version of gcc and auto-vectorization

Segher Boessenkool
Wed Mar 21 14:30:00 GMT 2007

> What does auto-vectorization mean??
> I think it must be converting 'for' loops which does
> not exploit SIMD features of a processor(say Pentium
> 4) to 'for' loops which exploit SIMD features(of
> course, it could be at any intermediate
> representation).

While (indexed) loops are the most obvious case,
auto vectorisation actually applies to *any* code.

Loops are easier to do than generic code, and you
get a better gain from them, so that's where all
the action is ;-)


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