powr

Computes a to the power b for elements of two vectors, where the elements of vector argument a are all non-negative.

Syntax

Buffer API:

void powr(queue &exec_queue, int64_t n, buffer<T, 1> &a, buffer<T, 1> &b, buffer<T, 1> &y, uint64_t mode = mode::not_defined, error_handler<T> errhandler = {})

USM API:

event powr(queue &exec_queue, int64_t n, T *a, T *b, T *y, vector_class<event> const &depends = {}, uint64_t mode = mode::not_defined, error_handler<T> errhandler = {})

powr supports the following precisions and devices:

T

Devices supported

float

Host, CPU, and GPU

double

Host, CPU, and GPU

Description

The powr(a,b) function raises each element of vector a by the corresponding element of vector b. The elements of a are all nonnegative (ai≥ 0).

Data Type

Threshold Limitations on Input Parameters

single precision

ai < (FLT_MAX)1/``b`i`

double precision

ai < (DBL_MAX)1/``b`i`

Special values and VM Error Status treatment for v?Powr function are the same as for pow, unless otherwise indicated in this table:

Argument 1

Argument 2

Result

Error Code

a < 0

any value b

NAN

status::errdom

0 < a < ∞

±0

1

±0

-∞ < b < 0

+∞

±0

-∞

+∞

±0

b > 0

+0

1

-∞ < b < ∞

1

±0

±0

NAN

+∞

±0

NAN

1

+∞

NAN

a≥ 0

NAN

NAN

NAN

any value b

NAN

0 < a <1

-∞

+∞

a > 1

-∞

+0

0 ≤a < 1

+∞

+0

a > 1

+∞

+∞

+∞

b < +0

+0

+∞

b > +0

+∞

QNAN

QNAN

QNAN

status::errdom

QNAN

SNAN

QNAN

status::errdom

SNAN

QNAN

QNAN

status::errdom

SNAN

SNAN

QNAN

status::errdom

Input Parameters

Buffer API:

exec_queue

The queue where the routine should be executed.

n

Specifies the number of elements to be calculated.

a

The buffer a containing 1st input vector of size n.

b

The buffer b containing 2nd input vector of size n.

mode

Overrides the global VM mode setting for this function call. See set_mode function for possible values and their description. This is an optional parameter. The default value is mode::not_defined.

errhandler

Sets local error handling mode for this function call. See the create_error_handler function for arguments and their descriptions. This is an optional parameter. The local error handler is disabled by default.

USM API:

exec_queue

The queue where the routine should be executed.

n

Specifies the number of elements to be calculated.

a

Pointer a to the 1st input vector of size n.

b

Pointer b to the 2nd input vector of size n.

depends

Vector of dependent events (to wait for input data to be ready).

mode

Overrides the global VM mode setting for this function call. See the set_mode function for possible values and their description. This is an optional parameter. The default value is mode::not_defined.

errhandler

Sets local error handling mode for this function call. See the create_error_handler function for arguments and their descriptions. This is an optional parameter. The local error handler is disabled by default.

Output Parameters

Buffer API:

y

The buffer y containing the output vector of size n.

USM API:

y

Pointer y to the output vector of size n.

return value (event)

Function end event.

Example

An example of how to use powrcan be found in the Intel® oneMKL installation directory, under:

examples/sycl/vml/vpowr.cpp