Re: [PATCH v2] LoongArch: testsuite:Added additional vectorization "-mlsx" option.

[chenglulu <chenglulu@loongson.cn>]

在 2024/1/15 下午2:42, Xi Ruoyao 写道:
> On Mon, 2024-01-15 at 14:32 +0800, YunQiang Su wrote:
>> Xi Ruoyao <xry111@xry111.site> 于2024年1月15日周一 12:11写道：
>>> On Mon, 2024-01-15 at 09:29 +0800, chenxiaolong wrote:
>>>> At 21:13 +0800 on Saturday, 2024-01-13, Xi Ruoyao wrote：
>>>>> At 15:28 +0800 on Saturday 2024-01-13, chenxiaolong wrote：
>>>>>> gcc/testsuite/ChangeLog:
>>>>>>
>>>>>>    * gcc.dg/pr104992.c: Added additional "-mlsx" compilation
>>>>>> options.
>>>>>>    * gcc.dg/signbit-2.c: Dito.
>>>>>>    * gcc.dg/tree-ssa/scev-16.c: Dito.
>>>>>>    * gfortran.dg/graphite/vect-pr40979.f90: Dito.
>>>>>>    * gfortran.dg/vect/fast-math-mgrid-resid.f: Dito.
>>>>> I don't feel it right about the changes to pr104992.c and scev-16.c
>>>>> because no other architectures add special options there.  Why are we
>>>>> so special?
>>>> Because on the LoongArch architecture, GCC requires the addition of
>>>> vectorization options in order to generate vector code. Use the
>>>> check_effective_target_vect_cmdline_needed command in the lib/target-
>>>> supports.exp file to set whether the command line option is needed to
>>>> enable vectorizations. For example, ia64,x86,aarch64, and riscv
>>>> architectures, vectorization is enabled by default.
>>> But no.  The default baseline of 32-bit x86 is i686, which is basically
>>> a Pentium III launched in 1999 without any vector instructions.
>>>
>>> We are still missing something here.
>>>
>> There is a line
>>       #define vector __attribute__((vector_size(4*sizeof(int))))
>> I guess it is the syntax needs to be supported.
> This is always supported.  If the target does not have vector
> instructions GCC will just expand vector arithmetic as a loop.
>
> Maybe we should just move this test into gcc.dg/vect where the framework
> automatically add options like -mlsx or -msse2?
>
The test contents of pr104992.c and scev-16.c are related to vectorization.

It would be great if these two could be moved to the gcc.dg/vect directory,

but we are not sure if this is allowed to be moved.

If it can be moved, how about modifying it in this patch?