PR c++/51662

[pf3gnuchains/gcc-fork.git] / gcc / dse.c

diff --git a/gcc/dse.c b/gcc/dse.c
index 8e9b645..a15b735 100644 (file)
--- a/gcc/dse.c
+++ b/gcc/dse.c
@@ -1,5 +1,5 @@
 /* RTL dead store elimination.
-   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010
+   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011
    Free Software Foundation, Inc.
 
    Contributed by Richard Sandiford <rsandifor@codesourcery.com>
@@ -47,6 +47,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "optabs.h"
 #include "dbgcnt.h"
 #include "target.h"
+#include "params.h"
 
 /* This file contains three techniques for performing Dead Store
    Elimination (dse).
@@ -387,6 +388,7 @@ static alloc_pool insn_info_pool;
 /* The linked list of stores that are under consideration in this
    basic block.  */
 static insn_info_t active_local_stores;
+static int active_local_stores_len;
 
 struct bb_info
 {
@@ -947,6 +949,7 @@ add_wild_read (bb_info_t bb_info)
     }
   insn_info->wild_read = true;
   active_local_stores = NULL;
+  active_local_stores_len = 0;
 }
 
 
@@ -1530,20 +1533,21 @@ record_store (rtx body, bb_info_t bb_info)
 
       /* An insn can be deleted if every position of every one of
         its s_infos is zero.  */
-      if (any_positions_needed_p (s_info)
-         || ptr->cannot_delete)
+      if (any_positions_needed_p (s_info))
        del = false;
 
       if (del)
        {
          insn_info_t insn_to_delete = ptr;
 
+         active_local_stores_len--;
          if (last)
            last->next_local_store = ptr->next_local_store;
          else
            active_local_stores = ptr->next_local_store;
 
-         delete_dead_store_insn (insn_to_delete);
+         if (!insn_to_delete->cannot_delete)
+           delete_dead_store_insn (insn_to_delete);
        }
       else
        last = ptr;
@@ -2074,6 +2078,7 @@ check_mem_read_rtx (rtx *loc, void *data)
              if (dump_file)
                dump_insn_info ("removing from active", i_ptr);
 
+             active_local_stores_len--;
              if (last)
                last->next_local_store = i_ptr->next_local_store;
              else
@@ -2163,6 +2168,7 @@ check_mem_read_rtx (rtx *loc, void *data)
              if (dump_file)
                dump_insn_info ("removing from active", i_ptr);
 
+             active_local_stores_len--;
              if (last)
                last->next_local_store = i_ptr->next_local_store;
              else
@@ -2222,6 +2228,7 @@ check_mem_read_rtx (rtx *loc, void *data)
              if (dump_file)
                dump_insn_info ("removing from active", i_ptr);
 
+             active_local_stores_len--;
              if (last)
                last->next_local_store = i_ptr->next_local_store;
              else
@@ -2426,6 +2433,7 @@ scan_insn (bb_info_t bb_info, rtx insn)
                  if (dump_file)
                    dump_insn_info ("removing from active", i_ptr);
 
+                 active_local_stores_len--;
                  if (last)
                    last->next_local_store = i_ptr->next_local_store;
                  else
@@ -2453,6 +2461,12 @@ scan_insn (bb_info_t bb_info, rtx insn)
                    fprintf (dump_file, "handling memset as BLKmode store\n");
                  if (mems_found == 1)
                    {
+                     if (active_local_stores_len++
+                         >= PARAM_VALUE (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES))
+                       {
+                         active_local_stores_len = 1;
+                         active_local_stores = NULL;
+                       }
                      insn_info->next_local_store = active_local_stores;
                      active_local_stores = insn_info;
                    }
@@ -2496,6 +2510,12 @@ scan_insn (bb_info_t bb_info, rtx insn)
      it as cannot delete.  This simplifies the processing later.  */
   if (mems_found == 1)
     {
+      if (active_local_stores_len++
+         >= PARAM_VALUE (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES))
+       {
+         active_local_stores_len = 1;
+         active_local_stores = NULL;
+       }
       insn_info->next_local_store = active_local_stores;
       active_local_stores = insn_info;
     }
@@ -2534,6 +2554,7 @@ remove_useless_values (cselib_val *base)
 
       if (del)
        {
+         active_local_stores_len--;
          if (last)
            last->next_local_store = insn_info->next_local_store;
          else
@@ -2584,6 +2605,7 @@ dse_step1 (void)
            = create_alloc_pool ("cse_store_info_pool",
                                 sizeof (struct store_info), 100);
          active_local_stores = NULL;
+         active_local_stores_len = 0;
          cselib_clear_table ();
 
          /* Scan the insns.  */