Index: cfe/trunk/lib/Driver/MinGWToolChain.cpp
===================================================================
--- cfe/trunk/lib/Driver/MinGWToolChain.cpp
+++ cfe/trunk/lib/Driver/MinGWToolChain.cpp
@@ -66,24 +66,20 @@
     : ToolChain(D, Triple, Args) {
   getProgramPaths().push_back(getDriver().getInstalledDir());
 
-// In Windows there aren't any standard install locations, we search
-// for gcc on the PATH. In Linux the base is always /usr.
+// On Windows if there is no sysroot we search for gcc on the PATH.
+
+if (getDriver().SysRoot.size())
+  Base = getDriver().SysRoot;
 #ifdef LLVM_ON_WIN32
-  if (getDriver().SysRoot.size())
-    Base = getDriver().SysRoot;
-  else if (llvm::ErrorOr<std::string> GPPName =
-               llvm::sys::findProgramByName("gcc"))
-    Base = llvm::sys::path::parent_path(
-        llvm::sys::path::parent_path(GPPName.get()));
-  else
-    Base = llvm::sys::path::parent_path(getDriver().getInstalledDir());
-#else
-  if (getDriver().SysRoot.size())
-    Base = getDriver().SysRoot;
-  else
-    Base = "/usr";
+else if (llvm::ErrorOr<std::string> GPPName =
+             llvm::sys::findProgramByName("gcc"))
+  Base = llvm::sys::path::parent_path(
+      llvm::sys::path::parent_path(GPPName.get()));
 #endif
 
+if (!Base.size())
+  Base = llvm::sys::path::parent_path(getDriver().getInstalledDir());
+
   Base += llvm::sys::path::get_separator();
   findGccLibDir();
   // GccLibDir must precede Base/lib so that the