Visible to Intel only — GUID: GUID-42F2398B-94C3-45CD-8F20-C823CF830DDA

Visible to Intel only — GUID: GUID-42F2398B-94C3-45CD-8F20-C823CF830DDA

## Functions Threaded with Intel® Threading Building Blocks

In this section, `?` stands for a precision prefix or suffix of the routine name and may have the value of `s, d, c`, or `z`.

The following Intel® oneAPI Math Kernel Library function domains are threaded with Intel® Threading Building Blocks (oneTBB):

LAPACK.

For a list of threaded routines, see LAPACK Routines.

Entire Level3 BLAS.

Level2 BLAS – ?GEMV.

Fast Poisson, Laplace, and Helmholtz Solver (Poisson Library).

All Vector Mathematics functions (except service functions).

Intel® oneAPI Math Kernel Library PARDISO, a direct sparse solver based on Parallel Direct Sparse Solver (PARDISO*).

For details, see oneMKL PARDISO Steps.

Sparse BLAS.

For a list of threaded routines, see Sparse BLAS Routines.

Product and Performance Information |
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Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex. Notice revision #20201201 |

### LAPACK Routines

The following LAPACK routines are threaded with oneTBB:

?geqrf, ?gelqf, ?getrf, ?potrf, ?unmqr*, ?ormqr*, ?unmrq*, ?ormrq*, ?unmlq*, ?ormlq*, ?unmql*, ?ormql*, ?sytrd, ?hetrd, ?syev, ?heev, and ?latrd.

A number of other LAPACK routines, which are based on threaded LAPACK or BLAS routines, make effective use of oneTBB threading:

?getrs, ?gesv, ?potrs, ?bdsqr, and ?gels.

### oneMKL PARDISO Steps

Intel® oneAPI Math Kernel Library PARDISO is threaded with oneTBB in the reordering and factorization steps. However, routines performing the solving step are still called sequentially when using oneTBB.

### Sparse BLAS Routines

The Sparse BLAS inspector-executor application programming interface routines mkl_sparse_?_mv are threaded with oneTBB for the general compressed sparse row (CSR) and block sparse row (BSR) formats.

The following Sparse BLAS inspector-executor application programming routines are threaded with oneTBB:

mkl_sparse_?_mv using the general compressed sparse row (CSR) and block sparse row (BSR) matrix formats.

mkl_sparse_?_mm using the general CSR sparse matrix format and both row and column major storage formats for the dense matrix.

**Parent topic:**Improving Performance with Threading