Consider debug info intrinsics pointing to null value as dead instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127922 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp
index e54dfb3..19b9997 100644
--- a/lib/Transforms/Utils/Local.cpp
+++ b/lib/Transforms/Utils/Local.cpp
@@ -211,7 +211,20 @@
bool llvm::isInstructionTriviallyDead(Instruction *I) {
if (!I->use_empty() || isa<TerminatorInst>(I)) return false;
- // We don't want debug info removed by anything this general.
+ // We don't want debug info removed by anything this general, unless
+ // debug info is empty.
+ if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(I)) {
+ if (DDI->getAddress())
+ return false;
+ else
+ return true;
+ } else if (DbgValueInst *DVI = dyn_cast<DbgValueInst>(I)) {
+ if (DVI->getValue())
+ return false;
+ else
+ return true;
+ }
+
if (isa<DbgInfoIntrinsic>(I)) return false;
if (!I->mayHaveSideEffects()) return true;