https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66487
--- Comment #7 from Martin Liška <marxin at gcc dot gnu.org> --- So the problematic transformation is: devirtualizing call in _ZL33nsSafeFileOutputStreamConstructorP11nsISupportsRK4nsIDPPv.part.50/986945 to __builtin_unreachable/39579 _ZL33nsSafeFileOutputStreamConstructorP11nsISupportsRK4nsIDPPv.part.50/986945 (_ZL33nsSafeFileOutputStreamConstructorP11nsISupportsRK4nsIDPPv.part.50) @0x7f909d3bfcf0 Type: function definition analyzed Visibility: artificial References: _ZTV22nsSafeFileOutputStream/985700 (addr)_ZTV22nsSafeFileOutputStream/985700 (addr)_ZTV22nsSafeFileOutputStream/985700 (addr)_ZTV22nsSafeFileOutputStream/985700 (addr)_ZTV22nsSafeFileOutputStream/985700 (read) Referring: Read from file: /home/marxin/Programming/gecko-dev/obj-lto/toolkit/library/../../netwerk/build/nsNetModule.o First run: 1 Function flags: local Called by: _ZL33nsSafeFileOutputStreamConstructorP11nsISupportsRK4nsIDPPv/979522 (0.03 per call) Calls: moz_xmalloc/985262 (1.00 per call) _ZN16nsFileStreamBaseC2Ev/985698 (1.00 per call) Polymorphic indirect call of type struct nsAtomicFileOutputStream token:1(0.53 per call) Outer type (dynamic):struct nsFileStreamBase offset 0 Speculative outer type:struct nsSafeFileOutputStream (or a derived type) at offset 0 Polymorphic indirect call of type struct nsAtomicFileOutputStream token:0(0.53 per call) Speculative outer type:struct nsFileStreamBase at offset 0 Polymorphic indirect call of type struct nsAtomicFileOutputStream token:2(0.53 per call) Speculative outer type:struct nsFileStreamBase at offset 0 Martin