https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78962
Bug ID: 78962
Summary: i386: Missed optimization: unaligned SSE movs with
force_align_arg_pointer
Product: gcc
Version: 5.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: daniel.santos at pobox dot com
Target Milestone: ---
void b (void); /* Normal System V function. */
__attribute__((ms_abi, force_align_arg_pointer)) void a (void)
{
b ();
}
When using __attribute__((force_align_arg_pointer)) on 64-bit code, the stack
pointer is re-aligned, but SSE movs in pro/epilogues to save/restore clobbers
caused by the Microsoft ABI function calling a System V function are emitted
unaligned. I posted a patchset for this problem here
https://gcc.gnu.org/ml/gcc-patches/2016-12/msg01924.html. Uros advised to
resubmit when the next stage 1 rolls around, so filing a bug for now.
