On Fri, Feb 20, 2015 at 5:51 AM, Martin Jambor <mjam...@suse.cz> wrote: > Hi, > > I have spent quite some time trying to build an x32 gcc to debug a PR > this week before I finally found the configure switch that made > everything work. In order to share this possibly valuable knowledge, > I have created a wiki mini-page detailing how I managed to get it > finally working: > > https://gcc.gnu.org/wiki/SettingUpX32GCC > > I've linked it from the "Tutorials, HOWTOs" section of the > GettingStarted page because I did not find a better place. Of course, > feel free to correct any mistakes I might have made. >
Thanks for doing this. X32 codegen is always enabled for Linux/x86-64 targets. You just need to compile x32 run-time to compile programs in x32. There are 2 ways to enable x32 run-time: 1. Configure GCC with --with-multilib-list=m32,m64,mx32. It will enable x32 multilib: [hjl@gnu-tools-1 gcc-x32]$ file build-x86_64-linux/gcc/cc1plus build-x86_64-linux/gcc/cc1plus: ELF 64-bit LSB executable, x86-64, version 1 (GNU/Linux), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.32, BuildID[sha1]=7fb3d0574eda3475dfb2247640524bb1099c9751, not stripped [hjl@gnu-tools-1 gcc-x32]$ ./build-x86_64-linux/gcc/xgcc -v Using built-in specs. COLLECT_GCC=./build-x86_64-linux/gcc/xgcc Target: x86_64-unknown-linux-gnu Configured with: /export/gnu/import/git/gcc/configure --enable-clocale=gnu --with-system-zlib --with-demangler-in-ld --enable-languages=c,c++,fortran,java,lto,objc,obj-c++,go --prefix=/usr/gcc-5.0.0-x32 --with-local-prefix=/usr/local --enable-gnu-indirect-function --with-multilib-list=m32,m64,mx32 --enable-linker-build-id --enable-gnu-unique-object --with-fpmath=sse Thread model: posix gcc version 5.0.0 20141231 (experimental) (GCC) [hjl@gnu-tools-1 gcc-x32]$ 2. Configure GCC with --with-abi=mx32. It will bootstrap GCC into x32 format with x32 run-time enabled: [hjl@gnu-tools-1 gcc-x32-mx32]$ file build-x86_64-linux/gcc/cc1plus build-x86_64-linux/gcc/cc1plus: ELF 32-bit LSB executable, x86-64, version 1 (GNU/Linux), dynamically linked, interpreter /libx32/ld-linux-x32.so.2, for GNU/Linux 3.4.0, BuildID[sha1]=b44082efbfec9ec5e7309445110f266d6f43cbfe, not stripped [hjl@gnu-tools-1 gcc-x32-mx32]$ ./build-x86_64-linux/gcc/xgcc -v Using built-in specs. COLLECT_GCC=./build-x86_64-linux/gcc/xgcc Target: x86_64-unknown-linux-gnu Configured with: /export/gnu/import/git/sources/gcc/configure --enable-languages=c,c++ --disable-bootstrap --prefix=/usr/gcc-5.0.0-mx32 --with-local-prefix=/usr/local --enable-gnu-indirect-function --with-multilib-list=m32,m64,mx32 --enable-linker-build-id --enable-gnu-unique-object --with-abi=mx32 --with-fpmath=sse Thread model: posix gcc version 5.0.0 20150122 (experimental) (GCC) [hjl@gnu-tools-1 gcc-x32-mx32]$ Either will produce GCC which support -mx32. x86_64-linux-gnux32 isn't required to configure GCC. -- H.J.
