Re: Why do some math functions return -0
[
Date Prev][
Date Next][
Thread Prev][
Thread Next]
[
Date Index]
[
Thread Index]
- Subject: Re: Why do some math functions return -0
- From: Tony Finch <dot@...>
- Date: 2010年9月21日 08:54:32 +0100
On 21 Sep 2010, at 02:35, Mike Pall <mikelu-1009@mike.de> wrote:
>
> Also note that your finding is unrelated to the problem at hand
> (no constant folding, no change of rounding mode). There's some
> prior evidence of buggy or miscompiled floor/ceil for OSX/PPC:
>
That explains it :-) I was wrong to blame rounding in general, but that was the only explanation I could think of late at night for subtraction giving -0 in the default rounding mode (nearest). Inconsistent constant folding effects are a red herring too because they don't explain the weird behaviour of Lua (where compile time constants aren't involved) but broken floor() does explain that.
Tony.
--
f.anthony.n.finch <dot@dotat.at> http://dotat.at/
- References:
- Why do some math functions return -0, Mike McGonagle
- Re: Why do some math functions return -0, Drake Wilson
- Re: Why do some math functions return -0, Mike McGonagle
- Re: Why do some math functions return -0, KHMan
- Re: Why do some math functions return -0, Mike McGonagle
- Re: Why do some math functions return -0, Tony Finch
- Re: Why do some math functions return -0, Mike McGonagle
- Re: Why do some math functions return -0, Tony Finch
- Re: Why do some math functions return -0, Tony Finch
- Re: Why do some math functions return -0, Mike Pall