https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110897
--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> --- (In reply to JuzheZhong from comment #6) > (In reply to Richard Biener from comment #3) > > it looks like you don't support vector short logical shift? For some reason > > vect_recog_over_widening_pattern doesn't check whether the demoted operation > > is supported ... > > > > The following helps on x86_64, it disables the demotion. I think the idea > > was that we eventually recognize a widening shift, so the narrow operation > > itself doesn't need to be supported, but clearly that doesn't work out > > when there is no such shift. > > > > diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc > > index e4ab8c2d65b..4e4191652e3 100644 > > --- a/gcc/tree-vect-patterns.cc > > +++ b/gcc/tree-vect-patterns.cc > > @@ -3091,6 +3091,11 @@ vect_recog_over_widening_pattern (vec_info *vinfo, > > if (!new_vectype || !op_vectype) > > return NULL; > > > > + optab optab; > > + if (!(optab = optab_for_tree_code (code, op_vectype, optab_vector)) > > + || optab_handler (optab, TYPE_MODE (op_vectype)) == CODE_FOR_nothing) > > + return NULL; > > + > > if (dump_enabled_p ()) > > dump_printf_loc (MSG_NOTE, vect_location, "demoting %T to %T\n", > > type, new_type); > > > > with the patch above x86 can vectorize both loops with AVX2 but not without. > > > > Can you confirm this helps on RISC-V as well? > > > > Richard, what was the idea here? > > Hi, Richi. > > I try this codes as you suggested: > optab optab; > if (!(optab = optab_for_tree_code (code, op_vectype, optab_vector)) > || optab_handler (optab, TYPE_MODE (op_vectype)) == CODE_FOR_nothing) > return NULL; > > [jzzhong@server1:/work/home/jzzhong/work/insn]$~/work/rvv-opensource/output/ > gcc-rv64/bin/riscv64-rivai-elf-gcc -march=rv64gcv -O3 > --param=riscv-autovec-preference=scalable -S -fopt-info-vec-missed rvv.c > rvv.c:14:1: missed: couldn't vectorize loop > rvv.c:14:1: missed: not vectorized: no vectype for stmt: _4 = *_3; > scalar_type: uint16_t > > > Still can not vectorize it. Well, that means we do not have a vector mode for HImode elements?!
