On 2015-08-21 08:47, Richard Henderson wrote: > 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...
It would be interesting to know if the time taking to generate code is actually used for code translation or code re-translation. The way the MMU is modelled might triggered plenty of costly retranslation. This happens for example on SH4, and to a lesser extent on MIPS. Aurelien -- Aurelien Jarno GPG: 4096R/1DDD8C9B aurel...@aurel32.net http://www.aurel32.net
