Re: [Qemu-devel] QEmu TCG SIMD extension?

[Wei-Ren Chen]

On Wed, Mar 06, 2013 at 11:47:58AM +0800, Peter Maydell wrote:
> On 6 March 2013 11:30, 陳韋任 (Wei-Ren Chen) <address@hidden> wrote:
> > While searching for QEMU SIMD issues, I found there was a paper presented
> > in 2011 [1], and the source code is also public on [2]. However, it seems
> > this project doesn't make any progress since last year. I update their
> > change to upstream and you can download from here:
> >
> >   $ git clone git://github.com/azru0512/qemu.git -b neon-simd
> >
> > Sadly, it can not boot the kernel image provided on [2]. Anyway, I
> > found there was only one thread has discussion on their work [3]. I want
> > to hear more feedback on their idea on adding SIMD TCG IR.
> 
> I think my opinions are still the same -- interesting idea, but getting
> it to work with a set of IR ops which aren't target or host specific
> and getting it to give correct bit-for-bit results, rounding, flags,
> etc, is likely to be tricky. It would also be important to determine
> first whether Neon (or other SIMD) emulation performance is truly
> a major bottleneck.

  I found the problem and now it can boot the kernel image and run the
test. The authors claim they design the general SIMD IR after studying
various SIMD ISA. I am not an expert, and only can decide if it's true
or not by writing another frontend. Well, one of reasons I am studying
their work is to see SIMD IR could benifit our QEMU+LLVM binary
translator. ;)

Regards,
chenwj

-- 
Wei-Ren Chen (陳韋任)
Computer Systems Lab, Institute of Information Science,
Academia Sinica, Taiwan (R.O.C.)
Tel:886-2-2788-3799 #1667
Homepage: http://people.cs.nctu.edu.tw/~chenwj