On 03/16/2016 08:38 AM, H.J. Lu wrote:
FAIL: g++.dg/abi/pr60336-1.C scan-assembler jmp[\t ]+[^$]*?_Z3xxx9true_type
FAIL: g++.dg/abi/pr60336-5.C scan-assembler jmp[\t ]+[^$]*?_Z3xxx9true_type
FAIL: g++.dg/abi/pr60336-6.C scan-assembler jmp[\t ]+[^$]*?_Z3xxx9true_type
FAIL: g++.dg/abi/pr60336-7.C scan-assembler jmp[\t ]+[^$]*?_Z3xxx9true_type
FAIL: g++.dg/abi/pr60336-9.C scan-assembler jmp[\t ]+[^$]*?_Z3xxx9true_type
FAIL: g++.dg/abi/pr68355.C scan-assembler jmp[\t
]+[^$]*?_Z3xxx17integral_constantIbLb1EE
These pass for me on x86_64, but I do see calls with -m32.
They are expected since get_ref_base_and_extent needs to be
changed to set bitsize to 0 for empty types so that when
ref_maybe_used_by_call_p_1 calls get_ref_base_and_extent to
get 0 as the maximum size on empty type. Otherwise, find_tail_calls
won't perform tail call optimization for functions with empty type
parameters.
That isn't why the optimization isn't happening in pr68355 with -m32;
the .optimized dump has
xxx (D.2289); [tail call]
Rather, the failure seems to happen in load_register_parameter, at
/* Check for overlap with already clobbered argument area,
providing that this has non-zero size. */
if (is_sibcall
&& (size == 0
|| mem_overlaps_already_clobbered_arg_p
(XEXP (args[i].value, 0), size)))
*sibcall_failure = 1;
The code seems to contradict the comment, and seems to have been broken
by r162402. Applying this additional patch fixes those tests.
commit b9e170023d97cef94f9b88ded1dfd3b4cf993294
Author: Jason Merrill <ja...@redhat.com>
Date: Wed Mar 16 12:57:37 2016 -0400
* calls.c (load_register_parameters): Fix zero size sibcall logic.
diff --git a/gcc/calls.c b/gcc/calls.c
index 7b28f43..6415e08 100644
--- a/gcc/calls.c
+++ b/gcc/calls.c
@@ -2083,9 +2083,9 @@ load_register_parameters (struct arg_data *args, int num_actuals,
/* Check for overlap with already clobbered argument area,
providing that this has non-zero size. */
if (is_sibcall
- && (size == 0
- || mem_overlaps_already_clobbered_arg_p
- (XEXP (args[i].value, 0), size)))
+ && size != 0
+ && (mem_overlaps_already_clobbered_arg_p
+ (XEXP (args[i].value, 0), size)))
*sibcall_failure = 1;
if (size % UNITS_PER_WORD == 0
