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Re: [Caml-list] Runtime overflow and what to do
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Date: -- (:)
From: Scott J, <jscott@p...>
Subject: Re: [Caml-list] Runtime overflow and what to do
Hi,

So it is not easy, perhaps even impossible if the processor doesn't set a
flag .

e.g. fact n begins first with a lis of negative numbers (after overflow)
then comes again a list with positive numbers and then it remains = 0

Scott
  ----- Original Message -----
  From: Xavier Leroy
  To: Sven LUTHER
  Cc: Luc Maranget ; Scott J, ; caml-list@inria.fr
  Sent: Thursday, October 10, 2002 8:57 PM
  Subject: Re: [Caml-list] Runtime overflow and what to do


  > But it is the lower bit that is ignored, no, si i guess incrementing an
  > ocaml integer by 1, correspond to incrementing the machine integer by
  > two, and would set the overflow flag in the processor status register
  > all the same, would it not ?

  Yes, except that not all processors have overflow flags.  The Alpha
  and the MIPS don't, for instance.  Integer arithmetic modulo a power
  of 2 is unpleasant for certain applications (and very useful for
  others, e.g. hash functions and cryptography), but this is really all
  what today's processors offer.

  - Xavier Leroy