diff --git a/bolt/CMakeLists.txt b/bolt/CMakeLists.txt
--- a/bolt/CMakeLists.txt
+++ b/bolt/CMakeLists.txt
@@ -4,6 +4,12 @@
 set(BOLT_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
 set(CMAKE_CXX_STANDARD 17)
 
+# Must go before the first `include(GNUInstallDirs)`.
+include(LLVMLibdirSuffix)
+
+include(GNUInstallDirs)
+include(GNUBinaryDirs)
+
 set(BOLT_ENABLE_RUNTIME OFF)
 if (CMAKE_SYSTEM_PROCESSOR MATCHES "x86_64")
   set(BOLT_ENABLE_RUNTIME ON)
diff --git a/clang/CMakeLists.txt b/clang/CMakeLists.txt
--- a/clang/CMakeLists.txt
+++ b/clang/CMakeLists.txt
@@ -1,5 +1,8 @@
 cmake_minimum_required(VERSION 3.13.4)
 
+set(CLANG_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
+set(CLANG_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
+
 # If we are not building as a part of LLVM, build Clang as an
 # standalone project, using LLVM as an external library:
 if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
@@ -7,8 +10,20 @@
   set(CLANG_BUILT_STANDALONE TRUE)
 endif()
 
+if(NOT DEFINED LLVM_COMMON_CMAKE_UTILS)
+  set(LLVM_COMMON_CMAKE_UTILS ${CLANG_SOURCE_DIR}/../cmake)
+endif()
+
+list(INSERT CMAKE_MODULE_PATH 0
+  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
+  )
+
+# Must go before the first `include(GNUInstallDirs)`.
+include(LLVMLibdirSuffix)
+
 # Must go below project(..)
 include(GNUInstallDirs)
+include(GNUBinaryDirs)
 
 if(CLANG_BUILT_STANDALONE)
   set(CMAKE_CXX_STANDARD 17 CACHE STRING "C++ standard to conform to")
@@ -35,15 +50,7 @@
   find_program(LLVM_TABLEGEN_EXE "llvm-tblgen" ${LLVM_TOOLS_BINARY_DIR}
     NO_DEFAULT_PATH)
 
-  # They are used as destination of target generators.
-  set(LLVM_RUNTIME_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin)
-  set(LLVM_LIBRARY_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX})
-  if(WIN32 OR CYGWIN)
-    # DLL platform -- put DLLs into bin.
-    set(LLVM_SHLIB_OUTPUT_INTDIR ${LLVM_RUNTIME_OUTPUT_INTDIR})
-  else()
-    set(LLVM_SHLIB_OUTPUT_INTDIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
-  endif()
+  include(LLVMSetIntDirs)
 
   option(LLVM_INSTALL_TOOLCHAIN_ONLY
     "Only include toolchain files in the 'install' target." OFF)
@@ -140,15 +147,10 @@
   set(BACKEND_PACKAGE_STRING "${PACKAGE_STRING}")
 endif() # standalone
 
-if(NOT DEFINED LLVM_COMMON_CMAKE_UTILS)
-  set(LLVM_COMMON_CMAKE_UTILS ${CMAKE_CURRENT_SOURCE_DIR}/../cmake)
-endif()
-
 # Make sure that our source directory is on the current cmake module path so that
 # we can include cmake files from this directory.
 list(INSERT CMAKE_MODULE_PATH 0
-  "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules"
-  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
+  "${CLANG_CURRENT_SOURCE_DIR}/cmake/modules"
   )
 
 if(LLVM_ENABLE_LIBXML2)
@@ -310,9 +312,6 @@
     "Path for binary subdirectory (defaults to '${CMAKE_INSTALL_BINDIR}')")
 mark_as_advanced(CLANG_TOOLS_INSTALL_DIR)
 
-set(CLANG_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
-set(CLANG_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
-
 if( CMAKE_SOURCE_DIR STREQUAL CMAKE_BINARY_DIR AND NOT MSVC_IDE )
   message(FATAL_ERROR "In-source builds are not allowed. "
 "Please create a directory and run cmake "
diff --git a/clang/tools/scan-build/CMakeLists.txt b/clang/tools/scan-build/CMakeLists.txt
--- a/clang/tools/scan-build/CMakeLists.txt
+++ b/clang/tools/scan-build/CMakeLists.txt
@@ -1,6 +1,7 @@
 option(CLANG_INSTALL_SCANBUILD "Install the scan-build tool" ON)
 
 include(GNUInstallDirs)
+include(GNUBinaryDirs)
 
 if (WIN32 AND NOT CYGWIN)
   set(BinFiles
diff --git a/cmake/Modules/GNUBinaryDirs.cmake b/cmake/Modules/GNUBinaryDirs.cmake
new file mode 100644
--- /dev/null
+++ b/cmake/Modules/GNUBinaryDirs.cmake
@@ -0,0 +1,14 @@
+if (NOT DEFINED CMAKE_BINARY_BINDIR)
+  set(CMAKE_BINARY_BINDIR "${CMAKE_BINARY_DIR}/bin")
+endif()
+
+if (NOT DEFINED CMAKE_BINARY_INCLUDEDIR)
+  set(CMAKE_BINARY_INCLUDEDIR "${CMAKE_BINARY_DIR}/include")
+endif()
+
+if (NOT DEFINED CMAKE_LIBDIR_BASENAME)
+  get_filename_component(CMAKE_LIBDIR_BASENAME "${CMAKE_INSTALL_LIBDIR}" NAME)
+endif()
+if (NOT DEFINED CMAKE_BINARY_LIBDIR)
+  set(CMAKE_BINARY_LIBDIR "${CMAKE_BINARY_DIR}/${CMAKE_LIBDIR_BASENAME}")
+endif()
diff --git a/cmake/Modules/LLVMLibdirSuffix.cmake b/cmake/Modules/LLVMLibdirSuffix.cmake
new file mode 100644
--- /dev/null
+++ b/cmake/Modules/LLVMLibdirSuffix.cmake
@@ -0,0 +1,5 @@
+# Must go before the first `include(GNUInstallDirs)`.
+
+if (NOT DEFINED CMAKE_INSTALL_LIBDIR AND DEFINED LLVM_LIBDIR_SUFFIX)
+  set(CMAKE_INSTALL_LIBDIR "lib${LLVM_LIBDIR_SUFFIX}")
+endif()
diff --git a/cmake/Modules/LLVMSetIntDirs.cmake b/cmake/Modules/LLVMSetIntDirs.cmake
new file mode 100644
--- /dev/null
+++ b/cmake/Modules/LLVMSetIntDirs.cmake
@@ -0,0 +1,9 @@
+# They are used as destination of target generators.
+set(LLVM_RUNTIME_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin)
+set(LLVM_LIBRARY_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/${CMAKE_LIBDIR_BASENAME})
+if(WIN32 OR CYGWIN)
+  # DLL platform -- put DLLs into bin.
+  set(LLVM_SHLIB_OUTPUT_INTDIR ${LLVM_RUNTIME_OUTPUT_INTDIR})
+else()
+  set(LLVM_SHLIB_OUTPUT_INTDIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
+endif()
diff --git a/compiler-rt/CMakeLists.txt b/compiler-rt/CMakeLists.txt
--- a/compiler-rt/CMakeLists.txt
+++ b/compiler-rt/CMakeLists.txt
@@ -22,6 +22,12 @@
   "${LLVM_COMMON_CMAKE_UTILS}/Modules"
   )
 
+# Must go before the first `include(GNUInstallDirs)`.
+include(LLVMLibdirSuffix)
+
+include(GNUInstallDirs)
+include(GNUBinaryDirs)
+
 if(CMAKE_CONFIGURATION_TYPES)
   set(CMAKE_CFG_RESOLVED_INTDIR "${CMAKE_CFG_INTDIR}/")
 else()
diff --git a/compiler-rt/cmake/base-config-ix.cmake b/compiler-rt/cmake/base-config-ix.cmake
--- a/compiler-rt/cmake/base-config-ix.cmake
+++ b/compiler-rt/cmake/base-config-ix.cmake
@@ -97,28 +97,34 @@
     string(TOLOWER ${CMAKE_SYSTEM_NAME} COMPILER_RT_OS_DIR)
   endif()
 endif()
+
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
   set(COMPILER_RT_OUTPUT_LIBRARY_DIR
     ${COMPILER_RT_OUTPUT_DIR}/lib)
   extend_path(default_install_path "${COMPILER_RT_INSTALL_PATH}" lib)
-  set(COMPILER_RT_INSTALL_LIBRARY_DIR "${default_install_path}" CACHE PATH
-    "Path where built compiler-rt libraries should be installed.")
 else(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
   set(COMPILER_RT_OUTPUT_LIBRARY_DIR
     ${COMPILER_RT_OUTPUT_DIR}/lib/${COMPILER_RT_OS_DIR})
   extend_path(default_install_path "${COMPILER_RT_INSTALL_PATH}" "lib/${COMPILER_RT_OS_DIR}")
-  set(COMPILER_RT_INSTALL_LIBRARY_DIR "${default_install_path}" CACHE PATH
-    "Path where built compiler-rt libraries should be installed.")
 endif()
+set(COMPILER_RT_INSTALL_LIBRARY_DIR "${default_install_path}" CACHE PATH
+  "Path where built compiler-rt libraries should be installed.")
+unset(default_install_path)
+
 extend_path(default_install_path "${COMPILER_RT_INSTALL_PATH}" "${CMAKE_INSTALL_BINDIR}")
 set(COMPILER_RT_INSTALL_BINARY_DIR "${default_install_path}" CACHE PATH
   "Path where built compiler-rt executables should be installed.")
+unset(default_install_path)
+
 extend_path(default_install_path "${COMPILER_RT_INSTALL_PATH}" "${CMAKE_INSTALL_INCLUDEDIR}")
 set(COMPILER_RT_INSTALL_INCLUDE_DIR "${default_install_path}" CACHE PATH
   "Path where compiler-rt headers should be installed.")
+unset(default_install_path)
+
 extend_path(default_install_path "${COMPILER_RT_INSTALL_PATH}" "${CMAKE_INSTALL_DATADIR}")
 set(COMPILER_RT_INSTALL_DATA_DIR "${default_install_path}" CACHE PATH
   "Path where compiler-rt data files should be installed.")
+unset(default_install_path)
 
 if(APPLE)
   # On Darwin if /usr/include/c++ doesn't exist, the user probably has Xcode but
diff --git a/flang/CMakeLists.txt b/flang/CMakeLists.txt
--- a/flang/CMakeLists.txt
+++ b/flang/CMakeLists.txt
@@ -8,6 +8,7 @@
 set(CMAKE_CXX_EXTENSIONS OFF)
 
 set(FLANG_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
+set(FLANG_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
 
 if (CMAKE_SOURCE_DIR STREQUAL CMAKE_BINARY_DIR AND NOT MSVC_IDE)
   message(FATAL_ERROR "In-source builds are not allowed. \
@@ -29,11 +30,22 @@
   set(FLANG_STANDALONE_BUILD OFF)
 endif()
 
+if(NOT DEFINED LLVM_COMMON_CMAKE_UTILS)
+  set(LLVM_COMMON_CMAKE_UTILS ${FLANG_SOURCE_DIR}/../cmake)
+endif()
+
+list(INSERT CMAKE_MODULE_PATH 0
+  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
+  )
+
+# Must go before the first `include(GNUInstallDirs)`.
+include(LLVMLibdirSuffix)
+
 # Must go below project(..)
 include(GNUInstallDirs)
+include(GNUBinaryDirs)
 
 if (FLANG_STANDALONE_BUILD)
-  set(FLANG_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
   if (NOT MSVC_IDE)
     set(LLVM_ENABLE_ASSERTIONS ${ENABLE_ASSERTIONS}
       CACHE BOOL "Enable assertions")
@@ -189,12 +201,6 @@
          ${LLVM_INCLUDE_TESTS})
   set(FLANG_GTEST_AVAIL 1)
 
-  if(FLANG_STANDALONE_BUILD)
-    set(FLANG_BINARY_DIR ${CMAKE_BINARY_DIR}/tools/flang)
-  else()
-    set(FLANG_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
-  endif()
-
   set(BACKEND_PACKAGE_STRING "${PACKAGE_STRING}")
   set(MLIR_MAIN_SRC_DIR ${LLVM_MAIN_SRC_DIR}/../mlir/include ) # --src-root
   set(MLIR_INCLUDE_DIR ${LLVM_MAIN_SRC_DIR}/../mlir/include ) # --includedir
@@ -225,8 +231,7 @@
 
 # tco tool and FIR lib output directories
 if(FLANG_STANDALONE_BUILD)
-  set(LLVM_RUNTIME_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/bin)
-  set(LLVM_LIBRARY_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/lib)
+  include(LLVMSetIntDirs)
 endif()
 # Always build tco tool
 set(LLVM_BUILD_TOOLS ON)
@@ -235,14 +240,9 @@
   ${FLANG_BINARY_DIR}/include
   ${FLANG_SOURCE_DIR}/include)
 
-if(NOT DEFINED LLVM_COMMON_CMAKE_UTILS)
-  set(LLVM_COMMON_CMAKE_UTILS ${FLANG_SOURCE_DIR}/../cmake)
-endif()
-
 # Add Flang-centric modules to cmake path.
 list(INSERT CMAKE_MODULE_PATH 0
   "${FLANG_SOURCE_DIR}/cmake/modules"
-  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
   )
 include(AddFlang)
 
diff --git a/libc/CMakeLists.txt b/libc/CMakeLists.txt
--- a/libc/CMakeLists.txt
+++ b/libc/CMakeLists.txt
@@ -3,6 +3,12 @@
 # Default to C++17
 set(CMAKE_CXX_STANDARD 17)
 
+# Must go before the first `include(GNUInstallDirs)`.
+include(LLVMLibdirSuffix)
+
+include(GNUInstallDirs)
+include(GNUBinaryDirs)
+
 # Use old version of target_sources command which converts the source
 # file paths to full paths.
 cmake_policy(SET CMP0076 OLD)
diff --git a/libcxx/CMakeLists.txt b/libcxx/CMakeLists.txt
--- a/libcxx/CMakeLists.txt
+++ b/libcxx/CMakeLists.txt
@@ -22,7 +22,11 @@
 set(LIBCXX_BINARY_DIR  ${CMAKE_CURRENT_BINARY_DIR})
 set(LIBCXX_BINARY_INCLUDE_DIR "${LIBCXX_BINARY_DIR}/include/c++build")
 
+# Must go before the first `include(GNUInstallDirs)`.
+include(LLVMLibdirSuffix)
+
 include(GNUInstallDirs)
+include(GNUBinaryDirs)
 
 # Require out of source build.
 include(MacroEnsureOutOfSourceBuild)
@@ -151,8 +155,6 @@
 endif()
 
 option(LIBCXX_INCLUDE_DOCS "Build the libc++ documentation." ${LLVM_INCLUDE_DOCS})
-set(LIBCXX_LIBDIR_SUFFIX "${LLVM_LIBDIR_SUFFIX}" CACHE STRING
-    "Define suffix of library directory name (32/64)")
 option(LIBCXX_INSTALL_HEADERS "Install the libc++ headers." ON)
 option(LIBCXX_INSTALL_LIBRARY "Install the libc++ library." ON)
 cmake_dependent_option(LIBCXX_INSTALL_STATIC_LIBRARY
@@ -415,31 +417,43 @@
 set(LIBCXX_INSTALL_RUNTIME_DIR "${CMAKE_INSTALL_BINDIR}" CACHE PATH
     "Path where built libc++ runtime libraries should be installed.")
 
+if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+  set(default_install_path "${CMAKE_INSTALL_INCLUDEDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++/v1")
+else()
+  set(default_install_path "${LIBCXX_INSTALL_INCLUDE_DIR}")
+endif()
+set(LIBCXX_INSTALL_INCLUDE_TARGET_DIR "${default_install_path}" CACHE PATH
+    "Path where target-specific libc++ headers should be installed.")
+unset(default_install_path)
+
+if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+  set(default_install_path "lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}")
+else()
+  set(default_install_path "lib${LLVM_LIBDIR_SUFFIX}")
+endif()
+set(LIBCXX_INSTALL_LIBRARY_DIR "${default_install_path}" CACHE PATH
+    "Path where built libc++ libraries should be installed.")
+unset(default_install_path)
+
+get_filename_component(LIBCXX_LIBDIR_BASENAME "${LIBCXX_INSTALL_LIBRARY_DIR}" NAME)
+
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
   set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE})
   set(LIBCXX_GENERATED_INCLUDE_DIR "${LLVM_BINARY_DIR}/include/c++/v1")
   set(LIBCXX_GENERATED_INCLUDE_TARGET_DIR "${LLVM_BINARY_DIR}/include/${LLVM_DEFAULT_TARGET_TRIPLE}/c++/v1")
-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE} CACHE PATH
-      "Path where built libc++ libraries should be installed.")
-  set(LIBCXX_INSTALL_INCLUDE_TARGET_DIR "${CMAKE_INSTALL_INCLUDEDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++/v1" CACHE PATH
-      "Path where target-specific libc++ headers should be installed.")
   if(LIBCXX_LIBDIR_SUBDIR)
-    string(APPEND LIBCXX_LIBRARY_DIR /${LIBCXX_LIBDIR_SUBDIR})
-    string(APPEND LIBCXX_INSTALL_LIBRARY_DIR /${LIBCXX_LIBDIR_SUBDIR})
+    string(APPEND LIBCXX_LIBRARY_DIR "/${LIBCXX_LIBDIR_SUBDIR}")
+    string(APPEND LIBCXX_INSTALL_LIBRARY_DIR "/${LIBCXX_LIBDIR_SUBDIR}")
   endif()
 else()
   if(LLVM_LIBRARY_OUTPUT_INTDIR)
-    set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
+    set(LIBCXX_LIBRARY_DIR "${LLVM_LIBRARY_OUTPUT_INTDIR}")
     set(LIBCXX_GENERATED_INCLUDE_DIR "${LLVM_BINARY_DIR}/include/c++/v1")
   else()
-    set(LIBCXX_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXX_LIBDIR_SUFFIX})
-    set(LIBCXX_GENERATED_INCLUDE_DIR "${CMAKE_BINARY_DIR}/include/c++/v1")
+    set(LIBCXX_LIBRARY_DIR "${CMAKE_BINARY_DIR}/${LIBCXX_LIBDIR_BASENAME}")
+    set(LIBCXX_GENERATED_INCLUDE_DIR "${CMAKE_BINARY_INCLUDEDIR}/c++/v1")
   endif()
   set(LIBCXX_GENERATED_INCLUDE_TARGET_DIR "${LIBCXX_GENERATED_INCLUDE_DIR}")
-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LIBCXX_LIBDIR_SUFFIX} CACHE PATH
-      "Path where built libc++ libraries should be installed.")
-  set(LIBCXX_INSTALL_INCLUDE_TARGET_DIR "${LIBCXX_INSTALL_INCLUDE_DIR}" CACHE PATH
-      "Path where target-specific libc++ headers should be installed.")
 endif()
 
 file(MAKE_DIRECTORY "${LIBCXX_BINARY_INCLUDE_DIR}")
diff --git a/libcxx/docs/BuildingLibcxx.rst b/libcxx/docs/BuildingLibcxx.rst
--- a/libcxx/docs/BuildingLibcxx.rst
+++ b/libcxx/docs/BuildingLibcxx.rst
@@ -235,11 +235,6 @@
   Build libc++ as a static library. Either `LIBCXX_ENABLE_SHARED` or
   `LIBCXX_ENABLE_STATIC` has to be enabled.
 
-.. option:: LIBCXX_LIBDIR_SUFFIX:STRING
-
-  Extra suffix to append to the directory where libraries are to be installed.
-  This option overrides `LLVM_LIBDIR_SUFFIX`.
-
 .. option:: LIBCXX_HERMETIC_STATIC_LIBRARY:BOOL
 
   **Default**: ``OFF``
@@ -267,7 +262,7 @@
 
 .. option:: LIBCXX_INSTALL_LIBRARY_DIR:PATH
 
-  **Default**: ``lib${LIBCXX_LIBDIR_SUFFIX}``
+  **Default**: ``lib${LLVM_LIBDIR_SUFFIX}``
 
   Path where built libc++ libraries should be installed. If a relative path,
   relative to ``CMAKE_INSTALL_PREFIX``.
diff --git a/libcxxabi/CMakeLists.txt b/libcxxabi/CMakeLists.txt
--- a/libcxxabi/CMakeLists.txt
+++ b/libcxxabi/CMakeLists.txt
@@ -23,7 +23,11 @@
 set(LIBCXXABI_LIBCXX_PATH "${CMAKE_CURRENT_LIST_DIR}/../libcxx" CACHE PATH
         "Specify path to libc++ source.")
 
+# Must go before the first `include(GNUInstallDirs)`.
+include(LLVMLibdirSuffix)
+
 include(GNUInstallDirs)
+include(GNUBinaryDirs)
 
 # Require out of source build.
 include(MacroEnsureOutOfSourceBuild)
@@ -74,8 +78,6 @@
 endif()
 
 option(LIBCXXABI_INCLUDE_TESTS "Generate build targets for the libc++abi unit tests." ${LLVM_INCLUDE_TESTS})
-set(LIBCXXABI_LIBDIR_SUFFIX "${LLVM_LIBDIR_SUFFIX}" CACHE STRING
-    "Define suffix of library directory name (32/64)")
 option(LIBCXXABI_INSTALL_HEADERS "Install the libc++abi headers." ON)
 option(LIBCXXABI_INSTALL_LIBRARY "Install the libc++abi library." ON)
 
@@ -184,25 +186,32 @@
 set(LIBCXXABI_INSTALL_RUNTIME_DIR "${CMAKE_INSTALL_BINDIR}" CACHE PATH
     "Path where built libc++abi runtime libraries should be installed.")
 
+if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+  set(default_install_path "lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}")
+else()
+  set(default_install_path "lib${LLVM_LIBDIR_SUFFIX}")
+endif()
+set(LIBCXXABI_INSTALL_LIBRARY_DIR "${default_install_path}" CACHE PATH
+    "Path where built libc++abi libraries should be installed.")
+unset(default_install_path)
+
+get_filename_component(LIBCXXABI_LIBDIR_BASENAME "${LIBCXXABI_INSTALL_LIBRARY_DIR}" NAME)
+
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
   set(LIBCXXABI_HEADER_DIR ${LLVM_BINARY_DIR})
   set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE})
-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE} CACHE PATH
-      "Path where built libc++abi libraries should be installed.")
   if(LIBCXX_LIBDIR_SUBDIR)
-    string(APPEND LIBCXXABI_LIBRARY_DIR /${LIBCXXABI_LIBDIR_SUBDIR})
-    string(APPEND LIBCXXABI_INSTALL_LIBRARY_DIR /${LIBCXXABI_LIBDIR_SUBDIR})
+    string(APPEND LIBCXXABI_LIBRARY_DIR "/${LIBCXXABI_LIBDIR_SUBDIR}")
+    string(APPEND LIBCXXABI_INSTALL_LIBRARY_DIR "/${LIBCXXABI_LIBDIR_SUBDIR}")
   endif()
 else()
   if(LLVM_LIBRARY_OUTPUT_INTDIR)
-    set(LIBCXXABI_HEADER_DIR ${LLVM_BINARY_DIR})
-    set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
+    set(LIBCXXABI_HEADER_DIR "${LLVM_BINARY_DIR}")
+    set(LIBCXXABI_LIBRARY_DIR "${LLVM_LIBRARY_OUTPUT_INTDIR}")
   else()
     set(LIBCXXABI_HEADER_DIR ${CMAKE_BINARY_DIR})
-    set(LIBCXXABI_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXXABI_LIBDIR_SUFFIX})
+    set(LIBCXXABI_LIBRARY_DIR "${CMAKE_BINARY_DIR}/${LIBCXXABI_LIBDIR_BASENAME}")
   endif()
-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LIBCXXABI_LIBDIR_SUFFIX} CACHE PATH
-      "Path where built libc++abi libraries should be installed.")
 endif()
 
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${LIBCXXABI_LIBRARY_DIR})
diff --git a/libunwind/CMakeLists.txt b/libunwind/CMakeLists.txt
--- a/libunwind/CMakeLists.txt
+++ b/libunwind/CMakeLists.txt
@@ -19,7 +19,11 @@
 set(LIBUNWIND_LIBCXX_PATH "${CMAKE_CURRENT_LIST_DIR}/../libcxx" CACHE PATH
         "Specify path to libc++ source.")
 
+# Must go before the first `include(GNUInstallDirs)`.
+include(LLVMLibdirSuffix)
+
 include(GNUInstallDirs)
+include(GNUBinaryDirs)
 
 #===============================================================================
 # Setup CMake Options
@@ -51,8 +55,6 @@
 option(LIBUNWIND_REMEMBER_HEAP_ALLOC "Use heap instead of the stack for .cfi_remember_state." OFF)
 option(LIBUNWIND_INSTALL_HEADERS "Install the libunwind headers." OFF)
 
-set(LIBUNWIND_LIBDIR_SUFFIX "${LLVM_LIBDIR_SUFFIX}" CACHE STRING
-    "Define suffix of library directory name (32/64)")
 option(LIBUNWIND_INSTALL_LIBRARY "Install the libunwind library." ON)
 cmake_dependent_option(LIBUNWIND_INSTALL_STATIC_LIBRARY
   "Install the static libunwind library." ON
@@ -116,21 +118,28 @@
     "Path where built libunwind runtime libraries should be installed.")
 
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
-  set(LIBUNWIND_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE})
-  set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE} CACHE PATH
-      "Path where built libunwind libraries should be installed.")
+  set(default_install_path "lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}")
+else()
+  set(default_install_path "lib${LLVM_LIBDIR_SUFFIX}")
+endif()
+set(LIBUNWIND_INSTALL_LIBRARY_DIR "${default_install_path}" CACHE PATH
+    "Path where built libunwind libraries should be installed.")
+unset(default_install_path)
+
+get_filename_component(LIBUNWIND_LIBDIR_BASENAME "${LIBUNWIND_INSTALL_LIBRARY_DIR}" NAME)
+
+if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+  set(LIBUNWIND_LIBRARY_DIR "${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}")
   if(LIBCXX_LIBDIR_SUBDIR)
-    string(APPEND LIBUNWIND_LIBRARY_DIR /${LIBUNWIND_LIBDIR_SUBDIR})
-    string(APPEND LIBUNWIND_INSTALL_LIBRARY_DIR /${LIBUNWIND_LIBDIR_SUBDIR})
+    string(APPEND LIBUNWIND_LIBRARY_DIR "/${LIBUNWIND_LIBDIR_SUBDIR}")
+    string(APPEND LIBUNWIND_INSTALL_LIBRARY_DIR "/${LIBUNWIND_LIBDIR_SUBDIR}")
   endif()
 else()
   if(LLVM_LIBRARY_OUTPUT_INTDIR)
-    set(LIBUNWIND_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
+    set(LIBUNWIND_LIBRARY_DIR "${LLVM_LIBRARY_OUTPUT_INTDIR}")
   else()
-    set(LIBUNWIND_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBUNWIND_LIBDIR_SUFFIX})
+    set(LIBUNWIND_LIBRARY_DIR "${CMAKE_BINARY_DIR}/${LIBUNWIND_LIBDIR_BASENAME}")
   endif()
-  set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LIBUNWIND_LIBDIR_SUFFIX} CACHE PATH
-      "Path where built libunwind libraries should be installed.")
 endif()
 
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${LIBUNWIND_LIBRARY_DIR})
diff --git a/libunwind/docs/BuildingLibunwind.rst b/libunwind/docs/BuildingLibunwind.rst
--- a/libunwind/docs/BuildingLibunwind.rst
+++ b/libunwind/docs/BuildingLibunwind.rst
@@ -144,7 +144,7 @@
 
 .. option:: LIBUNWIND_INSTALL_LIBRARY_DIR:PATH
 
-  **Default**: ``lib${LIBUNWIND_LIBDIR_SUFFIX}``
+  **Default**: ``lib${LLVM_LIBDIR_SUFFIX}``
 
   Path where built libunwind libraries should be installed. If a relative path,
   relative to ``CMAKE_INSTALL_PREFIX``.
diff --git a/lld/CMakeLists.txt b/lld/CMakeLists.txt
--- a/lld/CMakeLists.txt
+++ b/lld/CMakeLists.txt
@@ -1,5 +1,8 @@
 cmake_minimum_required(VERSION 3.13.4)
 
+set(LLD_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
+set(LLD_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
+
 # If we are not building as a part of LLVM, build LLD as an
 # standalone project, using LLVM as an external library:
 if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
@@ -7,8 +10,20 @@
   set(LLD_BUILT_STANDALONE TRUE)
 endif()
 
+if(NOT DEFINED LLVM_COMMON_CMAKE_UTILS)
+  set(LLVM_COMMON_CMAKE_UTILS ${LLD_SOURCE_DIR}/../cmake)
+endif()
+
+list(INSERT CMAKE_MODULE_PATH 0
+  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
+  )
+
+# Must go before the first `include(GNUInstallDirs)`.
+include(LLVMLibdirSuffix)
+
 # Must go below project(..)
 include(GNUInstallDirs)
+include(GNUBinaryDirs)
 
 if(LLD_BUILT_STANDALONE)
   set(CMAKE_CXX_STANDARD 17 CACHE STRING "C++ standard to conform to")
@@ -29,8 +44,7 @@
     NO_DEFAULT_PATH)
 
   # They are used as destination of target generators.
-  set(LLVM_RUNTIME_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin)
-  set(LLVM_LIBRARY_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX})
+  include(LLVMSetIntDirs)
 
   include(AddLLVM)
   include(TableGen)
@@ -105,9 +119,7 @@
     "Path for binary subdirectory (defaults to '${CMAKE_INSTALL_BINDIR}')")
 mark_as_advanced(LLD_TOOLS_INSTALL_DIR)
 
-set(LLD_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
 set(LLD_INCLUDE_DIR ${LLD_SOURCE_DIR}/include )
-set(LLD_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
 
 set(LLD_VENDOR ${PACKAGE_VENDOR} CACHE STRING
   "Vendor-specific text for showing with version information.")
@@ -140,14 +152,9 @@
 "`CMakeFiles'. Please delete them.")
 endif()
 
-if(NOT DEFINED LLVM_COMMON_CMAKE_UTILS)
-  set(LLVM_COMMON_CMAKE_UTILS ${LLD_SOURCE_DIR}/../cmake)
-endif()
-
 # Add path for custom modules.
 list(INSERT CMAKE_MODULE_PATH 0
   "${LLD_SOURCE_DIR}/cmake/modules"
-  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
   )
 
 include(AddLLD)
diff --git a/lldb/CMakeLists.txt b/lldb/CMakeLists.txt
--- a/lldb/CMakeLists.txt
+++ b/lldb/CMakeLists.txt
@@ -1,12 +1,5 @@
 cmake_minimum_required(VERSION 3.13.4)
 
-# Add path for custom modules.
-set(CMAKE_MODULE_PATH
-  ${CMAKE_MODULE_PATH}
-  "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
-  "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules"
-  )
-
 # If we are not building as part of LLVM, build LLDB as a standalone project,
 # using LLVM as an external library.
 if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
@@ -14,8 +7,26 @@
   set(LLDB_BUILT_STANDALONE TRUE)
 endif()
 
+if(NOT DEFINED LLVM_COMMON_CMAKE_UTILS)
+  set(LLVM_COMMON_CMAKE_UTILS ${CMAKE_CURRENT_SOURCE_DIR}/../cmake)
+endif()
+
+list(INSERT CMAKE_MODULE_PATH 0
+  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
+  )
+
+# Must go before the first `include(GNUInstallDirs)`.
+include(LLVMLibdirSuffix)
+
 # Must go below project(..)
 include(GNUInstallDirs)
+include(GNUBinaryDirs)
+
+# Add path for custom modules.
+list(INSERT CMAKE_MODULE_PATH 0
+  "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
+  "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules"
+  )
 
 if(LLDB_BUILT_STANDALONE)
   include(LLDBStandalone)
diff --git a/lldb/cmake/modules/LLDBStandalone.cmake b/lldb/cmake/modules/LLDBStandalone.cmake
--- a/lldb/cmake/modules/LLDBStandalone.cmake
+++ b/lldb/cmake/modules/LLDBStandalone.cmake
@@ -4,12 +4,6 @@
   cmake_policy(SET CMP0116 OLD)
 endif()
 
-if(NOT DEFINED LLVM_COMMON_CMAKE_UTILS)
-  set(LLVM_COMMON_CMAKE_UTILS ${CMAKE_CURRENT_SOURCE_DIR}/../cmake)
-endif()
-
-list(APPEND CMAKE_MODULE_PATH "${LLVM_COMMON_CMAKE_UTILS}/Modules")
-
 option(LLVM_INSTALL_TOOLCHAIN_ONLY "Only include toolchain files in the 'install' target." OFF)
 
 find_package(LLVM REQUIRED CONFIG HINTS ${LLVM_DIR} NO_CMAKE_FIND_ROOT_PATH)
@@ -74,15 +68,7 @@
   endif()
 endif()
 
-# They are used as destination of target generators.
-set(LLVM_RUNTIME_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin)
-set(LLVM_LIBRARY_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX})
-if(WIN32 OR CYGWIN)
-  # DLL platform -- put DLLs into bin.
-  set(LLVM_SHLIB_OUTPUT_INTDIR ${LLVM_RUNTIME_OUTPUT_INTDIR})
-else()
-  set(LLVM_SHLIB_OUTPUT_INTDIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
-endif()
+include(LLVMSetIntDirs)
 
 # We append the directory in which LLVMConfig.cmake lives. We expect LLVM's
 # CMake modules to be in that directory as well.
diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -51,20 +51,26 @@
   set(CMAKE_OSX_ARCHITECTURES "x86_64")
 endif()
 
+set(LLVM_COMMON_CMAKE_UTILS ${CMAKE_CURRENT_SOURCE_DIR}/../cmake)
+
+# Add path for common private CMake modules
+list(INSERT CMAKE_MODULE_PATH 0
+  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
+  )
+
 project(LLVM
   VERSION ${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR}.${LLVM_VERSION_PATCH}
   LANGUAGES C CXX ASM)
 
-if (NOT DEFINED CMAKE_INSTALL_LIBDIR AND DEFINED LLVM_LIBDIR_SUFFIX)
-  # Must go before `include(GNUInstallDirs)`.
-  set(CMAKE_INSTALL_LIBDIR "lib${LLVM_LIBDIR_SUFFIX}")
-endif()
+# Must go before the first `include(GNUInstallDirs)`.
+include(LLVMLibdirSuffix)
 
-# Must go after `DEFINED LLVM_LIBDIR_SUFFIX` check.
+# Must go after `include(LLVMLibdirSuffix)`.
 set(LLVM_LIBDIR_SUFFIX "" CACHE STRING "Define suffix of library directory name (32/64)" )
 
 # Must go after `project(..)`.
 include(GNUInstallDirs)
+include(GNUBinaryDirs)
 
 # This C++ standard is required to build LLVM.
 set(LLVM_REQUIRED_CXX_STANDARD 17)
@@ -279,7 +285,6 @@
 list(INSERT CMAKE_MODULE_PATH 0
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules"
-  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
   )
 
 # Generate a CompilationDatabase (compile_commands.json file) for our build,
@@ -381,14 +386,7 @@
 mark_as_advanced(LLVM_EXAMPLES_INSTALL_DIR)
 
 # They are used as destination of target generators.
-set(LLVM_RUNTIME_OUTPUT_INTDIR ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin)
-set(LLVM_LIBRARY_OUTPUT_INTDIR ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX})
-if(WIN32 OR CYGWIN)
-  # DLL platform -- put DLLs into bin.
-  set(LLVM_SHLIB_OUTPUT_INTDIR ${LLVM_RUNTIME_OUTPUT_INTDIR})
-else()
-  set(LLVM_SHLIB_OUTPUT_INTDIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
-endif()
+include(LLVMSetIntDirs)
 
 # Each of them corresponds to llvm-config's.
 set(LLVM_TOOLS_BINARY_DIR ${LLVM_RUNTIME_OUTPUT_INTDIR}) # --bindir
diff --git a/mlir/CMakeLists.txt b/mlir/CMakeLists.txt
--- a/mlir/CMakeLists.txt
+++ b/mlir/CMakeLists.txt
@@ -1,13 +1,28 @@
 # MLIR project.
 
+set(MLIR_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
+set(MLIR_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
+
 # Check if MLIR is built as a standalone project.
 if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
   project(mlir)
   set(MLIR_STANDALONE_BUILD TRUE)
 endif()
 
+if(NOT DEFINED LLVM_COMMON_CMAKE_UTILS)
+  set(LLVM_COMMON_CMAKE_UTILS ${CMAKE_CURRENT_SOURCE_DIR}/../cmake)
+endif()
+
+list(INSERT CMAKE_MODULE_PATH 0
+  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
+  )
+
+# Must go before the first `include(GNUInstallDirs)`.
+include(LLVMLibdirSuffix)
+
 # Must go below project(..)
 include(GNUInstallDirs)
+include(GNUBinaryDirs)
 
 if(MLIR_STANDALONE_BUILD)
   cmake_minimum_required(VERSION 3.13.4)
@@ -36,12 +51,10 @@
     "Path for binary subdirectory (defaults to '${CMAKE_INSTALL_BINDIR}')")
 mark_as_advanced(MLIR_TOOLS_INSTALL_DIR)
 
-set(MLIR_MAIN_SRC_DIR     ${CMAKE_CURRENT_SOURCE_DIR}  )
+set(MLIR_MAIN_SRC_DIR     ${MLIR_SOURCE_DIR}           )
 set(MLIR_MAIN_INCLUDE_DIR ${MLIR_MAIN_SRC_DIR}/include )
 
-set(MLIR_SOURCE_DIR  ${CMAKE_CURRENT_SOURCE_DIR})
-set(MLIR_BINARY_DIR  ${CMAKE_CURRENT_BINARY_DIR})
-set(MLIR_INCLUDE_DIR ${CMAKE_CURRENT_BINARY_DIR}/include)
+set(MLIR_INCLUDE_DIR ${MLIR_BINARY_DIR}/include)
 set(MLIR_TOOLS_DIR   ${CMAKE_RUNTIME_OUTPUT_DIRECTORY})
 
 if(NOT DEFINED LLVM_COMMON_CMAKE_UTILS)
@@ -52,7 +65,6 @@
 # that we can include cmake files from this directory.
 list(INSERT CMAKE_MODULE_PATH 0
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules"
-  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
   )
 
 include(AddMLIR)
diff --git a/openmp/CMakeLists.txt b/openmp/CMakeLists.txt
--- a/openmp/CMakeLists.txt
+++ b/openmp/CMakeLists.txt
@@ -1,12 +1,5 @@
 cmake_minimum_required(VERSION 3.13.4)
 
-set(LLVM_COMMON_CMAKE_UTILS ${CMAKE_CURRENT_SOURCE_DIR}/../cmake)
-
-# Add path for custom modules
-list(INSERT CMAKE_MODULE_PATH 0
-  "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
-  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
-  )
 
 # llvm/runtimes/ will set OPENMP_STANDALONE_BUILD.
 if (OPENMP_STANDALONE_BUILD OR "${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}")
@@ -14,6 +7,18 @@
   project(openmp C CXX)
 endif()
 
+if(NOT DEFINED LLVM_COMMON_CMAKE_UTILS)
+  set(LLVM_COMMON_CMAKE_UTILS ${CMAKE_CURRENT_SOURCE_DIR}/../cmake)
+endif()
+
+# Add path for custom modules
+list(INSERT CMAKE_MODULE_PATH 0
+  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
+  )
+
+# Must go before the first `include(GNUInstallDirs)`.
+include(LLVMLibdirSuffix)
+
 # Must go below project(..)
 include(GNUInstallDirs)
 
@@ -51,6 +56,11 @@
   endif()
 endif()
 
+# Add path for custom modules
+list(INSERT CMAKE_MODULE_PATH 0
+  "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
+  )
+
 # Check and set up common compiler flags.
 include(config-ix)
 include(HandleOpenMPOptions)
diff --git a/polly/CMakeLists.txt b/polly/CMakeLists.txt
--- a/polly/CMakeLists.txt
+++ b/polly/CMakeLists.txt
@@ -1,12 +1,28 @@
 # Check if this is a in tree build.
+
+set(POLLY_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
+set(POLLY_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
+
 if (NOT DEFINED LLVM_MAIN_SRC_DIR)
   project(Polly)
   cmake_minimum_required(VERSION 3.13.4)
   set(POLLY_STANDALONE_BUILD TRUE)
 endif()
 
+if(NOT DEFINED LLVM_COMMON_CMAKE_UTILS)
+  set(LLVM_COMMON_CMAKE_UTILS ${POLLY_SOURCE_DIR}/../cmake)
+endif()
+
+list(INSERT CMAKE_MODULE_PATH 0
+  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
+  )
+
+# Must go before the first `include(GNUInstallDirs)`.
+include(LLVMLibdirSuffix)
+
 # Must go below project(..)
 include(GNUInstallDirs)
+include(GNUBinaryDirs)
 
 if(POLLY_STANDALONE_BUILD)
   # Where is LLVM installed?
@@ -48,18 +64,10 @@
   set(POLLY_GTEST_AVAIL 1)
 endif ()
 
-set(POLLY_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
-set(POLLY_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
-
-if(NOT DEFINED LLVM_COMMON_CMAKE_UTILS)
-  set(LLVM_COMMON_CMAKE_UTILS ${POLLY_SOURCE_DIR}/../cmake)
-endif()
-
 # Make sure that our source directory is on the current cmake module path so that
 # we can include cmake files from this directory.
 list(INSERT CMAKE_MODULE_PATH 0
   "${POLLY_SOURCE_DIR}/cmake"
-  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
   )
 
 include("polly_macros")