On Fri, Mar 15, 2024 at 4:35 AM Hongtao Liu <crazy...@gmail.com> wrote: > > On Thu, Mar 14, 2024 at 11:42 PM Andrew Stubbs <a...@baylibre.com> wrote: > > > > Don't enable excess lanes when inverting vector bit-masks smaller than the > > integer mode. This is yet another case of wrong-code due to mishandling > > of oversized bitmasks. > > > > This issue shows up in vect/tsvc/vect-tsvc-s278.c and > > vect/tsvc/vect-tsvc-s279.c if I set the preferred vector size to V32 > > (down from V64) on amdgcn. > > > > OK for mainline? > > > > Andrew > > > > gcc/ChangeLog: > > > > * expr.cc (expand_expr_real_2): Use xor to invert vector masks. > > --- > > gcc/expr.cc | 11 +++++++++++ > > 1 file changed, 11 insertions(+) > > > > diff --git a/gcc/expr.cc b/gcc/expr.cc > > index 403eeaa108e4..3540327d879e 100644 > > --- a/gcc/expr.cc > > +++ b/gcc/expr.cc > > @@ -10497,6 +10497,17 @@ expand_expr_real_2 (sepops ops, rtx target, > > machine_mode tmode, > > immed_wide_int_const (mask, int_mode), > > target, 1, OPTAB_LIB_WIDEN); > > } > > + /* If it's a vector mask don't enable excess bits. */ > > + else if (VECTOR_BOOLEAN_TYPE_P (type) > > + && SCALAR_INT_MODE_P (mode) > > + && maybe_ne (GET_MODE_PRECISION (mode), > > + TYPE_VECTOR_SUBPARTS (type).to_constant ())) > > + { > > + auto nunits = TYPE_VECTOR_SUBPARTS (type).to_constant (); > > + temp = expand_binop (mode, xor_optab, op0, > > + GEN_INT ((HOST_WIDE_INT_1U << nunits) - 1), > > + target, true, OPTAB_WIDEN); > > + } > Not review, just curious, should the issue be fixed by the commit in PR113576. > Also wonder besides cbranch, excess land bits also matter? > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113576#c35
Yes, you patch BIT_NOT but we decided to patch final compares. Is it that we need to fixup every mask use in a .COND_* expansion as well? If so we should do it there. Richard. > > else > > temp = expand_unop (mode, one_cmpl_optab, op0, target, 1); > > gcc_assert (temp); > > -- > > 2.41.0 > > > > > -- > BR, > Hongtao