On Wed, 2015-05-20 at 14:40 -0400, David Edelsohn wrote: > The current definition of _GLIBC_READ_MEM_BARRIER in libstdc++ is too > weak for an ACQUIRE FENCE, which is what it is intended to be. The > original code emitted an "isync" instead of "lwsync". > > All of the guard acquire and set code needs to be cleaned up to use > GCC atomic intrinsics, but this is necessary for correctness. > > Steve, any comment about the Linux part? > This is correct for the PowerISA V2 (POWER4 and later) processors.
I assume the #ifdef __NO_LWSYNC guard is only set for older (ISA V1) processors. Thanks
