Julian Foad writes: > I experimented with the effect of inlining on code size and compile > times (but not run-time performance) on the src/FDM/JSBSim tree > within FlightGear CVS as of about a week ago. I did this by > supplying different compiler options with "make > CFLAGS=... CXXFLAGS=...".
> Code size: > seconds bytes options > Smallest: 203 761360 -g -O1 -finline-limit-6 -finline-functions > Smallest O2: 233 767064 -g -O2 -finline-limit-6 -finline-functions > Default: 388 1328284 -g -O2 > Largest: 388 1328284 -g -O2 This morning, I rebuilt both SimGear and FlightGear completely, with CFLAGS and CXXFLAGS set to -g -O1 -finline-limit=6 -finline-functions Here is the size of the old binary (using -O2): text data bss dec hex filename 3097230 500980 3121944 6720154 668a9a /usr/local/FlightGear/bin/fgfs Here is the size of the new binary (using -O1 etc.): text data bss dec hex filename 2484117 690300 3121976 6296393 601349 /usr/local/src/FlightGear/src/Main/fgfs The size saving is not all that dramatic: the old binary had text+data=3598210, while the new binary has text+data=3174417, resulting in about a 12% size saving. Compilation time felt much faster, but I didn't actually time it. I ran a few quick framerate tests, both on the ground and in the air, without panel or hud, in external and pilot view. The framerates for both binaries are always within 1fps of each other, so cutting out most of the inlining makes no measurable difference, positive or negative. If other people's tests show the same result, then I suggest that we switch the default CXXFLAGS and CFLAGS, if only for the sake of faster compiles and a slightly smaller executable. All the best, David -- David Megginson [EMAIL PROTECTED] _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
