Fix DebugLoc propagation for unreachable LoadInst

Summary: Currently, when GVN creates a load and when InstCombine creates a new store for unreachable Load, the DebugLoc info gets lost.

Reviewers: dberlin, davide, aprantl

Reviewed By: aprantl

Subscribers: davide, llvm-commits

Differential Revision: https://reviews.llvm.org/D34639

llvm-svn: 308404

1 files changed, 3 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
index c59e1ce69ac..45103654574 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
@@ -998,8 +998,9 @@ Instruction *InstCombiner::visitLoadInst(LoadInst &LI) {
     // that this code is not reachable.  We do this instead of inserting
     // an unreachable instruction directly because we cannot modify the
     // CFG.
-    new StoreInst(UndefValue::get(LI.getType()),
-                  Constant::getNullValue(Op->getType()), &LI);
+    StoreInst *SI = new StoreInst(UndefValue::get(LI.getType()),
+                                  Constant::getNullValue(Op->getType()), &LI);
+    SI->setDebugLoc(LI.getDebugLoc());
     return replaceInstUsesWith(LI, UndefValue::get(LI.getType()));
   }