------- Comment #15 from amylaar at gcc dot gnu dot org 2006-08-25 17:01 ------- (In reply to comment #13) > For any transparent sub-graph, considering the expression anticipatable > in this graph is beneficial if the sum of the frequencies of outgoing edges > on which the expression is anticipatable is larger than the sum of the > frequencies of incoming edges on which the expression is not available.
Actually, for SH variants with the FPCHG instruction, we could do a lower cost mode switch if the previous mode is known. Hence we can also add some benefit for the other mode being anticipatable, and the cost of the considered mode not being available is reduced when the other mode is available. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28764