Reorganize switch statement cases in pack and unpack functions by grouping
formats with similar function signatures together. This improves branch
prediction and CPU pipeline efficiency by reducing branch misprediction
overhead in the hot dispatch paths.
Key improvements:
- Pack dispatch: grouped by signature patterns (integer, float, string)
- Unpack dispatch: optimized both COUNT2 and element-by-element switches
- Better instruction cache usage through logical code organization
- Enhanced branch prediction for frequently used format combinations
- Maintained full backward compatibility with all existing functionality
Co-authored-by: Claude <noreply@anthropic.com>
Yukihiro "Matz" Matsumoto
6544195c43