__mul64hi

Applicability

Product	Supported
Atlas 350 Accelerator Card	√
Atlas A3 training product/Atlas A3 inference product	x
Atlas A2 training product/Atlas A2 inference product	x
Atlas 200I/500 A2 inference product	x
Atlas inference product AI Core	x
Atlas inference product Vector Core	x
Atlas training product	x

Function Usage

Obtains the upper 64 bits of the product of two int64 inputs, x and y.

$\text{[math]}$

Prototype

long long __mul64hi(long long x, long long y)

Parameters

**Table 1** Parameters
Parameter	Input/Output	Description
x	Input	Source operand, multiplier.
y	Input	Source operand, multiplier.

Returns

The upper 64 bits of the product of two int64 inputs, x and y.

Restrictions

For SIMT programming, this API is not supported.

Header File to Be Included

To use this API, the simt_api/device_functions.h header file must be included.

Examples

For SIMD and SIMT programming:

__simt_vf__ __launch_bounds__(1024) inline void KernelMul64hi(__gm__ long long* dst, __gm__ long long* x,  __gm__ long long* y)
{
    int idx = threadIdx.x + blockIdx.x * blockDim.x;
    dst[idx] = __mul64hi(x[idx], y[idx]);
}

Parent topic: Mathematical Functions