diff --git a/lib/CodeGen/SelectionDAG/InstrEmitter.cpp b/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
index 935679a..f36620c 100644
--- a/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
+++ b/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
@@ -604,9 +604,10 @@
   } else if (SD->getKind() == SDDbgValue::CONST) {
     const Value *V = SD->getConst();
     if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
-      // FIXME: SDDbgValues aren't updated with legalization, so it's possible
-      // to have i128 values in them at this point. As a crude workaround, just
-      // drop the debug info if this happens.
+      // FIXME: SDDbgValue constants aren't updated with legalization, so it's 
+      // possible to have i128 constants in them at this point. Dwarf writer
+      // does not handle i128 constants at the moment so, as a crude workaround,
+      // just drop the debug info if this happens.
       if (!CI->getValue().isSignedIntN(64))
         MIB.addReg(0U);
       else