Difference between revisions of "Shr"
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The reserved word '''Sh'''ift '''r'''ight (shr) performs a logical right bit-shift operation (opposite than [[Shl|shl]]). | The reserved word '''Sh'''ift '''r'''ight (shr) performs a logical right bit-shift operation (opposite than [[Shl|shl]]). | ||
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| + | Example: | ||
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| + | Command is: 00000100 shr 2 (shift right 2 bits) | ||
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| + | Action is: 00000100 -> 00 (00 gets added to the left of the value; right 00 "disappears") | ||
| + | |||
| + | Result is: 00000001 | ||
== Shr with signed types == | == Shr with signed types == | ||
| − | Note: unlike the >> operator in the C language, the shr operator is a logical (not arithmetic) bit shift, even if the left operand is a signed integer. An implicit typecast and extension to a larger unsigned type may be performed before the shift operation. Check what the following program actually prints. | + | Note: unlike the >> operator in the C language, the shr operator is a logical (not arithmetic) bit shift, even if the left operand is a signed integer. An implicit [[Typecast|typecast]] and extension to a larger unsigned type may be performed before the shift operation. Check what the following program actually prints. |
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| − | + | {{Logical operators}} | |
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* [[Const]] | * [[Const]] | ||
* [[Function]] | * [[Function]] | ||
* [[Integer]] | * [[Integer]] | ||
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Latest revision as of 05:30, 1 September 2021
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Back to Reserved words.
Overview
The reserved word Shift right (shr) performs a logical right bit-shift operation (opposite than shl).
Example:
Command is: 00000100 shr 2 (shift right 2 bits) Action is: 00000100 -> 00 (00 gets added to the left of the value; right 00 "disappears") Result is: 00000001
Shr with signed types
Note: unlike the >> operator in the C language, the shr operator is a logical (not arithmetic) bit shift, even if the left operand is a signed integer. An implicit typecast and extension to a larger unsigned type may be performed before the shift operation. Check what the following program actually prints.
program ShrTest;
begin
WriteLn(ShortInt(-3) shr 1);
end.
Is a bit set
function isBitSet(AValue, ABitNumber:integer):boolean;
begin
result:=odd(AValue shr ABitNumber);
end;
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