Do not move DBG_VALUE in middle of PHI nodes.

llvm-svn: 132161
diff --git a/llvm/lib/Transforms/Scalar/CodeGenPrepare.cpp b/llvm/lib/Transforms/Scalar/CodeGenPrepare.cpp
index 7ba92ba..da6bf31 100644
--- a/llvm/lib/Transforms/Scalar/CodeGenPrepare.cpp
+++ b/llvm/lib/Transforms/Scalar/CodeGenPrepare.cpp
@@ -557,7 +557,10 @@
       if (DVI->getParent() != VI->getParent() || DT->dominates(DVI, VI)) {
         DEBUG(dbgs() << "Moving Debug Value before :\n" << *DVI << ' ' << *VI);
         DVI->removeFromParent();
-        DVI->insertAfter(VI);
+        if (isa<PHINode>(VI))
+          DVI->insertBefore(VI->getParent()->getFirstNonPHI());
+        else
+          DVI->insertAfter(VI);
         return true;
       }