bkietz commented on a change in pull request #8728:
URL: https://github.com/apache/arrow/pull/8728#discussion_r528776241
##########
File path: cpp/src/arrow/compute/kernels/scalar_boolean.cc
##########
@@ -156,14 +307,94 @@ struct Xor {
}
};
+struct AndNot {
+ static void Call(KernelContext* ctx, const Scalar& left, const Scalar& right,
+ Scalar* out) {
+ And::Call(ctx, left, InvertScalar(right), out);
+ }
+
+ static void Call(KernelContext* ctx, const Scalar& left, const ArrayData&
right,
+ ArrayData* out) {
+ if (!left.is_valid) return; // all null case
+
+ return checked_cast<const BooleanScalar&>(left).value
+ ? GetBitmap(*out, 1).CopyFromInverted(GetBitmap(right, 1))
+ : GetBitmap(*out, 1).SetBitsTo(false);
+ }
+
+ static void Call(KernelContext* ctx, const ArrayData& left, const Scalar&
right,
+ ArrayData* out) {
+ And::Call(ctx, left, InvertScalar(right), out);
+ }
+
+ static void Call(KernelContext* ctx, const ArrayData& left, const ArrayData&
right,
+ ArrayData* out) {
+ ::arrow::internal::BitmapAndNot(left.buffers[1]->data(), left.offset,
+ right.buffers[1]->data(), right.offset,
right.length,
+ out->offset,
out->buffers[1]->mutable_data());
+ }
+};
+
+struct KleeneAndNot {
+ static void Call(KernelContext* ctx, const Scalar& left, const Scalar& right,
+ Scalar* out) {
+ KleeneAnd::Call(ctx, left, InvertScalar(right), out);
+ }
+
+ static void Call(KernelContext* ctx, const Scalar& left, const ArrayData&
right,
+ ArrayData* out) {
+ bool left_true = left.is_valid && checked_cast<const
BooleanScalar&>(left).value;
+ bool left_false = left.is_valid && !checked_cast<const
BooleanScalar&>(left).value;
+
+ if (left_false) {
+ return GetBitmap(*out, 0).SetBitsTo(true),
+ GetBitmap(*out, 1).SetBitsTo(false); // all false case
+ }
+
+ if (left_true) {
+ return GetBitmap(*out, 0).CopyFrom(GetBitmap(right, 0)),
+ GetBitmap(*out, 1).CopyFromInverted(GetBitmap(right, 1));
+ }
+
+ // scalar was null: out[i] is valid iff right[i] was true
+ ::arrow::internal::BitmapAnd(right.buffers[0]->data(), right.offset,
+ right.buffers[1]->data(), right.offset,
right.length,
+ out->offset, out->buffers[0]->mutable_data());
+ ::arrow::internal::InvertBitmap(right.buffers[1]->data(), right.offset,
right.length,
+ out->buffers[1]->mutable_data(),
out->offset);
+ }
+
+ static void Call(KernelContext* ctx, const ArrayData& left, const Scalar&
right,
+ ArrayData* out) {
+ KleeneAnd::Call(ctx, left, InvertScalar(right), out);
+ }
+
+ static void Call(KernelContext* ctx, const ArrayData& left, const ArrayData&
right,
+ ArrayData* out) {
+ if (left.GetNullCount() == 0 && right.GetNullCount() == 0) {
+ GetBitmap(*out, 0).SetBitsTo(true);
+ return AndNot::Call(ctx, left, right, out);
+ }
+
+ static auto compute_word = [](uint64_t left_true, uint64_t left_false,
+ uint64_t right_true, uint64_t right_false,
+ uint64_t* out_valid, uint64_t* out_data) {
+ *out_data = left_true & right_false;
+ *out_valid = left_false | right_true | (left_true & right_false);
Review comment:
`right_false` is derived from both the validity and the value bitmaps;
it's true iff a slot was valid&false. To unpack this expression a bit:
`and_not_kleene(left, right)` is valid if
- `left` is false, since `and_kleene(false, x)` is false (even if `x` is
null)
- `right` is true, since `and_kleene(x, not true)` is false (even if `x` is
null)
- `left` is true AND `right` is false, since `and_kleene(true, not false)`
is true
I believe the tests exercise the full truth table of and_not_kleene so if
this still looks suspicious then I'd look there first.
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