Index: lib/Driver/ToolChain.cpp
===================================================================
--- lib/Driver/ToolChain.cpp
+++ lib/Driver/ToolChain.cpp
@@ -412,7 +412,7 @@
   if (llvm::sys::path::is_absolute(UseLinker)) {
     // If we're passed what looks like an absolute path, don't attempt to
     // second-guess that.
-    if (llvm::sys::fs::exists(UseLinker))
+    if (llvm::sys::fs::can_execute(UseLinker))
       return UseLinker;
   } else if (UseLinker.empty() || UseLinker == "ld") {
     // If we're passed -fuse-ld= with no argument, or with the argument ld,
@@ -427,7 +427,7 @@
     LinkerName.append(UseLinker);
 
     std::string LinkerPath(GetProgramPath(LinkerName.c_str()));
-    if (llvm::sys::fs::exists(LinkerPath))
+    if (llvm::sys::fs::can_execute(LinkerPath))
       return LinkerPath;
   }
 
Index: test/Driver/fuse-ld-windows.c
===================================================================
--- /dev/null
+++ test/Driver/fuse-ld-windows.c
@@ -0,0 +1,25 @@
+// REQUIRES: system-windows
+
+// We used to require adding ".exe" suffix when cross-compiling on Windows.
+// RUN: %clang %s -### -o %t.o -target i386-unknown-linux \
+// RUN:     -B %S/Inputs/fuse_ld_windows -fuse-ld=foo 2>&1 \
+// RUN:   | FileCheck %s
+
+// Check that the old variant still works.
+// RUN: %clang %s -### -o %t.o -target i386-unknown-linux \
+// RUN:     -B %S/Inputs/fuse_ld_windows -fuse-ld=foo.exe 2>&1 \
+// RUN:   | FileCheck %s
+
+// With the full path, the extension can be omitted, too,
+// because Windows allows that.
+// RUN: %clang %s -### -o %t.o -target i386-unknown-linux \
+// RUN:     -fuse-ld=%S/Inputs/fuse_ld_windows/ld.foo 2>&1 \
+// RUN:   | FileCheck %s
+
+// Check that the full path with the extension works too.
+// RUN: %clang %s -### -o %t.o -target i386-unknown-linux \
+// RUN:     -fuse-ld=%S/Inputs/fuse_ld_windows/ld.foo.exe 2>&1 \
+// RUN:   | FileCheck %s
+
+// CHECK-NOT: invalid linker name
+// CHECK: /Inputs/fuse_ld_windows{{/|\\\\}}ld.foo