Re: [proto] proto::expr vs. proto::basic_expr
On 5/16/2011 12:31 PM, Thomas Heller wrote: > You might get even faster. I noticed some places in proto that still > instantiate a proto::expr. > That is in the creation of operators (the lazy_matches in > operators.hpp) instantiate a proto::expr. And the generator of > basic_expr is the default generator which instantiates, when called a > proto::expr as well. Not sure if that may actually matter Yeah, THAT's not right. Thanks for pointing it out. I fixed the problem on trunk. I had to muck with domain deduction, which makes me nervous. The regression tests aren't running right now, so please let me know if you spot any problems. Thanks, -- Eric Niebler BoostPro Computing http://www.boostpro.com ___ proto mailing list proto@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/proto
Re: [proto] proto::expr vs. proto::basic_expr
On Mon, May 16, 2011 at 7:22 AM, Eric Niebler wrote: > On 5/15/2011 9:19 PM, Thomas Heller wrote: >> Hi, >> >> Today I experimented a little bit with phoenix and proto. >> My goal was to decrease the compile time of phoenix. When I started the >> development of phoenix, Eric advised me to use proto::basic_expr to reduce >> compile times. >> Which makes sense giving the argumentation that on instatiating the >> expression >> node, basic_expr has a lot less functions etc. thus the compiler needs to >> instantiate less. So much for the theory. >> In practice this, sadly is not the case. Today I made sure that phoenix uses >> basic_expr exclusively (did not commit the changes). >> >> The result of this adventure was that compile times stayed the same. I was a >> little bit disappointed by this result. >> >> Does anybody have an explanation for this? > > Impossible to say with certainty. I suspect, though, that your use case > is different than mine or, say, Christophe's. With xpressive or MSM, > compiles weren't effected by pre-preprocessing, which shows that we're > hitting limits in the speed of semantic analysis and code gen (possibly > template instantiation). Pre-preprocessing sped up Phoenix, which shows > that you're more hamstrung by lexing. The choice of either proto::expr > or proto::basic_expr doesn't matter for lexing because they're both > going to be lexed regardless. Makes sense. > I know when I introduced basic_expr, I ran tests that showed it was a > perf win for xpressive. But it was a small win, on the order of about > 5%, IIRC. YMMV. You might get even faster. I noticed some places in proto that still instantiate a proto::expr. That is in the creation of operators (the lazy_matches in operators.hpp) instantiate a proto::expr. And the generator of basic_expr is the default generator which instantiates, when called a proto::expr as well. Not sure if that may actually matter ___ proto mailing list proto@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/proto
Re: [proto] proto::expr vs. proto::basic_expr
On 5/15/2011 9:19 PM, Thomas Heller wrote: > Hi, > > Today I experimented a little bit with phoenix and proto. > My goal was to decrease the compile time of phoenix. When I started the > development of phoenix, Eric advised me to use proto::basic_expr to reduce > compile times. > Which makes sense giving the argumentation that on instatiating the > expression > node, basic_expr has a lot less functions etc. thus the compiler needs to > instantiate less. So much for the theory. > In practice this, sadly is not the case. Today I made sure that phoenix uses > basic_expr exclusively (did not commit the changes). > > The result of this adventure was that compile times stayed the same. I was a > little bit disappointed by this result. > > Does anybody have an explanation for this? Impossible to say with certainty. I suspect, though, that your use case is different than mine or, say, Christophe's. With xpressive or MSM, compiles weren't effected by pre-preprocessing, which shows that we're hitting limits in the speed of semantic analysis and code gen (possibly template instantiation). Pre-preprocessing sped up Phoenix, which shows that you're more hamstrung by lexing. The choice of either proto::expr or proto::basic_expr doesn't matter for lexing because they're both going to be lexed regardless. I know when I introduced basic_expr, I ran tests that showed it was a perf win for xpressive. But it was a small win, on the order of about 5%, IIRC. YMMV. -- Eric Niebler BoostPro Computing http://www.boostpro.com ___ proto mailing list proto@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/proto
