configure.in: use SSE2

* configure.in: use SSE2 instructions for drop unexpected
  precisions.  [ruby-core:54738] [Bug #8358]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44474 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Wed Jan  1 11:12:29 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* configure.in: use SSE2 instructions for drop unexpected
+	  precisions.  [ruby-core:54738] [Bug #8358]
+
 Tue Dec 31 23:49:07 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* eval.c (rb_f_raise): add cause: optional keyword argument.

configure.in

@@ -801,6 +801,7 @@ if test "$GCC" = yes; then
       # various  headers.  Most frequent  situation is  the use  of //
       # comments.   We  bypass  ANSI   C  mode  for  them.   Otherwise
       # extension libs cannot include those headers.
+      RUBY_TRY_CFLAGS(-msse2 -mfpmath=sse, [RUBY_APPEND_OPTION(XCFLAGS, -msse2 -mfpmath=sse)])
     ],
     [cygwin*|darwin*|netbsd*], [
       # need lgamma_r(), finite()