Developer Reference for Intel® oneAPI Math Kernel Library for C
v?Log2
Computes the base 2 logarithm of vector elements.
Syntax
vhLog2 (n, a, y);
vhLog2I(n, a, inca, y, incy);
vmhLog2 (n, a, y, mode);
vmhLog2I(n, a, inca, y, incy, mode);
vsLog2 (n, a, y);
vsLog2I(n, a, inca, y, incy);
vmsLog2 (n, a, y, mode);
vmsLog2I(n, a, inca, y, incy, mode);
vdLog2 (n, a, y);
vdLog2I(n, a, inca, y, incy);
vmdLog2 (n, a, y, mode);
vmdLog2I(n, a, inca, y, incy, mode);
Include Files
- mkl.h
 
Input Parameters
Name  |  
      Type  |  
      Description  |  
     
|---|---|---|
n  |  
      const MKL_INT  |  
      Specifies the number of elements to be calculated.  |  
     
a  |  
      const _Float16* for vhLog2 const float* for vsLog2 const _Float16* for vmhLog2 const float* for vmsLog2 const double* for vdLog2 const double* for vmdLog2  |  
      Pointer to the array containing the input vector a.  |  
     
inca, incy  |  
      const MKL_INT  |  
      Specifies increments for the elements of a and y.  |  
     
mode  |  
      const MKL_INT64  |  
      Overrides the global VM mode setting for this function call. See vmlSetMode for possible values and their description.  |  
     
Output Parameters
Name  |  
      Type  |  
      Description  |  
     
|---|---|---|
y  |  
      _Float16* for vhLog2 float* for vsLog2 _Float16* for vmhLog2 float* for vmsLog2 double* for vdLog2 double* for vmdLog2  |  
      Pointer to an array containing the output vector y.  |  
     
Description
The v?Log2 function computes the base 2 logarithm of vector elements.
See Special Value Notations for the conventions used in this table:
| Argument | Result | VM Error Status | Exception | 
|---|---|---|---|
| +1 | +0 | ||
| x < +0 | QNAN | VML_STATUS_ERRDOM | INVALID | 
| +0 | -∞ | VML_STATUS_SING | ZERODIVIDE | 
| -0 | -∞ | VML_STATUS_SING | ZERODIVIDE | 
| -∞ | QNAN | VML_STATUS_ERRDOM | INVALID | 
| +∞ | +∞ | ||
| QNAN | QNAN | ||
| SNAN | QNAN | INVALID |