* Richard Sandiford <rdsandif...@googlemail.com> [2016-06-15 19:07:56 +0100]:
> 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 for taking the time to review and provide feedback. Sorry it
has take a while to get around to this patch again.
I've updated the patch inline with your feedback. How's this?
Thanks,
Andrew
---
gcc/genrecog: Don't warn for missing mode on special predicates
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}.
In genrecog, when validating a SET pattern, there is already a special
case for 'address_operand' which is a special predicate, however,
other special predicates fall through to the code which checks for
incorrect use of VOIDmode.
This commit adds a new function for detecting special predicates, and
then generalises the check in validate_pattern so that mode checking
is skipped for all special predicates.
gcc/ChangeLog:
* genrecog.c (special_predicate_operand_p): New function.
(predicate_name): Move function.
(validate_pattern): Don't warn about missing mode for all
define_special_predicate predicates.
---
gcc/ChangeLog | 7 +++++++
gcc/genrecog.c | 50 +++++++++++++++++++++++++++++++++++---------------
2 files changed, 42 insertions(+), 15 deletions(-)
diff --git a/gcc/genrecog.c b/gcc/genrecog.c
index a9f5a4a..7c56225 100644
--- a/gcc/genrecog.c
+++ b/gcc/genrecog.c
@@ -463,6 +463,38 @@ constraints_supported_in_insn_p (rtx insn)
|| GET_CODE (insn) == DEFINE_PEEPHOLE2);
}
+/* Return the name of the predicate matched by MATCH_RTX. */
+
+static const char *
+predicate_name (rtx match_rtx)
+{
+ if (GET_CODE (match_rtx) == MATCH_SCRATCH)
+ return "scratch_operand";
+ else
+ return XSTR (match_rtx, 1);
+}
+
+/* Return true if OPERAND is a MATCH_OPERAND using a special predicate
+ function. */
+
+static bool
+special_predicate_operand_p (rtx operand)
+{
+ if (GET_CODE (operand) == MATCH_OPERAND)
+ {
+ const char *pred_name = predicate_name (operand);
+ if (pred_name[0] != 0)
+ {
+ const struct pred_data *pred;
+
+ pred = lookup_predicate (pred_name);
+ return pred->special;
+ }
+ }
+
+ return false;
+}
+
/* Check for various errors in PATTERN, which is part of INFO.
SET is nonnull for a destination, and is the complete set pattern.
SET_CODE is '=' for normal sets, and '+' within a context that
@@ -651,10 +683,9 @@ validate_pattern (rtx pattern, md_rtx_info *info, rtx set,
int set_code)
dmode = GET_MODE (dest);
smode = GET_MODE (src);
- /* 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"))
+ /* Mode checking is not performed for special predicates. */
+ if (special_predicate_operand_p (src)
+ || special_predicate_operand_p (dest))
;
/* The operands of a SET must have the same mode unless one
@@ -3788,17 +3819,6 @@ operator < (const pattern_pos &e1, const pattern_pos &e2)
return diff < 0;
}
-/* Return the name of the predicate matched by MATCH_RTX. */
-
-static const char *
-predicate_name (rtx match_rtx)
-{
- if (GET_CODE (match_rtx) == MATCH_SCRATCH)
- return "scratch_operand";
- else
- return XSTR (match_rtx, 1);
-}
-
/* Add new decisions to S that check whether the rtx at position POS
matches PATTERN. Return the state that is reached in that case.
TOP_PATTERN is the overall pattern, as passed to match_pattern_1. */
--
2.4.11
