[llvm] r314254 - [Dominators] Invalidate DFS numbers upon edge deletions

[Jakub Kuderski via llvm-commits]

Author: kuhar
Date: Tue Sep 26 14:56:55 2017
New Revision: 314254

URL: http://llvm.org/viewvc/llvm-project?rev=314254&view=rev
Log:
[Dominators] Invalidate DFS numbers upon edge deletions

This patch makes DeleteEdge correctly invalidate DFS numbers in the
incremental updater. This should fix PR34466 and related bugs.

Modified:
    llvm/trunk/include/llvm/Support/GenericDomTreeConstruction.h

Modified: llvm/trunk/include/llvm/Support/GenericDomTreeConstruction.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/GenericDomTreeConstruction.h?rev=314254&r1=314253&r2=314254&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/GenericDomTreeConstruction.h (original)
+++ llvm/trunk/include/llvm/Support/GenericDomTreeConstruction.h Tue Sep 26 14:56:55 2017
@@ -923,6 +923,8 @@ struct SemiNCAInfo {
     // To dominates From -- nothing to do.
     if (ToTN == NCD) return;
 
+    DT.DFSInfoValid = false;
+
     const TreeNodePtr ToIDom = ToTN->getIDom();
     DEBUG(dbgs() << "\tNCD " << BlockNamePrinter(NCD) << ", ToIDom "
                  << BlockNamePrinter(ToIDom) << "\n");