On Sat, Aug 20, 2016 at 1:38 AM, Patrick Palka <[email protected]> wrote:
> On Fri, Aug 19, 2016 at 7:30 PM, Patrick Palka <[email protected]> wrote:
>> integer_nonzerop() currently unconditionally returns false for a
>> VECTOR_CST argument. This is confusing because one would expect that
>> integer_onep(x) => integer_nonzerop(x) for all x but that is currently
>> not the case. For a VECTOR_CST of all ones i.e. {1,1,1,1},
>> integer_onep() returns true but integer_nonzerop() returns false.
>>
>> This patch makes integer_nonzerop() handle VECTOR_CSTs in the obvious
>> way and also adds some self tests (the last of which fails without the
>> change). Does this look OK to commit afetr bootstrap + regtesting on
>> x86_64-pc-linux-gnu?
>
> Actually I guess there is some ambiguity as to whether
> integer_nonzerop() should return true for a VECTOR_CST only if it has
> at least one non-zero element or only if all of its elements are
> non-zero...
>From its documentation it looks like integer_nonzerop would be the
same as ! integer_zerop if you pass in a tree code that is handled
by integer_zerop. So I guess it doesn't really make sense to ask
this for a vector?
Richard.
>>
>> gcc/ChangeLog:
>>
>> * tree.c (integer_nonzerop): Rewrite to use a switch. Handle
>> VECTOR_CSTs.
>> (test_vector_constants): New static function.
>> (tree_c_tests): Call it.
>> ---
>> gcc/tree.c | 43 ++++++++++++++++++++++++++++++++++++++-----
>> 1 file changed, 38 insertions(+), 5 deletions(-)
>>
>> diff --git a/gcc/tree.c b/gcc/tree.c
>> index 33e6f97..48795c7 100644
>> --- a/gcc/tree.c
>> +++ b/gcc/tree.c
>> @@ -2439,11 +2439,24 @@ integer_pow2p (const_tree expr)
>> int
>> integer_nonzerop (const_tree expr)
>> {
>> - return ((TREE_CODE (expr) == INTEGER_CST
>> - && !wi::eq_p (expr, 0))
>> - || (TREE_CODE (expr) == COMPLEX_CST
>> - && (integer_nonzerop (TREE_REALPART (expr))
>> - || integer_nonzerop (TREE_IMAGPART (expr)))));
>> + switch (TREE_CODE (expr))
>> + {
>> + case INTEGER_CST:
>> + return !wi::eq_p (expr, 0);
>> + case COMPLEX_CST:
>> + return (integer_nonzerop (TREE_REALPART (expr))
>> + || integer_nonzerop (TREE_IMAGPART (expr)));
>> + case VECTOR_CST:
>> + {
>> + unsigned i;
>> + for (i = 0; i < VECTOR_CST_NELTS (expr); ++i)
>> + if (integer_nonzerop (VECTOR_CST_ELT (expr, i)))
>> + return true;
>> + return false;
>> + }
>> + default:
>> + return false;
>> + }
>> }
>>
>> /* Return 1 if EXPR is the integer constant one. For vector,
>> @@ -14230,6 +14243,25 @@ test_integer_constants ()
>> ASSERT_EQ (type, TREE_TYPE (zero));
>> }
>>
>> +/* Verify various predicates and operations on vector constants. */
>> +
>> +static void
>> +test_vector_constants ()
>> +{
>> + tree inner_type = integer_type_node;
>> + tree type = build_vector_type (inner_type, 8);
>> + tree zero = build_zero_cst (type);
>> + tree one = build_one_cst (type);
>> +
>> + ASSERT_TRUE (integer_zerop (zero));
>> + ASSERT_FALSE (integer_onep (zero));
>> + ASSERT_FALSE (integer_nonzerop (zero));
>> +
>> + ASSERT_FALSE (integer_zerop (one));
>> + ASSERT_TRUE (integer_onep (one));
>> + ASSERT_TRUE (integer_nonzerop (one));
>> +}
>> +
>> /* Verify identifiers. */
>>
>> static void
>> @@ -14258,6 +14290,7 @@ void
>> tree_c_tests ()
>> {
>> test_integer_constants ();
>> + test_vector_constants ();
>> test_identifiers ();
>> test_labels ();
>> }
>> --
>> 2.9.3.650.g20ba99f
>>
