Andrew Burgess <andrew.burg...@embecosm.com> writes:
> In md.texi it says:
>
> Predicates written with @code{define_special_predicate} do not get any
> automatic mode checks, and are treated as having special mode handling
> by @command{genrecog}.
>
> However, in genrecog, when validating a SET pattern, if either the
> source or destination is missing a mode then a warning is given, even if
> there's a predicate defined with define_special_predicate.
>
> This commit silences the warning for special predicates.
>
> gcc/ChangeLog:
>
> * genrecog.c (validate_pattern): Don't warn about missing mode for
> define_special_predicate predicates.
> Acked-by: Andrew Burgess <andrew.burg...@embecosm.com>
> ---
> gcc/ChangeLog | 5 +++++
> gcc/genrecog.c | 22 +++++++++++++++++++---
> 2 files changed, 24 insertions(+), 3 deletions(-)
>
> diff --git a/gcc/genrecog.c b/gcc/genrecog.c
> index a9f5a4a..7596552 100644
> --- a/gcc/genrecog.c
> +++ b/gcc/genrecog.c
> @@ -674,9 +674,25 @@ validate_pattern (rtx pattern, md_rtx_info *info, rtx
> set, int set_code)
> && !CONST_WIDE_INT_P (src)
> && GET_CODE (src) != CALL)
> {
> - const char *which;
> - which = (dmode == VOIDmode ? "destination" : "source");
> - message_at (info->loc, "warning: %s missing a mode?", which);
> + const char *which_msg;
> + rtx which;
> + const char *pred_name;
> + const struct pred_data *pred;
> +
> + which_msg = (dmode == VOIDmode ? "destination" : "source");
> + which = (dmode == VOIDmode ? dest : src);
> + pred_name = XSTR (which, 1);
> + if (pred_name[0] != 0)
> + {
> + pred = lookup_predicate (pred_name);
> + if (!pred)
> + error_at (info->loc, "unknown predicate '%s'", pred_name);
> + }
> + else
> + pred = 0;
> + if (!pred || !pred->special)
> + message_at (info->loc, "warning: %s missing a mode?",
> + which_msg);
There's no guarantee at this point that "which" is a match_operand.
Also, I think the earlier:
/* The operands of a SET must have the same mode unless one
is VOIDmode. */
else if (dmode != VOIDmode && smode != VOIDmode && dmode != smode)
error_at (info->loc, "mode mismatch in set: %smode vs %smode",
GET_MODE_NAME (dmode), GET_MODE_NAME (smode));
should be skipped for special predicates too.
How about generalising:
/* The mode of an ADDRESS_OPERAND is the mode of the memory
reference, not the mode of the address. */
if (GET_CODE (src) == MATCH_OPERAND
&& ! strcmp (XSTR (src, 1), "address_operand"))
;
to:
if (special_predicate_operand_p (src)
|| special_predicate_operand_p (dest))
;
with a new special_predicate_operand_p helper? I don't think we should
duplicate the "unknown predicate" error here; the helper can just return
false for unknown predicates.
Thanks,
Richard
