questions on haifa schedule

[Weiwen Liu]

Hi,

While fixing a bug in haifa schedule, I notice the following:

1. For note_list, only the end of the list is saved. Later the list is
scanned backwards to locate its header.  Is it better to store its header
in a variable to speed the program up?

2. In function unlink_other_notes, an insn may be unlinked, buth its
associated memory is not freed.  I believe this causes memory leak.
Should we have a function, delete_rtx, which removes a rtx and releases
its memory?

Weiwen