Developer Reference

  • 2021.1
  • 12/04/2020
  • Public Content
Contents

v?Logb

Computes the exponents of the elements of input vector
a
.

Syntax

vsLogb
(
n
,
a
,
y
);
vsLogbI(n, a, inca, y, incy);
vmsLogb
(
n
,
a
,
y
,
mode
);
vmsLogbI(n, a, inca, y, incy, mode);
vdLogb
(
n
,
a
,
y
);
vdLogbI(n, a, inca, y, incy);
vmdLogb
(
n
,
a
,
y
,
mode
);
vmdLogbI(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 float*
for
vsLogb
const float*
for
vmsLogb
const double*
for
vdLogb
const double*
for
vmdLogb
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
float*
for
vsLogb
float*
for
vmsLogb
double*
for
vdLogb
double*
for
vmdLogb
Pointer to an array containing the output vector
y
.
Description
The
v?Logb
function computes the exponents of the elements of the input vector
a
. For each element
a
i
of vector
a
, this is the integral part of log
2
|
a
i
|. 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:
Special values for Real Function
v?Logb(x)
Argument
Result
VM Error Status
Exception
+0
-
VML_STATUS_ERRDOM
ZERODIVIDE
-0
-
VML_STATUS_ERRDOM
ZERODIVIDE
-
+
+
+
QNAN
QNAN
SNAN
QNAN
INVALID

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.