code committed to dataflow branch

[Kenneth Zadeck]

This code removes all uses of flow from regrename.c  It splits the two
passes that were
in pass_regrename to pass_regrename and pass_cprop.  It also moves the
clear_df pass marker to before these passes.

This patch was bootstrapped and regression tested on three platforms.

x86_64-unknown-linux-gnu
powerpc64-unknown-linux-gnu
i686-pc-linux-gnu

Kenny


2006-04-09  Kenneth Zadeck <zadeck@naturalbridge.com>
    * regrename.c (merge_overlapping_regs, regrename_optimize):
    Threaded private instance of df.
    (regrename_optimize): Created private instance of df, removed
    all references or flow.
    (copyprop_hardreg_forward): Removed all references to flow.
    (gate_handle_regrename): Split reg rename and cprop into separate
    passes.
    (gate_handle_cprop): New function.
    (pass_cprop): New pass structure.
    * tree-pass.h (pass_cprop): New pass structure.
    * passes.c (init_optimization_passes): Added cprop pass and
    moved clear_df pass closer to beginning.