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Re: gEDA-user: Icarus Verilog building from CVS

On Aug 9, 2004, at 3:35 AM, Lars Segerlund wrote:
Well, I am running some computationally intensive code, ( CFD ), and gcc 3.5 ( upcoming ) is giving a boost of up to 30 % for FORTRAN and C code in some instances.
The 'new' gcc does have a much better optimization framework, and it is really starting to show, it should fx. be able to run head to head with intels compiler provided that it is supplied with a reasonable set of compiler flags, ( which is an area of itself :-) ).
SO if you look for the code generated by the 'state of the art' gcc i do not believe your statement to be true, ( check out code for the sh and h8 processors or the mips32 instruction set ).
My specifics are UltraSPARC and MIPS. Binaries generated with GCC (with intelligently-selected optimization flags...I've been a GCC user since v1.38 was current) are, in nearly all cases, significantly slower than with platform-specific vendor compilers.

I have no desire to get into a pissing match with you over this. All I can say is that I'm glad *you* have had good results with GCC. From my experience, if you're not running x86 (which I'm not) or VAX or M68K (which I rarely do anymore), it sucks.

If you have any cases which can be reduced to misoptimizations please post a bug report on gcc.gnu.org

If not, ( and from my opinion and experience ), I can only conider your statement an ill informed opinion.
Umm, no, frankly I don't have time to chase optimization issues in GCC. The current release of GCC doesn't even compile out-of-the-box on the current release of Solaris (my primary development platform).

I suppose it's possible that image processing and CFD bring out different strengths and weaknesses in compilers...while I can't imagine this being the case, this is the only thing I can think of that could possibly explain the results you're seeing.

And if you *have* managed to get a recent release of GCC to build under Solaris, perhaps you might share a patch.

The big thing I have against the beast is it's compilatioon speed and memory requirements, it's slow and big.
  We're in 100% agreement there.


Dave McGuire             "...it's a matter of how tightly
Cape Coral, FL             you pull the zip-tie."       -Nadine Miller