diff --git a/llvm/cmake/modules/GetHostTriple.cmake b/llvm/cmake/modules/GetHostTriple.cmake
--- a/llvm/cmake/modules/GetHostTriple.cmake
+++ b/llvm/cmake/modules/GetHostTriple.cmake
@@ -14,6 +14,12 @@
     else()
       set( value "i686-pc-windows-gnu" )
     endif()
+  elseif( CMAKE_HOST_SYSTEM_NAME STREQUAL AIX )
+    if( CMAKE_SIZEOF_VOID_P EQUAL 8 )
+      set( value "powerpc64-ibm-aix" )
+    else()
+      set( value "powerpc-ibm-aix" )
+    endif()
   else( MSVC )
     if(CMAKE_HOST_SYSTEM_NAME STREQUAL Windows AND NOT MSYS)
       message(WARNING "unable to determine host target triple")
@@ -26,8 +32,6 @@
       if( NOT TT_RV EQUAL 0 )
         message(FATAL_ERROR "Failed to execute ${config_guess}")
       endif( NOT TT_RV EQUAL 0 )
-      # Defer to dynamic detection of the host AIX version.
-      string(REGEX REPLACE "-aix[0-9][^-]*" "-aix" value ${TT_OUT})
     endif()
   endif( MSVC )
   set( ${var} ${value} PARENT_SCOPE )