https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115049
--- Comment #9 from LIU Hao <lh_mouse at 126 dot com> --- Created attachment 58656 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58656&action=edit reduced testcase After spending four days on this, I have reduced a testcase. `./test.sh` should reproduce the segfault. The bug exists around the initialization of a global variable in 'file2.cpp': ``` auto e = new std::discard_block_engine< int >; ``` We compile this file: ``` g++ -O2 -S -masm=intel file2.cpp ``` which produces ``` call "_Znwy" # %rax = ::operator new mov rcx, QWORD PTR "e"[rip] # %rcx = &e mov r10, rax # %r10 = %rax call "_ZNSt20discard_block_engineIiEclEv" # std::discard_block_engine<int>::operator()(%rcx) # -> `this` is passed via %rcx. mov QWORD PTR "d"[rip], r10 # d = %r10 # -> BUG. %r10 has been clobbered by the above call # and now contains a garbage value. mov DWORD PTR [r10], eax # *(DWORD*)%r10 = %eax # -> this faults. ```
