Comment by pella

4 hours ago

> "fc is a lossless compressor for streams of IEEE-754 64-bit doubles."

The new OpenZL SDDL2 (Simple Data Description Language) supports several different floating-point types. It would be worthwhile to contribute some of the FC project's experience to OpenZL. Now the OpenZL supported types:

  | Type           | Size    |Endian|
  |----------------|---------|-----|
  | `Int8`         | 1 byte  | N/A |
  | `UInt8`        | 1 byte  | N/A |
  | `Int16LE/BE`   | 2 bytes | Yes |
  | `UInt16LE/BE`  | 2 bytes | Yes |
  | `Int32LE/BE`   | 4 bytes | Yes |
  | `UInt32LE/BE`  | 4 bytes | Yes |
  | `Int64LE/BE`   | 8 bytes | Yes |
  | `UInt64LE/BE`  | 8 bytes | Yes |
  | `Float16LE/BE` | 2 bytes | Yes |
  | `Float32LE/BE` | 4 bytes | Yes |
  | `Float64LE/BE` | 8 bytes | Yes |
  | `BFloat16LE/BE`| 2 bytes | Yes |
  | `Bytes(n)`     | n bytes | N/A |

Some links:

- https://github.com/facebook/openzl/releases/tag/v0.2.0

- https://openzl.org/getting-started/introduction/

- https://openzl.org/sddl/sddl2-announcement/

- https://openzl.org/sddl/core-concepts/

1 comment

pella

enduku 1 hour ago

Thanks, this looks super relevant. I think the transferable part is the per-block selectrover predictors, strides, deltas, exponent/mantissa-ish structure, byte transpose, fallback raw/LZ, etc.sddl2 looks like a natural place to try some of that.