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(Created page with "{{DISPLAYTITLE:_ROR}} The _SHR function is used to shift the bits of a numerical value to the right. {{PageSyntax}} :{{Parameter|result}} = _SHR({{Parameter|numericalVariable}}, {{Parameter|numericalValue}}) {{Parameters}} * {{Parameter|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. * {{Parameter|numericalValue}} t...")
 
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{{DISPLAYTITLE:_ROR}}
{{DISPLAYTITLE:_ROR}}
The [[_SHR]] function is used to shift the bits of a numerical value to the right.
The [[_ROR]] function is used to rotate the bits of a numerical value to the right. A rotation (or circular shift) is an operation similar to shift ([[_SHL]] and [[_SHR]]) except that the bits that fall off at one end are put back to the other end.




{{PageSyntax}}
{{PageSyntax}}
:{{Parameter|result}} = [[_SHR]]({{Parameter|numericalVariable}}, {{Parameter|numericalValue}})
:{{Parameter|result}} = [[_ROR]]({{Parameter|numericalVariable}}, {{Parameter|numericalValue}})




{{Parameters}}
{{PageParameters}}
* {{Parameter|numericalVariable}} is the variable to shift the bits of and can be of the following types: [[INTEGER]], [[LONG]], [[_INTEGER64]], or [[_BYTE]].
* {{Parameter|numericalVariable}} is the variable to shift the bits of and can be of the following types: [[_BYTE]], [[INTEGER]], [[LONG]], or [[_INTEGER64]].
* Integer values can be signed or [[_UNSIGNED]].
* Integer values can be signed or [[_UNSIGNED]].
* {{Parameter|numericalValue}} the number of places to shift the bits.
* {{Parameter|numericalValue}} is the number of places to rotate the bits.
* While 0 is a valid value it will have no affect on the variable being shifted.
* While 0 is a valid value it will have no affect on the variable being rotated.




{{PageDescription}}
{{PageDescription}}
* Allows for division of a value by 2 faster than normal division (see example 2 below).
* In right rotation, the bits that fall off at right end are put back at left end.
* 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.
* 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'''.
{{PageAvailability}}
* '''QB64-PE v3.1.0 and up'''




{{PageExamples}}
{{PageExamples}}
''Example 1:''
{{CodeStart}}
{{CodeStart}}A~%% = 128 'set left most bit of an{{Cl|_UNSIGNED}} {{Cl|_BYTE}}
{{Cl|OPTION _EXPLICIT}}
{{Cl|PRINT}} A~%%
 
{{Cl|PRINT}} {{Cl|_SHR}}(A~%%,7)
{{Cl|DIM}} a {{Cl|AS}} {{Cl|_UNSIGNED}} {{Cl|_BYTE}}
{{Cl|PRINT}} {{Cl|_SHR}}(A~%%,8) 'shift the bit off the right 'edge'
{{Cl|DIM}} b {{Cl|AS}} {{Cl|_UNSIGNED}} {{Cl|INTEGER}}
{{CodeEnd}}
{{Cl|DIM}} c {{Cl|AS}} {{Cl|_UNSIGNED}} {{Cl|LONG}}
{{OutputStart}}
{{Cl|DIM}} d {{Cl|AS}} {{Cl|_UNSIGNED}} {{Cl|_INTEGER64}}
128
 
1
a = &B11110000
0
b = &B1111111100000000
{{OutputEnd}}
c = &B11111111111111110000000000000000
d = &B1111111111111111111111111111111100000000000000000000000000000000
 
{{Cl|DO}}
    a = {{Cl|_ROR}}(a, 1)
    b = {{Cl|_ROR}}(b, 1)
    c = {{Cl|_ROR}}(c, 1)
    d = {{Cl|_ROR}}(d, 1)


    {{Cl|LOCATE}} 1, 1: {{Cl|PRINT}} {{Cl|RIGHT$}}({{Cl|STRING$}}(8, "0") + {{Cl|_BIN$}}(a), 8);
    {{Cl|LOCATE}} 2, 1: {{Cl|PRINT}} {{Cl|RIGHT$}}({{Cl|STRING$}}(16, "0") + {{Cl|_BIN$}}(b), 16);
    {{Cl|LOCATE}} 3, 1: {{Cl|PRINT}} {{Cl|RIGHT$}}({{Cl|STRING$}}(32, "0") + {{Cl|_BIN$}}(c), 32);
    {{Cl|LOCATE}} 4, 1: {{Cl|PRINT}} {{Cl|RIGHT$}}({{Cl|STRING$}}(64, "0") + {{Cl|_BIN$}}(d), 64);


''Example 2:''
    {{Cl|_LIMIT}} 15
{{CodeStart}}
{{Cl|LOOP}} {{Cl|WHILE}} {{Cl|_KEYHIT}} <> 27
A~%% = 128
{{Cl|FOR}} I%% = 0 {{Cl|TO}} 8
    {{Cl|PRINT}} {{Cl|_SHR}}(A~%%, I%%)
{{Cl|FOR...NEXT|NEXT}} I%%
{{CodeEnd}}
{{CodeEnd}}
{{OutputStart}}
 
128
  64
  32
  16
  8
  4
  2
  1
  0
{{OutputEnd}}


{{PageSeeAlso}}
{{PageSeeAlso}}
* [[_SHL]], [[INTEGER]], [[LONG]]
* [[_ROL]], [[_SHL]], [[_SHR]]
* [[_BYTE]], [[_INTEGER64]]
* [[_BYTE]], [[INTEGER]]
* [[LONG]], [[_INTEGER64]]




{{PageNavigation}}
{{PageNavigation}}

Latest revision as of 02:18, 24 January 2023

The _ROR function is used to rotate the bits of a numerical value to the right. A rotation (or circular shift) is an operation similar to shift (_SHL and _SHR) except that the bits that fall off at one end are put back to the other end.


Syntax

result = _ROR(numericalVariable, numericalValue)


Parameters

  • numericalVariable is the variable to shift the bits of and can be of the following types: _BYTE, INTEGER, LONG, or _INTEGER64.
  • Integer values can be signed or _UNSIGNED.
  • numericalValue is the number of places to rotate the bits.
  • While 0 is a valid value it will have no affect on the variable being rotated.


Description

  • In right rotation, the bits that fall off at right end are put back at left end.
  • The type of variable used to store the results should match the type of the variable being shifted.


Availability

  • QB64-PE v3.1.0 and up


Examples

OPTION _EXPLICIT

DIM a AS _UNSIGNED _BYTE
DIM b AS _UNSIGNED INTEGER
DIM c AS _UNSIGNED LONG
DIM d AS _UNSIGNED _INTEGER64

a = &B11110000
b = &B1111111100000000
c = &B11111111111111110000000000000000
d = &B1111111111111111111111111111111100000000000000000000000000000000

DO
    a = _ROR(a, 1)
    b = _ROR(b, 1)
    c = _ROR(c, 1)
    d = _ROR(d, 1)

    LOCATE 1, 1: PRINT RIGHT$(STRING$(8, "0") + _BIN$(a), 8);
    LOCATE 2, 1: PRINT RIGHT$(STRING$(16, "0") + _BIN$(b), 16);
    LOCATE 3, 1: PRINT RIGHT$(STRING$(32, "0") + _BIN$(c), 32);
    LOCATE 4, 1: PRINT RIGHT$(STRING$(64, "0") + _BIN$(d), 64);

    _LIMIT 15
LOOP WHILE _KEYHIT <> 27


See also


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