On Friday 2009-12-11 23:23, Jan Engelhardt wrote: > >I observe that -m64 throws an error on the given configuration: > >$ touch x.c >$ gcc -m64 x.c >x.c:1: error: -mlong-double-64 not allowed with -m64 Replying to myself and the archive: The error can show up if one tries to use the sparc64-defaulting gcc frontend with a sparc32-defaulting(sparc64-capable) cc1. Pointing the gcc64 to the right cc1 using -B/appropriate/prefix solves it for me. Background: Let /ch be a chroot environment with a gcc64. When calling /ch/usr/bin/gcc, -B may be needed. Some distributions have cc1 in usr/lib/gcc rather than usr/libexec/gcc. Where this is the case, the gcc frontend seems to use a relative pathspec "../lib/gcc" (observed on openSUSE gcc -v) so that -B is not strictly needed. But it turns out Fedora uses an absolute pathspec "/usr/libexec/gcc".
