_SHR
From QB64.org wiki
The _SHR function is used to shift the bits of a numerical value to the right.
Syntax
- result = _SHR(numericalVariable, numericalValue)
Parameters
- numericalVariable is the variable to shift the bits of and can be of the following types: INTEGER, LONG, _INTEGER64, or _BYTE.
- Integer values can be signed or _UNSIGNED.
- numericalValue the number of places to shift the bits.
- While 0 is a valid value it will have no affect on the variable being shifted.
Description
- Allows for division of a value by 2 faster than normal division (see example 2 below).
- Bits that reach the end of a variables bit count are dropped.
- The type of variable used to store the results should match the type of the variable being shifted.
- NOTE: When dealing with SIGNED variables, shifting the bits right will leave the sign bit set. This is due to how C++ deals with bit shifting under the hood.
Availability
- Version 1.3 and up.
Examples
Example 1:
A~%% = 128 'set left most bit of an_UNSIGNED _BYTE PRINT A~%% PRINT _SHR(A~%%,7) PRINT _SHR(A~%%,8) 'shift the bit off the right 'edge'
128 1 0
Example 2:
A~%% = 128 FOR I%% = 0 TO 8 PRINT _SHR(A~%%, I%%) NEXT I%%
128 64 32 16 8 4 2 1 0
See also