Re: LoongArch: Backport r14-4674 "LoongArch: Delete macro definition ASM_OUTPUT_ALIGN_WITH_NOP."?

[chenglulu <chenglulu@loongson.cn>]

在 2024/2/20 下午7:54, Xi Ruoyao 写道:
> On Tue, 2024-02-20 at 19:50 +0800, chenglulu wrote:
>> 在 2024/2/20 下午7:31, Xi Ruoyao 写道:
>>> On Tue, 2024-02-20 at 19:25 +0800, Xi Ruoyao wrote:
>>>> On Tue, 2024-02-20 at 10:07 +0800, chenglulu wrote:
>>>>
>>>>> So I think that without worrying about performance and ensuring that
>>>>> there is no problem
>>>>>
>>>>> with binutils, I think we can make the following modifications:
>>>>>
>>>>>      -/* "nop" instruction 54525952 (andi $r0,$r0,0) is
>>>>>      -   used for padding.  */
>>>>>      +/* ".align num,,4" will insert "nop"(andi $r0,$r0,0) into padding by
>>>>>      +   default.  */
>>>>>       #define ASM_OUTPUT_ALIGN_WITH_NOP(STREAM, LOG) \
>>>>>      -  fprintf (STREAM, "\t.align\t%d,54525952,4\n", (LOG))
>>>>>      +  fprintf (STREAM, "\t.align\t%d,,4\n", (LOG))
>>>>>
>>>>> What do you think of it?
>>>> Unfortunately it will cause warnings with GAS 2.41 or earlier like
>>>>
>>>> t1.s:1: Warning: expected fill pattern missing
>>>> t1.s:5: Warning: expected fill pattern missing
>>>>
>>>> And AFAIK these things may cause many test failures due to "excessive
>>>> errors" if running the GCC test suite with these earlier GAS versions.
>>>> Maybe we'll have to add some autoconf-based probing for the linker
>>>> anyway?
>>> Or just silence the warning passing "--no-warn" to the assembler but I'm
>>> highly unsure if this is really a good idea :(.
>>>
>> I am not opposed to adding detection code, but I looked at this problem
>> today
>>
>> and I think this change is the smallest change. I asked Meng Qinggang and he
>>
>> said that the warning of GAS 2.41 can be removed.
> Yes, but we cannot change a released binutils-2.41 tarball and Binutils
> folks don't make point releases like GCC.
>
OK, I agree with you. I will backpoint r14-4674 and r14-5434 to gcc12 
and gcc13.