https://gcc.gnu.org/bugzilla/show_bug.cgi?id=10837
--- Comment #12 from H.J. Lu <hjl.tools at gmail dot com> --- (In reply to Richard Henderson from comment #2) > Working as designed. > (1) It often takes more insns to pop the stack frame than to make the call. > (2) You get a proper backtrace from abort. > (3) http://gcc.gnu.org/ml/gcc-patches/2000-10/msg00180.html Glibc has been using ENTRY (__memmove_chk) movl 12(%esp), %eax cmpl %eax, 16(%esp) jb __chk_fail jmp memmove END (__memmove_chk) since 2004. #1 and #2 shouldn't be the reason not to optimize. I am using: /* Due to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=10837 noreturn attribute disable tail call optimization. Removes noreturn attribute to enable tail call optimization. */ extern void *chk_fail (void) __asm__ ("__chk_fail") attribute_hidden; to work around this.