Move onlyUsedByLifetimeMarkers to ValueTracking so that it can be used by other
passes as well.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133904 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index dab5aeb..130e3ce 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -1783,3 +1783,19 @@
   }
   return V;
 }
+
+/// onlyUsedByLifetimeMarkers - Return true if the only users of this pointer
+/// are lifetime markers.
+///
+bool llvm::onlyUsedByLifetimeMarkers(const Value *V) {
+  for (Value::const_use_iterator UI = V->use_begin(), UE = V->use_end();
+       UI != UE; ++UI) {
+    const IntrinsicInst *II = dyn_cast<IntrinsicInst>(*UI);
+    if (!II) return false;
+
+    if (II->getIntrinsicID() != Intrinsic::lifetime_start &&
+        II->getIntrinsicID() != Intrinsic::lifetime_end)
+      return false;
+  }
+  return true;
+}