Hello All, I have a question regarding PowerPC64 bit ABI. Since GCC generates FP instructions for Non FP code, i was running in to issues with applications having interrupts (i have seen some threads with people complaining about this). So the other option to resolve this was to build the entire application with '-msoft-float' compiler option. It seems to work fine with 32-bit PPC.
But when i tried to do the same with 64bit PPC, i was getting 'cannot find -lgcc' error which was due to the MULTILIB option, that has been set to exclude building target libraries with '-msoft-float -m64' compiler option. I have discussed this in the IRC channel some one mentioned that it is because of 64bit ABI restriction even though some PPC Linux kernels are built using this option. I have gone through the ABI doc in the link given "http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html"; and there is no mention of 'soft-float' or floating point emulation. So it means i have to assume that '-msoft-float' is not defined by ABI? I have also gone through 32-bit PPC Linux ABI (sys V) doc, "http://refspecs.freestandards.org/elf/elfspec_ppc.pdf"; and there is no mention of 'soft-float' or floating point emulation either. But the PPC EABI doc does have reference to soft-float/FP emulation [CHAPTER 6 Libraries 20 - Software Floating Point Emulation Support Routines]. http://sources-redhat.mirrors.airband.net/binutils/ppc-docs/ppc-eabi-1995-01.pdf 1. Am i referring right documents? 2. Is there any restriction on '-msoft-float' ABI definition on 32bit Linux sys V ABI, 32-bit EABI, 64bit ABI? 3. If PPC linux kernels are built with '-msoft-float -m64' compiler option, is it reasonably safe to build the application with the same options? Thanks, Rohit
