Index: lld/trunk/COFF/Driver.h
===================================================================
--- lld/trunk/COFF/Driver.h
+++ lld/trunk/COFF/Driver.h
@@ -89,6 +89,7 @@
   Optional<StringRef> findLib(StringRef Filename);
   StringRef doFindFile(StringRef Filename);
   StringRef doFindLib(StringRef Filename);
+  StringRef doFindLibMinGW(StringRef Filename);
 
   // Parses LIB environment which contains a list of search paths.
   void addLibSearchPaths();
Index: lld/trunk/COFF/Driver.cpp
===================================================================
--- lld/trunk/COFF/Driver.cpp
+++ lld/trunk/COFF/Driver.cpp
@@ -371,13 +371,30 @@
   return Path;
 }
 
+// MinGW specific. If an embedded directive specified to link to
+// foo.lib, but it isn't found, try libfoo.a instead.
+StringRef LinkerDriver::doFindLibMinGW(StringRef Filename) {
+  if (Filename.contains('/') || Filename.contains('\\'))
+    return Filename;
+
+  SmallString<128> S = Filename;
+  sys::path::replace_extension(S, ".a");
+  StringRef LibName = Saver.save("lib" + S.str());
+  return doFindFile(LibName);
+}
+
 // Find library file from search path.
 StringRef LinkerDriver::doFindLib(StringRef Filename) {
   // Add ".lib" to Filename if that has no file extension.
   bool HasExt = Filename.contains('.');
   if (!HasExt)
     Filename = Saver.save(Filename + ".lib");
-  return doFindFile(Filename);
+  StringRef Ret = doFindFile(Filename);
+  // For MinGW, if the find above didn't turn up anything, try
+  // looking for a MinGW formatted library name.
+  if (Config->MinGW && Ret == Filename)
+    return doFindLibMinGW(Filename);
+  return Ret;
 }
 
 // Resolves a library path. /nodefaultlib options are taken into
Index: lld/trunk/test/COFF/libname-mingw.test
===================================================================
--- lld/trunk/test/COFF/libname-mingw.test
+++ lld/trunk/test/COFF/libname-mingw.test
@@ -0,0 +1,8 @@
+# RUN: mkdir -p %t/a
+# RUN: cp %p/Inputs/std64.lib %t/a/libstd64.a
+
+# RUN: lld-link /lldmingw /out:%t.exe /entry:main /verbose \
+# RUN:   /defaultlib:std64.lib /subsystem:console %p/Inputs/hello64.obj \
+# RUN:   /libpath:%t/a 2>&1 | FileCheck %s
+
+CHECK: a{{[/\\]}}libstd64.a