On 9/12/2011 4:06 AM, Thomas Heller wrote:
On Monday, September 12, 2011 02:57:21 PM Joel de Guzman wrote:
For example, here is the current CT status of Phoenix2 vs Phoenix3 comparing the elapsed (CT) time for the phoenix2 vs. phoenix3 lambda_tests.cpp (**):
MSVC 10: Phoenix2: 00:04.5 Phoenix3: 00:29.9
G++ 4.5: Phoenix2: 00:02.6 Phoenix3: 00:04.7
I wasn't aware that Phoenix3 was so bad under MSVC 10.
Me neither. If that's the case, we have work to do.
You all know that Phoenix2 uses Fusion exclusively. Phoenix3 uses proto, which according to Eric does not use Fusion, although IIRC the core of Phoenix3 uses some Fusion still (quick check: Thomas uses an optimized-PP version of fusion:: vector for phoenix3).
Heller did a helluva perf-tweaks for Phx3 to get that number for g++ (alas, not MSVC). In fairness, I did absolutely no CT perf-tweaks for both Phoenix2 and Fusion.
(** I made sure both tests have exactly the same code, so I removed the last test. I can post the exact code if need be)
OK, I retract everything I said. Fusion rulez, and Proto needs help. Sorry for the blind accusation. Let's stop this and figure out what needs to be fixed.
FWIW, there are some unit tests that outperform the compile times of Phoenix2 (with gcc), the current bad hit on compile times seem to only occur with let, lambda and switch/case expressions.
This /suggests/ to me that the core of Phx3 is sound, but that the implementation of let, lambda, and switch are heavy. But I'm not blaming Thomas. I'm just suggesting a logical place to begin an investigation. And regardless, we should point Steven's template profiler at the code and see what it says. Thomas, do you want to give that a shot? -- Eric Niebler BoostPro Computing http://www.boostpro.com