[llvm-commits] [llvm] r101565 - in /llvm/trunk: include/llvm/ADT/SCCIterator.h lib/Analysis/IPA/CallGraphSCCPass.cpp

[Chris Lattner]

Author: lattner
Date: Fri Apr 16 18:04:30 2010
New Revision: 101565

URL: http://llvm.org/viewvc/llvm-project?rev=101565&view=rev
Log:
building on the new CallGraphSCC abstraction, teach CallGraphSCCPassManager 
to keep the node entries in scc_iterator up to date instead of dangling as
the SCC mutates.

This is a really terrible problem which was causing -g to affect codegen 
because it would permute the memory image of the compiler process.

Thanks to Dale for expertly hunting it down.


Modified:
    llvm/trunk/include/llvm/ADT/SCCIterator.h
    llvm/trunk/lib/Analysis/IPA/CallGraphSCCPass.cpp

Modified: llvm/trunk/include/llvm/ADT/SCCIterator.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/SCCIterator.h?rev=101565&r1=101564&r2=101565&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/SCCIterator.h (original)
+++ llvm/trunk/include/llvm/ADT/SCCIterator.h Fri Apr 16 18:04:30 2010
@@ -183,6 +183,15 @@
         return true;
     return false;
   }
+                           
+  /// ReplaceNode - This informs the scc_iterator that the specified Old node
+  /// has been deleted, and New is to be used in its place.
+  void ReplaceNode(NodeType *Old, NodeType *New) {
+    assert(!nodeVisitNumbers.count(New) && "New already in scc_iterator?");
+    assert(nodeVisitNumbers.count(Old) && "Old not in scc_iterator?");
+    nodeVisitNumbers[New] = nodeVisitNumbers[Old];
+    nodeVisitNumbers.erase(Old);
+  }
 };
 
 

Modified: llvm/trunk/lib/Analysis/IPA/CallGraphSCCPass.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/IPA/CallGraphSCCPass.cpp?rev=101565&r1=101564&r2=101565&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/IPA/CallGraphSCCPass.cpp (original)
+++ llvm/trunk/lib/Analysis/IPA/CallGraphSCCPass.cpp Fri Apr 16 18:04:30 2010
@@ -417,6 +417,11 @@
     Nodes[i] = New;
     break;
   }
+  
+  // Update the active scc_iterator so that it doesn't contain dangling
+  // pointers to the old CallGraphNode.
+  scc_iterator<CallGraph*> *CGI = (scc_iterator<CallGraph*>*)Context;
+  CGI->ReplaceNode(Old, New);
 }