Phase 1: Enhance kernel registry for vectorized dt-robust functions

[ztripez]

Phase 1: Enhance Kernel Registry for Vectorized Functions

Part of Epic #247

Objective

Extend the kernel registry system to support vectorized execution hints and registration of both scalar and vectorized implementations for dt-robust operators.

Tasks

Enhance Kernel Registry Types

• Add VectorizedKernelDescriptor struct to kernel-registry
• Add VectorizedImpl function type for vectorized execution
• Extend registration to track vectorized implementations

Update Registration Macros

• Add vectorized = true attribute to #[kernel_fn] macro
• Create #[vectorized_kernel_fn] macro for vectorized implementations
• Update macro documentation with examples

Registry API Extensions

• Add get_vectorized(name: &str) function to kernel-registry
• Add has_vectorized_impl(name: &str) check function
• Update all_names() to indicate vectorized capability

Testing

• Add tests for vectorized registration
• Test macro expansion with vectorized attributes
• Verify registry lookup functions work correctly

Files to Modify

• crates/kernel-registry/src/lib.rs
• crates/kernel-macros/src/lib.rs
• crates/kernel-registry/src/types.rs (if exists)

Success Criteria

• Kernel functions can register vectorized implementations
• Registry can lookup vectorized variants
• Macros generate correct registration code
• All tests pass

Dependencies

None - this is the foundation for other phases.

Estimated Time: 1 week

[ztripez]

✅ Phase 1 Complete!

Completed Tasks

✅ Enhanced Kernel Registry Types

• Added VectorizedImpl enum with Pure and WithDt variants
• Extended KernelDescriptor with optional vectorized_impl field
• Added VRegBuffer type locally (avoiding circular dependencies)

✅ Updated Registration Macros

• Added vectorized attribute to #[kernel_fn] macro
• Added placeholder #[vectorized_kernel_fn] macro for Phase 2
• Enhanced argument parsing to handle vectorized flag

✅ Registry API Extensions

• Added get_vectorized(name) function
• Added has_vectorized_impl(name) check function
• Added eval_vectorized() for vectorized execution
• All functions properly handle optional vectorized implementations

✅ Testing

• All existing tests pass
• Added new tests for vectorized API functionality
• Verified vectorized attribute works without breaking builds
• Functions marked with vectorized attribute register correctly

Key Achievements

🎯 No Circular Dependencies: VRegBuffer defined locally in kernel-registry
🎯 Backward Compatibility: All existing kernel functions continue working
🎯 Future Ready: Infrastructure prepared for Phase 2 vectorized implementations
🎯 Clean API: Vectorized operations are optional and discoverable

Files Modified

• crates/kernel-registry/src/lib.rs - Enhanced registry types and API
• crates/kernel-macros/src/lib.rs - Added vectorized attribute support
• crates/kernels/functions/src/dt_operators.rs - Marked dt functions as vectorized

Next Phase

Phase 2 ready to begin: Complete dt-robust operators in standard library with vectorized implementations.

Commit: f1b39b6