Description

For upcoming VECTOR_FLOAT16 support in the Microsoft JDBC Driver for SQL Server, this change introduces complete serialization and deserialization logic for half-precision floating-point values used inside vector columns.

The driver performs IEEE-754–compliant bidirectional conversion between standard Java Float[] (FLOAT32, 4 bytes) and the compact FLOAT16 (2 bytes) wire format. Applications continue interacting with Float[], while the driver transparently handles precision conversion depending on the negotiated vector type.

Data Flow

Conversions Added

• floatToFloat16() : Converts a 32-bit float into its IEEE-754 half-precision (16-bit) representation, applying correct rounding, overflow handling, and encoding of NaN/Infinity.
• float16ToFloat() : Converts a 16-bit half-precision value back into a 32-bit float, preserving sign, exponent, and all special values.
• serializeFloat16Array() : Converts a Float[] into a compact byte array by encoding each element as float16, including support for null markers and special floating-point values.
• deserializeFloat16Array() : Converts a float16 byte array back into a Float[], restoring each element to its 32-bit float form with correct decoding of NaN, Infinity, and nulls.

Motivation

This enhancement enables efficient storage and transmission of VECTOR_FLOAT16 data between Java applications and SQL Server, providing a foundation for vector search, embeddings, and machine-learning workflows that benefit from reduced memory footprint.