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Re: Code gen error on PowerPC
On Mon, Mar 01, 1999 at 06:52:59PM +0100, Franz Sirl wrote:
> Ugh, that's not the answer I wanted to hear :-(. This probably means I have
> to do an extensive debugging session again... Isn't there any chance that
> you fixed a bug without knowing? :-)
I suppose it's possible -- a lot of code changed. It seems more
likely that differing combine_givs heuristics merely hid the problem.
> Any hints on what I should look at first during debugging?
If I understood your explanation right, you've got a GIV being
recognized that isn't. I'd start by finding out why that's so.
You'll want to put a breakpoint in strength_reduce, right before
the call to general_induction_var. Conditionalize it on the insn
that contains the GIV. Likely the meat of the problem will be in
simplify_giv_expr, cases REG and default.
r~