Index: tools/llvm-config/llvm-config.cpp
===================================================================
--- tools/llvm-config/llvm-config.cpp
+++ tools/llvm-config/llvm-config.cpp
@@ -351,7 +351,7 @@
   const Triple HostTriple(Triple::normalize(LLVM_HOST_TRIPLE));
   if (HostTriple.isOSWindows()) {
     SharedExt = "dll";
-    SharedVersionedExt = LLVM_DYLIB_VERSION ".dll";
+    SharedVersionedExt = ".dll";
     if (HostTriple.isOSCygMing()) {
       StaticExt = "a";
       StaticPrefix = "lib";
@@ -370,14 +370,14 @@
     StaticDir = ActiveLibDir;
   } else if (HostTriple.isOSDarwin()) {
     SharedExt = "dylib";
-    SharedVersionedExt = LLVM_DYLIB_VERSION ".dylib";
+    SharedVersionedExt = "-" LLVM_DYLIB_VERSION ".dylib";
     StaticExt = "a";
     StaticDir = SharedDir = ActiveLibDir;
     StaticPrefix = SharedPrefix = "lib";
   } else {
     // default to the unix values:
     SharedExt = "so";
-    SharedVersionedExt = LLVM_DYLIB_VERSION ".so";
+    SharedVersionedExt = "-" LLVM_DYLIB_VERSION ".so";
     StaticExt = "a";
     StaticDir = SharedDir = ActiveLibDir;
     StaticPrefix = SharedPrefix = "lib";
@@ -390,7 +390,7 @@
 
   bool DyLibExists = false;
   const std::string DyLibName =
-      (SharedPrefix + "LLVM-" + SharedVersionedExt).str();
+      (SharedPrefix + "LLVM" + SharedVersionedExt).str();
 
   // If LLVM_LINK_DYLIB is ON, the single shared library will be returned
   // for "--libs", etc, if they exist. This behaviour can be overridden with
@@ -416,7 +416,7 @@
   /// extension. Returns true if Lib is in a recognized format.
   auto GetComponentLibraryNameSlice = [&](const StringRef &Lib,
                                           StringRef &Out) {
-    if (Lib.startswith("lib")) {
+    if (Lib.startswith(SharedPrefix)) {
       unsigned FromEnd;
       if (Lib.endswith(StaticExt)) {
         FromEnd = StaticExt.size() + 1;
@@ -427,7 +427,7 @@
       }
 
       if (FromEnd != 0) {
-        Out = Lib.slice(3, Lib.size() - FromEnd);
+        Out = Lib.slice(SharedPrefix.size(), Lib.size() - FromEnd);
         return true;
       }
     }