ISHFT Function

Performs the bit shift operation on bytes, integers, and longwords.

result = ISHFT(p₁, p₂)

p₁ The scalar or array to be shifted.

p₂ The scalar containing the number of bit positions and direction of the shift.

result The shifted scalar or array value.

None.

If p₂ is positive, p₁ is left-shifted p₂ bit positions, with 0 bits filling vacated positions. If p₂ is negative, p₁ is right-shifted, again with 0 bits filling vacated positions.

In this example, ISHFT is used to multiply and divide each element of a five-element vector by powers of 2.

a = BYTARR(5)

; Create and initialize a five-element byte array.

FOR i = 0, 4 DO a(i) = 4 * i
PRINT, a

0     4     8     12     16

PRINT, a, ISHFT(a, -2)

0     4     8     12     16
0     1     2     3      4

; Divide each element of A by 4.

PRINT, a, ISHFT(a, 1)

0     4       8     12     16
0     8      16     24     32

; Multiply each element of A by 2.

SHIFT