block movement and eh

Jason Merrill jason@cygnus.com
Thu Sep 30 23:58:00 GMT 1999


>>>>> Richard Henderson <rth@cygnus.com> writes:

 > On Tue, Sep 21, 1999 at 12:03:31PM -0700, Jason Merrill wrote:
 >> Makes sense to me.  In fact, HP's proposal for ia64 EH involves using a
 >> table of EH PC values (i.e. the call sites), rather than ranges.

 > Hmm.  I wonder if we could do something like that, at least for
 > internal representation, now.  Correct me if I'm wrong:

 > The REG_EH_REGION note indicates what region a call can throw to.
 > We make an initial pass over the rtl, annotate all of the calls
 > that don't already have such notes.  We then delete all of the
 > NOTE_INSN_EH_REGION notes, and don't have to worry about regions
 > at all for the rest of compilation.

 > Just before (or during) final, we find the maximum span of calls
 > that have compatible region notes (the same region or 0 or -1 but
 > not no note) and re-create NOTE_INSN_EH_REGION notes.

Makes sense to me.

Jason



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