2015-04-09 Vladimir Makarov <vmakarov@redhat.com>

	PR target/65710
	* lra-int.h (lra_bad_spill_regno_start): New.
	* lra.c (lra_bad_spill_regno_start): New.
	(lra): Set up lra_bad_spill_regno_start.  Set up
	lra_constraint_new_regno_start unconditionally.
	* lra-assigns.c (spill_for): Use lra_bad_spill_regno_start for
	spill preferences.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@221956 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 13 insertions, 6 deletions

diff --git a/gcc/lra.c b/gcc/lra.c
index a29266e7ecc..f4d7a3c071f 100644
--- a/gcc/lra.c
+++ b/gcc/lra.c
@@ -2180,6 +2180,10 @@ int lra_new_regno_start;
 /* Start of reload pseudo regnos before the new spill pass.  */
 int lra_constraint_new_regno_start;
 
+/* Avoid spilling pseudos with regno more than the following value if
+   it is possible.  */
+int lra_bad_spill_regno_start;
+
 /* Inheritance pseudo regnos before the new spill pass.	 */
 bitmap_head lra_inheritance_pseudos;
 
@@ -2269,6 +2273,7 @@ lra (FILE *f)
      permit changing reg classes for pseudos created by this
      simplification.  */
   lra_constraint_new_regno_start = lra_new_regno_start = max_reg_num ();
+  lra_bad_spill_regno_start = INT_MAX;
   remove_scratches ();
   scratch_p = lra_constraint_new_regno_start != max_reg_num ();
 
@@ -2406,12 +2411,14 @@ lra (FILE *f)
       /* Assignment of stack slots changes elimination offsets for
 	 some eliminations.  So update the offsets here.  */
       lra_eliminate (false, false);
-      /* After switching off inheritance and rematerialization passes,
-	 don't forget reload pseudos after spilling sub-pass to avoid
-	 LRA cycling in some complicated cases.  */
-      if (lra_inheritance_iter <= LRA_MAX_INHERITANCE_PASSES
-	  || lra_rematerialization_iter <= LRA_MAX_REMATERIALIZATION_PASSES)
-	lra_constraint_new_regno_start = max_reg_num ();
+      lra_constraint_new_regno_start = max_reg_num ();
+      if (lra_bad_spill_regno_start == INT_MAX
+	  && lra_inheritance_iter > LRA_MAX_INHERITANCE_PASSES
+	  && lra_rematerialization_iter > LRA_MAX_REMATERIALIZATION_PASSES)
+	/* After switching off inheritance and rematerialization
+	   passes, avoid spilling reload pseudos will be created to
+	   prevent LRA cycling in some complicated cases.  */
+	lra_bad_spill_regno_start = lra_constraint_new_regno_start;
       lra_assignment_iter_after_spill = 0;
     }
   restore_scratches ();