geoffreyclaude commented on code in PR #23014:
URL: https://github.com/apache/datafusion/pull/23014#discussion_r3636805027
##########
datafusion/physical-expr/src/expressions/in_list/primitive_filter.rs:
##########
@@ -222,6 +223,241 @@ where
}
}
+pub(super) type BranchlessNative<T> =
+ <<T as BranchlessFilterType>::CompareType as ArrowPrimitiveType>::Native;
+
+/// Maximum list size for branchless lookup on 1-byte primitives.
+///
+/// Sixteen 1-byte values fit in one 128-bit SIMD vector, so this keeps the
+/// branchless list small enough for a single vectorized membership check.
+const BRANCHLESS_MAX_1B: usize = 16;
+
+/// Maximum list size for branchless lookup on 2-byte primitives.
+///
+/// Eight 2-byte values fit in one 128-bit SIMD vector, so this keeps the
+/// branchless list small enough for a single vectorized membership check.
+const BRANCHLESS_MAX_2B: usize = 8;
+
+/// Maximum list size for branchless lookup on 4-byte primitives.
+///
+/// Thirty-two 4-byte values keep the inline list at 128 bytes. Beyond that,
+/// the comparison chain and filter footprint grow enough that the hash/generic
+/// fallback is a better fit.
+const BRANCHLESS_MAX_4B: usize = 32;
+
+/// Maximum list size for branchless lookup on 8-byte primitives.
+///
+/// Sixteen 8-byte values use the same 128-byte inline-list budget as 4-byte
+/// primitives. Larger lists are left to the hash/generic fallback.
+const BRANCHLESS_MAX_8B: usize = 16;
+
+/// Maximum list size for branchless lookup on 16-byte primitives.
+///
+/// These comparisons are wider, so this path is limited to four values.
+/// Larger lists are left to the generic fallback.
+const BRANCHLESS_MAX_16B: usize = 4;
+
+/// Arrow primitive types supported by [`BranchlessFilter`].
+///
+/// `T` is the logical Arrow type accepted by the filter. `CompareType` is the
+/// same-width type used for the fixed comparison chain. Signed integers,
+/// floats, and temporal values use an unsigned comparison type so they compare
+/// by their raw bit pattern.
+pub(super) trait BranchlessFilterType:
+ ArrowPrimitiveType + Send + Sync + 'static
+{
+ type CompareType: ArrowPrimitiveType + Send + Sync + 'static;
+
+ /// Maximum number of non-null IN-list values to handle with
+ /// [`BranchlessFilter`] for this primitive type.
+ const MAX_LIST_LEN: usize;
+}
+
+macro_rules! branchless_filter_type {
+ ($logical:ty, $compare:ty, $max_len:expr) => {
+ // The branchless filter reads the same Arrow value buffer as the
+ // comparison type. That is only valid when both native types have the
+ // same width, so catch any bad mapping here at compile time.
+ const _: () = assert!(
+ size_of::<<$logical as ArrowPrimitiveType>::Native>()
+ == size_of::<<$compare as ArrowPrimitiveType>::Native>(),
+ "BranchlessFilterType::CompareType must use the same native width"
+ );
+
+ impl BranchlessFilterType for $logical {
+ type CompareType = $compare;
+ const MAX_LIST_LEN: usize = $max_len;
+ }
+ };
+}
+
+branchless_filter_type!(Int8Type, UInt8Type, BRANCHLESS_MAX_1B);
+branchless_filter_type!(UInt8Type, UInt8Type, BRANCHLESS_MAX_1B);
+branchless_filter_type!(Int16Type, UInt16Type, BRANCHLESS_MAX_2B);
+branchless_filter_type!(UInt16Type, UInt16Type, BRANCHLESS_MAX_2B);
+branchless_filter_type!(Float16Type, UInt16Type, BRANCHLESS_MAX_2B);
+
+branchless_filter_type!(Int32Type, UInt32Type, BRANCHLESS_MAX_4B);
Review Comment:
Yes, that was correct for the previous version: `UInt32` alone generated 32
copies of the full `BranchlessFilter` 😬.
The follow-up removes the list length from `BranchlessFilter`, so there is
now only one full filter per type. Only the small comparison function still
varies by length. I put the detailed size and performance results in my reply
to the overall review.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
