Looking into LLVM
Kevin Kofler
kevin.kofler at chello.at
Mon Oct 26 16:40:04 UTC 2009
Jakub Jelinek wrote:
> It is not just about horrible dwarf generation, the performance of LLVM
> generated code is worse than GCC, you can forget about all the
> security enhancements GCC has added in the last 10 years (say
> __builtin_object_size is parsed by clang/llvm, but always says it doesn't
> know the size, I'm not aware of LLVM supporting something like
> -fstack-protector), etc. A lot of stuff is just stubbed in LLVM, look at
> e.g. its __builtin_expect implementation. You need to look through the
> hype at what disadvantages it has.
And I don't think that's going to change as long as LLVM stays BSD-licensed.
Most people are unwilling to contribute to a project of which proprietary
software companies can make "improved" proprietary versions of, which even
they as the original author aren't allowed to use without paying the
company, let alone modify or redistribute. Contributing to the GPLed GCC is
much more attractive. So LLVM is always going to lag behind in some areas.
Just look at how many contributions the Linux kernel gets vs. how many the
BSD kernels get.
Kevin Kofler
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