Merge pull request #163 from georges-hatem/main

micro-optimizations

Author: gcarreno

entries/ghatem-fpc/src/OneBRC.lpr

@@ -465,8 +465,21 @@ procedure TOneBRC.ProcessData (aThreadNb: TThreadCount; aStartIdx: Int64; aEndId
       Inc (I, 5);
     end;
 
-    while FData[i] <> #10 do begin
-      Inc (I);
+    // unroll a few seems to be improving?
+    if FData[i] <> #10 then begin
+      Inc (i);
+      if FData[i] <> #10 then begin
+        Inc (i);
+        if FData[i] <> #10 then begin
+          Inc (I);
+          if FData[i] <> #10 then begin
+            Inc (i);
+            while FData[i] <> #10 do begin
+              Inc (I);
+            end;
+          end;
+        end;
+      end;
     end;
 
     // new line parsed, process its contents
@@ -563,13 +576,11 @@ function MyFormatInt (const aIn: SmallInt): AnsiString; inline;
 //---------------------------------------------------
 
 procedure TOneBRC.GenerateOutput;
-var vMean: Integer;
-    vStream: TStringStream;
-    I, N: Int64;
+var vStream: TStringStream;
+    I, N: Int32;
     vData: PStationData;
     vHash: Cardinal;
     vStations: TStringList;
-    iStationName: AnsiString;
     vIdx: THashSize;
     vRes: Boolean;
 begin
@@ -579,9 +590,11 @@ procedure TOneBRC.GenerateOutput;
   vStations.UseLocale := False;
   try
     vStations.BeginUpdate;
-    for iStationName in FDictionary.FStationNames do begin
-      vStations.Add(iStationName);
+    for i := 0 to cNumStations - 1 do begin
+      if FDictionary.FStationNames[i] <> '' then
+        vStations.Add (FDictionary.FStationNames[i]);
     end;
+
     vStations.EndUpdate;
     vStations.CustomSort (@Compare);
 
@@ -598,11 +611,9 @@ procedure TOneBRC.GenerateOutput;
       FDictionary.InternalFind (vHash, vRes, vIdx);
       vData := @FDictionary.FThreadData[0][FDictionary.FIndexes[vIdx]];
 
-      vMean := RoundExInteger(vData^.Sum/vData^.Count/10);
-
       vStream.WriteString(
         vStations[i] + '=' + MyFormatInt(vData^.Min)
-                     + '/' + MyFormatInt(vMean)
+                     + '/' + MyFormatInt(RoundExInteger(vData^.Sum/vData^.Count/10))
                      + '/' + MyFormatInt(vData^.Max) + ', '
       );
       Inc(I);