configure switches to cross-compiling mode if I call it with build != host like in
./configure --build=powerpc64-unknown-linux-gnu --host=powerpc-bgp-linux-gnu CC=bgxlc Can someone explain to me what implications that has for configure checks and the build in general? I can see that configure says checking for powerpc-bgp-linux-gnu-gcc... bgxlc and also the checks for ar, strip, ranlib are prefixed with $host, as well as several libtool checks. What else is done different? Are some tests omitted because you can't access the host during configure time (e.g. on Blue Gene/P you can't access the host/compute-nodes directly)? On Blue Gene/P systems you usually want to use the IBM xlc compiler instead of gcc. So you usually explicitly specify the cross-compiler via CC=bgxlc. If I specify CC directly, is there still the need to specify --build and --host? Does configure behaves differently when using gcc or bgxlc? Is there a way to switch to normal non-cross-compiling mode by issuing some commands in configure.ac? Thanks, Christian