On 11/23/2011 4:35 PM, Hartmut Kaiser wrote:
On 11/23/2011 04:15 PM, Matthew Chambers wrote: The spirit code isn't really optimal (see the slightly improved version attached).
OK. That would be nice in the docs...took me 15 minutes to figure out what I did have! :(
Also, did you turn on optimization?
I DID have optimization on but had some other junk on: debug symbols, /CLR (this was huge!), and the default _SECURE_SCL=1. After changing these, it got better but still not quite as good as MSVC 10. _SECURE_SCL was a major difference between MSVC9 and 10 (where it defaults to off).
Apparently not (MSVC2010, 64bit):
1000000 iterations of "123": atoi: 0.0366391 seconds strtol: 0.0327922 seconds Spirit: 0.0117357 seconds lexical_cast(string): 0.0702884 seconds lexical_cast(iterator_range): 0.742229 seconds lexical_cast(iterator_range->string): 0.0797006 seconds
1000000 iterations of "123567890": atoi: 0.0489029 seconds strtol: 0.0473159 seconds Spirit: 0.0209374 seconds lexical_cast(string): 0.0842183 seconds lexical_cast(iterator_range): 1.02365 seconds lexical_cast(iterator_range->string): 0.0912515 seconds
1000000 iterations of "1.23456": atof: 0.295518 seconds strtod: 0.279579 seconds Spirit: 0.0308074 seconds lexical_cast(string): 1.2818 seconds lexical_cast(iterator_range): 2.15233 seconds lexical_cast(iterator_range->string): 1.35335 seconds
1000000 iterations of "1.23456789e42": atof: 0.422748 seconds strtod: 0.407293 seconds Spirit: 0.0479103 seconds lexical_cast(string): 1.47888 seconds lexical_cast(iterator_range): 2.61988 seconds lexical_cast(iterator_range->string): 1.52793 seconds
That's more like it :-P
I added error checking to strto[dl] (what's the point of using it otherwise?).
My new figures (32-bit):
1000000 iterations of "123": atoi: 0.0434303 seconds strtol: 0.0385471 seconds Spirit: 0.27993 seconds lexical_cast(string): 0.337947 seconds lexical_cast(iterator_range): 3.13472 seconds lexical_cast(iterator_range->string): 0.441562 seconds
1000000 iterations of "123567890": atoi: 0.0635996 seconds strtol: 0.0627828 seconds Spirit: 0.550669 seconds lexical_cast(string): 0.440172 seconds lexical_cast(iterator_range): 4.85826 seconds lexical_cast(iterator_range->string): 0.516084 seconds
1000000 iterations of "1.23456": atof: 0.495972 seconds strtod: 0.507613 seconds Spirit: 0.685259 seconds lexical_cast(string): 2.74444 seconds lexical_cast(iterator_range): 4.62169 seconds lexical_cast(iterator_range->string): 2.8685 seconds
1000000 iterations of "1.23456789e42": atof: 0.700639 seconds strtod: 0.707499 seconds Spirit: 0.967519 seconds lexical_cast(string): 3.16936 seconds lexical_cast(iterator_range): 6.19912 seconds lexical_cast(iterator_range->string): 3.29152 seconds
Arash Partow pointed me at his thorough article: http://www.codeproject.com/KB/recipes/Tokenizer.aspx
Based on Boost 1.48 (not sure how many performance changes went into lexical_cast between 1.47 and 1.48). He's using Profile Guided Optimization though; it seems to make a big difference which has not been my experience in bigger projects.
Something is definitely fishy with your Spirit numbers. Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu