Taking -1 to integer powers <INT_MIN or >INT_MAX yields NaN
- From: Philipp Kutin <philipp.kutin@xxxxxxxxx>
- To: luajit@xxxxxxxxxxxxx
- Date: Mon, 18 Nov 2013 23:50:40 +0100
Just noticed this when I wanted to find out about the C library's
behavior in these corner cases. I attached a small test script. It
takes -1 to powers of INT_MIN+{-1,0,1} and INT_MAX+{-1,0,1} and gives
the following output for me on x86_86:
$ luajit pow32.lua
pow_lop: -nan 1 -1 1 -1 -nan -- Lua ^ operator
pow_c: -1 1 -1 1 -1 1 -- ffi.C.pow
pow_lm: -nan 1 -1 1 -1 -nan -- Lua math.pow
$ lua pow32.lua
pow_lm: -1 1 -1 1 -1 1
pow_lop: -1 1 -1 1 -1 1
Arguably, exponentiating by such large numbers is pretty cornerly and
-1 is about the only interesting LHS... I'm wondering if there are use
cases for that.
--Philipp
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