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

[Philip Armstrong]

On Thu, Jun 21, 2007 at 03:29:17PM -0400, Mark T.B. Carroll wrote:
>Philip Armstrong <phil at kantaka.co.uk> writes:
>(snip)
>> 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).
>
>Some googling suggests that point 2 on
>http://www.haskell.org/hawiki/FasterFloatingPointWithGhc
>might have been what I was thinking of.

That's the old wiki. The new one gives the opposite advice! (As does
the ghc manual):

  http://www.haskell.org/ghc/docs/latest/html/users_guide/faster.html
  http://www.haskell.org/haskellwiki/Performance/Floating_Point

Phil

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