[llvm] r255984 - [RS4GC] Use an value handle to help isolate errors quickly

[Philip Reames via llvm-commits]

Author: reames
Date: Thu Dec 17 21:53:28 2015
New Revision: 255984

URL: http://llvm.org/viewvc/llvm-project?rev=255984&view=rev
Log:
[RS4GC] Use an value handle to help isolate errors quickly

Inspired by the bug reported in 25846.  Whatever we end up doing about that one, the value handle change is a generally good one since it will help catch this type of mistake more quickly.

Patch by: Manuel Jacob


Modified:
    llvm/trunk/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp?rev=255984&r1=255983&r2=255984&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp Thu Dec 17 21:53:28 2015
@@ -641,7 +641,7 @@ public:
 
 private:
   Status status;
-  Value *base; // non null only if status == base
+  AssertingVH<Value> base; // non null only if status == base
 };
 }
 
@@ -1098,10 +1098,10 @@ static Value *findBasePointer(Value *I,
     NewInsts.erase(BaseI);
     ReverseMap.erase(BaseI);
     BaseI->replaceAllUsesWith(Replacement);
-    BaseI->eraseFromParent();
     assert(States.count(BDV));
     assert(States[BDV].isConflict() && States[BDV].getBase() == BaseI);
     States[BDV] = BDVState(BDVState::Conflict, Replacement);
+    BaseI->eraseFromParent();
   };
   const DataLayout &DL = cast<Instruction>(def)->getModule()->getDataLayout();
   while (!Worklist.empty()) {