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Re: unreviewed patch: opt/7409
- From: Ulrich Weigand <weigand at immd1 dot informatik dot uni-erlangen dot de>
- To: rth at redhat dot com (Richard Henderson)
- Cc: weigand at immd1 dot informatik dot uni-erlangen dot de (Ulrich Weigand), hpenner at de dot ibm dot com, uweigand at de dot ibm dot com, gcc-patches at gcc dot gnu dot org
- Date: Wed, 9 Oct 2002 00:40:30 +0200 (MET DST)
- Subject: Re: unreviewed patch: opt/7409
Richard Henderson wrote:
> Really? Hmm. How are global_regs handled?
It looks like they are marked as 'may_not_optimize',
because they are in regs_invalidated_by_call.
This doesn't apply to the case in opt/7409, because
our register 6 is call-saved, but at the same time
used to pass an argument (this is a distinctly weird
aspect of our ABI, but there's nothing now we can do
about it ...).
However, maybe it would be better to leave single_usage alone
and simply mark all registers in CALL_INSN_FUNCTION_USAGE as
'may_not_optimize'? Most of them will be marked such anyway
as they are usually call-clobbered.
Bye,
Ulrich
--
Dr. Ulrich Weigand
weigand@informatik.uni-erlangen.de