Re: [Qemu-devel] Debian 7.8.0 SPARC64 on qemu - anything i can do to speedup the emulation?

[Richard Henderson]

On 08/20/2015 11:05 PM, Dennis Luehring wrote:
>> > g++ src/pugixml.cpp -g -Wall -Wextra -Werror -pedantic -std=c++0x -c -MMD 
>> > -MP
>> >
>> > tcg-indirect: ~2:46.5
>> > qemu.org-git: ~2:51.2 (worst result)
>> > without-optimization: ~2:14.1 (best result)
>>
>> No compiler optimization?  I wouldn't expect there to be much for tcg to
>> optimize there -- dropping values to memory all the time doesn't leave much.
> 
> 
> without-optimization means qemu.org-git release build + undefine
> USE_TCG_OPTIMIZATIONS in tcg/tcg.c
> or what compiler do you mean?

The one for compiling the benchmark: g++ -O2.

>> These results are weird.  Unoptimized less than half the speed of mainline?
>> Improving optimization (with no extra work, mind) brings the results back 
>> down?
> 
> 
> yep they are - it seems that the assumption of the involved developers
> where speed can be improved / or slowbess comes from is not correct
> how are SPARC64 benchmarks done usually?

*shrug* No different than any other...


r~