On Jun 18, 2009, Alexandre Oliva <aol...@redhat.com> wrote: >> - Memory consumption in cc1/cc1plus at -Ox -g over that set of apps.
I had to use a different machine for this test. The one I was using had to be taken off line and moved, for reasons beyond my control, and I probably won't be able to get into it to collect the results before I hit the road later this week. Sorry. For the total memory uses below, I moved gcc to gcc.actual in both the trunk and vta install trees, and installed a new gcc script that ran maxmem2.sh $0.actual "$@". I modified maxmem-pipe2.py to output to a named pipe, and for maxmem2.sh to wait for the “cat >&2” from the named pipe to complete, just so that I could correlate the memory use output with the command that produced it. Without this change, in a number of cases the python script output the totals after make had already printed the following command, which got the output mangled and confusing. Having logged the build output of each of the trees that I had configured before (-O2 is used for all of them), now with the maxmem wrapper, I totaled the “total:” lines it printed for each of the builds, resulting the values in the memory column below. # name mem(KiB) %Δ#1 which gflags 1 g0-trunk 58114157 0 trunk -g0 2 g0 58114261 0 vta -g0 3 g-novt 59722133 2.77 vta -g -fno-$vt -fno-vta 4 g-novta 59840445 2.97 vta -g -f$vt -fno-$vta 5 g-novt-vta 59764629 2.84 vta -g -fno-$vt -f$vta 6 g 59997781 3.24 vta -g -f$vt -f$vta Conclusions: generating debug information incurred a memory penalty of nearly 3% before VTA, for a C-only optimized GCC build. Carrying VTA notes uses very little memory besides that which is required to generate debug info without VT (0.07% more). Actually using VTA notes to emit debug information in the VT pass increases maximum memory use, when compared with VT without VTA, by as little as 0.26%. Wow, this was actually much better than I had anticipated. -- Alexandre Oliva, freedom fighter http://FSFLA.org/~lxoliva/ You must be the change you wish to see in the world. -- Gandhi Be Free! -- http://FSFLA.org/ FSF Latin America board member Free Software Evangelist Red Hat Brazil Compiler Engineer
