https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66697
--- Comment #19 from Uroš Bizjak <ubizjak at gmail dot com> --- (In reply to Justas L from comment #18) > Out of curiosity, what could it be that makes -mincoming-stack-boundary=3 > successfully deal with rogue code while -mstackrealign fails at that? > Shouldn't -mstackrealign do the same job without being told what the outside > stack alignment is, or am I misunderstanding it? -mstackrealign conditionally generates realignment prologue, depending on presence of insns that require 128bit alignment. It looks that heuristics is not yet fully reliable on x86_64. Bugreports welcome! -mincoming-stack-boundary=3 and force_align_arg_pointer will always unconditionally generate realignment prologue
