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Subject: Re: [boost] Accelerating algorithms with SIMD - Segmented iterators and alternatives
From: Daniel Herring (dherring_at_[hidden])
Date: 2010-10-13 10:16:17


[probably my last post on this -- agreed it is OT, and the proposed SIMD
framework would be interesting]

On Wed, 13 Oct 2010, Bryce Lelbach wrote:

> There's nothing magic about JITing C++, even JITing non-trivial C++. It's
> basically pointless, because the LLVM bitcode/LLVM assembly generated by a C++
> program is absolutely, positively not portable.

Agreed on the portability, but I think you missed the point. People are
advocating something like JIT, not to VM bytecode but directly to machine
code, exactly to get non-portable optimizations.

> I think I saw some comments implying that C compilers were faster or better
> than C++ compilers. I know that I saw people claim that C compilers were
> faster, better or could optimize better than C++ compilers implemented using
> expression templates and metaprogramming techniques. Such claims are
> unfounded.

The normal example is Fortran being faster than C/C++ because it doesn't
have to worry about issues such as pointer aliasing.

Later,
Daniel


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