From 9d404f5e87380044ee53c63a01dd2cee533b8724 Mon Sep 17 00:00:00 2001
From: shahoian <ruben.shahoyan@cern.ch>
Date: Mon, 24 Jun 2024 21:03:56 +0200
Subject: [PATCH] Sort hits addresses before adding to raw stream

---
 .../ITSMFT/common/reconstruction/src/AlpideCoder.cxx   | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/Detectors/ITSMFT/common/reconstruction/src/AlpideCoder.cxx b/Detectors/ITSMFT/common/reconstruction/src/AlpideCoder.cxx
index cfea32eb383a9..33966203ae6af 100644
--- a/Detectors/ITSMFT/common/reconstruction/src/AlpideCoder.cxx
+++ b/Detectors/ITSMFT/common/reconstruction/src/AlpideCoder.cxx
@@ -76,7 +76,7 @@ int AlpideCoder::encodeChip(PayLoadCont& buffer, const o2::itsmft::ChipPixelData
 int AlpideCoder::procDoubleCol(PayLoadCont& buffer, short reg, short dcol)
 {
   // process double column: encoding
-  short hits[2 * NRows];
+  std::array<short, 2 * NRows> hits;
   int nHits = 0, nData = 0;
   //
   int nr = mFirstInRow.size();
@@ -84,9 +84,12 @@ int AlpideCoder::procDoubleCol(PayLoadCont& buffer, short reg, short dcol)
   int prevRow = -1;
   for (int ir = 0; ir < nr; ir++) {
     int linkID = mFirstInRow[ir];
-    if (linkID == -1 || mPix2Encode[linkID].col > col1) { // no pixels left on this row or higher column IDs
+    if (linkID == -1) { // no pixels left on this row
       continue;
     }
+    if (mPix2Encode[linkID].col > col1) { // all following hits will have higher columns
+      break;
+    }
     short rowID = mPix2Encode[linkID].row;
     // process fired pixels
     bool left = 0, right = 0;
@@ -122,6 +125,9 @@ int AlpideCoder::procDoubleCol(PayLoadCont& buffer, short reg, short dcol)
   }
   //
   int ih = 0;
+  if (nHits > 1) {
+    std::sort(hits.begin(), hits.begin() + nHits);
+  }
   while ((ih < nHits)) {
     short addrE, addrW = hits[ih++]; // address of the reference hit
     uint8_t mask = 0;