Index: llvm/CMakeLists.txt
===================================================================
--- llvm/CMakeLists.txt
+++ llvm/CMakeLists.txt
@@ -339,6 +339,12 @@
 
 set(LLVM_LIBDIR_SUFFIX "" CACHE STRING "Define suffix of library directory name (32/64)" )
 
+# LLVM_INSTALL_PACKAGE_DIR needs to be declared prior to adding the tools
+# subdirectory in order to have the value available for llvm-config.
+include(GNUInstallPackageDir)
+set(LLVM_INSTALL_PACKAGE_DIR "${CMAKE_INSTALL_PACKAGEDIR}/llvm" CACHE STRING
+  "Path for CMake subdirectory for LLVM (defaults to '${CMAKE_INSTALL_PACKAGEDIR}/llvm')")
+
 set(LLVM_TOOLS_INSTALL_DIR "${CMAKE_INSTALL_BINDIR}" CACHE STRING
     "Path for binary subdirectory (defaults to '${CMAKE_INSTALL_BINDIR}')")
 mark_as_advanced(LLVM_TOOLS_INSTALL_DIR)
Index: llvm/cmake/modules/CMakeLists.txt
===================================================================
--- llvm/cmake/modules/CMakeLists.txt
+++ llvm/cmake/modules/CMakeLists.txt
@@ -1,10 +1,7 @@
-include(GNUInstallPackageDir)
 include(ExtendPath)
 include(LLVMDistributionSupport)
 include(FindPrefixFromConfig)
 
-set(LLVM_INSTALL_PACKAGE_DIR "${CMAKE_INSTALL_PACKAGEDIR}/llvm" CACHE STRING
-  "Path for CMake subdirectory for LLVM (defaults to '${CMAKE_INSTALL_PACKAGEDIR}/llvm')")
 # CMAKE_INSTALL_PACKAGEDIR might be absolute, so don't reuse below.
 set(llvm_cmake_builddir "${LLVM_BINARY_DIR}/lib${LLVM_LIBDIR_SUFFIX}/cmake/llvm")