[Bug lto/78140] [7 Regression] libxul -flto uses 1GB more memory than gcc-6

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78140

--- Comment #20 from Richard Biener <rguenth at gcc dot gnu.org> ---
Look at tree-ssanames.c:range_info_def for "tricks" (make them variable size):

/* Value range information for SSA_NAMEs representing non-pointer variables. 
*/

struct GTY ((variable_size)) range_info_def {
  /* Minimum, maximum and nonzero bits.  */
  TRAILING_WIDE_INT_ACCESSOR (min, ints, 0)
  TRAILING_WIDE_INT_ACCESSOR (max, ints, 1)
  TRAILING_WIDE_INT_ACCESSOR (nonzero_bits, ints, 2)
  trailing_wide_ints <3> ints;
};