https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109093
--- Comment #35 from Uroš Bizjak <ubizjak at gmail dot com> --- (In reply to H.J. Lu from comment #17) > Created attachment 54666 [details] > A patch > > Change ix86_find_max_used_stack_alignment to find alignments of all stack > slot accesses. HJ, it looks that the current detection of instructions that need increase in stack alignment is insufficient, causing all sort of troubles (e.g. __builtin_memset expansion in PR109780#c34 for stack variable hits this issue). I see this problem as a defect in the x86 infrastructure (and the priority of the bug reflects that) that should be urgently fixed. I think that the direction your patch takes is the right approach, so I'd like to ask you to post the patch to gcc-patches to get the ball rolling. IMO, the increase of alignment should be triggered any time insn that requires increased stack alignment uses a register that holds a pointer, derived from stack or frame pointer.
