http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53112
--- Comment #4 from birender.singh at hotmail dot com 2012-04-30 11:48:46 UTC --- Sorry buddy, I have removed past code and setup the fresh code. This time have build 64 bit gmp and mpfr with ABI=64 @ --prefix path /usr/local/ and tried to build gcc in 64 bit. but it gave this error ELFCLASS64 for libmpfr.so and libgmp.so