On Thursday, 13 March 2014 at 05:51:05 UTC, Walter Bright wrote:
I'd like to address, in general, the issue of, what I term,
"performance by default" which is part of the argument for
final by default.
C, C++, and D are billed as languages for writing high
performance apps. And this is true. What is not true, or at
least has not been true in my experience, is that an
application is high performance merely because it is written in
C, C++ or D.
Let me emphasize, code is not fast just because it is written
using a high performance language.
High performance code does not happen by accident, it has to be
intentionally written that way. Furthermore, I can pretty much
guarantee you that if an application has never been profiled,
its speed can be doubled by using a profiler. And if you
really, really want high performance code, you're going to have
to spend time looking at the assembler dumps of the code and
tweaking the source code to get things right.
High performance code is not going to emanate from those
programmers who are not skilled in the art, it is not going to
happen by accident, it is not going to happen by following best
practices, it is not going to happen just because you're
writing in C/C++/D.
D certainly provides what is necessary to write code that blows
away conventional C or C++ code.
It reminds me of when I worked in a machine shop in college.
I'd toil for hours cutting parts, and the parts were not round,
the holes were off center, heck, the surfaces weren't that
smooth. There was an older machinist there who'd take pity on
me. He'd look at what I was doing, cluck cluck, he'd touch the
bit with a grinder, he'd tweak the feed speed, he'd make arcane
adjustments to the machine tool, and out would come perfect
parts. I am an awe to this day of his skill - I still don't
know how he did it. The point is, he and I were using the same
tools. He knew how to make them sing, I didn't.
I still cannot drill a goddam hole and get it where I measured
it should be.
Fully agree with you. That is how we get around writing
distributed applications in JVM/.NET with comparable performance
to the C++ ones being replaced.
--
Paulo
