[Proj] Geo Transfoms and calculations
Gerald I. Evenden
geraldi.evenden at gmail.com
Wed Jan 14 12:04:33 EST 2009
On Tuesday 13 January 2009 10:51:28 pm Hamish wrote:
> --- On Mon, 1/5/09, strebe <strebe at aol.com> wrote:
> > Not to start a war, but
> .... but some will try anyway ...
> :) I will bite with my tongue-in-cheek,
> > GCC is not quite "world
> > class". It is usable, but the code generation from MS
> > Visual Studio C++ is much better. Intel also supplies their
> > own compiler so that developers have access to world-class
> > code generation; I have read it's even better than
> > Microsoft's but have not used it myself, though I am
> > considering it for Macintosh.
> > How do I know this? The disinterested benchmarks say so.
> > Not content to take others' word for it, my own software
> > Geocart runs nearly twice as fast on VS C++ -generated code
> > than on GCC-generated code in compute-bound situations.
> > That's... important, when I have massive raster
> > reprojections that take minutes or even hours.
> > GCC's conformance to C++ standards used to be MUCH
> > better than VS C++, but that advantage has dwindled since VS
> > C++ 7 and pretty much disappeared in VSC++ 8, which I have
> > on occasion found to be even more conformant than GCC. VS
> > C++ 6 was a standards disaster.
> > <<< shudder >>>
> > So, I would agree GCC is world-class for standards
> > conformance, which is important. The same cannot be said for
> > code generation, which is also important. Since the best
> > performers in that regard come out of proprietary vendors, I
> > have to view "the world-class status of both Linux and
> > GCC is a result, largely, of their GPL status" to be
> > more ideological than a factual, particularly since there
> > are not many metrics the market cares about by which Linux
> > leads the world. Still, I am grateful to have the GPL, and I
> > agree it makes no sense to fault the GPL community for the
> > license or its implications. Fair's fair, and it's
> > not like developers would be better off if GPL did not
> > exist.
> it is a bit simplistic to judge only based on runtime speed.
> The goal of GCC besides standards conformance you should consider is
> the very tricky problem of portability across hardware architectures.
> Intel & VSC only have one target, while gcc has 14+ to consider*.
> Optimization will be least third down on gcc's list of priorities behind
> these two. actually, probably 4th behind code readability.
> compile-speed is another competing variable to consider, as is
> "Freedom" and cost.
> [*] debian; probably there are more
> and FWIW, millions and millions of professional users and successful
> deployments worldwide make these things world-class, not some benchmark
> or our opinions/ideologies.
> as with most things, be it a tool, license, projection, or a spouse,
> the best solution for you depends on your specific needs, and it is
> silly to argue which is "best" or unfit. but we try anyway :)
Exceptionally well put and I could not agree with you more. I have used more
compilers over 50 years than I care to count and I find gcc one of the most
stable and reliable.
If you want speed, do it in assembly language. ;-)
But we'd better do this fight in the alley.
The whole religious complexion of the modern world is due
to the absence from Jerusalem of a lunatic asylum.
-- Havelock Ellis (1859-1939) British psychologist
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