vlog2 - Vector binary logarithm log2(x)

8.8 vlog2 - Vector binary logarithm $log2(x)$

subroutine vlog2 (n, y, incy, x, incx); 
subroutine vlog2f(n, y, incy, x, incx); 
 
subroutine vlog2_64 (n, y, incy, x, incx); 
subroutine vlog2f_64(n, y, incy, x, incx);

Given an input vector $x$ and a result vector $y$ , this function computes:

y =log (x) 2

8.8.1 Parameters

N - INTEGER: ENTRY: Number of elements of $x$ and $y$ .
CONSTRAINT: $n ≥1$ .
Y - ARRAY OF REAL: EXIT: Result vector $y$ .
CONSTRAINT: Must contain $n× incy$ elements.
CONSTRAINT: Must not overlap with array $x$ .
INCY - INTEGER: ENTRY: Stride for the vector $y$ .
CONSTRAINT: $incy̸= 0$ .
BEHAVIOR: A negative stride will traverse the array in reverse.
X - ARRAY OF REAL: ENTRY: Input vector $x$ .
CONSTRAINT: Must contain $n× incx$ elements.
CONSTRAINT: Must not overlap with array $y$ .
INCX - INTEGER: ENTRY: Stride for the vector $x$ .
CONSTRAINT: $incx̸= 0$ .
BEHAVIOR: A negative stride will traverse the array in reverse.

[next] [prev] [prev-tail] [front] [up]