On Mon, 3 Jun 2019, Alexey Brodkin wrote: > Well I'm trying to solve a little bit different problem - to build > a universal multilib cross-toolchain which will be usable for building > binaries optimized for different ARC cores. Different I mean: > - Binary-incompatible architecture generations: ARCv1/ARCv2 (both still 32-bit) > - Hard/soft floating-point > - etc. That sort of thing generally uses a separate sysroot for each multilib. (Using GCC's t-sysroot-suffix avoids needing to define SYSROOT_SUFFIX_SPEC manually yourself.) Then the libraries don't need to use separate library directories if only one ABI makes sense on a target at a time. (But cases with different endianness / different function calling ABI / different struct layout etc. should still use different dynamic linker names.) > > Checking -mcpu in CC is a bad idea, given that the compiler might have > > been configured with a default CPU rather than passing it on the command > > line. > > Well this case (no "-mcpu" in CC) is handled - then we just installed > libs in default non-multilib location, i.e. simple "/lib". The locations should be a function of the ABI - *not* of whether the ABI is the default one for the compiler. (For example, /lib64 is the directory for non-x32 x86_64 libraries - both in an x86_64-linux-gnu toolchain, and also for the -m64 multilib of an i686-linux-gnu toolchain configured --enable-targets=all. If you use Debian-style multiarch layout, the locations are still a function of the ABI, just a different function.) -- Joseph S. Myers joseph@xxxxxxxxxxxxxxxx _______________________________________________ linux-snps-arc mailing list linux-snps-arc@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/linux-snps-arc
