[Bug tree-optimization/26854] Inordinate compile times on large routines

["zadeck at naturalbridge dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #46 from zadeck at naturalbridge dot com  2007-12-20 16:06 -------
Subject: Re:  Inordinate compile times on large
 routines


> indexes will be 0, 1, 2, 3.
>
> there are no def-def chains, and in particular there are no artificial
> def to artificial def chains.  those increments only happen for
> artificial defs or uses. Regular uses or defs have an insn.   a normal
> def-use chain will have index 0.
>
>
>   

however there is a bug with the patch that steven did not notice,  try
this one instead.


Index: df-problems.c
===================================================================
--- df-problems.c       (revision 131096)
+++ df-problems.c       (working copy)
@@ -1855,13 +1855,23 @@ df_live_verify_transfer_functions (void)

 #define df_chain_problem_p(FLAG) (((enum
df_chain_flags)df_chain->local_flags)&(FLAG))

+static long df_chain_counters[4];
+
 /* Create a du or ud chain from SRC to DST and link it into SRC.   */

 struct df_link *
 df_chain_create (struct df_ref *src, struct df_ref *dst)
 {
   struct df_link *head = DF_REF_CHAIN (src);
-  struct df_link *link = pool_alloc (df_chain->block_pool);;
+  struct df_link *link = pool_alloc (df_chain->block_pool);
+  int index = 0;
+
+  if (!src->insn)
+    index += (src->type == DF_REF_REG_DEF) ? 2 : 1;
+  if (!dst->insn)
+    index += (dst->type == DF_REF_REG_DEF) ? 2 : 1;
+
+  df_chain_counters[index]++;

   DF_REF_CHAIN (src) = link;
   link->next = head;
@@ -2156,11 +2166,18 @@ df_chain_finalize (bitmap all_blocks)
 {
   unsigned int bb_index;
   bitmap_iterator bi;
-  
+
+  memset (df_chain_counters, 0, 4*sizeof(long));
+
   EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
     {
       df_chain_create_bb (bb_index);
     }
+
+  fprintf (stderr, "real -> real = %ld\n", df_chain_counters[0]);
+  fprintf (stderr, "real -> art  = %ld\n", df_chain_counters[1]);
+  fprintf (stderr, "art  -> real = %ld\n", df_chain_counters[2]);
+  fprintf (stderr, "art  -> art  = %ld\n", df_chain_counters[3]);
 }




-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26854