[LLVMdev] LICM and SCEV AA?

[Renato Golin]

On 2 November 2013 05:59, Hal Finkel <hfinkel at anl.gov> wrote:

> > I would be scared to enable SCEV AA because it's not well tested
>
> This seems like a solvable problem. SCEV AA itself is something like 30
> lines of non-boilerplate code, and essentially does one thing (calls
> getMinusSCEV in both directions and uses getUnsignedRange on the result).
> We should look it over.
>

If SCEV AA itself is conservative, the worst that can happen is that it
won't detect all cases it could, but we can extend it later. It seems to me
that this piece of code was added as an experiment and never updated, but
since it's already there, we could come up with a few tests that would
check the boundaries of a 30 loc piece, no?

--renato
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