If an AllocaInst referred by DbgDeclareInst is used by a LoadInst then the LoadInst should also get a corresponding llvm.dbg.value intrinsic.

llvm-svn: 127924

1 files changed, 24 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 623d89b2f63..88c6f18c6ed 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -794,6 +794,28 @@ bool llvm::ConvertDebugDeclareToDebugValue(DbgDeclareInst *DDI,
   return true;
 }
 
+/// Inserts a llvm.dbg.value instrinsic before the stores to an alloca'd value
+/// that has an associated llvm.dbg.decl intrinsic.
+bool llvm::ConvertDebugDeclareToDebugValue(DbgDeclareInst *DDI,
+                                           LoadInst *LI, DIBuilder &Builder) {
+  DIVariable DIVar(DDI->getVariable());
+  if (!DIVar.Verify())
+    return false;
+
+  Instruction *DbgVal = 
+    Builder.insertDbgValueIntrinsic(LI->getOperand(0), 0,
+                                    DIVar, LI);
+  
+  // Propagate any debug metadata from the store onto the dbg.value.
+  DebugLoc LIDL = LI->getDebugLoc();
+  if (!LIDL.isUnknown())
+    DbgVal->setDebugLoc(LIDL);
+  // Otherwise propagate debug metadata from dbg.declare.
+  else
+    DbgVal->setDebugLoc(DDI->getDebugLoc());
+  return true;
+}
+
 /// LowerDbgDeclare - Lowers llvm.dbg.declare intrinsics into appropriate set
 /// of llvm.dbg.value intrinsics.
 bool llvm::LowerDbgDeclare(Function &F) {
@@ -815,6 +837,8 @@ bool llvm::LowerDbgDeclare(Function &F) {
            UI != E; ++UI)
         if (StoreInst *SI = dyn_cast<StoreInst>(*UI))
           ConvertDebugDeclareToDebugValue(DDI, SI, DIB);
+        else if (LoadInst *LI = dyn_cast<LoadInst>(*UI))
+          ConvertDebugDeclareToDebugValue(DDI, LI, DIB);
     }
     DDI->eraseFromParent();
   }