[Bug tree-optimization/54489] tree FRE uses an excessive amount of memory

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54489

--- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-09-05 
13:52:25 UTC ---
Testcase:

int foo (int a)
{
  int b = 0;
#define X if (a) b = b + 1;
#define XX X X X X X X X X X X
#define XXX XX XX XX XX XX XX XX XX XX XX
#define XXXX XXX XXX XXX XXX XXX XXX XXX XXX XXX XXX
#define XXXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX
#define XXXXXX XXXXX XXXXX XXXXX XXXXX XXXXX XXXXX XXXXX XXXXX XXXXX XXXXX
#define XXXXXXX XXXXXX XXXXXX XXXXXX XXXXXX XXXXXX XXXXXX XXXXXX XXXXXX XXXXXX
XXXXXX
  XXXXXX
  return b;
}

also relevant is the testcase from PR54492 which we should not regress.