Avoid duplicated map lookups. No functionality change intended.

llvm-svn: 273030
diff --git a/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp b/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
index e23cd81..9f96cba 100644
--- a/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
+++ b/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
@@ -365,9 +365,8 @@
       continue;
 
     if (auto *BCI = dyn_cast<BitCastInst>(Ptr)) {
-      if (!Seen.count(BCI->getOperand(0))) {
+      if (Seen.insert(BCI->getOperand(0)).second) {
         LoadOperandsQueue.push_back(BCI->getOperand(0));
-        Seen.insert(BCI->getOperand(0));
       }
     }
 
@@ -377,9 +376,8 @@
         continue;
 
       if (auto *BCI = dyn_cast<BitCastInst>(U)) {
-        if (!Seen.count(BCI)) {
+        if (Seen.insert(BCI).second) {
           LoadOperandsQueue.push_back(BCI);
-          Seen.insert(BCI);
         }
         continue;
       }