getrf (USM Version)

Computes the LU factorization of a general m-by-n matrix. This routine belongs to the oneapi::mkl::lapacknamespace.


cl::sycl::event getrf(cl::sycl::queue &queue, std::int64_t m, std::int64_t n, T *a, std::int64_t lda, std::int64_t *ipiv, T *scratchpad, std::int64_t scratchpad_size, const cl::sycl::vector_class<cl::sycl::event> &events = {})

getrf (USM version) supports the following precisions and devices:


Devices supported


Host, CPU, GPU


Host, CPU, GPU


Host, CPU, GPU


Host, CPU, GPU


The routine computes the LU factorization of a general m-by-n matrix A as

A = P*L*U,

where P is a permutation matrix, L is lower triangular with unit diagonal elements (lower trapezoidal if m > n) and U is upper triangular (upper trapezoidal if m < n). The routine uses partial pivoting, with row interchanges.

Input Parameters


Device queue where calculations will be performed.


The number of rows in the matrix A (0≤m).


The number of columns in the matrix A (0≤n).


Pointer to the array holding input matrix A. The second dimension of a must be at least max(1, n).


The leading dimension of a.


Pointer to scratchpad memory to be used by the routine for storing intermediate results.


Size of scratchpad memory as a number of floating point elements of type T. Size should not be less than the value returned by the getrf_scratchpad_size function.


List of events to wait for before starting computation. Defaults to empty list.

Output Parameters


Overwritten by L and U. the unit diagonal elements of L are not stored.


Array, size at least max(1,min(m,n)).

Contains the pivot indices; for 1 i min(m,n), row i was interchanged with row ipiv(i).



This exception is thrown when problems occur during calculations. You can obtain the info code of the problem using the info() method of the exception object: If info = -i, the i-th parameter had an illegal value. If info = i, uii is 0. The factorization has been completed, but U is exactly singular. Division by 0 will occur if you use the factor U for solving a system of linear equations. If info is equal to the value passed as scratchpad size, and detail() returns non zero, then the passed scratchpad has an insufficient size, and the required size should not be less than the value returned by the detail() method of the exception object.

Return Values

Output event to wait on to ensure computation is complete.