float("nan") in set or as key

Chris Angelico rosuav at gmail.com
Sun Jun 5 19:13:25 EDT 2011


On Mon, Jun 6, 2011 at 8:54 AM, Chris Torek <nospam at torek.net> wrote:
> A signalling NaN traps at (more or less -- details vary depending
> on FPU architecture) load time.

Load. By this you mean the operation of taking a bit-pattern in RAM
and putting it into a register? So, you can calculate 0/0, get a
signalling NaN, and then save that into a memory variable, all without
it trapping; and then it traps when you next perform an operation on
that number?

Apologies, this is getting quite off-topic and away from Python.

Chris Angelico



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