Richard Guenther <[EMAIL PROTECTED]> wrote on 05/02/2007 18:16:05: > On Mon, 5 Feb 2007, Jan Hubicka wrote: ... > > Did you run some benchmarks? > > Not yet - I'm looking at the C++ SPEC 2006 benchmarks at the moment > and using vectorization there seems to do a lot of collateral damage > (maybe not measurable though). >
Interesting. In SPEC 2000 there is also a hot small loop in the only C++ benchmark (eon), which get vectorized, and as a result degrades performance. We really should not vectorize such loops, and the solution is: 1. FORNOW: use --param min-vect-loop-bound=2 (or some value greater than 0). 2. SOON: rely on the vectorizer to do the cost analysis and decide not to vectorize such loops, using a cost model - this is in the works. dorit > Richard. > > -- > Richard Guenther <[EMAIL PROTECTED]> > Novell / SUSE Labs
