http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54419
--- Comment #33 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2012-09-05 12:31:06 UTC --- > Er, did you read comment #26? Do comments #24 and #25 answer this question? > Jack says the configure test is being run with > clang, which if true looks like a bug. It is not the way I read Jack's comments. Due to my own bias, I read it as "the as provided by Xcode 4.4 support `rdrand %eax' even if it is not supported by the CPU which will run the code", hence my second patch in comment #25 which uses ac_fn_c_try_run. Indeed I am assuming that everything occurs for the target when doing a cross compilation. > (doesn't change the fact that this PR is about assembler support, but > sometimes > studying one bug unearths other bugs) If you can show that the compiler used for the tests in libstdc++-v3/configure is not the right one, please open a new PR.
