On Tuesday, 18 August 2015 at 21:25:35 UTC, Walter Bright wrote:
On 8/18/2015 1:47 PM, deadalnix wrote:
Realistically, D does not have the man power required to reach
the same level of
optimization, and have many higher impact task to spend that
manpower on.
dmd also does a sludge of patterns. I'm just looking for a few
that would significantly impact the result.
There is none. There is a ton of 0.5% one that adds up to the 30%
difference.
If I'd were to bet on what would impact DMD perfs the most, I'd
go for SRAO, and a inliner in the middle end that works bottom up
:
- Explore the call graph to-down optimizing functions along the
way
- Backtrack bottom-up and check for inlining opportunities.
- Rerun optimizations on the function inlining was done in.
It require a fair amount of tweaking and probably need a way for
the backends to provide a cost heuristic for various functions,
but that would leverage the patterns already existing in the
backend.
