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Re: [Qemu-devel] [Bug 1594069] [NEW] SIMD instructions translated to sca
Re: [Qemu-devel] [Bug 1594069] [NEW] SIMD instructions translated to scalar host instructions
Sun, 19 Jun 2016 14:14:45 +0100
On 19 June 2016 at 06:33, Timothy Pearson <address@hidden> wrote:
> Public bug reported:
> SIMD instructions inside the guest (NEON, MMX, SSE, SSE2, AVX) are
> translated to scalar instructions on the host instead of SIMD
> instructions. It appears that there have been a few efforts to rectify
> this , and even a submitted patch series, but all discussion has
> effectively died out .
> I would like to see better SIMD performance on qemu, especially as
> non-x86 architectures are becoming widely used (e.g. ARM).
I agree it would be nice, but I'm not sure there's much benefit
from filing a bug about it. Bug reports don't magically become
code changes, and doing SIMD-to-SIMD is very difficult when
you need to support multiple host and guest architectures and
get all the details and corner cases correct. QEMU as it stands
isn't behaving wrongly.