* configure.in (erfc): erfc of glibc comes with Debian GNU/Linux Etch

on IA64 is broken.  erfc(10000.0) aborts.
  use missing/erf.c instead.
  http://sources.redhat.com/ml/libc-hacker/2005-08/msg00008.html


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@17841 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,10 @@
+Thu Jul  3 16:08:36 2008  Tanaka Akira  <akr@fsij.org>
+
+	* configure.in (erfc): erfc of glibc comes with Debian GNU/Linux Etch
+	  on IA64 is broken.  erfc(10000.0) aborts.
+	  use missing/erf.c instead.
+	  http://sources.redhat.com/ml/libc-hacker/2005-08/msg00008.html
+
 Thu Jul  3 12:49:39 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* lib/net/smtp.rb (Net::SMTP::start): use 'localhost' instead of

configure.in

@@ -700,6 +700,27 @@ powerpc-darwin*)
   ;;
 esac
 AC_FUNC_MEMCMP
+
+# http://sources.redhat.com/ml/libc-hacker/2005-08/msg00008.html
+# Debian GNU/Linux Etch's libc6.1 2.3.6.ds1-13etch5 has this problem.
+# Debian GNU/Linux Lenny's libc6.1 2.7-10 has no problem.
+AC_CACHE_CHECK(for broken erfc of glibc comes with Debian GNU/Linux Etch on IA64, rb_broken_glibc_ia64_erfc,
+  [AC_TRY_RUN([
+#include <math.h>
+int
+main()
+{
+   erfc(10000.0);
+   return 0;
+}
+],
+	rb_broken_glibc_ia64_erfc=no,
+	rb_broken_glibc_ia64_erfc=yes,
+	rb_broken_glibc_ia64_erfc=no)])
+case $rb_broken_glibc_ia64_erfc in
+  yes) ac_cv_func_erf=no;;
+esac
+
 AC_REPLACE_FUNCS(dup2 memmove strerror strftime\
 		 strchr strstr crypt flock vsnprintf\
 		 isnan finite isinf hypot acosh erf tgamma lgamma_r cbrt \