devsim-openblas

Run DEVSIM on the OpenBLAS that NumPy and SciPy ship, so pip install devsim devsim-openblas gives a working DEVSIM on Linux, macOS and Windows with no system BLAS/LAPACK and no Intel MKL.

import devsim_openblas

devsim_openblas.configure()  # before the first `import devsim`
import devsim

Why

DEVSIM loads BLAS/LAPACK at import time from whatever DEVSIM_MATH_LIBS names, falling back to Intel MKL or a system libopenblas. Pip alone cannot provide either on every platform: MKL wheels cover Linux x86_64 and Windows x64 only (and DEVSIM does not load MKL on macOS), while the portable OpenBLAS wheel, scipy-openblas32, prefixes its symbols (scipy_dgetrf_), so DEVSIM cannot find them.

This package ships a small shim library that exports, under their plain names, the 16 routines DEVSIM and its UMFPACK solver look up, and forwards each to its scipy_-prefixed counterpart:

• LAPACK and BLAS-1, loaded by DEVSIM: dgetrf_ dgetrs_ zgetrf_ zgetrs_ drotg_ zrotg_
• BLAS-2/3, loaded by the UMFPACK direct solver: dgemm_ dgemv_ dger_ dtrsm_ dtrsv_ and zgemm_ zgemv_ zgeru_ ztrsm_ ztrsv_

configure() loads OpenBLAS behind the shim and sets DEVSIM_MATH_LIBS to the shim, overriding any value already set. It must run before DEVSIM is imported, because DEVSIM reads the variable once. MKL PARDISO is not available through the shim; DEVSIM's UMFPACK and SuperLU solvers are.

devsim_openblas.calls() reports how many times DEVSIM has called each forwarded routine, which is handy to check the shim is in use.

Platforms

Wheels are built and tested in CI on every platform DEVSIM publishes wheels for: Linux x86_64 and aarch64, macOS arm64 and Windows x64. One wheel per platform serves every Python 3 version.

Status

This is a stopgap. A fallback that lets DEVSIM load scipy-openblas32 directly has been proposed upstream in devsim/devsim#167; once a DEVSIM release includes it, this package is no longer needed.