[Python-Dev] Caching float(0.0) (original) (raw)

"Martin v. Löwis" martin at v.loewis.de
Wed Oct 4 07:34:51 CEST 2006

Alastair Houghton schrieb:

On 3 Oct 2006, at 17:47, James Y Knight wrote:

On Oct 3, 2006, at 8:30 AM, Martin v. Löwis wrote: As Michael Hudson observed, this is difficult to implement, though: You can't distinguish between -0.0 and +0.0 easily, yet you should.

Of course you can. It's absolutely trivial. The only part that's even the least bit sketchy in this is assuming that a double is 64 bits. Practically speaking, that is true on all architectures I know of, How about doing 1.0 / x, where x is the number you want to test?

This is a bad idea. It may cause a trap, leading to program termination.

Regards, Martin

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