https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63890
--- Comment #12 from Jan Hubicka <hubicka at ucw dot cz> ---
Hi,
the problem is that darwin output profiler after prologue.
With ACCUMULATE_OUTGOING_ARGS we leave stack pointer aligned to boundary - 4
(for return pointer) without we leave it aligned.
I guess it is possible to compensate this in FUNCTION_PROFILER, but I am not
convinced this will work reliably. Probably disabling combine-stack-adjustments
would be needed, too.
(I do not think it is reliable with ACCUMULATE_OUTGOING_ARGS either)
Honza
Index: config/i386/darwin.h
===================================================================
--- config/i386/darwin.h (revision 221034)
+++ config/i386/darwin.h (working copy)
@@ -210,6 +210,8 @@ extern int darwin_emit_branch_islands;
#undef FUNCTION_PROFILER
#define FUNCTION_PROFILER(FILE, LABELNO) \
do { \
+ if (!ACCUMULATE_OUTGOING_ARGS) \
+ fprintf (FILE, "\tpushl %%ebx\n"); /* Align stack */ \
if (TARGET_MACHO_BRANCH_ISLANDS \
&& MACHOPIC_INDIRECT && !TARGET_64BIT) \
{ \
@@ -218,6 +220,8 @@ extern int darwin_emit_branch_islands;
machopic_validate_stub_or_non_lazy_ptr (name); \
} \
else fprintf (FILE, "\tcall mcount\n"); \
+ if (!ACCUMULATE_OUTGOING_ARGS) \
+ fprintf (FILE, "\tpopl %%ebx\n"); /* Align stack */ \
} while (0)
#define C_COMMON_OVERRIDE_OPTIONS \
Index: config/i386/i386.c
===================================================================
--- config/i386/i386.c (revision 221034)
+++ config/i386/i386.c (working copy)
@@ -10061,6 +10061,13 @@ ix86_compute_frame_layout (struct ix86_f
if (crtl->stack_alignment_needed < PREFERRED_STACK_BOUNDARY)
crtl->stack_alignment_needed = PREFERRED_STACK_BOUNDARY;
}
+ /* Be sure we get stack aligned for mcount call. */
+ else if (crtl->profile && flag_fentry)
+ {
+ crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
+ if (crtl->stack_alignment_needed < PREFERRED_STACK_BOUNDARY)
+ crtl->stack_alignment_needed = PREFERRED_STACK_BOUNDARY;
+ }
stack_alignment_needed = crtl->stack_alignment_needed / BITS_PER_UNIT;
preferred_alignment = crtl->preferred_stack_boundary / BITS_PER_UNIT;
