getri_batch (Group Version)#

Computes the batch of inverses of an LU-factored general matrices determined by the getrf_batch (Group Version) function. This routine belongs to the oneapi::mkl::lapack namespace.

Description#

The routine computes the inverses A i-1 of a general matrices A i, iϵ{1...batch_size}. Before calling this routine, call getrf_batch (Group Version) function to factorize A i.

The total number of problems to solve, batch_size, is a sum of sizes of all of the groups of parameters as provided by group_sizesarray.

API#

Syntax#

namespace oneapi::mkl::lapack {
  sycl::event getri_batch(sycl::queue &queue,
  int64_t *n,
  T **a,
  int64_t *lda,
  const int64_t * const *ipiv,
  int64_t group_count,
  int64_t *group_sizes,
  T *scratchpad,
  int64_t scratchpad_size,
  const std::vector<sycl::event> &events = {})
}

This function supports the following precisions and devices:

T

Devices supported

float

CPU and GPU

double

CPU and GPU

std::complex<float>

CPU and GPU

std::complex<double>

CPU and GPU

Input Parameters#

queue

Device queue where calculations will be performed.

n

Array of group_count parameters ng specifying the order of the matrices Ai belonging to group g (ng ≥ 0).

a

Result of the getrf_batch (Group Version) function. The pointers must be device-accessible.

lda

Array of group_count parameters ldag specifying the leading dimension of Ai belonging to group g (ldagmax(1, ng)).

ipiv

The array as returned by getrf_batch (Group Version). The pointers must be device-accessible.

group_count

Specifies the number of groups of parameters. Must be at least 0.

group_sizes

Array of group_count integers. Array element with index g specifies the number of problems to solve for each of the groups of parameters g. So the total number of problems to solve, batch_size, is a sum of all parameter group sizes.

scratchpad

Scratchpad memory to be used by routine for storing intermediate results.

scratchpad_size

Size of scratchpad memory as a number of floating point elements of type T. Size should not be less then the value returned by getri_batch_scratchpad_size (Group Version).

events

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

Output Parameters#

a

Overwritten by the ng-by-ng matrices Ai-1.

Exceptions#

Exception

Description

mkl::lapack::batch_exception

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 = -n, the n-th parameter had an illegal value.

If info equals the value passed as scratchpad size, and detail() returns non-zero, then the passed scratchpad is of insufficient size, and the required size should be not less then value returned by the detail() method of the exception object.

Return Values#

Output event to wait on to ensure computation is complete.