"Amker.Cheng" <amker.ch...@gmail.com> writes: > > Thanks for replying. > Sorry if I misunderstood anything below, and please correct me. > > insn 882 : cc <- compare (r684, 0) > jump_insn 883 : if (cc != 0) goto insn 46 > insn 49 : r291 <- r684 > ...... > insn 46 > > cc contains the result of subtracting 0 from r684; > control flow goes to insn_49 only if (cc == 0), which implies (r684 == 0). > Then at insn_49 we have conditional const propagation "r684 <- 0", is it > right? > > Thanks again.
Nobody mentioned this so I might be way off but cc doesn't get (minus (reg r684) (const_int 0)). It gets the `condition codes` modification as a consequence of the subtraction. -- PMatos
