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
@@ -5,6 +5,8 @@
 if( CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR )
   project(Clang)
 
+  include(GNUInstallDirs)
+
   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 +420,7 @@
 
 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 +429,7 @@
     )
 
   install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/include/clang
-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
     COMPONENT clang-headers
     FILES_MATCHING
     PATTERN "CMakeFiles" EXCLUDE
@@ -447,7 +449,7 @@
 
   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
@@ -123,9 +123,9 @@
         install(TARGETS ${lib}
           COMPONENT ${lib}
           ${export_to_clangtargets}
-          LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
-          ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
-          RUNTIME DESTINATION bin)
+          LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+          ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+          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/lib/Headers/CMakeLists.txt b/clang/lib/Headers/CMakeLists.txt
--- a/clang/lib/Headers/CMakeLists.txt
+++ b/clang/lib/Headers/CMakeLists.txt
@@ -219,7 +219,7 @@
   FOLDER "Misc"
   RUNTIME_OUTPUT_DIRECTORY "${output_dir}")
 
-set(header_install_dir lib${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION}/include)
+set(header_install_dir ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION}/include)
 
 install(
   FILES ${files} ${generated_files}
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
@@ -180,7 +180,7 @@
           COMPONENT
             libclang-python-bindings
           DESTINATION
-            "lib${LLVM_LIBDIR_SUFFIX}/python${PythonVersion}/site-packages")
+            "${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/python${PythonVersion}/site-packages")
 endforeach()
 if(NOT LLVM_ENABLE_IDE)
   add_custom_target(libclang-python-bindings)
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 ${Depends})
diff --git a/compiler-rt/CMakeLists.txt b/compiler-rt/CMakeLists.txt
--- a/compiler-rt/CMakeLists.txt
+++ b/compiler-rt/CMakeLists.txt
@@ -8,6 +8,7 @@
 # Check if compiler-rt is built as a standalone project.
 if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR COMPILER_RT_STANDALONE_BUILD)
   project(CompilerRT C CXX ASM)
+  include(GNUInstallDirs)
   set(COMPILER_RT_STANDALONE_BUILD TRUE)
   set_property(GLOBAL PROPERTY USE_FOLDERS ON)
 endif()
diff --git a/compiler-rt/cmake/Modules/AddCompilerRT.cmake b/compiler-rt/cmake/Modules/AddCompilerRT.cmake
--- a/compiler-rt/cmake/Modules/AddCompilerRT.cmake
+++ b/compiler-rt/cmake/Modules/AddCompilerRT.cmake
@@ -510,7 +510,7 @@
   add_custom_target(${target_name} DEPENDS ${dst_file})
   # Install in Clang resource directory.
   install(FILES ${file_name}
-    DESTINATION ${COMPILER_RT_INSTALL_PATH}/share
+    DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_INCLUDEDIR}
     COMPONENT ${component})
   add_dependencies(${component} ${target_name})
 
@@ -527,7 +527,7 @@
   add_custom_target(${name} DEPENDS ${dst})
   install(FILES ${dst}
     PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE
-    DESTINATION ${COMPILER_RT_INSTALL_PATH}/bin)
+    DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_BINDIR})
 endmacro(add_compiler_rt_script src name)
 
 # Builds custom version of libc++ and installs it in <prefix>.
diff --git a/compiler-rt/cmake/Modules/CompilerRTDarwinUtils.cmake b/compiler-rt/cmake/Modules/CompilerRTDarwinUtils.cmake
--- a/compiler-rt/cmake/Modules/CompilerRTDarwinUtils.cmake
+++ b/compiler-rt/cmake/Modules/CompilerRTDarwinUtils.cmake
@@ -508,7 +508,7 @@
     set(DARWIN_macho_embedded_LIBRARY_OUTPUT_DIR
       ${COMPILER_RT_OUTPUT_DIR}/lib/macho_embedded)
     set(DARWIN_macho_embedded_LIBRARY_INSTALL_DIR
-      ${COMPILER_RT_INSTALL_PATH}/lib/macho_embedded)
+      ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_LIBDIR}/macho_embedded)
       
     set(CFLAGS_armv7 "-target thumbv7-apple-darwin-eabi")
     set(CFLAGS_i386 "-march=pentium")
diff --git a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
--- a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
+++ b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
@@ -386,7 +386,7 @@
 function(get_compiler_rt_install_dir arch install_dir)
   if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
     get_compiler_rt_target(${arch} target)
-    set(${install_dir} ${COMPILER_RT_INSTALL_PATH}/lib/${target} PARENT_SCOPE)
+    set(${install_dir} ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_LIBDIR}/${target} PARENT_SCOPE)
   else()
     set(${install_dir} ${COMPILER_RT_LIBRARY_INSTALL_DIR} PARENT_SCOPE)
   endif()
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
@@ -65,11 +65,11 @@
 else()
     # Take output dir and install path from the user.
   set(COMPILER_RT_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR} CACHE PATH
-    "Path where built compiler-rt libraries should be stored.")
+    "Path where built compiler-rt build artifacts should be stored.")
   set(COMPILER_RT_EXEC_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR}/bin CACHE PATH
     "Path where built compiler-rt executables should be stored.")
-  set(COMPILER_RT_INSTALL_PATH ${CMAKE_INSTALL_PREFIX} CACHE PATH
-    "Path where built compiler-rt libraries should be installed.")
+  set(COMPILER_RT_INSTALL_PATH "" CACHE PATH
+    "Prefix where built compiler-rt artifacts should be installed, comes before CMAKE_INSTALL_PREFIX.")
   option(COMPILER_RT_INCLUDE_TESTS "Generate and build compiler-rt unit tests." OFF)
   option(COMPILER_RT_ENABLE_WERROR "Fail and stop if warning is triggered" OFF)
   # Use a host compiler to compile/link tests.
@@ -97,7 +97,7 @@
   set(COMPILER_RT_LIBRARY_OUTPUT_DIR
     ${COMPILER_RT_OUTPUT_DIR}/lib/${COMPILER_RT_OS_DIR})
   set(COMPILER_RT_LIBRARY_INSTALL_DIR
-    ${COMPILER_RT_INSTALL_PATH}/lib/${COMPILER_RT_OS_DIR})
+    ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_LIBDIR}/${COMPILER_RT_OS_DIR})
 endif()
 
 if(APPLE)
diff --git a/compiler-rt/include/CMakeLists.txt b/compiler-rt/include/CMakeLists.txt
--- a/compiler-rt/include/CMakeLists.txt
+++ b/compiler-rt/include/CMakeLists.txt
@@ -69,22 +69,22 @@
 install(FILES ${SANITIZER_HEADERS}
   COMPONENT compiler-rt-headers
   PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
-  DESTINATION ${COMPILER_RT_INSTALL_PATH}/include/sanitizer)
+  DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_INCLUDEDIR}/sanitizer)
 # Install fuzzer headers.
 install(FILES ${FUZZER_HEADERS}
   COMPONENT compiler-rt-headers
   PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
-  DESTINATION ${COMPILER_RT_INSTALL_PATH}/include/fuzzer)
+  DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_INCLUDEDIR}/fuzzer)
 # Install xray headers.
 install(FILES ${XRAY_HEADERS}
   COMPONENT compiler-rt-headers
   PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
-  DESTINATION ${COMPILER_RT_INSTALL_PATH}/include/xray)
+  DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_INCLUDEDIR}/xray)
 # Install profile headers.
 install(FILES ${PROFILE_HEADERS}
   COMPONENT compiler-rt-headers
   PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
-  DESTINATION ${COMPILER_RT_INSTALL_PATH}/include/profile)
+  DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_INCLUDEDIR}/profile)
 
 if (NOT CMAKE_CONFIGURATION_TYPES) # don't add this for IDEs.
   add_custom_target(install-compiler-rt-headers
diff --git a/compiler-rt/lib/dfsan/CMakeLists.txt b/compiler-rt/lib/dfsan/CMakeLists.txt
--- a/compiler-rt/lib/dfsan/CMakeLists.txt
+++ b/compiler-rt/lib/dfsan/CMakeLists.txt
@@ -62,4 +62,4 @@
                    DEPENDS done_abilist.txt libc_ubuntu1404_abilist.txt)
 add_dependencies(dfsan dfsan_abilist)
 install(FILES ${dfsan_abilist_filename}
-        DESTINATION ${COMPILER_RT_INSTALL_PATH}/share)
+        DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_DATADIR})
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)
@@ -423,7 +425,7 @@
 
 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
@@ -74,9 +74,9 @@
       install(TARGETS ${name}
         COMPONENT ${name}
         ${export_to_flangtargets}
-        LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
-        ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
-        RUNTIME DESTINATION bin)
+        LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+        ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+        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/libc/lib/CMakeLists.txt b/libc/lib/CMakeLists.txt
--- a/libc/lib/CMakeLists.txt
+++ b/libc/lib/CMakeLists.txt
@@ -5,9 +5,9 @@
 )
 
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR)
-  set(LIBC_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE})
+  set(LIBC_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE})
 else()
-  set(LIBC_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX})
+  set(LIBC_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
 endif()
 
 install(
diff --git a/libcxx/CMakeLists.txt b/libcxx/CMakeLists.txt
--- a/libcxx/CMakeLists.txt
+++ b/libcxx/CMakeLists.txt
@@ -28,6 +28,8 @@
 if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBCXX_STANDALONE_BUILD)
   project(libcxx CXX C)
 
+  include(GNUInstallDirs)
+
   set(PACKAGE_NAME libcxx)
   set(PACKAGE_VERSION 13.0.0git)
   set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
@@ -406,7 +408,7 @@
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
   set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
   set(LIBCXX_HEADER_DIR ${LLVM_BINARY_DIR})
-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+  set(LIBCXX_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
   if(LIBCXX_LIBDIR_SUBDIR)
     string(APPEND LIBCXX_LIBRARY_DIR /${LIBCXX_LIBDIR_SUBDIR})
     string(APPEND LIBCXX_INSTALL_LIBRARY_DIR /${LIBCXX_LIBDIR_SUBDIR})
@@ -414,11 +416,11 @@
 elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
   set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
   set(LIBCXX_HEADER_DIR  ${LLVM_BINARY_DIR})
-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${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_HEADER_DIR  ${CMAKE_BINARY_DIR})
-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${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 ${LIBCXX_INSTALL_HEADER_PREFIX}include/c++/v1/${dstdir}
+            DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}${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
@@ -255,7 +255,7 @@
   foreach(file ${files})
     get_filename_component(dir ${file} DIRECTORY)
     install(FILES ${file}
-      DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}include/c++/v1/${dir}
+      DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}${CMAKE_INSTALL_INCLUDEDIR}/c++/v1/${dir}
       COMPONENT cxx-headers
       PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
     )
@@ -263,7 +263,7 @@
 
   # Install the generated header as __config.
   install(FILES ${LIBCXX_BINARY_DIR}/__generated_config
-    DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}include/c++/v1
+    DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}${CMAKE_INSTALL_INCLUDEDIR}/c++/v1
     PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
     RENAME __config
     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
@@ -367,21 +367,21 @@
   install(TARGETS cxx_shared
     ARCHIVE DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
     LIBRARY DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
-    RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}bin COMPONENT cxx)
+    RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
 endif()
 
 if (LIBCXX_INSTALL_STATIC_LIBRARY)
   install(TARGETS cxx_static
     ARCHIVE DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
     LIBRARY DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
-    RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}bin COMPONENT cxx)
+    RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
 endif()
 
 if(LIBCXX_INSTALL_EXPERIMENTAL_LIBRARY)
   install(TARGETS cxx_experimental
     LIBRARY DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
     ARCHIVE DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
-    RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}bin COMPONENT cxx)
+    RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}${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
@@ -27,6 +27,8 @@
 if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBCXXABI_STANDALONE_BUILD)
   project(libcxxabi CXX C)
 
+  include(GNUInstallDirs)
+
   set(PACKAGE_NAME libcxxabi)
   set(PACKAGE_VERSION 11.0.0git)
   set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
@@ -181,17 +183,17 @@
 
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
   set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+  set(LIBCXXABI_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
   if(LIBCXX_LIBDIR_SUBDIR)
     string(APPEND LIBCXXABI_LIBRARY_DIR /${LIBCXXABI_LIBDIR_SUBDIR})
     string(APPEND LIBCXXABI_INSTALL_LIBRARY_DIR /${LIBCXXABI_LIBDIR_SUBDIR})
   endif()
 elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
   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_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(LIBCXXABI_INSTALL_PREFIX "" CACHE STRING "Define libc++abi destination prefix.")
diff --git a/libunwind/CMakeLists.txt b/libunwind/CMakeLists.txt
--- a/libunwind/CMakeLists.txt
+++ b/libunwind/CMakeLists.txt
@@ -23,6 +23,8 @@
 if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBUNWIND_STANDALONE_BUILD)
   project(libunwind LANGUAGES C CXX ASM)
 
+  include(GNUInstallDirs)
+
   set(PACKAGE_NAME libunwind)
   set(PACKAGE_VERSION 13.0.0git)
   set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
@@ -116,17 +118,17 @@
 
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
   set(LIBUNWIND_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
-  set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+  set(LIBUNWIND_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
   if(LIBCXX_LIBDIR_SUBDIR)
     string(APPEND LIBUNWIND_LIBRARY_DIR /${LIBUNWIND_LIBDIR_SUBDIR})
     string(APPEND LIBUNWIND_INSTALL_LIBRARY_DIR /${LIBUNWIND_LIBDIR_SUBDIR})
   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 ${LIBUNWIND_INSTALL_PREFIX}${LIBUNWIND_INSTALL_LIBRARY_DIR} COMPONENT unwind
     ARCHIVE DESTINATION ${LIBUNWIND_INSTALL_PREFIX}${LIBUNWIND_INSTALL_LIBRARY_DIR} COMPONENT unwind
-    RUNTIME DESTINATION ${LIBUNWIND_INSTALL_PREFIX}bin COMPONENT unwind)
+    RUNTIME DESTINATION ${LIBUNWIND_INSTALL_PREFIX}${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
@@ -6,6 +6,8 @@
   set(CMAKE_INCLUDE_CURRENT_DIR ON)
   set(LLD_BUILT_STANDALONE TRUE)
 
+  include(GNUInstallDirs)
+
   find_program(LLVM_CONFIG_PATH "llvm-config" DOC "Path to llvm-config binary")
   if(NOT LLVM_CONFIG_PATH)
     message(FATAL_ERROR "llvm-config not found: specify LLVM_CONFIG_PATH")
@@ -183,7 +185,7 @@
 
 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
@@ -20,9 +20,9 @@
     install(TARGETS ${name}
       COMPONENT ${name}
       ${export_to_lldtargets}
-      LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
-      ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
-      RUNTIME DESTINATION bin)
+      LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+      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
@@ -10,6 +10,8 @@
 # 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)
+  include(GNUInstallDirs)
+
   project(lldb)
   include(LLDBStandalone)
 
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
@@ -107,13 +107,13 @@
   endif()
 
   if(PARAM_SHARED)
-    set(install_dest lib${LLVM_LIBDIR_SUFFIX})
+    set(install_dest ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
     if(PARAM_INSTALL_PREFIX)
       set(install_dest ${PARAM_INSTALL_PREFIX})
     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/lldb/tools/intel-features/CMakeLists.txt b/lldb/tools/intel-features/CMakeLists.txt
--- a/lldb/tools/intel-features/CMakeLists.txt
+++ b/lldb/tools/intel-features/CMakeLists.txt
@@ -65,4 +65,4 @@
 endif()
 
 install(TARGETS lldbIntelFeatures
-  LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX})
+  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
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
@@ -1029,7 +1032,7 @@
 
 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"
@@ -1040,7 +1043,7 @@
     )
 
   install(DIRECTORY ${LLVM_INCLUDE_DIR}/llvm ${LLVM_INCLUDE_DIR}/llvm-c
-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
     COMPONENT llvm-headers
     FILES_MATCHING
     PATTERN "*.def"
@@ -1054,13 +1057,13 @@
 
   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
@@ -802,9 +802,9 @@
 
       install(TARGETS ${name}
               ${export_to_llvmexports}
-              LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
-              ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
-              RUNTIME DESTINATION bin COMPONENT ${name})
+              LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+              ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+              RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT ${name})
 
       if (NOT LLVM_ENABLE_IDE)
         add_llvm_install_targets(install-${name}
@@ -1013,7 +1013,7 @@
 
       ## Part 1: Extension header to be included whenever we need extension
       #  processing.
-      set(LLVM_INSTALL_PACKAGE_DIR lib${LLVM_LIBDIR_SUFFIX}/cmake/llvm)
+      set(LLVM_INSTALL_PACKAGE_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/cmake/llvm)
       set(llvm_cmake_builddir "${LLVM_BINARY_DIR}/${LLVM_INSTALL_PACKAGE_DIR}")
       file(WRITE
           "${llvm_cmake_builddir}/LLVMConfigExtensions.cmake"
@@ -1240,7 +1240,7 @@
   endif()
   add_llvm_executable(${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)
@@ -1864,7 +1864,7 @@
   set(full_name ${CMAKE_${type}_LIBRARY_PREFIX}${name}${CMAKE_${type}_LIBRARY_SUFFIX})
   set(full_dest ${CMAKE_${type}_LIBRARY_PREFIX}${dest}${CMAKE_${type}_LIBRARY_SUFFIX})
 
-  set(output_dir lib${LLVM_LIBDIR_SUFFIX})
+  set(output_dir ${CMAKE_INSTALL_FULL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
   if(WIN32 AND "${type}" STREQUAL "SHARED")
     set(output_dir bin)
   endif()
@@ -1875,7 +1875,7 @@
 
 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)
@@ -1898,7 +1898,7 @@
   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)
@@ -1981,7 +1981,8 @@
     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()
@@ -2104,15 +2105,15 @@
 
   if (APPLE)
     set(_install_name_dir INSTALL_NAME_DIR "@rpath")
-    set(_install_rpath "@loader_path/../lib${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+    set(_install_rpath "@loader_path/../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
   elseif(${CMAKE_SYSTEM_NAME} MATCHES "AIX" AND BUILD_SHARED_LIBS)
     # $ORIGIN is not interpreted at link time by aix ld.
     # Since BUILD_SHARED_LIBS is only recommended for use by developers,
     # hardcode the rpath to build/install lib dir first in this mode.
     # FIXME: update this when there is better solution.
-    set(_install_rpath "${LLVM_LIBRARY_OUTPUT_INTDIR}" "${CMAKE_INSTALL_PREFIX}/lib${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+    set(_install_rpath "${LLVM_LIBRARY_OUTPUT_INTDIR}" "${CMAKE_INSTALL_FULL_LIBDIR}${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
   elseif(UNIX)
-    set(_install_rpath "\$ORIGIN/../lib${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+    set(_install_rpath "\$ORIGIN/../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
     if(${CMAKE_SYSTEM_NAME} MATCHES "(FreeBSD|DragonFly)")
       set_property(TARGET ${name} APPEND_STRING PROPERTY
                    LINK_FLAGS " -Wl,-z,origin ")
diff --git a/llvm/cmake/modules/AddOCaml.cmake b/llvm/cmake/modules/AddOCaml.cmake
--- a/llvm/cmake/modules/AddOCaml.cmake
+++ b/llvm/cmake/modules/AddOCaml.cmake
@@ -144,9 +144,9 @@
   endforeach()
 
   if( APPLE )
-    set(ocaml_rpath "@executable_path/../../../lib${LLVM_LIBDIR_SUFFIX}")
+    set(ocaml_rpath "@executable_path/../../../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}")
   elseif( UNIX )
-    set(ocaml_rpath "\\$ORIGIN/../../../lib${LLVM_LIBDIR_SUFFIX}")
+    set(ocaml_rpath "\\$ORIGIN/../../../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}")
   endif()
   list(APPEND ocaml_flags "-ldopt" "-Wl,-rpath,${ocaml_rpath}")
 
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 ${CMAKE_INSTALL_LIBDIR}${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_LIBRARY_DIRS "\${LLVM_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}\${LLVM_LIBDIR_SUFFIX}")
 set(LLVM_CONFIG_CMAKE_DIR "\${LLVM_INSTALL_PREFIX}/${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
@@ -357,11 +357,21 @@
         ("-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());
-    ActiveLibDir = ActivePrefix + "/lib" + LLVM_LIBDIR_SUFFIX;
+    {
+      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());
+    }
+    {
+      SmallString<256> path(StringRef(LLVM_INSTALL_LIBDIR LLVM_LIBDIR_SUFFIX));
+      sys::fs::make_absolute(ActivePrefix, path);
+      ActiveLibDir = std::string(path.str());
+    }
     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
@@ -5,6 +5,8 @@
   project(mlir)
   cmake_minimum_required(VERSION 3.13.4)
 
+  include(GNUInstallDirs)
+
   find_package(LLVM CONFIG REQUIRED)
   set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${LLVM_CMAKE_DIR})
   include(HandleLLVMOptions)
@@ -158,7 +160,7 @@
 
 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 +171,7 @@
     )
 
   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
@@ -152,9 +152,9 @@
   install(TARGETS ${name}
     COMPONENT ${name}
     ${export_to_mlirtargets}
-    LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
-    ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
-    RUNTIME DESTINATION bin)
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+    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
@@ -8,6 +8,8 @@
   set(OPENMP_STANDALONE_BUILD TRUE)
   project(openmp C CXX)
 
+  include(GNUInstallDirs)
+
   # 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
@@ -3,6 +3,8 @@
   project(Polly)
   cmake_minimum_required(VERSION 3.13.4)
 
+  include(GNUInstallDirs)
+
   # Where is LLVM installed?
   find_package(LLVM CONFIG REQUIRED)
   set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${LLVM_CMAKE_DIR})
@@ -122,13 +124,13 @@
 
 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
@@ -79,18 +79,18 @@
 
 # Generate PollyConfig.cmake for the install tree.
 unset(POLLY_EXPORTS)
-set(POLLY_INSTALL_PREFIX "${CMAKE_INSTALL_PREFIX}")
+set(POLLY_INSTALL_PREFIX "")
 set(POLLY_CONFIG_LLVM_CMAKE_DIR "${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${LLVM_LIBDIR_SUFFIX}")
+set(POLLY_CONFIG_CMAKE_DIR "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_PREFIX}/${POLLY_INSTALL_PACKAGE_DIR}")
+set(POLLY_CONFIG_LIBRARY_DIRS "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_LIBDIR}${LLVM_LIBDIR_SUFFIX}")
 if (POLLY_BUNDLED_ISL)
   set(POLLY_CONFIG_INCLUDE_DIRS
-    "${POLLY_INSTALL_PREFIX}/include"
-    "${POLLY_INSTALL_PREFIX}/include/polly"
+    "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_LIBDIR}"
+    "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_LIBDIR}/polly"
     )
 else()
   set(POLLY_CONFIG_INCLUDE_DIRS
-    "${POLLY_INSTALL_PREFIX}/include"
+    "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_INCLUDEDIR}"
     ${ISL_INCLUDE_DIRS}
     )
 endif()
diff --git a/polly/cmake/polly_macros.cmake b/polly/cmake/polly_macros.cmake
--- a/polly/cmake/polly_macros.cmake
+++ b/polly/cmake/polly_macros.cmake
@@ -44,8 +44,8 @@
   if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY OR ${name} STREQUAL "LLVMPolly")
     install(TARGETS ${name}
       EXPORT LLVMExports
-      LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
-      ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX})
+	  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
   endif()
   set_property(GLOBAL APPEND PROPERTY LLVM_EXPORTS ${name})
 endmacro(add_polly_library)
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)