SHL and SHR

SHL and SHR

Bit Shift Instructions

Syntax

 <expr> SHL <distance>

 <expr> SHR <distance>

Bit shifts <expr> expression by <distance> bits to the left (SHL) or to the right (SHR). SHR can be replaced by >> and SHL by << for more legibility.

The argument should be of an integer type: uByte, Byte, uInteger, Integer, uLong or Long. Use of bitshifting with fixed and float gives undefined results. CAST or INT should be used to convert floating point numbers into integer type numbers before use of the bit shift instructions.

Owing to the nature of moving bits right and left, SHL n is the equivalent of a multiply by 2ⁿ, and SHR would be the equivalent of an integer division by 2ⁿ (destroying any fractional part).

Examples

PRINT 2 << 1: REM prints 4
PRINT 16 SHR 2: REM again 4

Remarks

• This function is not available in Sinclair BASIC.
• The syntax is similar to C’s << and >> operators.