--- a/gcc/config/rs6000/aix64.opt	Sun Aug 21 07:07:55 2011 +0900
+++ b/gcc/config/rs6000/aix64.opt	Fri Oct 27 22:46:09 2017 +0900
@@ -1,6 +1,6 @@
 ; Options for the 64-bit flavor of AIX.
 ;
-; Copyright (C) 2005, 2007, 2010, 2011 Free Software Foundation, Inc.
+; Copyright (C) 2005-2017 Free Software Foundation, Inc.
 ; Contributed by Aldy Hernandez <aldy@quesejoda.com>.
 ;
 ; This file is part of GCC.
@@ -20,16 +20,33 @@
 ; <http://www.gnu.org/licenses/>.
 
 maix64
-Target Report RejectNegative Negative(maix32) Mask(64BIT)
-Compile for 64-bit pointers
+Target Report RejectNegative Negative(maix32) Mask(64BIT) Var(rs6000_isa_flags)
+Compile for 64-bit pointers.
 
 maix32
-Target Report RejectNegative Negative(maix64) InverseMask(64BIT)
-Compile for 32-bit pointers
+Target Report RejectNegative Negative(maix64) InverseMask(64BIT) Var(rs6000_isa_flags)
+Compile for 32-bit pointers.
+
+mcmodel=
+Target RejectNegative Joined Enum(rs6000_cmodel) Var(rs6000_current_cmodel)
+Select code model.
+
+Enum
+Name(rs6000_cmodel) Type(enum rs6000_cmodel)
+Known code models (for use with the -mcmodel= option):
+
+EnumValue
+Enum(rs6000_cmodel) String(small) Value(CMODEL_SMALL)
+
+EnumValue
+Enum(rs6000_cmodel) String(medium) Value(CMODEL_MEDIUM)
+
+EnumValue
+Enum(rs6000_cmodel) String(large) Value(CMODEL_LARGE)
 
 mpe
 Target Report RejectNegative Var(internal_nothing_1) Save
-Support message passing with the Parallel Environment
+Support message passing with the Parallel Environment.
 
 posix
 Driver