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Comparing Linux C and C++ Compilers
ChaoticCoyote writes "I've posted a comparison of recent GCC versions (3.3, 3.4, and the coming 4.0) with Intel C++ 8.1, including several benchmarks and "state-of-the-product" reviews. The new article replaces an older piece I published in late 2002. This
new comparison marks what I hope will be an ongoing series that tracks the quality of Linux compilers."
I hear people complain about gnu C++ alot because its not as good as commercial compilers.
However from what I see is the performance of the compiled code is the same with the exception that the resulting binaries are alot bigger.
Maybe gcc is good on x86 but sucks on other architectures? I know the Sun and SGI geeks have complained for years that gcc does not run well on their platforms compared to expensive alternatives by their vendors.
Has anyone run ICC and VC++.net on Windows? How does it compare to Borland and MS compilers under Windows2k?
http://saveie6.com/
I think the author had better mark the tests whose inner loops have been vectorized, since while some algorithms are easily vectorizable, some are not, so the performance of both are interesting. After all, we care most about the features (such as automatic vectorization) of the compiler, while benchmarks only very roughly reflect the existence of such features, the applicability of them, and their effects.
The OpenBSD team use it, and I think they know better than you or I.
Not by technical choice, they want to use plan9's C compiler but have licence quibbles.
Quoting Theo : "in particular we were interested in the c compiler"
There are places where the networks are not touching,and there are places where they are-Boeing's Lori Gunter
I find it interesting that there are only two C/C++ compilers available for Linux, as compared with seven Fortran 90/95 compilers (soon to be eight with the release of GCC 4.0). This not only dispels the myth that Fortran is a dead language, it also suggests that there is much more of a competitive market in compiling numerical code, than in producing other types of software.
Tubal-Cain smokes the white owl.
TCC (tiny c compiler).
Compaq Alpha C compiler.
OpenWatcom C/C++ compiler
TenDra C/C++ compiler
egcs compiler (which merged into gcc- they saw that it had some advantages.)
ChEmbeddable
Cint c/c++ interpreter (not exactly a compiler)
CC65 Commodore C compiler
Absoft C/C++ Fortran compiler
lcc
These all run on linux. Some are open, some are not. GCC is used mainly because it is portable to just about anything-- so there goes your argument of GCC restricting choice. GCC exists to promote choice, and it does this.
Take your code written for Visual Studio and compile it on Sun. Can't do that with Visual Studio? No MFC on Sun? Your best bet will probably be good old GCC with WINE. So how are you restricted by gcc?
Now, if you want to make a cross compiler to compete with gcc- one with seperate front ends and back ends, so it can accept multiple languages, and can compile to just about every machine on earth-- then nothing is stopping you. Oh, what is that? Not interested. Neither is anyone else. Programers see no need to duplicate something that has been done well the first time. One good cross compiler is enough- GCC represents a NATURAL MONOPOLY.
Tree-SSA is not new, it's new to GCC but the concept of Single Static Assignment itself is ancient and using it for optimizing trees in not new.
The problem is the GCC codebase is so badly designed it takes major changes to many parts to introduce a very old concept of SSA into it. So you can't take advantage of a generic SSA but have to introduce different patches for the system.
Back in my university days we did SSA in our own compilers, for a 5 week course! GCC needs a complete rewrite or a switch to something like TenDRA, which right now produces good solid code, but not extremely optimized machinecode. On the other hand TenDRA is really well designed so it would catch up really fast if more people worked on it.
Erm. If you look at the current top500 you'll see that there's a Xeon machine in the top 5.
Have you actually tried other platforms? The best compiler on a given architecture is usually the chip vendor compiler -- IBM's compiler beats GNU on PPC 970, HP's beats GNU on Alpha, etc.
Sure you can find the odd piece of code where Gnu will beat vendor compilers but overall, and particularly for large scientific workloads, vendor compilers win for raw speed.