https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63890
--- Comment #11 from Jan Hubicka <hubicka at ucw dot cz> ---
>
> Index: config/i386/i386.h
> ===================================================================
> --- config/i386/i386.h (revision 220946)
> +++ config/i386/i386.h (working copy)
> @@ -1606,7 +1606,7 @@ enum reg_class
>
> #define ACCUMULATE_OUTGOING_ARGS \
> ((TARGET_ACCUMULATE_OUTGOING_ARGS && optimize_function_for_speed_p (cfun))
> \
> - || TARGET_STACK_PROBE || TARGET_64BIT_MS_ABI)
> + || TARGET_STACK_PROBE || TARGET_64BIT_MS_ABI || crtl->profile)
I do not see how ACCUMULATE_OUTGOING_ARGS is going to ensure mcount stack
alignment.
the calls are output into assembly code by:
/* Output assembler code to FILE to increment profiler label # LABELNO
for profiling a function entry. */
void
x86_function_profiler (FILE *file, int labelno ATTRIBUTE_UNUSED)
{
const char *mcount_name = (flag_fentry ? MCOUNT_NAME_BEFORE_PROLOGUE
: MCOUNT_NAME);
if (TARGET_64BIT)
{
#ifndef NO_PROFILE_COUNTERS
fprintf (file, "\tleaq\t%sP%d(%%rip),%%r11\n", LPREFIX, labelno);
#endif
if (!TARGET_PECOFF && flag_pic)
fprintf (file, "1:\tcall\t*%s@GOTPCREL(%%rip)\n", mcount_name);
else
x86_print_call_or_nop (file, mcount_name);
}
that does not care about ACCUMULATE_OUTGOING_ARGS. We basically get alignment
by accident because we push RBP.
My guess is that you want to bump crtl->stack_alignment_needed to 64bits for
every function with crtl->profile
