What problem does it solve? Hot-path scalar loops in .NET applications leave significant performance on the table when they process contiguous numeric arrays element by element. This Skill guides the conversion of those loops into hardware-accelerated vectorized code, choosing the right approach for each situation. ## Core Features & Use Cases - Decision-gated optimization: Checks built-in Span<T>/MemoryExtensions methods first, then TensorPrimitives APIs, and only falls back to manual SIMD intrinsics when necessary. - TensorPrimitives API reference: Complete tables for reductions, element-wise transforms, two-span operations, and fused three-span operations like AddMultiply and FusedMultiplyAdd. - Manual SIMD patterns: Three-tier Vector512/Vector256/Vector128 dispatch, unsigned range validation, nibble-lookup character counting, and cross-type widening/narrowing conversions. - Use Case: Given a scalar loop that validates whether all bytes in a buffer fall within a range, the Skill rewrites it using Vector128 unsigned comparison tricks with a scalar fallback, preserving the original method signature. ## Quick Start Optimize the scalar loop in my .NET 8 project that sums a float array using SIMD vectorization.