On Thu, 20 May 2010, Steven Bosscher wrote: > * The C front end (preprocessing+lexing+parsing) costs ~17%. For an > optimizing compiler with so many passes, this is quite a lot.
Unlike C++ where a lot of speedups were done around 2004-5, I don't think much has been done about speeding up the C front end outside the preprocessor, so there are likely to be lots of opportunities available (there are probably still a fair number for C++ as well). Preprocessor (including preprocessed output) speed is of relevance for use with tools such as distcc, and whole-compilation speed is of obvious relevance for general use of the compiler. Front-end-only speed (-fsyntax-only, approximately) is less important on its own as that's not a normal compiler use (I think) - it's only relevant as a contribution to the speed of a whole compilation. -- Joseph S. Myers jos...@codesourcery.com
