https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98667
--- Comment #4 from Matthew Whitehead <tedheadster at gmail dot com> --- It looks like /usr/bin/gdb 10.1 also has this opcode in it: objdump -D /usr/bin/gdb | grep -B6 -A6 endbr32 60d7b5: 3f aas 60d7b6: 1a 3b sbb (%ebx),%bh 60d7b8: 2a 32 sub (%edx),%dh 60d7ba: 24 22 and $0x22,%al 60d7bc: 00 00 add %al,(%eax) 60d7be: 00 00 add %al,(%eax) 60d7c0: f3 0f 1e fb endbr32 60d7c4: ff a3 00 00 00 00 jmp *0x0(%ebx) 60d7ca: 66 0f 1f 44 00 00 nopw 0x0(%eax,%eax,1) 60d7d0: f3 0f 1e fb endbr32 60d7d4: ff 25 00 00 00 00 jmp *0x0 60d7da: 66 0f 1f 44 00 00 nopw 0x0(%eax,%eax,1) 60d7e0: ff b3 04 00 00 00 pushl 0x4(%ebx) 60d7e6: ff a3 08 00 00 00 jmp *0x8(%ebx) 60d7ec: 0f 1f 40 00 nopl 0x0(%eax) 60d7f0: f3 0f 1e fb endbr32 60d7f4: 68 00 00 00 00 push $0x0 60d7f9: e9 00 00 00 00 jmp 60d7fe <_IO_stdin_used@@Base+0xd77fa> 60d7fe: 66 90 xchg %ax,%ax 60d800: ff 35 00 00 00 00 pushl 0x0 60d806: ff 25 00 00 00 00 jmp *0x0 60d80c: 0f 1f 40 00 nopl 0x0(%eax) i686-pentium4-mpentium4-lenovo /usr/lib/debug/usr/bin # /usr/bin/gdb --version GNU gdb (Gentoo 10.1 vanilla) 10.1 Copyright (C) 2020 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. I will provide the gcc compile switches if asked, but it is long: 2156 items.