From af56858b0c261d955bb6f0a6c32601111f2c536c Mon Sep 17 00:00:00 2001
From: Georges Hatem <georges@hatem.ws>
Date: Thu, 9 May 2024 01:27:23 +0300
Subject: [PATCH 1/4] no iterator / interim vars

---
 entries/ghatem-fpc/src/OneBRC.lpr | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/entries/ghatem-fpc/src/OneBRC.lpr b/entries/ghatem-fpc/src/OneBRC.lpr
index cbf75af..5731b9d 100644
--- a/entries/ghatem-fpc/src/OneBRC.lpr
+++ b/entries/ghatem-fpc/src/OneBRC.lpr
@@ -563,13 +563,11 @@ function MyFormatInt (const aIn: SmallInt): AnsiString; inline;
 //---------------------------------------------------
 
 procedure TOneBRC.GenerateOutput;
-var vMean: Integer;
-    vStream: TStringStream;
+var vStream: TStringStream;
     I, N: Int64;
     vData: PStationData;
     vHash: Cardinal;
     vStations: TStringList;
-    iStationName: AnsiString;
     vIdx: THashSize;
     vRes: Boolean;
 begin
@@ -579,8 +577,8 @@ procedure TOneBRC.GenerateOutput;
   vStations.UseLocale := False;
   try
     vStations.BeginUpdate;
-    for iStationName in FDictionary.FStationNames do begin
-      vStations.Add(iStationName);
+    for I := 0 to N - 1 do begin
+      vStations.Add(FDictionary.FStationNames[I]);
     end;
     vStations.EndUpdate;
     vStations.CustomSort (@Compare);
@@ -598,11 +596,9 @@ 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);

From d8e6a94a3ad475825a61ec27a38fb77a1c56e123 Mon Sep 17 00:00:00 2001
From: Georges Hatem <georges@hatem.ws>
Date: Thu, 9 May 2024 01:44:48 +0300
Subject: [PATCH 2/4] undo some changes, problematic for 400 stations

---
 entries/ghatem-fpc/src/OneBRC.lpr | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/entries/ghatem-fpc/src/OneBRC.lpr b/entries/ghatem-fpc/src/OneBRC.lpr
index 5731b9d..a791166 100644
--- a/entries/ghatem-fpc/src/OneBRC.lpr
+++ b/entries/ghatem-fpc/src/OneBRC.lpr
@@ -577,9 +577,11 @@ procedure TOneBRC.GenerateOutput;
   vStations.UseLocale := False;
   try
     vStations.BeginUpdate;
-    for I := 0 to N - 1 do begin
-      vStations.Add(FDictionary.FStationNames[I]);
+    for i := 0 to cNumStations - 1 do begin
+      if FDictionary.FStationNames[i] <> '' then
+        vStations.Add (FDictionary.FStationNames[i]);
     end;
+
     vStations.EndUpdate;
     vStations.CustomSort (@Compare);
 

From 5df50953dfb47edd4ddce6cc94f6a48ea06e510a Mon Sep 17 00:00:00 2001
From: Georges Hatem <georges@hatem.ws>
Date: Thu, 9 May 2024 01:58:40 +0300
Subject: [PATCH 3/4] reduce int sizes

---
 entries/ghatem-fpc/src/OneBRC.lpr | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/entries/ghatem-fpc/src/OneBRC.lpr b/entries/ghatem-fpc/src/OneBRC.lpr
index a791166..d838112 100644
--- a/entries/ghatem-fpc/src/OneBRC.lpr
+++ b/entries/ghatem-fpc/src/OneBRC.lpr
@@ -564,7 +564,7 @@ function MyFormatInt (const aIn: SmallInt): AnsiString; inline;
 
 procedure TOneBRC.GenerateOutput;
 var vStream: TStringStream;
-    I, N: Int64;
+    I, N: Int32;
     vData: PStationData;
     vHash: Cardinal;
     vStations: TStringList;

From 40a245b072e5d5718423e505dec15b5c1f4c310d Mon Sep 17 00:00:00 2001
From: Georges Hatem <georges@hatem.ws>
Date: Thu, 9 May 2024 02:15:08 +0300
Subject: [PATCH 4/4] unroll loop a bit

---
 entries/ghatem-fpc/src/OneBRC.lpr | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/entries/ghatem-fpc/src/OneBRC.lpr b/entries/ghatem-fpc/src/OneBRC.lpr
index d838112..5b7486d 100644
--- a/entries/ghatem-fpc/src/OneBRC.lpr
+++ b/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