Avoid potential iterator invalidation problems.

llvm-svn: 40607

1 files changed, 4 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/Scalar/GVN.cpp b/llvm/lib/Transforms/Scalar/GVN.cpp
index fee0eedcc77..42e9ee8900f 100644
--- a/llvm/lib/Transforms/Scalar/GVN.cpp
+++ b/llvm/lib/Transforms/Scalar/GVN.cpp
@@ -895,11 +895,14 @@ bool GVN::runOnFunction(Function &F) {
       currAvail = availableOut[DI->getIDom()->getBlock()];
 
     for (BasicBlock::iterator BI = BB->begin(), BE = BB->end();
-         BI != BE; ++BI) {
+         BI != BE; ) {
       changed_function |= processInstruction(BI, currAvail, lastSeenLoad, toErase);
       
       NumGVNInstr += toErase.size();
       
+      // Avoid iterator invalidation
+      ++BI;
+      
       for (SmallVector<Instruction*, 4>::iterator I = toErase.begin(),
            E = toErase.end(); I != E; ++I)
         (*I)->eraseFromParent();