Hello, > >To see what kind of code GCC generates for FOR_EACH_EDGE, I wrote a > >simple dummy function. > > Kazu, I hope I have time to look in detail at your investigation, however > one thing that might be causing a problem is that FOR_EACH_EDGE is an > iterator > that works for a non-constant VEC. This means there's an extra level of > indirection that the optimizer cannot remove, unless it completely inlines > the body of the loop (there might be some cases it can do it without > inlining, > but I suspect not). I wonder if it is worthwhile implementing FOR_EACH_EDGE > and FOR_EACH_EDGE_VOLATILE (I want the default, shorter name, to be the > constant iterator, so that you have to chose to use the non-constant one). > > Even with a constant iterator, it might be necessary to help the optimizer > by copying the vector length to somewhere local that the optimizer can see > cannot be changed by the body of the loop. Hmm, I guess that does mean you > need a proper iterator object, rather than the integer index that > VEC_iterate > employs.
you can always start the index from number of edges - 1 and iterate to zero. But a proper iterator might be useful anyway. Zdenek
