On 12/18/2016 02:02 PM, Andreas Schwab wrote: >> I knew m68k has CAS/CAS2, but my suspicion was that lock-free atomics >> require LDREX/STREX-alike instructions since older ARM implementations >> have SWP/SWPB as well. So it shouldn't be too different from the CAS >> instructions on m68k, should it? > > SWP is UP-only, and armv8 doesn't implement it.
I think the main problem with SWP/SWPB is that they don't allow to implement real lock-free atomics, isn't it? [1] I'm just trying to figure out whether there is a way I can help the Debian armel porters to get lock-free atomics in the toolchain so they can have full C++11 support including std::future, possibly with the help of existing kernel helper functions. Adrian > [1] > http://infocenter.arm.com/help/topic/com.arm.doc.dht0008a/DHT0008A_arm_synchronization_primitives.pdf -- .''`. John Paul Adrian Glaubitz : :' : Debian Developer - glaub...@debian.org `. `' Freie Universitaet Berlin - glaub...@physik.fu-berlin.de `- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913
