move insns.

From-SVN: r266358

gcc/ChangeLog

 2018-11-21  Uros Bizjak  <ubizjak@gmail.com>
 
+	Revert the revert:
+	2013-10-26  Vladimir Makarov  <vmakarov@redhat.com>
+
+	Revert:
+	2013-10-25  Vladimir Makarov  <vmakarov@redhat.com>
+
+	* lra-spills.c (lra_final_code_change): Remove useless move insns.
+
+2018-11-21  Uros Bizjak  <ubizjak@gmail.com>
+
 	PR middle-end/88129
 	* function.c (expand_function_end): Do not emit extra blockage insn.
 

gcc/lra-spills.c

@@ -740,6 +740,7 @@ lra_final_code_change (void)
   int i, hard_regno;
   basic_block bb;
   rtx_insn *insn, *curr;
+  rtx set;
   int max_regno = max_reg_num ();
 
   for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
@@ -818,5 +819,19 @@ lra_final_code_change (void)
 	      }
 	  if (insn_change_p)
 	    lra_update_operator_dups (id);
+
+	  if ((set = single_set (insn)) != NULL
+	      && REG_P (SET_SRC (set)) && REG_P (SET_DEST (set))
+	      && REGNO (SET_SRC (set)) == REGNO (SET_DEST (set)))
+	    {
+	      /* Remove an useless move insn.  IRA can generate move
+		 insns involving pseudos.  It is better remove them
+		 earlier to speed up compiler a bit.  It is also
+		 better to do it here as they might not pass final RTL
+		 check in LRA, (e.g. insn moving a control register
+		 into itself).  */
+	      lra_invalidate_insn_data (insn);
+	      delete_insn (insn);
+	    }
 	}
 }