Richard Henderson <r...@twiddle.net> writes:
On 01/14/2013 10:14 AM, Torbjorn Granlund wrote:
> Is it in such a state that grabbing that repo and building a
> qemu-system-x86_64 would give me MULX support?
Yes, and "-cpu Haswell" will enable the BMI extensions.
A review of the code and docs reveals that I missed RORX
from the BMI2 insns, but that's the only one I missed.
Note that I also incorrectly set the overflow flag in
several of the BMI insns. It ought to be 0, and I currently
set it as if by a standard arithmetic insn.
I can also suggest using "qemu-x86_64" for userland linux
emulation, rather than full system emulation, for testing
something as well-behaved as gmp. In partiular, the way
memory accesses are translated is significantly faster.
I compiled your version. It does not work for me:
tutu$ gcc -static^C/foo.s && qemu-x86_64 -cpu Haswell ./a.out
tutu$ cat ~/foo.s
.text
.globl main
.type main, @function
main: mulx %rax, %r8, %r9
ret
tutu$ gcc ~/foo.s
tutu$ qemu-x86_64 -cpu Haswell ./a.out
qemu: uncaught target signal 4 (Illegal instruction) - core dumped
Illegal instruction
If I remove the mulx, the example runs.
I copied your sources using this command:
git clone git://repo.or.cz/qemu/rth.git qemu-x86-rth
There seem to be no mention of MULX in the i386 subdirectory.
--
Torbjörn
