Developer ports Intel SSE intrinsics to ARM NEON, documents real-world porting challenges

A developer ported a deliberately x86-specific C project using Intel SSE intrinsics to ARM64 NEON using a tool called Miruri. Rather than simply replacing intrinsic names one-for-one, the porting process produced a structured result with three separate backends: SSE for x86, NEON for ARM64, and a scalar C fallback for other architectures. The exercise highlighted that real porting work goes beyond mapping function names and involves compiler flags, floating-point semantics, and build-system assumptions. Notably, the tool preserved separate multiply and add operations instead of collapsing them into a fused multiply-add, which would alter floating-point rounding behavior. The developer noted that while compatibility layers like sse2neon suit large codebases, explicit per-architecture implementations are preferable for smaller libraries.