Re: decremnt IV patch create fails on PowerPC

2023-05-30 Thread Richard Biener via Gcc-patches
On Tue, 30 May 2023, Richard Sandiford wrote: > Richard Biener writes: > >> But how easy would it be to extend SCEV analysis, via a pattern match? > >> The evolution of the IV phi wrt the inner loop is still a normal SCEV. > > > > No, the IV isn't a normal SCEV, the final value is different. >

Re: Re: decremnt IV patch create fails on PowerPC

2023-05-30 Thread juzhe.zh...@rivai.ai
...@rivai.ai From: Richard Biener Date: 2023-05-30 17:50 To: juzhe.zh...@rivai.ai CC: gcc-patches; richard.sandiford; linkw Subject: Re: Re: decremnt IV patch create fails on PowerPC On Tue, 30 May 2023, juzhe.zh...@rivai.ai wrote: > Ok. > > It seems that for this conditions: > >

Re: decremnt IV patch create fails on PowerPC

2023-05-30 Thread Richard Sandiford via Gcc-patches
Richard Biener writes: >> But how easy would it be to extend SCEV analysis, via a pattern match? >> The evolution of the IV phi wrt the inner loop is still a normal SCEV. > > No, the IV isn't a normal SCEV, the final value is different. Which part of the IV though? Won't all executions of the

Re: decremnt IV patch create fails on PowerPC

2023-05-30 Thread Richard Biener via Gcc-patches
On Tue, 30 May 2023, Richard Sandiford wrote: > My understanding was that we went into this knowing that the IVs > would defeat SCEV analysis. Apparently that wasn't a problem for RVV, > but it's not surprising that it is a problem in general. > > This isn't just about SELECT_VL though. We use

Re: decremnt IV patch create fails on PowerPC

2023-05-30 Thread Richard Sandiford via Gcc-patches
My understanding was that we went into this knowing that the IVs would defeat SCEV analysis. Apparently that wasn't a problem for RVV, but it's not surprising that it is a problem in general. This isn't just about SELECT_VL though. We use the same type of IV for cases what aren't going to use

Re: Re: decremnt IV patch create fails on PowerPC

2023-05-30 Thread juzhe.zh...@rivai.ai
have a try and send a patch. Thank you so much. By the way, could you take a look at SELECT_VL patch? I guess you want to defer it to Richard and I will wait but still I think your comment is very important. Thanks. juzhe.zh...@rivai.ai From: Richard Biener Date: 2023-05-30 18:00 To: Kewen.Lin CC:

Re: decremnt IV patch create fails on PowerPC

2023-05-30 Thread Richard Biener via Gcc-patches
On Tue, 30 May 2023, Kewen.Lin wrote: > on 2023/5/30 17:26, juzhe.zh...@rivai.ai wrote: > > Ok. > > > > It seems that for this conditions: > > > > + /* If we're vectorizing a loop that uses length "controls" and > > + can iterate more than once, we apply decrementing IV approach > > +

Re: Re: decremnt IV patch create fails on PowerPC

2023-05-30 Thread juzhe.zh...@rivai.ai
I am not familiar with SCEV and I am not sure how to do that SCEV can analysis the decrement IV. juzhe.zh...@rivai.ai From: Richard Biener Date: 2023-05-30 17:50 To: juzhe.zh...@rivai.ai CC: gcc-patches; richard.sandiford; linkw Subject: Re: Re: decremnt IV patch create fails on PowerPC O

Re: decremnt IV patch create fails on PowerPC

2023-05-30 Thread Kewen.Lin via Gcc-patches
on 2023/5/30 17:26, juzhe.zh...@rivai.ai wrote: > Ok. > > It seems that for this conditions: > > + /* If we're vectorizing a loop that uses length "controls" and > + can iterate more than once, we apply decrementing IV approach > + in loop control. */ > + if

Re: Re: decremnt IV patch create fails on PowerPC

2023-05-30 Thread Richard Biener via Gcc-patches
gt; > juzhe.zh...@rivai.ai > > From: Richard Biener > Date: 2023-05-30 17:22 > To: juzhe.zh...@rivai.ai > CC: gcc-patches; richard.sandiford; linkw > Subject: Re: Re: decremnt IV patch create fails on PowerPC > On Fri, 26 May 2023, juzhe.zh...@rivai.ai wrote: > > >

Re: Re: decremnt IV patch create fails on PowerPC

2023-05-30 Thread juzhe.zh...@rivai.ai
23-05-30 17:22 To: juzhe.zh...@rivai.ai CC: gcc-patches; richard.sandiford; linkw Subject: Re: Re: decremnt IV patch create fails on PowerPC On Fri, 26 May 2023, juzhe.zh...@rivai.ai wrote: > Hi, Richi. Thanks for your analysis and helps. > > >> We could simply retain t

Re: Re: decremnt IV patch create fails on PowerPC

2023-05-30 Thread Richard Biener via Gcc-patches
> I think Richard may help to explain decrement IV more clearly. > > Thanks > > > juzhe.zh...@rivai.ai > > From: Richard Biener > Date: 2023-05-26 14:46 > To: ??? > CC: gcc-patches; richard.sandiford; linkw > Subject: Re: decremnt IV patch create fails o

Re: Re: decremnt IV patch create fails on PowerPC

2023-05-26 Thread juzhe.zh...@rivai.ai
richard.sandiford; linkw Subject: Re: decremnt IV patch create fails on PowerPC On Fri, 26 May 2023, ??? wrote: > Yesterday's patch has been approved (decremnt IV support): > https://gcc.gnu.org/pipermail/gcc-patches/2023-May/619663.html > > However, it creates fails on PowerPC: >

Re: decremnt IV patch create fails on PowerPC

2023-05-26 Thread Richard Biener via Gcc-patches
On Fri, 26 May 2023, ??? wrote: > Yesterday's patch has been approved (decremnt IV support): > https://gcc.gnu.org/pipermail/gcc-patches/2023-May/619663.html > > However, it creates fails on PowerPC: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109971 > > I am really sorry for causing

decremnt IV patch create fails on PowerPC

2023-05-25 Thread 钟居哲
Yesterday's patch has been approved (decremnt IV support): https://gcc.gnu.org/pipermail/gcc-patches/2023-May/619663.html However, it creates fails on PowerPC: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109971 I am really sorry for causing inconvinience. I wonder as we disccussed: + /* If