https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78140
--- Comment #16 from Martin Liška <marxin at gcc dot gnu.org> --- It's still reproducible with current trunk, it's over 1GB on my development machine. I did a simple script that dumps sizes of all LTO object loaded to WPA: GCC 7: asm : 19.67 KB profile : 31.76 KB pureconst : 1.08 MB refs : 1.66 MB icf : 2.44 MB inline : 7.05 MB symbol_nodes : 13.63 MB jmpfuncs : 14.98 MB symtab : 59.27 MB decls : 287.71 MB symbols : 564.43 MB total : 952.31 MB Total symbols: 505244 GCC 6: ./parse-lto.py /tmp/6.txt asm : 19.66 KB profile : 34.56 KB pureconst : 1.09 MB refs : 1.67 MB icf : 2.43 MB inline : 7.03 MB jmpfuncs : 10.30 MB symbol_nodes : 13.66 MB symtab : 59.89 MB decls : 284.59 MB symbols : 559.50 MB total : 940.21 MB Total symbols: 503275 Thus I guess there's no difference in amount of streamed data.