> Sorry, my fault. I was using the original type names in this
> suggestion, rather than the TYPE1…TYPE5 ones. Should be:
>
> WIDEN_ABD exists to optimize the case where TYPE4 is at least
> twice as wide as TYPE3.
Change made.
> Lingering use of “L” suffixes here. Maybe:
>
> stmts that constitute the pattern, principally:
> out = IFN_ABD (x, y)
> out = IFN_WIDEN_ABD (x, y)
Change made.
> > + if (TYPE_PRECISION (out_type) >= TYPE_PRECISION (abd_in_type) * 2
> > + && TYPE_PRECISION (abd_out_type) != stmt_vinfo->min_output_precision)
>
> Sorry for not noticing last time, but I think the second condition
> would be more natural as:
>
> && stmt_vinfo->min_output_precision >= TYPE_PRECISION (abd_in_type) * 2)
>
> (There's no distinction between abs_in_type and abs_out_type at this point,
> so it seems clearer to use the same value in both conditions.)
Change made.
> > + gassign *last_stmt = dyn_cast <gassign *> (STMT_VINFO_STMT (stmt_vinfo));
> > + if (!last_stmt || !gimple_assign_cast_p (last_stmt))
>
> I think this should be:
>
> if (!last_stmt || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (last_stmt)))
>
> gimple_assign_cast_p is more general, and allows conversions
> between integral and non-integral types.
Change made.
> > + tree in_type = TREE_TYPE (last_rhs);
> > + tree out_type = TREE_TYPE (gimple_assign_lhs (last_stmt));
> > + if (TYPE_PRECISION (in_type) * 2 != TYPE_PRECISION (out_type))
> > + return NULL;
>
> I think this also needs to require TYPE_UNSIGNED (in_type):
>
> if (TYPE_PRECISION (in_type) * 2 != TYPE_PRECISION (out_type)
> || !TYPE_UNSIGNED (in_type))
> return NULL;
>
> That is, the extension has to be a zero extension rather than
> a sign extension.
>
> For example:
>
> int32_t a, b, c;
> int64_t d;
>
> c = IFN_ABD (a, b);
> d = (int64_t) c;
>
> sign-extends the ABD result to 64 bits, and so a == INT_MAX
> && b == INT_MIN gives:
>
> c = -1 (UINT_MAX converted to signed)
> d = -1
>
> But IFN_WIDEN_ABD would give d == UINT_MAX instead.
Change made.
> > + gimple *pattern_stmt = STMT_VINFO_STMT (abd_pattern_vinfo);
> > + if (gimple_assign_cast_p (pattern_stmt))
> > + {
> > + tree op = gimple_assign_rhs1 (pattern_stmt);
> > + vect_unpromoted_value unprom;
> > + op = vect_look_through_possible_promotion (vinfo, op, &unprom);
> > +
> > + if (!op)
> > + return NULL;
> > +
> > + abd_pattern_vinfo = vect_get_internal_def (vinfo, op);
> > + if (!abd_pattern_vinfo)
> > + return NULL;
> > +
> > + pattern_stmt = STMT_VINFO_STMT (abd_pattern_vinfo);
> > + }
>
> I think the code quoted above reduces to:
>
> vect_unpromoted_value unprom;
> tree op = vect_look_through_possible_promotion (vinfo, last_rhs, &unprom);
> if (!op || TYPE_PRECISION (TREE_TYPE (op)) != TYPE_PRECISION (in_type))
> return NULL;
>
> stmt_vec_info abd_pattern_vinfo = vect_get_internal_def (vinfo, op);
> if (!abd_pattern_vinfo)
> return NULL;
> abd_pattern_vinfo = vect_stmt_to_vectorize (abd_pattern_vinfo);
>
> ...
>
> > + tree abd_oprnd0 = gimple_call_arg (abd_stmt, 0);
> > + tree abd_oprnd1 = gimple_call_arg (abd_stmt, 1);
> > + if (TYPE_PRECISION (TREE_TYPE (abd_oprnd0)) != TYPE_PRECISION (in_type))
> > + return NULL;
>
> With the changes above, this check would not be necessary.
Both changes made.
Updated patch will be in the next email.
