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Date: Tue, 8 Feb 2005 20:15:31 +0100
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Subject: 'double' / 'float' revised.. think about it.
From: r.korving@xit.nl ("Ron Korving")

Personal recent frustrating float issues made me think of the following...

At the moment apparently the C-type double is used for PHP's float (or
double if you please) storage. I believe it is the philosophy of PHP to make
things easy for its users, and in this perspective I was thinking.. hasn't
the time come to reimplement the PHP float type in a decimal-safe way? Of
course it would be a small performance hit, but not too noticable I think,
especially when utilizing simd instructions which a compiler may or may not
already do. I think, especially with todays powerful systems, performance
(although still a big concern) is no longer the only primary concern.
Shouldn't PHP abandon the speed of the double in C on this one, and
implement a custom implementation of the floating point type which is much
more accurate, even at the cost of a few extra bytes and cycles?
Userfriendlyness over performance. I think it would be one hell of a feature
for PHP to be mathematically correct, a world in which 1.5555 is really
1.5555 and not something that approaches it, and where (for example)
rounding it would result in expected behaviour. I think PHP would
automagically be more suitable for various (financial for example)
applications which could potentially result in more popularity for PHP as a
whole.

I know there are alternatives for accurate mathematics, but they (naturally)
depend on strings which make them a lot slower than a native solution would
be, and besides that, they are less nice to use compared to +,-,/,*,%
operators.

It's just an idea of course, and I'm curious if there are others who feel
the same way about this.

Ron