src/uni20/backend/blas

This directory contains BLAS discovery and backend-library integration. It owns vendor selection, integer-width configuration, link flags, and the raw BLAS interface targets used by higher layers. LAPACK provider declarations live in the sibling `lapack/` directory.

Contents

• backend_blas.hpp: aggregate include point for BLAS backend support.
• blas_int.hpp: shared checked and non-throwing conversion to the configured signed BLAS integer ABI.
• blas_vendor.*: detected BLAS vendor reporting.
• mplapack_binary128.hpp: binary128 hooks for MPLAPACK-backed scalar support.
• `reference/`: raw configured-provider BLAS declarations and interface target.
• `mkl/`: MKL-specific target wiring.
• `openblas/`: OpenBLAS extension target wiring.

Notes

• This layer should expose external BLAS availability, not tensor or linalg policy.
• Keep LP64/ILP64 handling centralized here so callers do not duplicate BLAS integer assumptions.
• The generic BLAS wrappers are currently gated to the portable N/T/C GEMM transpose opcodes. Some providers expose a conjugate-no-transpose extension: OpenBLAS defines CblasConjNoTrans, and its develop-branch Fortran GEMM dispatcher recognizes R. This is a provider-specific fast path, not the baseline ABI contract. Higher linalg wrappers should decline direct no-copy conjugate-only complex GEMM until a prepared wrapper materializes the conjugated operand or an explicit backend extension handles it.

Related Documentation

• Backend source layer
• BLAS/LAPACK mdspan wrappers
• Mdspan linear algebra dispatch
• MPLAPACK binary128