[Haskell-cafe] Haskell version of ray tracer code is much slower than the original ML

Philip Armstrong phil at kantaka.co.uk
Thu Jun 21 14:30:44 EDT 2007

On Thu, Jun 21, 2007 at 01:29:56PM -0400, Mark T.B. Carroll wrote:
>Philip Armstrong <phil at kantaka.co.uk> writes:
>> Because the optimisation page on the haskell wiki is very explicit
>> about never using Float when you can use Double, that's why.
>Is that still true if you use -fexcess-precision ?

Why on earth would you use -fexcess-precision if you're using Floats?
The excess precision only apples to Doubles held in registers on x86
IIRC. (If you spill a Double from a register to memory, then you lose
the extra precision bits in the process).

Unless -fexcess-precision with ghc does something completely different
to the analogous gcc setting that is.


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