[Bug libgomp/64707] New: FAIL: libgomp.c/target-9.c with -ftree-parallelize-loops=0

[vries at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64707

            Bug ID: 64707
           Summary: FAIL: libgomp.c/target-9.c with
                    -ftree-parallelize-loops=0
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libgomp
          Assignee: unassigned at gcc dot gnu.org
          Reporter: vries at gcc dot gnu.org
                CC: jakub at gcc dot gnu.org

When running libgomp testsuite with
--target_board=unix/-ftree-parallelize-loops=0, we run into this failure:
...
FAIL: libgomp.c/target-9.c (internal compiler error)
FAIL: libgomp.c/target-9.c (test for excess errors)
UNRESOLVED: libgomp.c/target-9.c compilation failed to produce executable
...

More specifically:
...
lto1: internal compiler error: in streamer_get_builtin_tree, at
tree-streamer-in.c:1151^M
0xfea939 streamer_get_builtin_tree(lto_input_block*, data_in*)^M
        /home/vries/gcc_versions/devel/master/src/gcc/tree-streamer-in.c:1151^M
0xb579f3 lto_input_tree_1(lto_input_block*, data_in*, LTO_tags, unsigned int)^M
        /home/vries/gcc_versions/devel/master/src/gcc/lto-streamer-in.c:1320^M
0xb577ba lto_input_scc(lto_input_block*, data_in*, unsigned int*, unsigned
int*)^M
        /home/vries/gcc_versions/devel/master/src/gcc/lto-streamer-in.c:1248^M
0x6a8238 lto_read_decls^M
        /home/vries/gcc_versions/devel/master/src/gcc/lto/lto.c:1900^M
0x6a8efa lto_file_finalize^M
        /home/vries/gcc_versions/devel/master/src/gcc/lto/lto.c:2229^M
0x6a8f47 lto_create_files_from_ids^M
        /home/vries/gcc_versions/devel/master/src/gcc/lto/lto.c:2239^M
0x6a906e lto_file_read^M
        /home/vries/gcc_versions/devel/master/src/gcc/lto/lto.c:2280^M
0x6ac807 read_cgraph_and_symbols^M
        /home/vries/gcc_versions/devel/master/src/gcc/lto/lto.c:2981^M
0x6ad803 lto_main()^M
        /home/vries/gcc_versions/devel/master/src/gcc/lto/lto.c:3436^M
Please submit a full bug report,^M
...

Investigating the ICE site:
...
(gdb) 
#5  0x0000000000fea93a in streamer_get_builtin_tree (ib=0x7fffffffd860,
data_in=0x2ea2390)
    at /home/vries/gcc_versions/devel/master/src/gcc/tree-streamer-in.c:1151
1151          gcc_assert (result);
(gdb) l
1146        {
1147          fcode = (enum built_in_function) (fcode - BEGIN_CHKP_BUILTINS -
1);
1148          result = builtin_decl_explicit (fcode);
1149          result = chkp_maybe_clone_builtin_fndecl (result);
1150        }
1151          gcc_assert (result);
1152        }
1153      else if (fclass == BUILT_IN_MD)
1154        {
1155          result = targetm.builtin_decl (fcode, true);
(gdb) p fcode
$1 = BUILT_IN_GOMP_TARGET
(gdb) p builtin_info
builtin_info       builtin_info_type  
(gdb) p builtin_info.decl[BUILT_IN_GOMP_TARGET]
$3 = (tree_node *) 0x0
...

The omp builtin is not enabled in lto1 (consistent with the observation in PR
64672 comment 9).