[fpc-devel] LLVM Backend?
vsnijders at vodafonevast.nl
Tue Nov 17 08:18:34 CET 2009
Jonas Maebe schreef:
> On 17 Nov 2009, at 07:31, Matej Spiller-Muys wrote:
>>> I have no idea. All I know that's slightly related is the alioth computer
>>> language benchmark game (with the stress on "game"), where you have at least
>>> both FPC and GCC results.
>> Yup, the FPC factor is 2x-10x slower.
> That's because you are looking at x86_64 results for FPC 2.2.2, which does not support register variables on x86_64. The i386 results are 20% slower than G++ on average. And as mentioned before, it's with the stress on "game": the results on that site depend on almost as much on the implementation effort that people have put in optimizing the source code for "their" language as it does on the compiler.
If you look at CPU secs, then the factor is 3 at most. What helps the C++ programs
most is that they use 4 cores more, the fpc programs are mostly singlethreaded. LLVM
doesn't help to solve this (AFAIK).
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