trunc#

Computes the element-wise rounding of vector elements to the nearest integer towards zero.

Description#

The trunc(a) function computes an integer value rounded towards zero for each vector element.

\[ \begin{align}\begin{aligned}a_i \geq 0, y_i = \lfloor a_i \rfloor\\a < 0, y_i = \lceil a_i \rceil\end{aligned}\end{align} \]

Argument

Result

Error Code

+0

+0

-0

-0

+\(\infty\)

+\(\infty\)

-\(\infty\)

-\(\infty\)

QNAN

QNAN

SNAN

QNAN

The trunc function does not generate any errors.

API#

Syntax#

Buffer API

namespace oneapi::mkl::vm {

sycl::event trunc(sycl::queue & exec_queue,
      std::int64_t n,
      sycl::buffer<T> & a,
      sycl::buffer<T> & y,
      oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined);

}
namespace oneapi::mkl::vm {

sycl::event trunc(sycl::queue & exec_queue,
      sycl::buffer<T> & a,
      oneapi::mkl::slice sa,
      sycl::buffer<T> & y,
      oneapi::mkl::slice sy,
      oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined);

}

USM API

namespace oneapi::mkl::vm {

sycl::event trunc(sycl::queue & exec_queue,
      std::int64_t n,
      T const * a,
      T * y,
      std::vector<sycl::event> const & depends = {},
      oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined);

}
namespace oneapi::mkl::vm {

sycl::event trunc(sycl::queue & exec_queue,
      T const * a,
      oneapi::mkl::slice sa,
      T * y,
      oneapi::mkl::slice sy,
      std::vector<sycl::event> const & depends = {},
      oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined);

}

trunc supports the following precisions and devices:

T

Devices supported

sycl::half

GPU

_Float16

CPU

float

CPU and GPU

double

CPU and GPU

Input Parameters#

Buffer API

exec_queue

The queue where the routine will be executed.

n

Specifies the number of elements to be calculated.

a

The buffer containing the input vector.

sa

Slice selector for a. See Data Types for a description of the oneMKL slice type.

sy

Slice selector for y. See See Data Types for a description of the oneMKL slice type.

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.

USM API

exec_queue

The queue where the routine will be executed.

n

Specifies the number of elements to be calculated.

a

Pointer to the input vector.

sa

Slice selector for a. See Data Types for a description of the oneMKL slice type.

sy

Slice selector for y. See Data Types for a description of the oneMKL slice type.

depends

Vector of dependent events (to wait for input data to be ready). This is an optional parameter. The default is an empty vector.

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.

Output Parameters#

Buffer API

y

The buffer containing the output vector.

return value (event)

Computation end event.

USM API

y

Pointer to the output vector.

return value (event)

Computation end event.

Examples#

An example of how to use trunc can be found in the oneMKL installation directory, under:

share/doc/mkl/examples/sycl/vml/source/vtrunc.cpp