On Wed, 11 Nov 2020, Richard Sandiford wrote: > [Andrew: cc:ing you in case this affects/helps GCN.] > > The vcond code requires the compared vectors and the selected > vectors to have both the same size and the same number of elements > as each other. But the operation makes logical sense even for > different vector sizes. E.g. you could compare two V4SIs and > use the result to select between two V4DIs. > > The underlying optab already allows the compared mode and the selected > mode to be specified separately. Since the vectoriser now also > supports mixed vector sizes, I think we can simply remove the > equal-size check and just keep the equal-lanes check. It's then > up to the target to decide which (if any) mixtures of sizes it > supports. > > Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install?
OK. Thanks, Richard. > Richard > > > gcc/ > * optabs-tree.c (expand_vec_cond_expr_p): Allow the compared values > and the selected values to have different mode sizes. > * gimple-isel.cc (gimple_expand_vec_cond_expr): Likewise. > --- > gcc/gimple-isel.cc | 5 ++--- > gcc/optabs-tree.c | 3 +-- > 2 files changed, 3 insertions(+), 5 deletions(-) > > diff --git a/gcc/gimple-isel.cc b/gcc/gimple-isel.cc > index 9186ff55cdd..b5362cc4b01 100644 > --- a/gcc/gimple-isel.cc > +++ b/gcc/gimple-isel.cc > @@ -199,9 +199,8 @@ gimple_expand_vec_cond_expr (gimple_stmt_iterator *gsi, > unsignedp = TYPE_UNSIGNED (TREE_TYPE (op0a)); > > > - gcc_assert (known_eq (GET_MODE_SIZE (mode), GET_MODE_SIZE (cmp_op_mode)) > - && known_eq (GET_MODE_NUNITS (mode), > - GET_MODE_NUNITS (cmp_op_mode))); > + gcc_assert (known_eq (GET_MODE_NUNITS (mode), > + GET_MODE_NUNITS (cmp_op_mode))); > > icode = get_vcond_icode (mode, cmp_op_mode, unsignedp); > if (icode == CODE_FOR_nothing) > diff --git a/gcc/optabs-tree.c b/gcc/optabs-tree.c > index badd30bfda8..4dfda756932 100644 > --- a/gcc/optabs-tree.c > +++ b/gcc/optabs-tree.c > @@ -377,8 +377,7 @@ expand_vec_cond_expr_p (tree value_type, tree > cmp_op_type, enum tree_code code) > TYPE_MODE (cmp_op_type)) != CODE_FOR_nothing) > return true; > > - if (maybe_ne (GET_MODE_SIZE (value_mode), GET_MODE_SIZE (cmp_op_mode)) > - || maybe_ne (GET_MODE_NUNITS (value_mode), GET_MODE_NUNITS > (cmp_op_mode))) > + if (maybe_ne (GET_MODE_NUNITS (value_mode), GET_MODE_NUNITS (cmp_op_mode))) > return false; > > if (TREE_CODE_CLASS (code) != tcc_comparison) > -- Richard Biener <rguent...@suse.de> SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany; GF: Felix Imend
