Janne Grunau j@jannau.net writes:
On 2014-02-25 15:54:37 +0000, Alex Bennée wrote:
<snip>
Have you got the log file "unsupported" line? I seem to recall you did ping me but maybe it was just on IRC? I just want to make sure I do the right ones. I'm working on this now.
We spoke on irc about it. a quick test commenting unsupported instructions out revealed that rshrn/2, sqrshrun and shrn/2 are the only NEON instructions used in libav still missing support in qemu master. Unsoppurted lines from qemu master 0459650d94d1 below.
target-arm/translate-a64.c:6884: unsupported instruction encoding 0x0f0a8e10 at pc=00000000008632c8 target-arm/translate-a64.c:6884: unsupported instruction encoding 0x2f0b8f9c at pc=0000000000865764 target-arm/translate-a64.c:6884: unsupported instruction encoding 0x0f0a8610 at pc=0000000000863afc
I've just pushed support for the various shrn opcodes to:
https://github.com/stsquad/qemu/tree/ajb-a64-working
I suspect if libav uses them heavily there could be some optimisation to be made as the narrow operations make heavy use of helpers to do the saturation stuff.