https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78105
--- Comment #9 from PeteVine <tulipawn at gmail dot com> --- Ha! It's not about the extra options, thank you! ;) Completely vanilla environment and gcc 5.4 produce this after a while: ../build-lto-noflags/./gcc/xgcc -B../build-lto-noflags/./gcc/ -B/usr/gcc7/aarch64-linux-gnu/bin/ -B/usr/gcc7/aarch64-linux-gnu/lib/ -isystem /usr/gcc7/aarch64-linux-gnu/include -isystem /usr/gcc7/aarch64-linux-gnu/sys-include -g -O2 -O2 -g -O2 -DIN_GCC -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition -isystem ./include -fPIC -g -DIN_LIBGCC2 -fbuilding-libgcc -fno-stack-protector -fPIC -I. -I. -I../.././gcc -I../../../libgcc -I../../../libgcc/. -I../../../libgcc/../gcc -I../../../libgcc/../include -DHAVE_CC_TLS -o _muldi3.o -MT _muldi3.o -MD -MP -MF _muldi3.dep -DL_muldi3 -c ../../../libgcc/libgcc2.c -fvisibility=hidden -DHIDE_EXPORTS In file included from /usr/include/string.h:630:0, from ../../../libgcc/../gcc/tsystem.h:100, from ../../../libgcc/libgcc2.c:27: /usr/include/aarch64-linux-gnu/bits/string2.h: In function ‘__strspn_c2’: /usr/include/aarch64-linux-gnu/bits/string2.h:1039:3: internal compiler error: Segmentation fault while (__s[__result] == __accept1 || __s[__result] == __accept2) ^~~~~ 0x84173b crash_signal ../../gcc/toplev.c:338 0x5d9020 c_parser_binary_expression ../../gcc/c/c-parser.c:6855 0x5d9a23 c_parser_conditional_expression ../../gcc/c/c-parser.c:6495 0x5d9f4b c_parser_expr_no_commas ../../gcc/c/c-parser.c:6412 0x5dc2bf c_parser_expression ../../gcc/c/c-parser.c:8608 0x5dd823 c_parser_expression_conv ../../gcc/c/c-parser.c:8641 0x5dd89b c_parser_condition ../../gcc/c/c-parser.c:5458 0x5df1bf c_parser_paren_condition ../../gcc/c/c-parser.c:5477 0x5ebd1f c_parser_while_statement ../../gcc/c/c-parser.c:5789 0x5e7293 c_parser_statement_after_labels ../../gcc/c/c-parser.c:5265 0x5e608f c_parser_compound_statement_nostart ../../gcc/c/c-parser.c:4944 0x5e68b3 c_parser_compound_statement ../../gcc/c/c-parser.c:4777 0x5e5853 c_parser_declaration_or_fndef ../../gcc/c/c-parser.c:2176 0x5f3ecb c_parser_external_declaration ../../gcc/c/c-parser.c:1574 0x5f4907 c_parser_translation_unit ../../gcc/c/c-parser.c:1454 0x5f4907 c_parse_file() ../../gcc/c/c-parser.c:18173 0xe3f497 c_common_parse_file() ../../gcc/c-family/c-opts.c:1087