.rst .pdf

Contents

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 A₁^-1 of a general matrices A₁, iϵ{1...batch_size}. Before calling this routine, call getrf_batch (Group Version) function to factorize A₁.

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

Function supports the following precisions and devices.

T	Devices supported
float	Host, CPU, and GPU
double	Host, CPU, and GPU
std::complex<float>	Host, CPU, and GPU
std::complex<double>	Host, CPU, and GPU

Input Parameters

queue

Device queue where calculations will be performed.

n

Array of group_count parameters n_g specifying the order of the matrices A_i (0 ≤ n_g) belonging to group g.

a

Result of the getrf_batch (Group Version) function

lda

Array of group_count parameters lda_g specifying the leading dimension of A_i (n_g ≤ lda_g) belonging to group g.

ipiv

The array as returned by getrf_batch (Group Version).

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 n_g-by-n_g matrices A_i^-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.

getri (USM Version) getri_batch (USM Strided Version)