do not use grouped cell calculation for just a single cell

We do threaded calculations per row, so there's no point in setting
up all the thread stuff effectively just for a single thread (all
but one would be called to do nothing). No point in setting up
OpenCL in this case either.

Change-Id: I91ea5a7f219f8518a934ecbb04667fa7fba1cdff
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/125026
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>

1 files changed, 12 insertions, 9 deletions

diff --git a/sc/source/core/data/formulacell.cxx b/sc/source/core/data/formulacell.cxx
index d678fad353c7..409b14767a82 100644
--- a/sc/source/core/data/formulacell.cxx
+++ b/sc/source/core/data/formulacell.cxx
@@ -4652,15 +4652,6 @@ bool ScFormulaCell::InterpretFormulaGroup(SCROW nStartOffset, SCROW nEndOffset)
         }
     }
 
-    // Guard against endless recursion of Interpret() calls, for this to work
-    // ScFormulaCell::InterpretFormulaGroup() must never be called through
-    // anything else than ScFormulaCell::Interpret(), same as
-    // ScFormulaCell::InterpretTail()
-    RecursionCounter aRecursionCounter( rRecursionHelper, this);
-
-    bool bDependencyComputed = false;
-    bool bDependencyCheckFailed = false;
-
     // Get rid of -1's in offsets (defaults) or any invalid offsets.
     SCROW nMaxOffset = mxGroup->mnLength - 1;
     nStartOffset = nStartOffset < 0 ? 0 : std::min(nStartOffset, nMaxOffset);
@@ -4672,6 +4663,18 @@ bool ScFormulaCell::InterpretFormulaGroup(SCROW nStartOffset, SCROW nEndOffset)
         nEndOffset = nMaxOffset;
     }
 
+    if (nEndOffset == nStartOffset)
+        return false; // Do not use threads for a single row.
+
+    // Guard against endless recursion of Interpret() calls, for this to work
+    // ScFormulaCell::InterpretFormulaGroup() must never be called through
+    // anything else than ScFormulaCell::Interpret(), same as
+    // ScFormulaCell::InterpretTail()
+    RecursionCounter aRecursionCounter( rRecursionHelper, this);
+
+    bool bDependencyComputed = false;
+    bool bDependencyCheckFailed = false;
+
     // Preference order: First try OpenCL, then threading.
     // TODO: Do formula-group span computation for OCL too if nStartOffset/nEndOffset are non default.
     if( InterpretFormulaGroupOpenCL(aScope, bDependencyComputed, bDependencyCheckFailed))