Intel® Math Kernel Library 2018 Developer Reference - C
Computes the exponents of the elements of input vector a.
vsLogb (n, a, y);
vmsLogb (n, a, y, mode);
vdLogb (n, a, y);
vmdLogb (n, a, y, mode);
Name |
Type |
Description |
---|---|---|
n |
const MKL_INT |
Specifies the number of elements to be calculated. |
a |
const float* for vsLogb const float* for vmsLogb const double* for vdLogb const double* for vmdLogb |
Pointer to the array containing the input vector a. |
mode |
const MKL_INT64 |
Overrides the global VM mode setting for this function call. See vmlSetMode for possible values and their description. |
Name |
Type |
Description |
---|---|---|
y |
float* for vsLogb float* for vmsLogb double* for vdLogb double* for vmdLogb |
Pointer to an array containing the output vector y. |
The v?Logb function computes the exponents of the elements of the input vector a. For each element ai of vector a, this is the integral part of log2|ai|. The returned value is exact and is independent of the current rounding direction mode.
See Special Value Notations for the conventions used in this table:
Argument | Result | VM Error Status | Exception |
---|---|---|---|
+0 | -∞ | VML_STATUS_ERRDOM | ZERODIVIDE |
-0 | -∞ | VML_STATUS_ERRDOM | ZERODIVIDE |
-∞ | +∞ | ||
+∞ | +∞ | ||
QNAN | QNAN | ||
SNAN | QNAN | INVALID |