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

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5e09cd6d04ff539ebf0f65533cafb9960440b4a5..ee5f1835b9522569b2b927995c376a697ad31e9c 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+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

diff --git a/gcc/lra-spills.c b/gcc/lra-spills.c
index 33caf9f4564953c9e0bdc78ee00fcfbfa7aa2ed1..008d7399687d0717ee7021e1d0b4feb97214475d 100644 (file)
--- a/gcc/lra-spills.c
+++ b/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);
+           }
        }
 }