Developer Reference

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gesvd_scratchpad_size

Computes size of scratchpad memory required for
gesvd
(USM Version) function. This routine belongs to the
oneapi::mkl::lapack
namespace.

Description

Computes the number of elements of type T the scratchpad memory to be passed to the
gesvd
(buffer or USM version) function should be able to hold.

API

Syntax
namespace oneapi::mkl::lapack { template<typename T> std::int64_t gesvd_scratchpad_size(cl::sycl::queue &queue, mkl::jobsvd jobu, mkl::jobsvd jobvt, std::int64_t m, std::int64_t n, std::int64_t lda, std::int64_t ldu, std::int64_t ldvt) }
Input Parameters
queue
Device queue where calculations by the gesvd (buffer or USM version) function will be performed.
jobu
Must be
jobsvd::vectors
,
jobsvd::somevec
,
jobsvd::vectorsina
, or
jobsvd::novec
. Specifies options for computing all or part of the matrix
U
.
If
jobu = jobsvd::vectors
, all
m
columns of
U
are returned in the array u;
if
jobu = jobsvd::somevec
, the first
min(m, n)
columns of
U
(the left singular vectors) are returned in the array u;
if
jobu = jobsvd::vectorsina
, the first
min(m, n)
columns of
U
(the left singular vectors) are overwritten on the array a;
if
jobu = jobsvd::novec
, no columns of
U
(no left singular vectors) are computed.
jobvt
Must be
jobsvd::vectors, jobsvd::somevec
,
jobsvd::vectorsina
, or
jobsvd::novec
. Specifies options for computing all or part of the matrix
VT/VH
.
If
jobvt = jobsvd::vectors
, all n columns of
VT/VH
are returned in the array vt;
if
jobvt = jobsvd::somevec
, the first
min(m, n)
columns of
VT/VH
(the left singular vectors) are returned in the array vt;
if
jobvt = jobsvd::vectorsina
, the first
min(m, n)
columns of
VT/VH
(the left singular vectors) are overwritten on the array a;
if
jobvt = jobsvd::novec
, no columns of
VT/VH
(no left singular vectors) are computed.
jobvt and jobu cannot both be
job::overwritevec
.
m
The number of rows in the matrix
A
(
0≤m
).
n
The number of columns in the matrix
A
(
0≤n
).
lda
The leading dimension of a.
ldu
The leading dimension of u.
ldvt
The leading dimension of vt.
Exceptions
Exception
Description
mkl::lapack::exception
This exception is thrown when an incorrect argument value is supplied. You can determine the position of the incorrect argument by the get_info() method of the exception object.
Return Values
The number of elements of type
T
the scratchpad memory to be passed to the
gesvd
(buffer or USM version) function should be able to hold.

Product and Performance Information

1

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