https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107432
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |rguenth at gcc dot gnu.org,
| |rsandifo at gcc dot gnu.org
Target|X86_64 |x86_64-*-*
Last reconfirmed| |2022-10-28
Status|UNCONFIRMED |NEW
Ever confirmed|0 |1
Version|unknown |13.0
--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Hongtao.liu from comment #6)
> > Guess expand_vector_conversion can be optimized.
>
> if (INTEGRAL_TYPE_P (TREE_TYPE (ret_type))
> && SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg_type)))
> code = FIX_TRUNC_EXPR;
> else if (INTEGRAL_TYPE_P (TREE_TYPE (arg_type))
> && SCALAR_FLOAT_TYPE_P (TREE_TYPE (ret_type)))
> code = FLOAT_EXPR;
>
> It only supports floatmn2/fix_truncmn2 for float <-> integer.
>
> But we can also supports extendmn2/zero_extendmn2/truncmn2 for float <->
> float, integer <-> integer.
>
> Or are there any concerns and VEC_PACK_TRUNC_EXPR,
> VEC_PACK_FIX_TRUNC_EXPR,VEC_PACK_FLOAT_EXPR are used on purpose?
I think we do support FIX_TRUNC_EXPR or FLOAT_EXPR for float <-> int
conversion of vectors like we now support {CONVERT,NOP}_EXPR for
just widening/shortening. At least the GIMPLE verifier allows that.
The obtabs would be [us]fix and [us]float, not sure if aarch64 makes use
of those for vector modes or if Richard extended the vectorizer to
consider those (I only remember int <-> int conversions).
So I think if x86_64 can do float <-> int for vectors implementing
[us]fix/[us]float would be the way to go (and of course then make use
of those in lowering/vectorization).
