Hello, I wrote: > for some years I've been running into problems with exorbitant link > times from time to time with different g++ and binutils releases. > Sometimes just switching either binutils or g++ to e.g. a self-built > one solved the problem. Now that I've been running into it again, I > decided to find the cause. >[...] > I do not have an idea, what I can do to make sure, that a toolchain > will not have those long link times. What options do I have to build > gcc or binutils or my code with to avoid it? That's the question I'm > posting for.
A partial answer is here http://sourceware.org/ml/binutils/2006-08/msg00334.html Indeed, using a recent snapshot of binutils provides the fastest linking time I have seen ever. There is no official release including the patch, yet. During configuration gcc finds out a few things about ld, among them some COMDAT section settings. When building gcc-4.1.2-20070129, it found out that my system linker does not support COMDAT sections, so gcc switches to .gnu.linkonce.t, which makes a fast link in this combination. That was the fast link in my first posting. When building gcc-4.1.2-20070129 against the latest official binutils release, COMDAT sections are supported, and due to the patch from above missing, linking is slow with those binutils. My system gcc is compiled with COMDAT section support, but the system linker is not and obviously falls back to slow mode on object files with comdat sections. This lead to the slow link in my first posting. The snapshot binutils seem to make the fastest out of it, whenever they get used, but at the cost of a some 30% bigger binary. And I need not wonder, why there are so few answers, this is deep in active development of binutils and gcc. There are quite some problems open, e.g. how to handle debug information correctly and efficiently, and it is only due to hacks, that the situation is bearable. As always, it is no bad idea to keep an eye on the latest (snapshot) releases. Bernd Strieder _______________________________________________ help-gplusplus mailing list help-gplusplus@gnu.org http://lists.gnu.org/mailman/listinfo/help-gplusplus
