Re: Building C++ with --enable-languages=c,fortran
On Saturday 06 August 2011 00:52:02 Thomas Koenig wrote: Hello world, I just noticed that C++ now appears to be built by default, even when only the C and fortran are specified. Yes, but it doesn't make much difference in practice. The only difference I saw is the debugging symbols including the full prototype (not only the function name) in the debugger. WRT to bootstrap time, as usual: it's too long. Mikael
Re: Building C++ with --enable-languages=c,fortran
On 08/06/2011 11:22 AM, Mikael Morin wrote: WRT to bootstrap time, as usual: it's too long. Well, that all depends on your (time) frame of reference, of course. In the summer months leading up to Craig Burley asking for volunteers testing g77 (the g77-alpha phase), i.e., during the summer of 1992, a bootstrap of GCC (C and C++) took 8 hours on my single 25 Mhz Motorola 68040 powered Next Station. With the new gcc, I could build a fresh f2c in minutes, and, using that combo (f2c+gcc) a recompile of our weather forecasting code took another 10 minutes. Nowadays, on a *4 year old* quad core Core 2 machine, building C, C++, Ada and Fortran takes less than 2 hours, so given that I put in 4 times as many processors, the rest of the hardware keeps up with providing me a bootstrap in 1/4th of the time it took 19 years ago, giving me twice the number of front ends plus run time libraries. I think the outlook is good :-) -- Toon Moene - e-mail: t...@moene.org - phone: +31 346 214290 Saturnushof 14, 3738 XG Maartensdijk, The Netherlands At home: http://moene.org/~toon/; weather: http://moene.org/~hirlam/ Progress of GNU Fortran: http://gcc.gnu.org/wiki/GFortran#news
Re: Building C++ with --enable-languages=c,fortran
On Sat, Aug 06, 2011 at 03:16:43PM +0200, Toon Moene wrote: On 08/06/2011 11:22 AM, Mikael Morin wrote: WRT to bootstrap time, as usual: it's too long. Well, that all depends on your (time) frame of reference, of course. In the summer months leading up to Craig Burley asking for volunteers testing g77 (the g77-alpha phase), i.e., during the summer of 1992, a bootstrap of GCC (C and C++) took 8 hours on my single 25 Mhz Motorola 68040 powered Next Station. With the new gcc, I could build a fresh f2c in minutes, and, using that combo (f2c+gcc) a recompile of our weather forecasting code took another 10 minutes. Nowadays, on a *4 year old* quad core Core 2 machine, building C, C++, Ada and Fortran takes less than 2 hours, so given that I put in 4 times as many processors, the rest of the hardware keeps up with providing me a bootstrap in 1/4th of the time it took 19 years ago, giving me twice the number of front ends plus run time libraries. I think the outlook is good :-) You left out the crucial hardware spec. How much memory did you have 19 years ago compared to the system today? My experience with g++ is that it will consume more memory than gcc. -- Steve
Re: Building C++ with --enable-languages=c,fortran
On 08/06/2011 05:14 PM, Steve Kargl wrote: You left out the crucial hardware spec. How much memory did you have 19 years ago compared to the system today? My experience with g++ is that it will consume more memory than gcc. That might be true - I have never experienced memory shortage *building* C and C++ in 1992 - I had 16 Mbyte of RAM at that time. Nowadays I have 4 Gbyte of RAM, but still *bootstrapping* doesn't seem to be a problem (certain parts of the weather forecasting system these days stretch the virtual memory system, but with 4 Gbyte RAM and 11 Gbyte SWAP I still survive). -- Toon Moene - e-mail: t...@moene.org - phone: +31 346 214290 Saturnushof 14, 3738 XG Maartensdijk, The Netherlands At home: http://moene.org/~toon/; weather: http://moene.org/~hirlam/ Progress of GNU Fortran: http://gcc.gnu.org/wiki/GFortran#news
Building C++ with --enable-languages=c,fortran
Hello world, I just noticed that C++ now appears to be built by default, even when only the C and fortran are specified. The configure line ../trunk/configure --prefix=$HOME --enable-languages=c,fortran --with-mpc=/usr/local --with-mpfr=/usr/local leads to the message checking for version 0.11 (revision 0 or later) of PPL... no The following languages will be built: c,c++,fortran,lto I see recent changes by Ian in this area, but nothing in the ChangeLog suggests to me that this was intentional. Any ideas?
Re: Building C++ with --enable-languages=c,fortran
On Sat, Aug 06, 2011 at 12:52:02AM +0200, Thomas Koenig wrote: Hello world, I just noticed that C++ now appears to be built by default, even when only the C and fortran are specified. The configure line ../trunk/configure --prefix=$HOME --enable-languages=c,fortran --with-mpc=/usr/local --with-mpfr=/usr/local leads to the message checking for version 0.11 (revision 0 or later) of PPL... no The following languages will be built: c,c++,fortran,lto I see recent changes by Ian in this area, but nothing in the ChangeLog suggests to me that this was intentional. Any ideas? It appears the original thread starts here http://gcc.gnu.org/ml/gcc-patches/2011-07/msg01304.html -- Steve
Re: Building C++ with --enable-languages=c,fortran
Thomas Koenig tkoe...@netcologne.de writes: I just noticed that C++ now appears to be built by default, even when only the C and fortran are specified. The configure line ../trunk/configure --prefix=$HOME --enable-languages=c,fortran --with-mpc=/usr/local --with-mpfr=/usr/local leads to the message checking for version 0.11 (revision 0 or later) of PPL... no The following languages will be built: c,c++,fortran,lto I see recent changes by Ian in this area, but nothing in the ChangeLog suggests to me that this was intentional. It is intentional. In current mainline stages 2 and 3 are now by default built with the C++ compiler, not the C compiler. Therefore, the C++ compiler must be built in stages 1 and 2, in order to use to build the stages 2 and 3 compiler. And then of course we build the C++ compiler in stage 3 in order to compare it. The ChangeLog entry says that if --enable-build-poststage1-with-cxx is set, C++ becomes a boot language. That is what you are seeing. I guess what the ChangeLog entry does not say is that --enable-build-poststage1-with-cxx is set by default. Ian
Re: Building C++ with --enable-languages=c,fortran
On Fri, Aug 05, 2011 at 06:51:12PM -0700, Ian Lance Taylor wrote: Thomas Koenig tkoe...@netcologne.de writes: I just noticed that C++ now appears to be built by default, even when only the C and fortran are specified. The configure line ../trunk/configure --prefix=$HOME --enable-languages=c,fortran --with-mpc=/usr/local --with-mpfr=/usr/local leads to the message checking for version 0.11 (revision 0 or later) of PPL... no The following languages will be built: c,c++,fortran,lto I see recent changes by Ian in this area, but nothing in the ChangeLog suggests to me that this was intentional. It is intentional. In current mainline stages 2 and 3 are now by default built with the C++ compiler, not the C compiler. Therefore, the C++ compiler must be built in stages 1 and 2, in order to use to build the stages 2 and 3 compiler. And then of course we build the C++ compiler in stage 3 in order to compare it. The ChangeLog entry says that if --enable-build-poststage1-with-cxx is set, C++ becomes a boot language. That is what you are seeing. I guess what the ChangeLog entry does not say is that --enable-build-poststage1-with-cxx is set by default. What are the additional resource requirements? Some of us have old hardware and limited $. -- Steve
Re: Building C++ with --enable-languages=c,fortran
Steve Kargl s...@troutmask.apl.washington.edu writes: The ChangeLog entry says that if --enable-build-poststage1-with-cxx is set, C++ becomes a boot language. That is what you are seeing. I guess what the ChangeLog entry does not say is that --enable-build-poststage1-with-cxx is set by default. What are the additional resource requirements? Some of us have old hardware and limited $. The main additional resource requirement is building libstdc++ in stage 1 (and stages 2 and 3 if you were previously not building the C++ compiler at all). The C++ compiler proper is fairly small by comparison. At present you can use --disable-build-poststage1-with-cxx. However, in the future, I would like to change gcc to always build with C++. Yes, this will take more resources. Ian
