On 11/28/2017 05:22 AM, Jakub Jelinek wrote:
> On Mon, Nov 27, 2017 at 05:02:32PM -0600, Daniel Santos wrote:
>>> --- gcc/testsuite/gcc.target/x86_64/abi/ms-sysv/gen.cc.jj 2017-05-22
>>> 10:49:45.000000000 +0200
>>> +++ gcc/testsuite/gcc.target/x86_64/abi/ms-sysv/gen.cc 2017-11-27
>>> 11:57:14.889570915 +0100
>>> @@ -392,7 +392,7 @@ static void make_do_tests_decl (const ve
>>> continue;
>>>
>>> comma.reset ();
>>> - out << "static __attribute__ ((ms_abi)) long (*const do_test_"
>>> + out << "static __attribute__ ((ms_abi)) long (*do_test_"
>>> << (unaligned ? "u" : "")
>>> << (varargs ? "v" : "") << i << ") (";
>> I don't have a problem with removing const, it's only there for
>> const-correctness and caution. I just posted to the PR a bit ago and
>> I'm curious if there is a better approach when using assembly stubs that
>> are meant to be called in varying ways. CV would work also, although
>> there's no real need to refetch the address before each use.
>>
>> If you don't have a better way to do this then please use this patch.
> I've verified the resulting *.optimized dump as well as assembly is
> practically identical without/with the patch, only differences are in
> SSA_NAME versions, in assembly the .LCNNNN and .LCFINNNN constants are
> different but otherwise it is the same - the functions are emitted in
> different orders by cgraph and committed the patch.
>
> Using assembly stubs that are meant to be called in varying ways should
> just be avoided in portable programs, you could e.g. in the generator
> instead of all those:
> extern __attribute__ ((ms_abi)) long do_test_aligned ();
> extern __attribute__ ((ms_abi)) long do_test_unaligned ();
> static __attribute__ ((ms_abi)) long (*do_test_1) (long a) =
> (void*)do_test_aligned;
> static __attribute__ ((ms_abi)) long (*do_test_v1) (long a, ...) =
> (void*)do_test_aligned;
> static __attribute__ ((ms_abi)) long (*do_test_u1) (long a) =
> (void*)do_test_unaligned;
> static __attribute__ ((ms_abi)) long (*do_test_uv1) (long a, ...) =
> (void*)do_test_unaligned;
> emit:
> extern __attribute__ ((ms_abi)) long do_test_1 (long a);
> asm (".text; do_test_1: jmp do_test_aligned; .previous");
> extern __attribute__ ((ms_abi)) long do_test_v1 (long a, ...);
> asm (".text; do_test_v1: jmp do_test_aligned; .previous");
> extern __attribute__ ((ms_abi)) long do_test_1 (long a);
> asm (".text; do_test_u1: jmp do_test_unaligned; .previous");
> extern __attribute__ ((ms_abi)) long do_test_1 (long a, ...);
> asm (".text; do_test_uv1: jmp do_test_unaligned; .previous");
> or something similar.
>
> Jakub
Ah hah! That would indeed work. Thanks for the tip. I have some
improvements to make to this set of tests, mostly tests triggered by
GCC_TEST_RUN_EXPENSIVE, but perhaps I can make this modification as
well. Come to think of it, attribute naked might work too.
Thanks,
Daniel
