logbf

Applicability

Function Usage

Computes the logarithm of the input data with base 2, rounds down the result, and returns a floating-point number.

Prototype

1

inline float logbf(float x)

Parameters

Returns

Rounded-down value of the logarithm of x with base 2 and rounded down.

• If x is inf, the return value is inf.
• If x is -inf, the return value is inf.
• If x is nan, the return value is nan.
• If x is 0, the return value is -inf.

Restrictions

For SIMT programming, this API is not supported.

Header File to Be Included

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

1

#include "simt_api/math_functions.h"

Examples

1
2
3
4
5

__simt_vf__ __launch_bounds__(1024) inline void KernelLogb(__gm__ float* dst, __gm__ float* x)
{
    int idx = threadIdx.x + blockIdx.x * blockDim.x;
    dst[idx] = logbf(x[idx]);
}