--- ruby-1.8.7-p330/mkconfig.rb.multilib	2010-11-24 16:38:41.000000000 +0900

+++ ruby-1.8.7-p330/mkconfig.rb	2010-12-26 02:16:32.000000000 +0900

@@ -40,6 +40,7 @@

 has_patchlevel = false

 continued_name = nil

 continued_line = nil

+lib_64 = ''

 File.foreach "config.status" do |line|

   next if /^#/ =~ line

   name = nil

@@ -102,13 +103,21 @@

     when "PATCHLEVEL"

       has_patchlevel = true

     end

+

+    # If the target architecture is one of the following,

+    #   ppc64 s390x sparc64 x86_64

+    # then use "lib64", not "lib" in prefix.

+    if name == "target_cpu" and (/64"$/ =~ val or val == '"s390x"')

+      lib_64 = '64'

+    end

   end

 #  break if /^CEOF/

 end

 drive = File::PATH_SEPARATOR == ';'

-prefix = '/lib/ruby/' + RUBY_VERSION.sub(/\.\d+$/, '') + '/' + RUBY_PLATFORM

+prefix = "/lib#{lib_64}/ruby/" \

+  + RUBY_VERSION.sub(/\.\d+$/, '') + '/' + RUBY_PLATFORM

 print "  TOPDIR = File.dirname(__FILE__).chomp!(#{prefix.dump})\n"

 print "  DESTDIR = ", (drive ? "TOPDIR && TOPDIR[/\\A[a-z]:/i] || " : ""), "'' unless defined? DESTDIR\n"

 print "  CONFIG = {}\n"