var-tracking.c (vt_initialize): Scan insns in ebb chunks instead of bb.

	* var-tracking.c (vt_initialize): Scan insns in ebb chunks instead
	of bb.

Co-Authored-By: Steven Bosscher <steven@gcc.gnu.org>

From-SVN: r157164

gcc/ChangeLog

+2010-03-02  Jakub Jelinek  <jakub@redhat.com>
+	    Steven Bosscher  <steven@gcc.gnu.org>
+
+	* var-tracking.c (vt_initialize): Scan insns in ebb chunks instead
+	of bb.
+
 2010-03-02  Reza Yazdani  <reza.yazdani@amd.com>
 
 	PR middle-end/42640

gcc/var-tracking.c

@@ -7399,9 +7399,9 @@ vt_initialize (void)
     {
       rtx insn;
       HOST_WIDE_INT pre, post = 0;
-      int count;
       unsigned int next_uid_before = cselib_get_next_uid ();
       unsigned int next_uid_after = next_uid_before;
+      basic_block first_bb, last_bb;
 
       if (MAY_HAVE_DEBUG_INSNS)
 	{
@@ -7411,7 +7411,23 @@ vt_initialize (void)
 		     cselib_get_next_uid ());
 	}
 
+      first_bb = bb;
+      for (;;)
+	{
+	  edge e;
+	  if (bb->next_bb == EXIT_BLOCK_PTR
+	      || ! single_pred_p (bb->next_bb))
+	    break;
+	  e = find_edge (bb, bb->next_bb);
+	  if (! e || (e->flags & EDGE_FALLTHRU) == 0)
+	    break;
+	  bb = bb->next_bb;
+	}
+      last_bb = bb;
+
       /* Count the number of micro operations.  */
+      FOR_BB_BETWEEN (bb, first_bb, last_bb->next_bb, next_bb)
+	{
 	  VTI (bb)->n_mos = 0;
 	  for (insn = BB_HEAD (bb); insn != NEXT_INSN (BB_END (bb));
 	       insn = NEXT_INSN (insn))
@@ -7457,8 +7473,7 @@ vt_initialize (void)
 		    }
 		}
 	    }
-
-      count = VTI (bb)->n_mos;
+	}
 
       if (MAY_HAVE_DEBUG_INSNS)
 	{
@@ -7472,7 +7487,10 @@ vt_initialize (void)
 	}
 
       /* Add the micro-operations to the array.  */
-      VTI (bb)->mos = XNEWVEC (micro_operation, VTI (bb)->n_mos);
+      FOR_BB_BETWEEN (bb, first_bb, last_bb->next_bb, next_bb)
+	{
+	  int count = VTI (bb)->n_mos;
+	  VTI (bb)->mos = XNEWVEC (micro_operation, count);
 	  VTI (bb)->n_mos = 0;
 	  for (insn = BB_HEAD (bb); insn != NEXT_INSN (BB_END (bb));
 	       insn = NEXT_INSN (insn))
@@ -7484,7 +7502,8 @@ vt_initialize (void)
 		      insn_stack_adjust_offset_pre_post (insn, &pre, &post);
 		      if (pre)
 			{
-		      micro_operation *mo = VTI (bb)->mos + VTI (bb)->n_mos++;
+			  micro_operation *mo
+			    = VTI (bb)->mos + VTI (bb)->n_mos++;
 
 			  mo->type = MO_ADJUST;
 			  mo->u.adjust = pre;
@@ -7524,6 +7543,10 @@ vt_initialize (void)
 		}
 	    }
 	  gcc_assert (count == VTI (bb)->n_mos);
+	}
+
+      bb = last_bb;
+
       if (MAY_HAVE_DEBUG_INSNS)
 	{
 	  cselib_preserve_only_values (true);