------- Comment #44 from bonzini at gnu dot org 2009-02-13 16:05 ------- A simplified (local, noncascading) fwprop not using UD chains would not be hard to do... Basically, at -O1 use FOR_EACH_BB/FOR_EACH_BB_INSN instead of walking the uses, keep a (regno, insn) map of pseudos (cleared at the beginning of every basic block), and use that info instead of UD chains in use_killed_between...
-- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33928