Re: [Qemu-devel] [PATCH v2 10/27] tcg: Add atomic128 helpers

2016-08-11 Thread Alex Bennée
Richard Henderson writes: > Force the use of cmpxchg16b on x86_64. > > Wikipedia suggests that only very old AMD64 (circa 2004) did not have > this instruction. Further, it's required by Windows 8 so no new cpus > will ever omit it. > > If we truely care about these, then we

Re: [Qemu-devel] [PATCH v2 10/27] tcg: Add atomic128 helpers

2016-07-07 Thread Richard Henderson
On 07/07/2016 08:00 PM, Emilio G. Cota wrote: On Fri, Jul 01, 2016 at 10:04:36 -0700, Richard Henderson wrote: Force the use of cmpxchg16b on x86_64. Wikipedia suggests that only very old AMD64 (circa 2004) did not have this instruction. Further, it's required by Windows 8 so no new cpus will

Re: [Qemu-devel] [PATCH v2 10/27] tcg: Add atomic128 helpers

2016-07-07 Thread Emilio G. Cota
On Fri, Jul 01, 2016 at 10:04:36 -0700, Richard Henderson wrote: > Force the use of cmpxchg16b on x86_64. > > Wikipedia suggests that only very old AMD64 (circa 2004) did not have > this instruction. Further, it's required by Windows 8 so no new cpus > will ever omit it. > > If we truely care

[Qemu-devel] [PATCH v2 10/27] tcg: Add atomic128 helpers

2016-07-01 Thread Richard Henderson
Force the use of cmpxchg16b on x86_64. Wikipedia suggests that only very old AMD64 (circa 2004) did not have this instruction. Further, it's required by Windows 8 so no new cpus will ever omit it. If we truely care about these, then we could check this at startup time and then avoid executing