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improvement of the rng function #11

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Merged
merged 3 commits into from
Mar 5, 2024
Merged

improvement of the rng function #11

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045c04e
improvement of the rng function
paweld Mar 5, 2024
a8c02df
Merge branch 'gus' of https://github.com/paweld/1brc-ObjectPascal int…
paweld Mar 5, 2024
698fd46
Tekst źródłowy ​ 53 / 5 000 Wyniki tłumaczenia Tłumaczenie changes al…
paweld Mar 5, 2024
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24 changes: 11 additions & 13 deletions generator/Common/generate.common.pas
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Original file line number Diff line number Diff line change
Expand Up @@ -17,6 +17,7 @@ interface

TGenerator = class(TObject)
private
rndState: Array [0..1] of Cardinal;
FInputFile: String;
FOutPutFile: String;
FLineCount: Int64;
Expand Down Expand Up @@ -52,7 +53,7 @@ implementation
;

const
cSeed: LongInt = 46668267; // '1BRC' in ASCII
cSeed = 46668267; // '1BRC' in ASCII
linesPercent = 10;
stationsCapacity = 50000;
chunkBatch = 10000;
Expand Down Expand Up @@ -160,17 +161,15 @@ function TGenerator.GenerateProgressBar(APBPosition, APBMax, APBWIdth, AFileSize
end;

function TGenerator.Rng1brc(Range: longint): longint;
const
state: Array [0..1] of DWord = (46668267, 7266);
var
s0, s1, s2: DWord;
s0, s1, s2: Cardinal;
begin
s0 := state[0];
s1 := state[1] xor s0;
s2 := RolDWord(s1 * 3, 5) * 7;
s0 := rndState[0];
s1 := rndState[1] xor s0;
s2 := ((s1 * 3) xor 5) * 7;
Result := longint(Int64(s2 * range) shr 32);
state[0] := s2;
state[1] := s0 xor (s1 shl 9);
rndState[0] := s2;
rndState[1] := s0 xor (s1 shl 9);
end;

procedure TGenerator.Generate;
Expand All @@ -186,10 +185,9 @@ procedure TGenerator.Generate;
chunkCount, chunkLen, stationsCount, temperaturesCount: Integer;
start: TDateTime;
begin
// Randomize sets this variable depending on the current time
// We just set it to our own value
RandSeed := cSeed;

//random init
rndState[0] := cSeed;
rndState[1] := 7266;
// Build list of station names
BuildStationNames;

Expand Down