Re: [PING] [PATCH] Avoid atomic for guard acquire when that is expensive
On 11/30/20 3:08 PM, Bernd Edlinger wrote: Hi, I'd like to ping for this patch: I reviewed it on the 24th: https://gcc.gnu.org/pipermail/gcc-patches/2020-November/560118.html https://gcc.gnu.org/pipermail/gcc-patches/2020-November/559882.html Thanks Bernd. On 11/22/20 9:05 AM, Bernd Edlinger wrote: Hi, this avoids the need to use -fno-threadsafe-statics on arm-none-eabi or working around that problem by supplying a dummy __sync_synchronize function which might just lead to silent code failure of the worst kind (non-reproducable, racy) at runtime, as was pointed out on previous discussions here. When the atomic access involves a call to __sync_synchronize it is better to call __cxa_guard_acquire unconditionally, since it handles the atomics too, or is a non-threaded implementation when there is no gthread support for this target. This fixes also a bug for the ARM EABI big-endian target, that is, previously the wrong bit was checked. Regression tested successfully on arm-none-eabi with newlib-3.3.0. Is it OK for trunk? Thanks Bernd.
[PING] [PATCH] Avoid atomic for guard acquire when that is expensive
Hi, I'd like to ping for this patch: https://gcc.gnu.org/pipermail/gcc-patches/2020-November/559882.html Thanks Bernd. On 11/22/20 9:05 AM, Bernd Edlinger wrote: > Hi, > > this avoids the need to use -fno-threadsafe-statics on > arm-none-eabi or working around that problem by supplying > a dummy __sync_synchronize function which might > just lead to silent code failure of the worst kind > (non-reproducable, racy) at runtime, as was pointed out > on previous discussions here. > > When the atomic access involves a call to __sync_synchronize > it is better to call __cxa_guard_acquire unconditionally, > since it handles the atomics too, or is a non-threaded > implementation when there is no gthread support for this target. > > This fixes also a bug for the ARM EABI big-endian target, > that is, previously the wrong bit was checked. > > > Regression tested successfully on arm-none-eabi with newlib-3.3.0. > > Is it OK for trunk? > > > Thanks > Bernd. >
