Intel® oneAPI Math Kernel Library (oneMKL) - Data Parallel C++ Developer Reference

Developer Reference

Contents

getri

Computes the inverse of an LU-factored general matrix determined by getrf. This routine belongs to the
oneapi::mkl::lapack
 namespace.

Description

The routine computes the inverse
inv(A)
 of a general matrix
A
. Before calling this routine, call getrf to factorize
A
.

API

Syntax
 namespace oneapi::mkl::lapack {
   void getri(cl::sycl::queue &queue,
   std::int64_t n,
   cl::sycl::buffer<T> &a,
   std::int64_t lda,
   std::int64_t *ipiv,
   cl::sycl::buffer<T> &scratchpad, std::int64_t scratchpad_size)
}
getri
 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
The order of the matrix
A
(0≤n)
.
a
The buffer returned by getrf. Must be of size at least
lda*max(1,n)
.
lda
The leading dimension of a
(n≤lda)
.
ipiv
The array as returned by getrf. The dimension of ipiv must be at least
max(1, n)
.
scratchpad
Pointer to scratchpad memory to be used by the 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 than the value returned by the getri_scratchpad_size function.
Output Parameters
a
Overwritten by the n-by-n matrix
A
.
Exceptions
Exception
Description
mkl::lapack::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 = -i
, the
i
-th parameter had an illegal value.
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.
Known Limitations
  • GPU support is for only real precisions.
  • For GPU support, errors are reported through the
    info
     parameter, but computation does not halt for an algorithmic error.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.