On Sat, 29 Apr 2017, Richard Biener wrote: > On April 29, 2017 3:59:27 AM GMT+02:00, Palmer Dabbelt <pal...@dabbelt.com> > wrote: > >We've been telling people that "riscv32-*" and "riscv64-*" are exactly > >the same toolchain aside from defaults for "-march" and "-mabi", but it > >appears we were lying. As far as I can tell, binutils doesn't support > >64-bit targets when it has been configured for a 32-bit target. This > >seems to be an upstream limitation that we can't fix in the RISC-V > >port. > >This means that building the toolchain with "--with-arch=rv32i > >--enable-multilib" will fail when building the 64-bit multilibs. > > > >This patch adds two new multilib target fragments that don't add the > >64-bit multilibs. This fixes the build, but has the disadvantage of > >making our 32-bit and 64-bit toolchains very different. > > PowerPC for 32bit can use powerpc64 as target and enable 32bit code-gen > by default at configure time. Maybe this is an option for riscv as > well.
Specifically, in such cases the GCC configure option is --enable-target=all to enable 64-bit multilibs for a default-32-bit target, and the binutils/GDB configure option is --enable-64-bit-bfd. But you can also make a binutils/GDB target include 64-bit support unconditionally without requiring --enable-64-bit-bfd. -- Joseph S. Myers jos...@codesourcery.com
