On Monday, 14 September 2015 at 13:58:33 UTC, Fredrik Boulund
wrote:
On Monday, 14 September 2015 at 13:37:18 UTC, John Colvin wrote:
On Monday, 14 September 2015 at 13:05:32 UTC, Andrea Fontana
wrote:
On Monday, 14 September 2015 at 12:30:21 UTC, Fredrik Boulund
wrote:
[...]
Also if problem probabily is i/o related, have you tried with:
-O -inline -release -noboundscheck
?
-inline in particular is likely to have a strong impact here
Why would -inline be particularly likely to make a big
difference in this case? I'm trying to learn, but I don't see
what inlining could be done in this case.
Range-based code like you are using leads to *huge* numbers of
function calls to get anything done. The advantage of inlining is
twofold: 1) you don't have to pay the cost of the function call
itself and 2) often more optimisation can be done once a function
is inlined.
Anyway I think it's a good idea to test it against gdc and
ldc that are known to generate faster executables.
Andrea
+1 I would expect ldc or gdc to strongly outperform dmd on
this code.
Why is that? I would love to learn to understand why they could
be expected to perform much better on this kind of code.
Because there are much better at inlining. dmd is quick to
compile your code and is most up-to-date, but ldc and gdc will
produce somewhat faster code in almost all cases, sometimes very
dramatically much faster.
