From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerald Pfeifer To: Loren James Rittle Cc: Subject: Re: C++ compile-time regressions (was: GCC 3.0.1 Status Report) Date: Mon, 23 Jul 2001 05:17:00 -0000 Message-id: References: <200107202341.f6KNfkC62782@latour.rsch.comm.mot.com> X-SW-Source: 2001-07/msg01510.html On Fri, 20 Jul 2001, Loren James Rittle wrote: > From what I understand, the above data is for the build of an entire > program and not just one source translation. Is that correct, Gerald? Yes. > [This issue was studied a bit before the 3.0 release, see > http://gcc.gnu.org/ml/libstdc++/2001-02/msg00365.html and followup.] > [...] > I conclude that in terms of header declaration processing, g++ 3.0 is > slower than g++ 2.95.3 by a factor of 1.6 (4.3/2.7) to 2.1 (9.1/4.2). > When one considers that the standard headers are now bigger (much > bigger, in some common cases), it appears slower by a larger factor > when comparing compilation speed of user-provided code. Very interesting; thanks! > I am the only one that finds it odd that -O0 takes longer to compile > than -O1, -O2 and -O3 under 2.95.3? Having rerun the tests in the meantime to analyse this particular strange data point, it seems that the timing for -O0 using GCC 2.95.3 indeed must have been skewed by some external influences; I now obtained timings also for -O0 along the lines you'd expect. Gerald -- Gerald "Jerry" pfeifer@dbai.tuwien.ac.at http://www.dbai.tuwien.ac.at/~pfeifer/