http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55293
--- Comment #15 from Mikael Pettersson <mikpe at it dot uu.se> 2012-11-14 08:34:11 UTC --- FWIW, I bootstrapped a pure 64-bit gcc-4.7.2 on Solaris 10/SPARC64 yesterday, with C, Ada, and C++, using a normal 32-bit-but-64-bit-capable gcc-4.7.2 as host compiler. About the only issue was that I had to coerce the host compiler to generate 64-bit code by default; for that I put #!/bin/sh exec gcc -m64 "$@" in a "gcc64" shell script and passed the path to it in CC when configuring gcc. Overriding CFLAGS might have worked too, but I didn't try that.
