[plt-scheme] dead code elimination/closure optimization?

From: Matthew Flatt (mflatt at cs.utah.edu)
Date: Sun Apr 8 23:52:18 EDT 2007

At Sat, 7 Apr 2007 22:05:48 -0400 (EDT), Dimitris Vyzovitis wrote:
> For the profitable part, it is not that you write this code by hand
> normally; but it may be generated by macros and it can become pretty
> expensive (relative to the code in the body).

I agree. I double-checked the Macro-Writer's Bill of Rights, and
dead-code elimination seem to be the one part of the Guaranteed
Optimization Clause that is not sufficiently satisfied by MzScheme.

I'll have to learn some more about compilers, but I put this on my list
of things to fix in the near future.

> > also the optimizer
> > does iterate to a fixed point already, iiuc.)
> >
> Uhm, shouldn't the 'this removal comes later' part get fixed then?

Right. There is a fixed-point calculation or two in the current
optimizer, but not in general. And simply iterating the current
optimizer pass is likely to be too expensive.


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