Hello, predcom branch is now ready for testing. We basically implemented second-order predictive commoning (quick overview can be found e.g. in http://www.cs.ualberta.ca/~amaral/cascon/CDP04/slides/tal.pdf, or at the beginning of tree-predcom.c file). There are still some issues we are working on (in SPEC2000, bzip2 and applu are misscompiled, and some of the implementation details are realized in a very inefficient way), but we are now getting the expected results for mgrid, as well as other smaller testcases. The recommended flags for testing are -O2 -funsafe-math-optimizations versus -O2 -funsafe-math-optimizations -fno-predictive-commoning (-funsafe-math-optimizations is necessary to get advantage of aggressive reasociation in mgrid and other testcases that use fp arithmetics).
Zdenek
