https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88559
--- Comment #4 from James Almer <jamrial at gmail dot com> --- To expand, as i mentioned and showed in the OP this code has compiled without issues up to some point between December 10 and December 17 with gcc trunk. I'm not arguing about clobbering the stack pointer being correct or not, I'm wondering if this a valid error for the code in question and not a bogus one product of a regression in gcc. Does the inline asm in the attached preprocessed output effectively try to clobber the stack pointer? And if so, why would it start erroring out now only after a recent gcc trunk commit if it was never meant to work? Has gcc been generating invalid assembly all this time?