[Bug c++/71937] out of memory on very large fuction

["trippels at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71937

--- Comment #8 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
  Frame:             Ir Backtrace for Thread 1
   [ 0]          85,518 brk (9503 x)
   [ 1]         645,718 sbrk (9502 x)
   [ 2]         787,930 __default_morecore (9498 x)
   [ 3]     345,696,969 _int_malloc (1634374 x)
   [ 4]     429,049,064 malloc (1634371 x)
   [ 5]     424,601,116 0x0000000010174d90 (1573948 x)
   [ 6]      40,785,111 xmalloc (141360 x)
   [ 7]      43,846,513 mempool_obstack_chunk_alloc(unsigned long) (160495 x)
   [ 8]      56,593,460 _obstack_newchunk (145510 x)
   [ 9]  10,642,493,461 bitmap_set_bit(bitmap_head*, int) (107039144 x)
   [10]  40,631,180,636 coalesce_ssa_name() (122 x)
   [11]  40,967,370,411 rewrite_out_of_ssa(ssaexpand*) (122 x)
   [12]  41,081,413,163 (anonymous namespace)::pass_expand::execute(function*)
(122 x)
   [13]  41,820,088,098 execute_one_pass(opt_pass*) (4536 x)
   [14]  42,589,456,759 execute_pass_list(function*, opt_pass*) (122 x)
   [15]  42,664,521,643 cgraph_node::expand() (122 x)
   [16]  42,672,880,045 output_in_order(bool) (1 x)
   [17]  55,222,713,798 symbol_table::compile() (1 x)
   [18]  55,860,373,675 symbol_table::finalize_compilation_unit() (1 x)
   [19]  62,683,937,902 compile_file() (1 x)
   [20]  62,699,127,487 toplev::main(int, char**) (1 x)
   [21]  62,699,127,511 main (1 x)