2014-01-10 11:07 UTC+0100 Przemyslaw Czerpak (druzus/at/poczta.onet.pl)
  * include/hbatomic.h
    * for GCC >= 4.1 (except MinGW) use build-in GCC __sync_*() atomic
      functions instead of our x86 assembler macros. This can be disabled
      by HB_USE_GCCATOMIC_OFF macro. Please make tests on different
      platforms. If you find some platforms on which compile or link
      errors bound with __sync_*() functions are reported then please
      send information about used platform and GCC version. GCC 4.1 or
      higher should support it during compilation but not all runtime
      libraries have implementation for __sync_*() functions. Low level
      implementations were added later for different platforms. In such
      case adding -DHB_USE_GCCATOMIC_OFF to HB_USER_CFLAGS should be
      sufficient workaround but I want to document such cases so please
      send information about it to devel list.
    ; This modification fixes problem with x86_64 CentOS and RH builds
      were default GCC does not respect volatile in our ASM macros and
      "optimize" them breaking our memory barriers.
Merge https://github.com/harbour/core