Hi, Richards. Could you take a look at this patch: https://gcc.gnu.org/pipermail/gcc-patches/2023-May/618241.html
Thanks juzhe.zh...@rivai.ai From: Richard Sandiford Date: 2023-05-11 20:42 To: juzhe.zhong\@rivai.ai CC: gcc-patches; rguenther Subject: Re: [PATCH V4] VECT: Add decrement IV iteration loop control by variable amount support "juzhe.zh...@rivai.ai" <juzhe.zh...@rivai.ai> writes: > Thanks. I have read rgroup descriptions again. > Still I am not fully understand it clearly, bear with me :) > > I don't known how to differentiate Case 2 and Case 3. > > Case 2 is multiple rgroup for SLP. > Case 3 is multiple rgroup for non-SLP (VEC_PACK_TRUNC) > > Is it correct: > case 2: rgc->max_nscalarper_iter != 1 Yes. > Case 3 : rgc->max_nscalarper_iter == 1 but rgc->factor != 1? For case 3 it's: rgc->max_nscalars_per_iter == 1 && rgc != &LOOP_VINFO_LENS (loop_vinfo)[0] rgc->factor is controlled by the target and just says what units IFN_LOAD_LEN works in. E.g. if we're loading 16-byte elements, but the underlying instruction measures bytes, the factor would be 2. Thanks, Richard
