[Bug fortran/54332] [4.8 Regression] 481.wrf in SPEC CPU 2006 takes > 10GB memory to compile

["dnovillo at google dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54332

--- Comment #18 from dnovillo at google dot com <dnovillo at google dot com> 2012-08-21 18:31:51 UTC ---
OK, I think this is the hunk that's causing grief:

diff --git a/gcc/df-scan.c b/gcc/df-scan.c
index 39f444f..35100d1 100644
--- a/gcc/df-scan.c
+++ b/gcc/df-scan.c
@@ -4392,7 +4392,6 @@ df_bb_verify (basic_block bb)
        if (!INSN_P (insn))
          continue;
        df_insn_refs_verify (&collection_rec, bb, insn, true);
-      df_free_collection_rec (&collection_rec);
      }

    /* Do the artificial defs and uses.  */


I remember that I ran into this during the VEC conversion 
(http://gcc.gnu.org/ml/gcc/2012-05/msg00271.html) and after some 
discussion I ended up convincing myself that taking it out was harmless. 
  Clearly, I was wrong.

I've hooked gdb to the running f951 and it's stuck in df_bb_verify().

Odd that this has not triggered anywhere else.