On Thu, Feb 02, 2017 at 10:12:32AM -0700, Jeff Law wrote:
> On 02/01/2017 03:45 AM, Richard Biener wrote:
> >
> > I agree. But this means we should look for a vectorizer-local fix
> > without a new global predicate then (there seem to be subtly different
> > needs and coming up with good names for all of them sounds difficult...).
> Well, we could go with Jakub's INTEGRAL_BOOLEAN_TYPE as posted, but in
> contexts where we use it and really depend on single bit objects, we add the
> precision == 1 check back. Jakub's patch removes the type precision check
> in tree-vect-patterns for example. There's likely all kinds of places where
> we need to add that check as well.
The 3 cases in tree-vect-patterns.c where I've removed the check were
exactly what the proposed macro does, i.e.
if ((TYPE_PRECISION (TREE_TYPE (rhs1)) != 1
|| !TYPE_UNSIGNED (TREE_TYPE (rhs1)))
&& TREE_CODE (TREE_TYPE (rhs1)) != BOOLEAN_TYPE)
return false;
i.e. bail out unless the rhs1 type is a BOOLEAN_TYPE (any precision,
assuming it has only valid values of 0 and 1) or unless it is unsigned
precision type 1 integer (i.e. something that (if it has also QImode)
forwprop etc. could have changed a BOOLEAN_TYPE with precision 1 into.
Note Fortran has been using I think precision one boolean_type_node even in GCC
6.x,
it had:
boolean_type_node = gfc_get_logical_type (gfc_default_logical_kind);
boolean_true_node = build_int_cst (boolean_type_node, 1);
boolean_false_node = build_int_cst (boolean_type_node, 0);
Fortran logical(4) etc. are built using:
new_type = make_unsigned_type (bit_size);
TREE_SET_CODE (new_type, BOOLEAN_TYPE);
TYPE_MAX_VALUE (new_type) = build_int_cst (new_type, 1);
TYPE_PRECISION (new_type) = 1;
thus I believe they have e.g. SImode or DImode rather than QImode, but still
TYPE_PRECISION of 1. The non-Ada boolean is also:
boolean_type_node = make_unsigned_type (BOOL_TYPE_SIZE);
TREE_SET_CODE (boolean_type_node, BOOLEAN_TYPE);
TYPE_PRECISION (boolean_type_node) = 1;
where BOOL_TYPE_SIZE is CHAR_TYPE_SIZE everywhere but on powerpc*-darwin*
with some command line option.
Ada is
boolean_type_node = make_unsigned_type (8);
TREE_SET_CODE (boolean_type_node, BOOLEAN_TYPE);
and thus it is indeed precision 8 QImode.
So, requiring precision 1 for all BOOLEAN_TYPEs in the vectorizer would
only affect Ada. Requiring QImode or whatever other fixed TYPE_MODE
in the macro for precision 1 unsigned non-BOOLEAN_TYPE integers would
actually also affect Fortran a lot, because e.g. SImode precision 1
INTEGER_TYPE is considered compatible with SImode precision 1 BOOLEAN_TYPE.
> /me is frustrated that we have booleans with nonstandard precision, even
> though I understand why it was done. It creates numerous headaches.
Ditto.
Jakub
