http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54419
--- Comment #39 from Jack Howarth <howarth at nitro dot med.uc.edu> 2012-09-06 14:11:49 UTC --- The attached revised patch is Ulrich's original with the change of the test in configure.ac from... AC_TRY_COMPILE(, [void f(void){asm("rdrand %eax");}], [ac_cv_x86_rdrand=yes], [ac_cv_x86_rdrand=no]) to AC_TRY_COMPILE(,[asm("rdrand %eax");], [ac_cv_x86_rdrand=yes], [ac_cv_x86_rdrand=no]) and the additional missing conditional on the definition of _GLIBCXX_X86_RDRAND ... @@ -118,7 +118,7 @@ namespace std _GLIBCXX_VISIBILITY(defaul random_device::result_type random_device::_M_getval() { -#if (defined __i386__ || defined __x86_64__) +#if (defined __i386__ || defined __x86_64__) && defined _GLIBCXX_X86_RDRAND if (! _M_file) return __x86_rdrand(); #endif in libstdc++-v3/src/c++11/random.cc.