diff --git a/clang-tools-extra/clang-doc/tool/CMakeLists.txt b/clang-tools-extra/clang-doc/tool/CMakeLists.txt
--- a/clang-tools-extra/clang-doc/tool/CMakeLists.txt
+++ b/clang-tools-extra/clang-doc/tool/CMakeLists.txt
@@ -19,9 +19,9 @@
   )
 
 install(FILES ../assets/clang-doc-default-stylesheet.css
-  DESTINATION share/clang
+  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
   COMPONENT clang-doc)
 
 install(FILES ../assets/index.js
-  DESTINATION share/clang
+  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
   COMPONENT clang-doc)
diff --git a/clang-tools-extra/clang-include-fixer/find-all-symbols/tool/CMakeLists.txt b/clang-tools-extra/clang-include-fixer/find-all-symbols/tool/CMakeLists.txt
--- a/clang-tools-extra/clang-include-fixer/find-all-symbols/tool/CMakeLists.txt
+++ b/clang-tools-extra/clang-include-fixer/find-all-symbols/tool/CMakeLists.txt
@@ -20,5 +20,5 @@
   )
 
 install(PROGRAMS run-find-all-symbols.py
-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
   COMPONENT find-all-symbols)
diff --git a/clang-tools-extra/clang-include-fixer/tool/CMakeLists.txt b/clang-tools-extra/clang-include-fixer/tool/CMakeLists.txt
--- a/clang-tools-extra/clang-include-fixer/tool/CMakeLists.txt
+++ b/clang-tools-extra/clang-include-fixer/tool/CMakeLists.txt
@@ -21,8 +21,8 @@
   )
 
 install(PROGRAMS clang-include-fixer.el
-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
   COMPONENT clang-include-fixer)
 install(PROGRAMS clang-include-fixer.py
-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
   COMPONENT clang-include-fixer)
diff --git a/clang-tools-extra/clang-tidy/CMakeLists.txt b/clang-tools-extra/clang-tidy/CMakeLists.txt
--- a/clang-tools-extra/clang-tidy/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/CMakeLists.txt
@@ -113,7 +113,7 @@
 
 if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
   install(DIRECTORY .
-    DESTINATION include/clang-tidy
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/clang-tidy
     COMPONENT clang-tidy-headers
     FILES_MATCHING
     PATTERN "*.h"
diff --git a/clang-tools-extra/clang-tidy/tool/CMakeLists.txt b/clang-tools-extra/clang-tidy/tool/CMakeLists.txt
--- a/clang-tools-extra/clang-tidy/tool/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/tool/CMakeLists.txt
@@ -52,9 +52,9 @@
 
 
 install(PROGRAMS clang-tidy-diff.py
-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
   COMPONENT clang-tidy)
 install(PROGRAMS run-clang-tidy.py
-  DESTINATION bin
+  DESTINATION ${CMAKE_INSTALL_BINDIR}
   COMPONENT clang-tidy
   RENAME run-clang-tidy)
diff --git a/clang-tools-extra/modularize/CMakeLists.txt b/clang-tools-extra/modularize/CMakeLists.txt
--- a/clang-tools-extra/modularize/CMakeLists.txt
+++ b/clang-tools-extra/modularize/CMakeLists.txt
@@ -23,5 +23,5 @@
   )
 
 install(TARGETS modularize
-        RUNTIME DESTINATION bin
+        RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
         COMPONENT clang-extras)
diff --git a/clang/CMakeLists.txt b/clang/CMakeLists.txt
--- a/clang/CMakeLists.txt
+++ b/clang/CMakeLists.txt
@@ -4,7 +4,11 @@
 # standalone project, using LLVM as an external library:
 if( CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR )
   project(Clang)
+endif()
+
+include(GNUInstallDirs)
 
+if( CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR )
   set(CMAKE_CXX_STANDARD 14 CACHE STRING "C++ standard to conform to")
   set(CMAKE_CXX_STANDARD_REQUIRED YES)
   set(CMAKE_CXX_EXTENSIONS NO)
@@ -418,7 +422,7 @@
 
 if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
   install(DIRECTORY include/clang include/clang-c
-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
     COMPONENT clang-headers
     FILES_MATCHING
     PATTERN "*.def"
@@ -427,7 +431,7 @@
     )
 
   install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/include/clang
-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
     COMPONENT clang-headers
     FILES_MATCHING
     PATTERN "CMakeFiles" EXCLUDE
@@ -447,7 +451,7 @@
 
   add_custom_target(bash-autocomplete DEPENDS utils/bash-autocomplete.sh)
   install(PROGRAMS utils/bash-autocomplete.sh
-          DESTINATION share/clang
+          DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
           COMPONENT bash-autocomplete)
   if(NOT LLVM_ENABLE_IDE)
     add_llvm_install_targets(install-bash-autocomplete
diff --git a/clang/cmake/modules/AddClang.cmake b/clang/cmake/modules/AddClang.cmake
--- a/clang/cmake/modules/AddClang.cmake
+++ b/clang/cmake/modules/AddClang.cmake
@@ -125,7 +125,7 @@
           ${export_to_clangtargets}
           LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
           ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
-          RUNTIME DESTINATION bin)
+          RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
 
         if (NOT LLVM_ENABLE_IDE)
           add_llvm_install_targets(install-${lib}
@@ -170,7 +170,7 @@
 
     install(TARGETS ${name}
       ${export_to_clangtargets}
-      RUNTIME DESTINATION bin
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
       COMPONENT ${name})
 
     if(NOT LLVM_ENABLE_IDE)
@@ -185,7 +185,7 @@
 macro(add_clang_symlink name dest)
   add_llvm_tool_symlink(${name} ${dest} ALWAYS_GENERATE)
   # Always generate install targets
-  llvm_install_symlink(${name} ${dest} ALWAYS_GENERATE)
+  llvm_install_symlink(${name} ${dest} ${CMAKE_INSTALL_FULL_BINDIR} ALWAYS_GENERATE)
 endmacro()
 
 function(clang_target_link_libraries target type)
diff --git a/clang/tools/c-index-test/CMakeLists.txt b/clang/tools/c-index-test/CMakeLists.txt
--- a/clang/tools/c-index-test/CMakeLists.txt
+++ b/clang/tools/c-index-test/CMakeLists.txt
@@ -54,7 +54,7 @@
     set_property(TARGET c-index-test APPEND PROPERTY INSTALL_RPATH
        "@executable_path/../../lib")
   else()
-    set(INSTALL_DESTINATION bin)
+    set(INSTALL_DESTINATION ${CMAKE_INSTALL_BINDIR})
   endif()
 
   install(TARGETS c-index-test
diff --git a/clang/tools/clang-format/CMakeLists.txt b/clang/tools/clang-format/CMakeLists.txt
--- a/clang/tools/clang-format/CMakeLists.txt
+++ b/clang/tools/clang-format/CMakeLists.txt
@@ -21,20 +21,20 @@
 endif()
 
 install(PROGRAMS clang-format-bbedit.applescript
-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
   COMPONENT clang-format)
 install(PROGRAMS clang-format-diff.py
-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
   COMPONENT clang-format)
 install(PROGRAMS clang-format-sublime.py
-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
   COMPONENT clang-format)
 install(PROGRAMS clang-format.el
-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
   COMPONENT clang-format)
 install(PROGRAMS clang-format.py
-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
   COMPONENT clang-format)
 install(PROGRAMS git-clang-format
-  DESTINATION bin
+  DESTINATION ${CMAKE_INSTALL_BINDIR}
   COMPONENT clang-format)
diff --git a/clang/tools/clang-rename/CMakeLists.txt b/clang/tools/clang-rename/CMakeLists.txt
--- a/clang/tools/clang-rename/CMakeLists.txt
+++ b/clang/tools/clang-rename/CMakeLists.txt
@@ -19,8 +19,8 @@
   )
 
 install(PROGRAMS clang-rename.py
-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
   COMPONENT clang-rename)
 install(PROGRAMS clang-rename.el
-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
   COMPONENT clang-rename)
diff --git a/clang/tools/libclang/CMakeLists.txt b/clang/tools/libclang/CMakeLists.txt
--- a/clang/tools/libclang/CMakeLists.txt
+++ b/clang/tools/libclang/CMakeLists.txt
@@ -150,7 +150,7 @@
 if(INTERNAL_INSTALL_PREFIX)
   set(LIBCLANG_HEADERS_INSTALL_DESTINATION "${INTERNAL_INSTALL_PREFIX}/include")
 else()
-  set(LIBCLANG_HEADERS_INSTALL_DESTINATION include)
+  set(LIBCLANG_HEADERS_INSTALL_DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
 endif()
 
 install(DIRECTORY ../../include/clang-c
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
@@ -47,7 +47,7 @@
                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/bin/${BinFile})
     list(APPEND Depends ${CMAKE_BINARY_DIR}/bin/${BinFile})
     install(PROGRAMS bin/${BinFile}
-            DESTINATION bin
+            DESTINATION ${CMAKE_INSTALL_BINDIR}
             COMPONENT scan-build)
   endforeach()
 
@@ -61,7 +61,7 @@
                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/libexec/${LibexecFile})
     list(APPEND Depends ${CMAKE_BINARY_DIR}/libexec/${LibexecFile})
     install(PROGRAMS libexec/${LibexecFile}
-            DESTINATION libexec
+            DESTINATION ${CMAKE_INSTALL_LIBEXECDIR}
             COMPONENT scan-build)
   endforeach()
 
@@ -89,7 +89,7 @@
                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/share/scan-build/${ShareFile})
     list(APPEND Depends ${CMAKE_BINARY_DIR}/share/scan-build/${ShareFile})
     install(FILES share/scan-build/${ShareFile}
-            DESTINATION share/scan-build
+            DESTINATION ${CMAKE_INSTALL_DATADIR}/scan-build
             COMPONENT scan-build)
   endforeach()
 
diff --git a/clang/tools/scan-view/CMakeLists.txt b/clang/tools/scan-view/CMakeLists.txt
--- a/clang/tools/scan-view/CMakeLists.txt
+++ b/clang/tools/scan-view/CMakeLists.txt
@@ -20,7 +20,7 @@
                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/bin/${BinFile})
     list(APPEND Depends ${CMAKE_BINARY_DIR}/bin/${BinFile})
     install(PROGRAMS bin/${BinFile}
-            DESTINATION bin
+            DESTINATION ${CMAKE_INSTALL_BINDIR}
             COMPONENT scan-view)
   endforeach()
 
@@ -34,7 +34,7 @@
                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/share/${ShareFile})
     list(APPEND Depends ${CMAKE_BINARY_DIR}/share/scan-view/${ShareFile})
     install(FILES share/${ShareFile}
-            DESTINATION share/scan-view
+            DESTINATION ${CMAKE_INSTALL_DATADIR}/scan-view
             COMPONENT scan-view)
   endforeach()
 
diff --git a/clang/utils/hmaptool/CMakeLists.txt b/clang/utils/hmaptool/CMakeLists.txt
--- a/clang/utils/hmaptool/CMakeLists.txt
+++ b/clang/utils/hmaptool/CMakeLists.txt
@@ -10,7 +10,7 @@
 
 list(APPEND Depends ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin/${CLANG_HMAPTOOL})
 install(PROGRAMS ${CLANG_HMAPTOOL}
-        DESTINATION bin
+        DESTINATION ${CMAKE_INSTALL_BINDIR}
         COMPONENT hmaptool)
 
 add_custom_target(hmaptool ALL DEPENDS ${Depends})
diff --git a/flang/CMakeLists.txt b/flang/CMakeLists.txt
--- a/flang/CMakeLists.txt
+++ b/flang/CMakeLists.txt
@@ -9,6 +9,8 @@
 set(CMAKE_CXX_STANDARD_REQUIRED TRUE)
 set(CMAKE_CXX_EXTENSIONS OFF)
 
+include(GNUInstallDirs)
+
 set(FLANG_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
 
 if (CMAKE_SOURCE_DIR STREQUAL CMAKE_BINARY_DIR AND NOT MSVC_IDE)
@@ -437,7 +439,7 @@
 
 if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
   install(DIRECTORY include/flang
-    DESTINATION include
+    DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}"
     COMPONENT flang-headers
     FILES_MATCHING
     PATTERN "*.def"
diff --git a/flang/cmake/modules/AddFlang.cmake b/flang/cmake/modules/AddFlang.cmake
--- a/flang/cmake/modules/AddFlang.cmake
+++ b/flang/cmake/modules/AddFlang.cmake
@@ -76,7 +76,7 @@
         ${export_to_flangtargets}
         LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
         ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
-        RUNTIME DESTINATION bin)
+        RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
 
       if (NOT LLVM_ENABLE_IDE)
         add_llvm_install_targets(install-${name}
@@ -119,7 +119,7 @@
 
     install(TARGETS ${name}
       ${export_to_flangtargets}
-      RUNTIME DESTINATION bin
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
       COMPONENT ${name})
 
     if(NOT LLVM_ENABLE_IDE)
@@ -134,6 +134,6 @@
 macro(add_flang_symlink name dest)
   add_llvm_tool_symlink(${name} ${dest} ALWAYS_GENERATE)
   # Always generate install targets
-  llvm_install_symlink(${name} ${dest} ALWAYS_GENERATE)
+  llvm_install_symlink(${name} ${dest} ${CMAKE_INSTALL_FULL_BINDIR} ALWAYS_GENERATE)
 endmacro()
 
diff --git a/flang/tools/f18/CMakeLists.txt b/flang/tools/f18/CMakeLists.txt
--- a/flang/tools/f18/CMakeLists.txt
+++ b/flang/tools/f18/CMakeLists.txt
@@ -55,17 +55,17 @@
     DEPENDS ${base}.mod
     COMMAND ${CMAKE_COMMAND} -E copy ${base}.mod ${base}.f18.mod)
   list(APPEND MODULE_FILES ${base}.mod ${base}.f18.mod)
-  install(FILES ${base}.mod ${base}.f18.mod DESTINATION include/flang)
+  install(FILES ${base}.mod ${base}.f18.mod DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/flang)
 endforeach()
 
 add_custom_target(module_files ALL DEPENDS ${MODULE_FILES})
 
-install(TARGETS f18 DESTINATION bin)
+install(TARGETS f18 DESTINATION ${CMAKE_INSTALL_BINDIR})
 
 # This flang shell script will only work in a POSIX shell.
 if (NOT WIN32)
   file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/flang
     DESTINATION ${CMAKE_BINARY_DIR}/bin
     FILE_PERMISSIONS OWNER_EXECUTE OWNER_READ OWNER_WRITE)
-  install(PROGRAMS ${CMAKE_BINARY_DIR}/bin/flang DESTINATION bin)
+  install(PROGRAMS ${CMAKE_BINARY_DIR}/bin/flang DESTINATION ${CMAKE_INSTALL_BINDIR})
 endif()
diff --git a/flang/tools/flang-driver/CMakeLists.txt b/flang/tools/flang-driver/CMakeLists.txt
--- a/flang/tools/flang-driver/CMakeLists.txt
+++ b/flang/tools/flang-driver/CMakeLists.txt
@@ -27,4 +27,4 @@
   clangBasic
 )
 
-install(TARGETS flang-new DESTINATION bin)
+install(TARGETS flang-new DESTINATION ${CMAKE_INSTALL_BINDIR})
diff --git a/libc/CMakeLists.txt b/libc/CMakeLists.txt
--- a/libc/CMakeLists.txt
+++ b/libc/CMakeLists.txt
@@ -1,5 +1,7 @@
 cmake_minimum_required(VERSION 3.13.4)
 
+include(GNUInstallDirs)
+
 # 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
@@ -27,7 +27,11 @@
 
 if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBCXX_STANDALONE_BUILD)
   project(libcxx CXX C)
+endif()
+
+include(GNUInstallDirs)
 
+if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBCXX_STANDALONE_BUILD)
   set(PACKAGE_NAME libcxx)
   set(PACKAGE_VERSION 13.0.0git)
   set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
@@ -416,11 +420,11 @@
 elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
   set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
   set(LIBCXX_GENERATED_INCLUDE_DIR "${LLVM_BINARY_DIR}/include/c++/v1")
-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LIBCXX_LIBDIR_SUFFIX})
+  set(LIBCXX_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXX_LIBDIR_SUFFIX})
 else()
   set(LIBCXX_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXX_LIBDIR_SUFFIX})
   set(LIBCXX_GENERATED_INCLUDE_DIR "${CMAKE_BINARY_DIR}/include/c++/v1")
-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LIBCXX_LIBDIR_SUFFIX})
+  set(LIBCXX_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXX_LIBDIR_SUFFIX})
 endif()
 
 file(MAKE_DIRECTORY "${LIBCXX_BINARY_INCLUDE_DIR}")
diff --git a/libcxx/cmake/Modules/HandleLibCXXABI.cmake b/libcxx/cmake/Modules/HandleLibCXXABI.cmake
--- a/libcxx/cmake/Modules/HandleLibCXXABI.cmake
+++ b/libcxx/cmake/Modules/HandleLibCXXABI.cmake
@@ -63,7 +63,7 @@
 
         if (LIBCXX_INSTALL_HEADERS)
           install(FILES "${LIBCXX_BINARY_INCLUDE_DIR}/${fpath}"
-            DESTINATION include/c++/v1/${dstdir}
+            DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/c++/v1/${dstdir}
             COMPONENT cxx-headers
             PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
             )
diff --git a/libcxx/include/CMakeLists.txt b/libcxx/include/CMakeLists.txt
--- a/libcxx/include/CMakeLists.txt
+++ b/libcxx/include/CMakeLists.txt
@@ -219,7 +219,7 @@
   foreach(file ${files})
     get_filename_component(dir ${file} DIRECTORY)
     install(FILES ${file}
-      DESTINATION include/c++/v1/${dir}
+      DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/c++/v1/${dir}
       COMPONENT cxx-headers
       PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
     )
@@ -227,7 +227,7 @@
 
   # Install the generated __config_site.
   install(FILES ${LIBCXX_GENERATED_INCLUDE_DIR}/__config_site
-    DESTINATION include/c++/v1
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/c++/v1
     PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
     COMPONENT cxx-headers)
 
diff --git a/libcxx/src/CMakeLists.txt b/libcxx/src/CMakeLists.txt
--- a/libcxx/src/CMakeLists.txt
+++ b/libcxx/src/CMakeLists.txt
@@ -368,21 +368,21 @@
   install(TARGETS cxx_shared
     ARCHIVE DESTINATION ${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
     LIBRARY DESTINATION ${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
-    RUNTIME DESTINATION bin COMPONENT cxx)
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
 endif()
 
 if (LIBCXX_INSTALL_STATIC_LIBRARY)
   install(TARGETS cxx_static
     ARCHIVE DESTINATION ${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
     LIBRARY DESTINATION ${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
-    RUNTIME DESTINATION bin COMPONENT cxx)
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
 endif()
 
 if(LIBCXX_INSTALL_EXPERIMENTAL_LIBRARY)
   install(TARGETS cxx_experimental
     LIBRARY DESTINATION ${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
     ARCHIVE DESTINATION ${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
-    RUNTIME DESTINATION bin COMPONENT cxx)
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
 endif()
 
 # NOTE: This install command must go after the cxx install command otherwise
diff --git a/libcxxabi/CMakeLists.txt b/libcxxabi/CMakeLists.txt
--- a/libcxxabi/CMakeLists.txt
+++ b/libcxxabi/CMakeLists.txt
@@ -26,7 +26,11 @@
 
 if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBCXXABI_STANDALONE_BUILD)
   project(libcxxabi CXX C)
+endif()
+
+include(GNUInstallDirs)
 
+if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBCXXABI_STANDALONE_BUILD)
   set(PACKAGE_NAME libcxxabi)
   set(PACKAGE_VERSION 11.0.0git)
   set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
@@ -204,11 +208,11 @@
 elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
   set(LIBCXXABI_HEADER_DIR ${LLVM_BINARY_DIR})
   set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LIBCXXABI_LIBDIR_SUFFIX})
+  set(LIBCXXABI_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXXABI_LIBDIR_SUFFIX})
 else()
   set(LIBCXXABI_HEADER_DIR ${CMAKE_BINARY_DIR})
   set(LIBCXXABI_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXXABI_LIBDIR_SUFFIX})
-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LIBCXXABI_LIBDIR_SUFFIX})
+  set(LIBCXXABI_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXXABI_LIBDIR_SUFFIX})
 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
@@ -22,7 +22,11 @@
 
 if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBUNWIND_STANDALONE_BUILD)
   project(libunwind LANGUAGES C CXX ASM)
+endif()
+
+include(GNUInstallDirs)
 
+if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBUNWIND_STANDALONE_BUILD)
   set(PACKAGE_NAME libunwind)
   set(PACKAGE_VERSION 13.0.0git)
   set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
@@ -123,10 +127,10 @@
   endif()
 elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
   set(LIBUNWIND_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
-  set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LIBUNWIND_LIBDIR_SUFFIX})
+  set(LIBUNWIND_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBUNWIND_LIBDIR_SUFFIX})
 else()
   set(LIBUNWIND_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBUNWIND_LIBDIR_SUFFIX})
-  set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LIBUNWIND_LIBDIR_SUFFIX})
+  set(LIBUNWIND_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBUNWIND_LIBDIR_SUFFIX})
 endif()
 
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${LIBUNWIND_LIBRARY_DIR})
diff --git a/libunwind/src/CMakeLists.txt b/libunwind/src/CMakeLists.txt
--- a/libunwind/src/CMakeLists.txt
+++ b/libunwind/src/CMakeLists.txt
@@ -184,7 +184,7 @@
   install(TARGETS ${LIBUNWIND_INSTALL_TARGETS}
     LIBRARY DESTINATION ${LIBUNWIND_INSTALL_LIBRARY_DIR} COMPONENT unwind
     ARCHIVE DESTINATION ${LIBUNWIND_INSTALL_LIBRARY_DIR} COMPONENT unwind
-    RUNTIME DESTINATION bin COMPONENT unwind)
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT unwind)
 endif()
 
 if (NOT CMAKE_CONFIGURATION_TYPES AND LIBUNWIND_INSTALL_LIBRARY)
diff --git a/lld/CMakeLists.txt b/lld/CMakeLists.txt
--- a/lld/CMakeLists.txt
+++ b/lld/CMakeLists.txt
@@ -1,4 +1,10 @@
 # Check if lld is built as a standalone project.
+if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+  project(lld)
+endif()
+
+include(GNUInstallDirs)
+
 if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
   project(lld)
   cmake_minimum_required(VERSION 3.13.4)
@@ -183,7 +189,7 @@
 
 if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
   install(DIRECTORY include/
-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
     FILES_MATCHING
     PATTERN "*.h"
     )
diff --git a/lld/cmake/modules/AddLLD.cmake b/lld/cmake/modules/AddLLD.cmake
--- a/lld/cmake/modules/AddLLD.cmake
+++ b/lld/cmake/modules/AddLLD.cmake
@@ -22,7 +22,7 @@
       ${export_to_lldtargets}
       LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
       ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
-      RUNTIME DESTINATION bin)
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
 
     if (${ARG_SHARED} AND NOT CMAKE_CONFIGURATION_TYPES)
       add_llvm_install_targets(install-${name}
@@ -54,7 +54,7 @@
 
     install(TARGETS ${name}
       ${export_to_lldtargets}
-      RUNTIME DESTINATION bin
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
       COMPONENT ${name})
 
     if(NOT CMAKE_CONFIGURATION_TYPES)
@@ -69,5 +69,5 @@
 macro(add_lld_symlink name dest)
   add_llvm_tool_symlink(${name} ${dest} ALWAYS_GENERATE)
   # Always generate install targets
-  llvm_install_symlink(${name} ${dest} ALWAYS_GENERATE)
+  llvm_install_symlink(${name} ${dest} ${CMAKE_INSTALL_FULL_BINDIR} ALWAYS_GENERATE)
 endmacro()
diff --git a/lld/tools/lld/CMakeLists.txt b/lld/tools/lld/CMakeLists.txt
--- a/lld/tools/lld/CMakeLists.txt
+++ b/lld/tools/lld/CMakeLists.txt
@@ -21,7 +21,7 @@
   )
 
 install(TARGETS lld
-  RUNTIME DESTINATION bin)
+  RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
 
 if(NOT LLD_SYMLINKS_TO_CREATE)
   set(LLD_SYMLINKS_TO_CREATE
diff --git a/lldb/CMakeLists.txt b/lldb/CMakeLists.txt
--- a/lldb/CMakeLists.txt
+++ b/lldb/CMakeLists.txt
@@ -11,6 +11,11 @@
 # using LLVM as an external library.
 if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
   project(lldb)
+endif()
+
+include(GNUInstallDirs)
+
+if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
   include(LLDBStandalone)
 
   set(CMAKE_CXX_STANDARD 14 CACHE STRING "C++ standard to conform to")
diff --git a/lldb/cmake/modules/AddLLDB.cmake b/lldb/cmake/modules/AddLLDB.cmake
--- a/lldb/cmake/modules/AddLLDB.cmake
+++ b/lldb/cmake/modules/AddLLDB.cmake
@@ -113,7 +113,7 @@
     endif()
     # RUNTIME is relevant for DLL platforms, FRAMEWORK for macOS
     install(TARGETS ${name} COMPONENT ${name}
-      RUNTIME DESTINATION bin
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
       LIBRARY DESTINATION ${install_dest}
       ARCHIVE DESTINATION ${install_dest}
       FRAMEWORK DESTINATION ${install_dest})
diff --git a/lldb/cmake/modules/LLDBConfig.cmake b/lldb/cmake/modules/LLDBConfig.cmake
--- a/lldb/cmake/modules/LLDBConfig.cmake
+++ b/lldb/cmake/modules/LLDBConfig.cmake
@@ -225,7 +225,7 @@
 if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
   install(DIRECTORY include/
     COMPONENT lldb-headers
-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
     FILES_MATCHING
     PATTERN "*.h"
     PATTERN ".cmake" EXCLUDE
@@ -233,7 +233,7 @@
 
   install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/include/
     COMPONENT lldb-headers
-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
     FILES_MATCHING
     PATTERN "*.h"
     PATTERN ".cmake" EXCLUDE
diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -256,9 +256,12 @@
   message(FATAL_ERROR "Invalid value for CMAKE_BUILD_TYPE: ${CMAKE_BUILD_TYPE}")
 endif()
 
+include(GNUInstallDirs)
+
 set(LLVM_LIBDIR_SUFFIX "" CACHE STRING "Define suffix of library directory name (32/64)" )
 
-set(LLVM_TOOLS_INSTALL_DIR "bin" CACHE STRING "Path for binary subdirectory (defaults to 'bin')")
+set(LLVM_TOOLS_INSTALL_DIR "${CMAKE_INSTALL_BINDIR}" CACHE STRING
+    "Path for binary subdirectory (defaults to 'bin')")
 mark_as_advanced(LLVM_TOOLS_INSTALL_DIR)
 
 set(LLVM_UTILS_INSTALL_DIR "${LLVM_TOOLS_INSTALL_DIR}" CACHE STRING
@@ -567,9 +570,9 @@
 option (LLVM_ENABLE_OCAMLDOC "Build OCaml bindings documentation." ON)
 option (LLVM_ENABLE_BINDINGS "Build bindings." ON)
 
-set(LLVM_INSTALL_DOXYGEN_HTML_DIR "share/doc/llvm/doxygen-html"
+set(LLVM_INSTALL_DOXYGEN_HTML_DIR "${CMAKE_INSTALL_DOCDIR}/${project}/doxygen-html"
     CACHE STRING "Doxygen-generated HTML documentation install directory")
-set(LLVM_INSTALL_OCAMLDOC_HTML_DIR "share/doc/llvm/ocaml-html"
+set(LLVM_INSTALL_OCAMLDOC_HTML_DIR "${CMAKE_INSTALL_DOCDIR}/${project}/ocaml-html"
     CACHE STRING "OCamldoc-generated HTML documentation install directory")
 
 option (LLVM_BUILD_EXTERNAL_COMPILER_RT
@@ -1032,7 +1035,7 @@
 
 if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
   install(DIRECTORY include/llvm include/llvm-c
-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
     COMPONENT llvm-headers
     FILES_MATCHING
     PATTERN "*.def"
@@ -1043,7 +1046,7 @@
     )
 
   install(DIRECTORY ${LLVM_INCLUDE_DIR}/llvm ${LLVM_INCLUDE_DIR}/llvm-c
-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
     COMPONENT llvm-headers
     FILES_MATCHING
     PATTERN "*.def"
@@ -1057,13 +1060,13 @@
 
   if (LLVM_INSTALL_MODULEMAPS)
     install(DIRECTORY include/llvm include/llvm-c
-            DESTINATION include
+            DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
             COMPONENT llvm-headers
             FILES_MATCHING
             PATTERN "module.modulemap"
             )
     install(FILES include/llvm/module.install.modulemap
-            DESTINATION include/llvm
+            DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/llvm
             COMPONENT llvm-headers
             RENAME "module.extern.modulemap"
             )
diff --git a/llvm/cmake/modules/AddLLVM.cmake b/llvm/cmake/modules/AddLLVM.cmake
--- a/llvm/cmake/modules/AddLLVM.cmake
+++ b/llvm/cmake/modules/AddLLVM.cmake
@@ -805,7 +805,7 @@
               ${export_to_llvmexports}
               LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
               ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
-              RUNTIME DESTINATION bin COMPONENT ${name})
+              RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT ${name})
 
       if (NOT LLVM_ENABLE_IDE)
         add_llvm_install_targets(install-${name}
@@ -1241,7 +1241,7 @@
   endif()
   add_llvm_executable(${name} ${ARGN})
   if( LLVM_BUILD_EXAMPLES )
-    install(TARGETS ${name} RUNTIME DESTINATION examples)
+    install(TARGETS ${name} RUNTIME DESTINATION ${CMAKE_INSTALL_DOCDIR}/examples)
   endif()
   set_target_properties(${name} PROPERTIES FOLDER "Examples")
 endmacro(add_llvm_example name)
@@ -1876,7 +1876,7 @@
 
 endfunction()
 
-function(llvm_install_symlink name dest)
+function(llvm_install_symlink name dest output_dir)
   cmake_parse_arguments(ARG "ALWAYS_GENERATE" "COMPONENT" "" ${ARGN})
   foreach(path ${CMAKE_MODULE_PATH})
     if(EXISTS ${path}/LLVMInstallSymlink.cmake)
@@ -1899,7 +1899,7 @@
   set(full_dest ${dest}${CMAKE_EXECUTABLE_SUFFIX})
 
   install(SCRIPT ${INSTALL_SYMLINK}
-          CODE "install_symlink(${full_name} ${full_dest} ${LLVM_TOOLS_INSTALL_DIR})"
+          CODE "install_symlink(${full_name} ${full_dest} ${output_dir})"
           COMPONENT ${component})
 
   if (NOT LLVM_ENABLE_IDE AND NOT ARG_ALWAYS_GENERATE)
@@ -1982,7 +1982,8 @@
     endif()
 
     if ((TOOL_IS_TOOLCHAIN OR NOT LLVM_INSTALL_TOOLCHAIN_ONLY) AND LLVM_BUILD_TOOLS)
-      llvm_install_symlink(${link_name} ${target})
+      GNUInstallDirs_get_absolute_install_dir(output_dir LLVM_TOOLS_INSTALL_DIR)
+      llvm_install_symlink(${link_name} ${target} ${output_dir})
     endif()
   endif()
 endfunction()
diff --git a/llvm/cmake/modules/AddSphinxTarget.cmake b/llvm/cmake/modules/AddSphinxTarget.cmake
--- a/llvm/cmake/modules/AddSphinxTarget.cmake
+++ b/llvm/cmake/modules/AddSphinxTarget.cmake
@@ -90,7 +90,7 @@
         endif()
       elseif (builder STREQUAL html)
         string(TOUPPER "${project}" project_upper)
-        set(${project_upper}_INSTALL_SPHINX_HTML_DIR "share/doc/${project}/html"
+        set(${project_upper}_INSTALL_SPHINX_HTML_DIR "${CMAKE_INSTALL_DOCDIR}/${project}/html"
             CACHE STRING "HTML documentation install directory for ${project}")
 
         # '/.' indicates: copy the contents of the directory directly into
diff --git a/llvm/cmake/modules/CMakeLists.txt b/llvm/cmake/modules/CMakeLists.txt
--- a/llvm/cmake/modules/CMakeLists.txt
+++ b/llvm/cmake/modules/CMakeLists.txt
@@ -1,4 +1,4 @@
-set(LLVM_INSTALL_PACKAGE_DIR lib${LLVM_LIBDIR_SUFFIX}/cmake/llvm)
+set(LLVM_INSTALL_PACKAGE_DIR lib${LLVM_LIBDIR_SUFFIX}/cmake/llvm CACHE STRING "Path for CMake subdirectory (defaults to 'cmake/llvm')")
 set(llvm_cmake_builddir "${LLVM_BINARY_DIR}/${LLVM_INSTALL_PACKAGE_DIR}")
 
 # First for users who use an installed LLVM, create the LLVMExports.cmake file.
@@ -107,13 +107,13 @@
   set(LLVM_CONFIG_CODE "${LLVM_CONFIG_CODE}
 get_filename_component(LLVM_INSTALL_PREFIX \"\${LLVM_INSTALL_PREFIX}\" PATH)")
 endforeach(p)
-set(LLVM_CONFIG_INCLUDE_DIRS "\${LLVM_INSTALL_PREFIX}/include")
+set(LLVM_CONFIG_INCLUDE_DIRS "\${LLVM_INSTALL_PREFIX}/${CMAKE_INSTALL_INCLUDEDIR}")
 set(LLVM_CONFIG_INCLUDE_DIR "${LLVM_CONFIG_INCLUDE_DIRS}")
 set(LLVM_CONFIG_MAIN_INCLUDE_DIR "${LLVM_CONFIG_INCLUDE_DIRS}")
 set(LLVM_CONFIG_LIBRARY_DIRS "\${LLVM_INSTALL_PREFIX}/lib\${LLVM_LIBDIR_SUFFIX}")
 set(LLVM_CONFIG_CMAKE_DIR "\${LLVM_INSTALL_PREFIX}/${LLVM_INSTALL_PACKAGE_DIR}")
 set(LLVM_CONFIG_BINARY_DIR "\${LLVM_INSTALL_PREFIX}")
-set(LLVM_CONFIG_TOOLS_BINARY_DIR "\${LLVM_INSTALL_PREFIX}/bin")
+set(LLVM_CONFIG_TOOLS_BINARY_DIR "\${LLVM_INSTALL_PREFIX}/${CMAKE_INSTALL_BINDIR}")
 
 # Generate a default location for lit
 if (LLVM_INSTALL_UTILS AND LLVM_BUILD_UTILS)
diff --git a/llvm/cmake/modules/LLVMInstallSymlink.cmake b/llvm/cmake/modules/LLVMInstallSymlink.cmake
--- a/llvm/cmake/modules/LLVMInstallSymlink.cmake
+++ b/llvm/cmake/modules/LLVMInstallSymlink.cmake
@@ -10,7 +10,7 @@
     set(LINK_OR_COPY copy)
   endif()
 
-  set(bindir "${DESTDIR}${CMAKE_INSTALL_PREFIX}/${outdir}/")
+  set(bindir "${DESTDIR}${outdir}/")
 
   message(STATUS "Creating ${name}")
 
diff --git a/llvm/docs/CMake.rst b/llvm/docs/CMake.rst
--- a/llvm/docs/CMake.rst
+++ b/llvm/docs/CMake.rst
@@ -196,7 +196,7 @@
 **LLVM_LIBDIR_SUFFIX**:STRING
   Extra suffix to append to the directory where libraries are to be
   installed. On a 64-bit architecture, one could use ``-DLLVM_LIBDIR_SUFFIX=64``
-  to install libraries to ``/usr/lib64``.
+  to install libraries to ``/usr/lib64``. See also ``CMAKE_INSTALL_LIBDIR``.
 
 **CMAKE_C_FLAGS**:STRING
   Extra flags to use when compiling C source files.
@@ -550,8 +550,8 @@
 
 **LLVM_INSTALL_DOXYGEN_HTML_DIR**:STRING
   The path to install Doxygen-generated HTML documentation to. This path can
-  either be absolute or relative to the CMAKE_INSTALL_PREFIX. Defaults to
-  `share/doc/llvm/doxygen-html`.
+  either be absolute or relative to the ``CMAKE_INSTALL_PREFIX``. Defaults to
+  `${CMAKE_INSTALL_DOCDIR}/${project}/doxygen-html`.
 
 **LLVM_ENABLE_SPHINX**:BOOL
   If specified, CMake will search for the ``sphinx-build`` executable and will make
@@ -582,13 +582,33 @@
 
 **LLVM_INSTALL_SPHINX_HTML_DIR**:STRING
   The path to install Sphinx-generated HTML documentation to. This path can
-  either be absolute or relative to the CMAKE_INSTALL_PREFIX. Defaults to
-  `share/doc/llvm/html`.
+  either be absolute or relative to the ``CMAKE_INSTALL_PREFIX``. Defaults to
+  `${CMAKE_INSTALL_DOCDIR}/${project}/html`.
 
 **LLVM_INSTALL_OCAMLDOC_HTML_DIR**:STRING
   The path to install OCamldoc-generated HTML documentation to. This path can
-  either be absolute or relative to the CMAKE_INSTALL_PREFIX. Defaults to
-  `share/doc/llvm/ocaml-html`.
+  either be absolute or relative to the ``CMAKE_INSTALL_PREFIX``. Defaults to
+  `${CMAKE_INSTALL_DOCDIR}/${project}/ocaml-html`.
+
+**CMAKE_INSTALL_BINDIR**:STRING
+  The path to install binary tools, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `bin`.
+
+**CMAKE_INSTALL_LIBDIR**:STRING
+  The path to install libraries, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `lib`.
+
+**CMAKE_INSTALL_INCLUDEDIR**:STRING
+  The path to install header files, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `include`.
+
+**CMAKE_INSTALL_DOCDIR**:STRING
+  The path to install documentation, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `share/doc`.
+
+**CMAKE_INSTALL_MANDIR**:STRING
+  The path to install manpage files, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `share/man`.
 
 **LLVM_CREATE_XCODE_TOOLCHAIN**:BOOL
   macOS Only: If enabled CMake will generate a target named
diff --git a/llvm/examples/Bye/CMakeLists.txt b/llvm/examples/Bye/CMakeLists.txt
--- a/llvm/examples/Bye/CMakeLists.txt
+++ b/llvm/examples/Bye/CMakeLists.txt
@@ -14,6 +14,6 @@
     BUILDTREE_ONLY
    )
 
-  install(TARGETS ${name} RUNTIME DESTINATION examples)
+  install(TARGETS ${name} RUNTIME DESTINATION ${CMAKE_INSTALL_DOCDIR}/examples)
   set_target_properties(${name} PROPERTIES FOLDER "Examples")
 endif()
diff --git a/llvm/include/llvm/CMakeLists.txt b/llvm/include/llvm/CMakeLists.txt
--- a/llvm/include/llvm/CMakeLists.txt
+++ b/llvm/include/llvm/CMakeLists.txt
@@ -5,5 +5,5 @@
 # If we're doing an out-of-tree build, copy a module map for generated
 # header files into the build area.
 if (NOT "${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_BINARY_DIR}")
-  configure_file(module.modulemap.build module.modulemap COPYONLY)
+  configure_file(module.modulemap.build ${LLVM_INCLUDE_DIR}/module.modulemap COPYONLY)
 endif (NOT "${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_BINARY_DIR}")
diff --git a/llvm/tools/llvm-config/BuildVariables.inc.in b/llvm/tools/llvm-config/BuildVariables.inc.in
--- a/llvm/tools/llvm-config/BuildVariables.inc.in
+++ b/llvm/tools/llvm-config/BuildVariables.inc.in
@@ -23,6 +23,9 @@
 #define LLVM_CXXFLAGS "@LLVM_CXXFLAGS@"
 #define LLVM_BUILDMODE "@LLVM_BUILDMODE@"
 #define LLVM_LIBDIR_SUFFIX "@LLVM_LIBDIR_SUFFIX@"
+#define LLVM_INSTALL_BINDIR "@CMAKE_INSTALL_BINDIR@"
+#define LLVM_INSTALL_LIBDIR "@CMAKE_INSTALL_LIBDIR@"
+#define LLVM_INSTALL_INCLUDEDIR "@CMAKE_INSTALL_INCLUDEDIR@"
 #define LLVM_TARGETS_BUILT "@LLVM_TARGETS_BUILT@"
 #define LLVM_SYSTEM_LIBS "@LLVM_SYSTEM_LIBS@"
 #define LLVM_BUILD_SYSTEM "@LLVM_BUILD_SYSTEM@"
diff --git a/llvm/tools/llvm-config/llvm-config.cpp b/llvm/tools/llvm-config/llvm-config.cpp
--- a/llvm/tools/llvm-config/llvm-config.cpp
+++ b/llvm/tools/llvm-config/llvm-config.cpp
@@ -357,10 +357,16 @@
         ("-I" + ActiveIncludeDir + " " + "-I" + ActiveObjRoot + "/include");
   } else {
     ActivePrefix = CurrentExecPrefix;
-    ActiveIncludeDir = ActivePrefix + "/include";
-    SmallString<256> path(StringRef(LLVM_TOOLS_INSTALL_DIR));
-    sys::fs::make_absolute(ActivePrefix, path);
-    ActiveBinDir = std::string(path.str());
+    {
+      SmallString<256> Path(StringRef(LLVM_INSTALL_INCLUDEDIR));
+      sys::fs::make_absolute(ActivePrefix, Path);
+      ActiveIncludeDir = std::string(Path.str());
+    }
+    {
+      SmallString<256> Path(StringRef(LLVM_INSTALL_BINDIR));
+      sys::fs::make_absolute(ActivePrefix, Path);
+      ActiveBinDir = std::string(Path.str());
+    }
     ActiveLibDir = ActivePrefix + "/lib" + LLVM_LIBDIR_SUFFIX;
     ActiveCMakeDir = ActiveLibDir + "/cmake/llvm";
     ActiveIncludeOption = "-I" + ActiveIncludeDir;
diff --git a/llvm/tools/lto/CMakeLists.txt b/llvm/tools/lto/CMakeLists.txt
--- a/llvm/tools/lto/CMakeLists.txt
+++ b/llvm/tools/lto/CMakeLists.txt
@@ -25,7 +25,7 @@
     intrinsics_gen)
 
 install(FILES ${LLVM_MAIN_INCLUDE_DIR}/llvm-c/lto.h
-  DESTINATION include/llvm-c
+  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/llvm-c
   COMPONENT LTO)
 
 if (APPLE)
diff --git a/llvm/tools/opt-viewer/CMakeLists.txt b/llvm/tools/opt-viewer/CMakeLists.txt
--- a/llvm/tools/opt-viewer/CMakeLists.txt
+++ b/llvm/tools/opt-viewer/CMakeLists.txt
@@ -8,7 +8,7 @@
 
 foreach (file ${files})
   install(PROGRAMS ${file}
-    DESTINATION share/opt-viewer
+    DESTINATION ${CMAKE_INSTALL_DATADIR}/opt-viewer
     COMPONENT opt-viewer)
 endforeach (file)
 
diff --git a/llvm/tools/remarks-shlib/CMakeLists.txt b/llvm/tools/remarks-shlib/CMakeLists.txt
--- a/llvm/tools/remarks-shlib/CMakeLists.txt
+++ b/llvm/tools/remarks-shlib/CMakeLists.txt
@@ -19,7 +19,7 @@
   endif()
   
   install(FILES ${LLVM_MAIN_INCLUDE_DIR}/llvm-c/Remarks.h
-    DESTINATION include/llvm-c
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/llvm-c
     COMPONENT Remarks)
 
   if (APPLE)
diff --git a/mlir/CMakeLists.txt b/mlir/CMakeLists.txt
--- a/mlir/CMakeLists.txt
+++ b/mlir/CMakeLists.txt
@@ -4,7 +4,11 @@
 if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
   project(mlir)
   cmake_minimum_required(VERSION 3.13.4)
+endif()
+
+include(GNUInstallDirs)
 
+if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
   find_package(LLVM CONFIG REQUIRED)
   set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${LLVM_CMAKE_DIR})
   include(HandleLLVMOptions)
@@ -158,7 +162,7 @@
 
 if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
   install(DIRECTORY include/mlir include/mlir-c
-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
     COMPONENT mlir-headers
     FILES_MATCHING
     PATTERN "*.def"
@@ -169,7 +173,7 @@
     )
 
   install(DIRECTORY ${MLIR_INCLUDE_DIR}/mlir ${MLIR_INCLUDE_DIR}/mlir-c
-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
     COMPONENT mlir-headers
     FILES_MATCHING
     PATTERN "*.def"
diff --git a/mlir/cmake/modules/AddMLIR.cmake b/mlir/cmake/modules/AddMLIR.cmake
--- a/mlir/cmake/modules/AddMLIR.cmake
+++ b/mlir/cmake/modules/AddMLIR.cmake
@@ -154,7 +154,7 @@
     ${export_to_mlirtargets}
     LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
     ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
-    RUNTIME DESTINATION bin)
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
 
   if (NOT LLVM_ENABLE_IDE)
     add_llvm_install_targets(install-${name}
diff --git a/openmp/CMakeLists.txt b/openmp/CMakeLists.txt
--- a/openmp/CMakeLists.txt
+++ b/openmp/CMakeLists.txt
@@ -7,7 +7,11 @@
 if (OPENMP_STANDALONE_BUILD OR "${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}")
   set(OPENMP_STANDALONE_BUILD TRUE)
   project(openmp C CXX)
+endif()
+
+include(GNUInstallDirs)
 
+if (OPENMP_STANDALONE_BUILD OR "${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}")
   # CMAKE_BUILD_TYPE was not set, default to Release.
   if (NOT CMAKE_BUILD_TYPE)
     set(CMAKE_BUILD_TYPE Release)
diff --git a/openmp/libomptarget/plugins/amdgpu/CMakeLists.txt b/openmp/libomptarget/plugins/amdgpu/CMakeLists.txt
--- a/openmp/libomptarget/plugins/amdgpu/CMakeLists.txt
+++ b/openmp/libomptarget/plugins/amdgpu/CMakeLists.txt
@@ -67,7 +67,7 @@
 
 # Install plugin under the lib destination folder.
 # When we build for debug, OPENMP_LIBDIR_SUFFIX get set to -debug
-install(TARGETS omptarget.rtl.amdgpu LIBRARY DESTINATION "lib${OPENMP_LIBDIR_SUFFIX}")
+install(TARGETS omptarget.rtl.amdgpu LIBRARY DESTINATION "${CMAKE_INSTALL_LIBDIR}${OPENMP_LIBDIR_SUFFIX}")
 
 set_property(TARGET omptarget.rtl.amdgpu PROPERTY INSTALL_RPATH "$ORIGIN")
 target_link_libraries(
diff --git a/openmp/libomptarget/plugins/ve/CMakeLists.txt b/openmp/libomptarget/plugins/ve/CMakeLists.txt
--- a/openmp/libomptarget/plugins/ve/CMakeLists.txt
+++ b/openmp/libomptarget/plugins/ve/CMakeLists.txt
@@ -32,7 +32,7 @@
 
   # Install plugin under the lib destination folder.
   install(TARGETS "omptarget.rtl.${tmachine_libname}"
-    LIBRARY DESTINATION lib${OPENMP_LIBDIR_SUFFIX})
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${OPENMP_LIBDIR_SUFFIX})
 
   target_link_libraries(
     "omptarget.rtl.${tmachine_libname}"
diff --git a/openmp/runtime/src/CMakeLists.txt b/openmp/runtime/src/CMakeLists.txt
--- a/openmp/runtime/src/CMakeLists.txt
+++ b/openmp/runtime/src/CMakeLists.txt
@@ -311,7 +311,7 @@
   set(LIBOMP_HEADERS_INSTALL_PATH "${OPENMP_INSTALL_LIBDIR}/clang/${CLANG_VERSION}/include")
 endif()
 if(WIN32)
-  install(TARGETS omp RUNTIME DESTINATION bin)
+  install(TARGETS omp RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
   install(TARGETS ${LIBOMP_IMP_LIB_TARGET} ARCHIVE DESTINATION "${OPENMP_INSTALL_LIBDIR}")
   # Create aliases (regular copies) of the library for backwards compatibility
   set(LIBOMP_ALIASES "libiomp5md")
diff --git a/openmp/tools/multiplex/CMakeLists.txt b/openmp/tools/multiplex/CMakeLists.txt
--- a/openmp/tools/multiplex/CMakeLists.txt
+++ b/openmp/tools/multiplex/CMakeLists.txt
@@ -4,7 +4,7 @@
   add_library(ompt-multiplex INTERFACE)
   target_include_directories(ompt-multiplex INTERFACE ${CMAKE_CURRENT_SOURCE_DIR})
 
-  install(FILES ompt-multiplex.h DESTINATION include)
+  install(FILES ompt-multiplex.h DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
 
   add_subdirectory(tests)
 endif()
diff --git a/polly/CMakeLists.txt b/polly/CMakeLists.txt
--- a/polly/CMakeLists.txt
+++ b/polly/CMakeLists.txt
@@ -2,7 +2,11 @@
 if (NOT DEFINED LLVM_MAIN_SRC_DIR)
   project(Polly)
   cmake_minimum_required(VERSION 3.13.4)
+endif()
+
+include(GNUInstallDirs)
 
+if (NOT DEFINED LLVM_MAIN_SRC_DIR)
   # Where is LLVM installed?
   find_package(LLVM CONFIG REQUIRED)
   set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${LLVM_CMAKE_DIR})
@@ -122,13 +126,13 @@
 
 if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
   install(DIRECTORY include/
-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
     FILES_MATCHING
     PATTERN "*.h"
     )
 
   install(DIRECTORY ${POLLY_BINARY_DIR}/include/
-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
     FILES_MATCHING
     PATTERN "*.h"
     PATTERN "CMakeFiles" EXCLUDE
diff --git a/polly/cmake/CMakeLists.txt b/polly/cmake/CMakeLists.txt
--- a/polly/cmake/CMakeLists.txt
+++ b/polly/cmake/CMakeLists.txt
@@ -83,14 +83,15 @@
 set(POLLY_CONFIG_LLVM_CMAKE_DIR "${LLVM_BINARY_DIR}/${LLVM_INSTALL_PACKAGE_DIR}")
 set(POLLY_CONFIG_CMAKE_DIR "${POLLY_INSTALL_PREFIX}/${POLLY_INSTALL_PACKAGE_DIR}")
 set(POLLY_CONFIG_LIBRARY_DIRS "${POLLY_INSTALL_PREFIX}/lib${LLVM_LIBDIR_SUFFIX}")
+get_filename_component(base_includedir ${CMAKE_INSTALL_INCLUDEDIR} ABSOLUTE BASE_DIR ${POLLY_INSTALL_PREFIX)}
 if (POLLY_BUNDLED_ISL)
   set(POLLY_CONFIG_INCLUDE_DIRS
-    "${POLLY_INSTALL_PREFIX}/include"
-    "${POLLY_INSTALL_PREFIX}/include/polly"
+    "${base_includedir}"
+    "${base_includedir}/polly"
     )
 else()
   set(POLLY_CONFIG_INCLUDE_DIRS
-    "${POLLY_INSTALL_PREFIX}/include"
+    "${base_includedir}"
     ${ISL_INCLUDE_DIRS}
     )
 endif()
diff --git a/polly/lib/External/CMakeLists.txt b/polly/lib/External/CMakeLists.txt
--- a/polly/lib/External/CMakeLists.txt
+++ b/polly/lib/External/CMakeLists.txt
@@ -275,7 +275,7 @@
     install(DIRECTORY
       ${ISL_SOURCE_DIR}/include/
       ${ISL_BINARY_DIR}/include/
-      DESTINATION include/polly
+      DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/polly
       FILES_MATCHING
       PATTERN "*.h"
       PATTERN "CMakeFiles" EXCLUDE
diff --git a/pstl/CMakeLists.txt b/pstl/CMakeLists.txt
--- a/pstl/CMakeLists.txt
+++ b/pstl/CMakeLists.txt
@@ -7,6 +7,8 @@
 #===----------------------------------------------------------------------===##
 cmake_minimum_required(VERSION 3.13.4)
 
+include(GNUInstallDirs)
+
 set(PARALLELSTL_VERSION_FILE "${CMAKE_CURRENT_SOURCE_DIR}/include/pstl/internal/pstl_config.h")
 file(STRINGS "${PARALLELSTL_VERSION_FILE}" PARALLELSTL_VERSION_SOURCE REGEX "#define _PSTL_VERSION .*$")
 string(REGEX REPLACE "#define _PSTL_VERSION (.*)$" "\\1" PARALLELSTL_VERSION_SOURCE "${PARALLELSTL_VERSION_SOURCE}")
@@ -81,15 +83,15 @@
 install(EXPORT ParallelSTLTargets
         FILE ParallelSTLTargets.cmake
         NAMESPACE pstl::
-        DESTINATION lib/cmake/ParallelSTL)
+        DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/ParallelSTL)
 install(FILES "${CMAKE_CURRENT_BINARY_DIR}/ParallelSTLConfig.cmake"
               "${CMAKE_CURRENT_BINARY_DIR}/ParallelSTLConfigVersion.cmake"
-        DESTINATION lib/cmake/ParallelSTL)
+        DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/ParallelSTL)
 install(DIRECTORY include/
-        DESTINATION include
+        DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
         PATTERN "*.in" EXCLUDE)
 install(FILES "${PSTL_CONFIG_SITE_PATH}"
-        DESTINATION include)
+        DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
 
 add_custom_target(install-pstl
                   COMMAND "${CMAKE_COMMAND}" -P "${PROJECT_BINARY_DIR}/cmake_install.cmake" -DCOMPONENT=ParallelSTL)