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04:51:31 <proteusguy> you can always use the double xor to swap between two items without having an intermediate variable.
04:56:50 <cbridge_> <eris[m]1> double xor?
09:07:17 <cbridge_> <crc> eris[m]1: I'd assume it's the trick that lets you do something like `x = x ^ y`, `y = x ^ y`
09:07:57 <cbridge_> <crc> `x = x ^ y`
09:10:23 <cbridge_> <eris[m]1> ahh
09:10:38 <cbridge_> <eris[m]1> i wonder what that would look like on the stack
10:05:31 <cbridge_> <tangentstorm> kinda doesn't make sense on a stack, unless it's how you implement swap internally.
10:09:23 <cbridge_> <tangentstorm> the double xor trick for swapping two values without an intermediate.
10:22:15 <cbridge_> <siraben> the limitation is of course the items cannot be the same because x ^ x = 0
10:22:24 <cbridge_> <siraben> for x : bool
10:27:04 <cbridge_> <tangentstorm> they can be the same.  x=1, y=1 ... x=x^y -> x=0 ... y=x^y -> y=1 .. x=x^y -> x=1... final state:  x=1, y=1.
10:28:18 <cbridge_> <siraben> oh I mean if x and y are the same storage location
10:28:25 <cbridge_> <siraben> but yeah as long as they're separate it's fine
10:28:32 <cbridge_> <tangentstorm> ohh
10:32:51 <cbridge_> <siraben> remexre: ^ would be a nice exercise to formally verify
10:33:31 <cbridge_> <siraben> I would opt for a Hoare logic assertion, {{ X ::= a ; Y ::= b }} XOR_SWAP {{ X ::= b ; Y ::= a }}
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15:56:12 <cbridge_> <dave0> maw
20:07:09 <cbridge_> <dave0> re maw
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