[Bug 1851095] Re: [feature request] awareness of instructions that are well emulated

[Shawn Landden]

ok, here is a double precision exponent implementation that works on
arm32 hardware, but fails in qemu with the wrong checksum.
https://github.com/shawnl/zig-libmvec/blob/master/exp.zig

You need to build zig with the above patch-set.

I guess I am starting from a pessimistic perspective, where I have only
ever seen SIMD work with arm64 emulation (which is quite new), and am
sorry for that.

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1851095

Title:
  [feature request] awareness of instructions that are well emulated

Status in QEMU:
  New

Bug description:
  While qemu's scalar emulation tends to be excellent, qemu's SIMD
  emulation tends to be incorrect (except for arm64 from x86_64)--i have
  found this both for mipsel and arm32. Until these code paths are
  audited, which is probably a large job, it would be nice if qemu knew
  its emulation of this class of instructions was not very good, and
  thus it would give up on finding these instructions if a "careful"
  operation is passed.

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1851095/+subscriptions