Index: clang/include/clang/Driver/Options.td
===================================================================
--- clang/include/clang/Driver/Options.td
+++ clang/include/clang/Driver/Options.td
@@ -3416,10 +3416,12 @@
 def EB : Flag<["-"], "EB">, Alias<mbig_endian>;
 def m16 : Flag<["-"], "m16">, Group<m_Group>, Flags<[NoXarchOption, CoreOption]>;
 def m32 : Flag<["-"], "m32">, Group<m_Group>, Flags<[NoXarchOption, CoreOption]>;
+def maix32 : Flag<["-"], "maix32">, Alias<m32>;
 def mqdsp6_compat : Flag<["-"], "mqdsp6-compat">, Group<m_Group>, Flags<[NoXarchOption,CC1Option]>,
   HelpText<"Enable hexagon-qdsp6 backward compatibility">,
   MarshallingInfoFlag<LangOpts<"HexagonQdsp6Compat">>;
 def m64 : Flag<["-"], "m64">, Group<m_Group>, Flags<[NoXarchOption, CoreOption]>;
+def maix64 : Flag<["-"], "maix64">, Alias<m64>;
 def mx32 : Flag<["-"], "mx32">, Group<m_Group>, Flags<[NoXarchOption, CoreOption]>;
 def mabi_EQ : Joined<["-"], "mabi=">, Group<m_Group>;
 def miamcu : Flag<["-"], "miamcu">, Group<m_Group>, Flags<[NoXarchOption, CoreOption]>,
Index: clang/test/Driver/aix-maix.c
===================================================================
--- /dev/null
+++ clang/test/Driver/aix-maix.c
@@ -0,0 +1,10 @@
+// Check GCC AIX bitmode compat options.
+
+// RUN: %clang -target powerpc-ibm-aix -maix64 -### -c %s 2>&1 | \
+// RUN:   FileCheck --check-prefix=CHECK64 %s
+
+// RUN: %clang -target powerpc64-ibm-aix -maix32 -### -c %s 2>&1 | \
+// RUN:   FileCheck --check-prefix=CHECK32 %s
+
+// CHECK32: Target: powerpc-ibm-aix
+// CHECK64: Target: powerpc64-ibm-aix