Hi Ian; thanks for the reply! On Wed, 2011-04-27 at 08:20 -0700, Ian Lance Taylor wrote: > Paul Smith <paul@xxxxxxxxxxxxxxxxx> writes: > > > I'd like to create a 32bit version of GCC (+ binutils) that can compile > > for both 32bit and 64bit output. > > Do you mean that you want a gcc which is itself a 32-bit binary? Or do > you mean that you want the default to be -m32? What I'm trying to get is a GCC which is a 32bit app (so I can run it on a 32bit version of Linux, and "file gcc" says it's i686 or similar). But I want to be able to run both "gcc -m32" and "gcc -m64" and get the appropriate outputs. Obviously if I run this gcc on a 32bit system and use -m64 I won't be able to run that output on that system (it would basically be a cross-compiler). When I run this compiler, I'll be using --sysroot to point to an appropriate multilib sysroot. I don't much care whether the default is 32bit or 64bit although a default of 32bit would be slightly preferable (but only very, very slightly). > I think the simplest way to do this would be to configure as usual on a > 64-bit system, and build it using something like > make BOOT_CFLAGS="-m32 -g -O2" I tried to build on a 64bit system setting CC="gcc -m32" and CXX="g++ -m32" when running configure. But this failed. I'll look up BOOT_CFLAGS and see what I can find out. If I can get advice on the best way to proceed I'll go off and whack at it for a while and come back with more specific issues. The main options seem to me to be: One, build on a 32bit host and use --target=x86_64-pc-linux-gnu (or something) to get a 64bit cross compiler (I assume(?) the resulting compiler will also be able to build 32bit targets). Two, build on a 64bit host and figure out a way to force the resulting compiler to be a 32bit application. Would the best way of doing that be using configure with CC="gcc -m32"? Or setting --host=i686-pc-linux-gnu (or similar)? Or...? Or is there a third, better method? > > I am using --enable-targets=all to configure. > > That only affects the binutils. It's listed in the GCC install.info file... is it relevant only for binutils?
