Developer Reference for Intel® oneAPI Math Kernel Library for Fortran
v?InvSqrt
vsInvSqrt vdInvSqrt vmsInvSqrt vmdInvSqrt Computes an inverse square root of vector elements.
Syntax
call vsinvsqrt ( n , a , y )
call vsinvsqrti(n, a, inca, y, incy)
call vmsinvsqrt ( n , a , y , mode )
call vmsinvsqrti(n, a, inca, y, incy, mode)
call vdinvsqrt ( n , a , y )
call vdinvsqrti(n, a, inca, y, incy)
call vmdinvsqrt ( n , a , y , mode )
call vmdinvsqrti(n, a, inca, y, incy, mode)
Include Files
mkl_vml.f90
Input Parameters
Name |
Type |
Description |
|---|---|---|
n |
Specifies the number of elements to be calculated. |
|
a |
Fortran 77: DOUBLE PRECISION for vdinvsqrt , vmdinvsqrtFortran 90: REAL , INTENT(IN) for vsinvsqrt , vmsinvsqrtFortran 90: DOUBLE PRECISION , INTENT(IN) for vdinvsqrt , vmdinvsqrt |
Array that specifies the input vector a . |
inca , incy |
INTEGER, INTENT(IN) |
Specifies increments for the elements of a and y . |
mode |
INTEGER(KIND=8) , INTENT(IN) |
Overrides global VM mode setting for this function call. See vmlSetMode (Sets a new mode for VM functions according to the mode parameter and stores the previous VM mode to oldmode.) for possible values and their description. |
Output Parameters
Name |
Type |
Description |
|---|---|---|
y |
Fortran 77: DOUBLE PRECISION for vdinvsqrt , vmdinvsqrtFortran 90: REAL , INTENT(OUT) for vsinvsqrt , vmsinvsqrtFortran 90: DOUBLE PRECISION , INTENT(OUT) for vdinvsqrt , vmdinvsqrt |
Array that specifies the output vector y . |
Description
The v?InvSqrt function computes an inverse square root of vector elements.
Special Values for Real Function v?InvSqrt(x)
Argument |
Result |
VM Error Status |
Exception |
|---|---|---|---|
X < +0 |
QNAN |
VML_STATUS_ERRDOM |
INVALID |
+0 |
|
VML_STATUS_SING |
ZERODIVIDE |
-0 |
|
VML_STATUS_SING |
ZERODIVIDE |
|
QNAN |
VML_STATUS_ERRDOM |
INVALID |
|
+0 |
||
QNAN |
QNAN |
||
SNAN |
QNAN |
INVALID |