On Oct 13, 2011, at 10:40 PM, Jan Kratochvil wrote: > On Wed, 12 Oct 2011 16:18:07 +0200, Jan Kratochvil wrote: >> On Wed, 12 Oct 2011 16:07:24 +0200, Tristan Gingold wrote: >>> I fear that this may degrade performance of other debuggers. What about >>> adding a command line option ? >> >> I can test idb, > > I do not find the difference measurable. Dropping DW_AT_sibling is 0.25% > performance _improvement_ but I guess it is just less than the measurement > error. > > libstdc++ built with gcc -gdwarf-2 as with gcc -gdwarf-4 -fdebug-types-section > it crashes. i7-920 x86_64 used for testing: > Intel(R) Debugger for applications running on Intel(R) 64, Version 12.1, > Build [76.472.14] > > with DW_AT_sibling > real 2m34.206s 2m31.822s 2m31.709s 2m32.316s > avg = 152.51325 seconds > > patched GCC without DW_AT_sibling > real 2m32.528s 2m30.524s 2m33.767s 2m31.719s > avg = 152.1345 seconds > > I do not see a point in keeping DW_AT_sibling there.
I am not against this patch, my only concern is that there are many many dwarf consumers and I have no idea how they will react to this change. Tristan.