Index: cmake/modules/CheckCompilerVersion.cmake
===================================================================
--- cmake/modules/CheckCompilerVersion.cmake
+++ cmake/modules/CheckCompilerVersion.cmake
@@ -1,5 +1,5 @@
-# Check if the host compiler is new enough. LLVM requires at least GCC 4.8,
-# MSVC 2015 (Update 3), or Clang 3.1.
+# Check if the host compiler is new enough. LLVM requires at least GCC 5.0,
+# MSVC 2015 (Update 3), or Clang 3.4.
 
 include(CheckCXXSourceCompiles)
 
@@ -8,12 +8,12 @@
 
   if(NOT LLVM_FORCE_USE_OLD_TOOLCHAIN)
     if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
-      if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.8)
-        message(FATAL_ERROR "Host GCC version must be at least 4.8!")
+      if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5.0)
+        message(FATAL_ERROR "Host GCC version must be at least 5.0!")
       endif()
     elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
-      if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.1)
-        message(FATAL_ERROR "Host Clang version must be at least 3.1!")
+      if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.4)
+        message(FATAL_ERROR "Host Clang version must be at least 3.4!")
       endif()
 
       if (CMAKE_CXX_SIMULATE_ID MATCHES "MSVC")