[Bug fortran/66860] [5/6 Regression] FAIL: gfortran.dg/graphite/pr42393.f90 -O (internal compiler error)

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66860

ktkachov at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |4.9.4
            Summary|]FAIL:                      |[5/6 Regression] FAIL:
                   |gfortran.dg/graphite/pr4239 |gfortran.dg/graphite/pr4239
                   |3.f90 -O (internal compiler |3.f90 -O (internal compiler
                   |error)                      |error)
      Known to fail|                            |5.1.0, 6.0

--- Comment #1 from ktkachov at gcc dot gnu.org ---
The top of the gdb backtrace looks like this:
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff759dc90 in __GI___libc_malloc (bytes=8) at malloc.c:2924
2924    malloc.c: No such file or directory.
(gdb) bt
#0  0x00007ffff759dc90 in __GI___libc_malloc (bytes=8) at malloc.c:2924
#1  0x000000000123bad9 in __gmp_default_allocate ()
#2  0x0000000001221695 in __gmpz_init ()
#3  0x00000000011add83 in isl_seq_elim ()
#4  0x000000000116abc3 in eliminate_var_using_equality ()
#5  0x000000000116cc11 in isl_basic_map_gauss ()
#6  0x000000000116d6f9 in isl_basic_map_simplify ()
#7  0x00000000011545f0 in isl_basic_map_intersect ()
#8  0x00000000011281f5 in domain_follows_at_depth ()
#9  0x00000000011bf889 in isl_tarjan_components ()
#10 0x00000000011bfaf0 in isl_tarjan_graph_init ()
#11 0x00000000011a5576 in isl_basic_set_list_foreach_scc ()
#12 0x000000000112a349 in generate_sorted_domains ()
#13 0x000000000112b804 in add_nodes ()
#14 0x00000000011a57c1 in isl_basic_set_list_foreach_scc ()
#15 0x000000000112a349 in generate_sorted_domains ()
#16 0x000000000112b804 in add_nodes ()
#17 0x00000000011a57c1 in isl_basic_set_list_foreach_scc ()
#18 0x000000000112a349 in generate_sorted_domains ()
#19 0x000000000112b804 in add_nodes ()
#20 0x00000000011a57c1 in isl_basic_set_list_foreach_scc ()
#21 0x000000000112a349 in generate_sorted_domains ()
#22 0x000000000112b804 in add_nodes ()
#23 0x00000000011a57c1 in isl_basic_set_list_foreach_scc ()
#24 0x000000000112a349 in generate_sorted_domains ()
#25 0x000000000112b804 in add_nodes ()
#26 0x00000000011a57c1 in isl_basic_set_list_foreach_scc ()
#27 0x000000000112a349 in generate_sorted_domains ()
#28 0x000000000112b804 in add_nodes ()
#29 0x00000000011a57c1 in isl_basic_set_list_foreach_scc ()
#30 0x000000000112a349 in generate_sorted_domains ()
#31 0x000000000112b804 in add_nodes ()
#32 0x00000000011a57c1 in isl_basic_set_list_foreach_scc ()

So it seems to be trying to allocate too much memory.
This compiles fine on the 4.9 branch
The options used are -O2  -fgraphite-identity -fno-loop-block
-fno-loop-interchange -fno-loop-strip-mine