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Re: [RFA patch] PR18749: epilogue not tracked in dwarf2 unwind-info
On Mon, Jun 12, 2006 at 11:02:38PM +0200, Michael Matz wrote:
> If you are saying that currently it could happen that CFA-(1) != CFA-(2),
> then this non-epilogue instruction would need to have an effect on the
> CFA, without actually producing code (or the next epilogue insn must not
> produce code), as otherwise you would have the same runtime effect twice
> (once from the non-epilogue insn, once from the epilogue compensation).
> Can this happen?
I have no idea :-) I'm way out in hypothetical cases here, don't worry
about it overmuch.
But here's an example using conditional execution:
popeq lr
sub sp, #64
addeq sp, #68
bxeq lr
Of course it'd be a somewhat silly thing to generate.
--
Daniel Jacobowitz
CodeSourcery