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- Subject: Re: Patch to use colored NaNs on LP64
- From: Ivo Beltchev <ivo@...>
- Date: Mon, 01 Jun 2009 08:17:42 -0700
This is a bit OT.
I have a special NaN to represent a NIL value - see my other thread
"Comparing userdata with other types". My experiments show that it gets
preserved by the FPU operations:
In your experience, do you think I can count on that? (I'm only
interested in 32/64-bit Windows).
Mike Pall wrote:
So there's no need to canonicalize NaNs after
every operation, which is an expensive step in your patch. The FPU
on its own only generates 0xfff80000_00000000. Canonicalization is
only needed for the two ingress points (lua_pushnumber and