mul#

Performs element by element multiplication of vector a and vector b.

Syntax

Buffer API:

namespace oneapi::math::vm {

sycl::event mul(
        sycl::queue& exec_queue,
        std::int64_t n,
        sycl::buffer<T,1>& a,
        sycl::buffer<T,1>& b,
        sycl::buffer<T,1>& y,
        oneapi::math::vm::mode mode = oneapi::math::vm::mode::not_defined,
        oneapi::math::vm::error_handler<T> errhandler = {});

} // namespace oneapi::math::vm

USM API:

namespace oneapi::math::vm {

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

} // namespace oneapi::math::vm

mul supports the following precisions.

T
`float`
`double`
`std::complex<float>`
`std::complex<double>`

Description

The mul(a, b) function performs element by element multiplication of vector a and vector b.

Argument 1	Argument 2	Result
+0	+0	+0
+0	-0	-0
-0	+0	-0
-0	-0	+0
+0	+∞	QNAN
+0	-∞	QNAN
-0	+∞	QNAN
-0	-∞	QNAN
+∞	+0	QNAN
+∞	-0	QNAN
-∞	+0	QNAN
-∞	-0	QNAN
+∞	+∞	+∞
+∞	-∞	-∞
-∞	+∞	-∞
-∞	-∞	+∞
SNAN	any value	QNAN
any value	SNAN	QNAN
QNAN	non-SNAN	QNAN
non-SNAN	QNAN	QNAN

Specifications for special values of the complex functions are defined according to the following formula

mul(x1+i*y1, x2+i*y2) = (x1*x2-y1*y2) + i*(x1*y2+y1*x2)

Overflow in a complex function occurs (supported in the HA/LA accuracy modes only) when all RE(x), RE(y), IM(x), IM(y) arguments are finite numbers, but the real or imaginary part of the computed result is so large that it does not fit the target precision. In this case, the function returns ∞ in that part of the result, and sets the VM status code to oneapi::math::vm::status::overflow (overriding any possible oneapi::math::vm::status::accuracy_warning status).

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 oneapi::math::vm::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 oneapi::math::vm::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): Event, signifying availability of computed output and status code(s).

Exceptions

For list of generated exceptions please refer to Exceptions

Parent topic: VM Mathematical Functions