diff --git a/lld/MachO/Driver.cpp b/lld/MachO/Driver.cpp
--- a/lld/MachO/Driver.cpp
+++ b/lld/MachO/Driver.cpp
@@ -80,16 +80,29 @@
   }
 }
 
+static DenseMap<CachedHashStringRef, StringRef> resolvedLibraries;
 static Optional<StringRef> findLibrary(StringRef name) {
+  CachedHashStringRef key(name);
+  auto entry = resolvedLibraries.find(key);
+  if (entry != resolvedLibraries.end())
+    return entry->second;
+
   if (config->searchDylibsFirst) {
     if (Optional<StringRef> path = findPathCombination(
-            "lib" + name, config->librarySearchPaths, {".tbd", ".dylib"}))
+            "lib" + name, config->librarySearchPaths, {".tbd", ".dylib"})) {
+      resolvedLibraries[key] = *path;
       return path;
-    return findPathCombination("lib" + name, config->librarySearchPaths,
-                               {".a"});
+    }
+    auto path =
+        findPathCombination("lib" + name, config->librarySearchPaths, {".a"});
+    if (path)
+      resolvedLibraries[key] = *path;
+    return path;
   }
-  return findPathCombination("lib" + name, config->librarySearchPaths,
-                             {".tbd", ".dylib", ".a"});
+  auto path = findPathCombination("lib" + name, config->librarySearchPaths,
+                                  {".tbd", ".dylib", ".a"});
+  resolvedLibraries[key] = *path;
+  return path;
 }
 
 static DenseMap<CachedHashStringRef, StringRef> resolvedPaths;