Oh. I realize this patch increase FAIL that I recently fixed:
https://gcc.gnu.org/pipermail/gcc-patches/2023-October/632247.html 

This fail because RVV doesn't have vec_pack_trunc_optab (Loop vectorizer will failed at first time but succeed at 2nd time), 
then RVV will dump 4 times FOLD_EXTRACT_LAST instead of 2  (ARM SVE 2 times because they have vec_pack_trunc_optab).

I think the root cause of RVV failing at multiple tests of "vect" is that we don't enable vec_pack/vec_unpack/... stuff, 
we still succeed at vectorizations and we want to enable tests of them 
(Mostly just using different approach to vectorize it (cause dump FAIL) because of some changing I have done previously in the middle-end).

So enabling "vec_pack" for RVV will fix some FAILs but increase some other FAILs.

CC to Richi to see more reasonable suggestions.



juzhe.zhong@rivai.ai
 
发件人： Maciej W. Rozycki
发送时间： 2023-10-10 06:38
收件人： 钟居哲
抄送： gcc-patches; Jeff Law; rdapp.gcc; kito.cheng
主题： Re: 回复: [PATCH] RISC-V/testsuite: Enable `vect_pack_trunc'
On Tue, 10 Oct 2023, 钟居哲 wrote:
 
> Btw, could you rebase to the trunk and run regression again?
 
Full regression-testing takes roughly 40 hours here and I do not normally
update the tree midway through my work so as not to add variables and end 
up chasing a moving target, especially with such an unstable state that we 
have ended up with recently with the RISC-V port.  Since I'm done with 
this part I can refresh and schedule another run if you are curious as to 
how it looks like from my side.  For the C subset alone it'll take less.
 
  Maciej