cgal/Packages/Interval_arithmetic/TODO

[See also the file TODO_static_filters]

- DOCUMENT enough for the new to_interval() requirement.
- Filtered_kernel<> should be a proper kernel.  It should be possible to use
  the Kernel_base stuff (see Kernel_traits paper)...
- mv test/include/*.C *.def ; Or use template functions ?
- Use Self instead of IA as the internal typedef ?

Concerning the main code:
-------------------------
- Lazy_exact_nt<Traits>, where :
  class Traits {
    typedef leda_real  ET;
    typedef Tag_true   Protection; // due, this won't work nicely... const ?
  }
  In any case worth it for my multi-type kernel ?
- DAG : voir include/CGAL/Td_dag.h
- Have a scheme for counting each try{} and each catch{} of each predicate ?
  (request by Michael Seel).  Maybe not worth it : gcov or any profiling tool
  should be fine for that.
- Remove the "return false" after overlap_action(), if possible, and see
  produced code.  Or re-arrange the code in order to remove it ?
- Specializations for is_zero() and co, and make use of them in the kernel.
  [Filtered_exact<> doesn't define them either, it's a bug...]
- Implement CGAL_ms_sqrt() with asms so that no special install procedure is
  needed ?  Should not be too hard, and should be faster (no function call).
  If M$ has a flag like __OPTIMIZE__, then we can use in the non-optimize case,
  something like (test again) :
   
  inline double my_sqrt (double d)
  {
    _asm
    {
      fld d
      fsqrt
      fstp d
    }
    return d;
  }
  
Sous optimal, mais si on peut lui dire de l'utiliser quand il n'optimise pas
(genre #ifndef __OPTIMIZE__), ca peut faire l'affaire.
De toute facon, c'est le fsqrt qui prend un max de temps, donc l'enrobage...

- SunPro 5.1 ?  Mike says it supports interval arithmetic...
  http://docs.sun.com/htmlcoll/coll.693.1/iso-8859-1/CPPARITHPROG/iapg_bookTOC.html
  http://www.sun.com/forte/cplusplus/interval/index.html;$sessionid$GSXJDFYAABWVTAMTA1FU45Q
- Does KCC 4.0 still fails when optimizing ?  Ask Stefan.
- Try to see if KCC can use the GCC asm() on x86 ?
- Try to get rid of the libc5 compatible version (make benchmarks first).
- Avec des predicats function_objects, on pourrait se passer du script
  autogenerateur pour les filtres dynamiques (voir comment marchent les trucs
  de la STL dans ce domaine) ?  Le convertisseur prenant comme parametre
  template un entier qui serait le nombre d'arguments du predicat :) ?
  A revoir en tout cas dans l'optique d'un noyau filtre.
- Have determinant_by_formula() overloading for Lazy_exact_nt<> ?
  And what about for Interval_nt<> too ?
- Turn CGAL_IA_CHECK_RESTRICT into an [expensive] assertion ?
- Get rid of convert_to() ?  This is a mess for nothing (benchmark first).
  Target convert_from_to (const Target, const Source) is fine ?
  It could maybe be made better this way:
    void convert_from_to(Target &, const Source &) ?
  Suggest that to Stefan for misc.h ?
- Handle in_smallest_orthogonalcircle_ftC2.h correctly (needs an include)
  Note : this is already in the kernel, this file should disappear !
- Bench -fbranch-probabilities ?  Use __builtin_expect() for GCC 3 ?
- Mark the cache as "mutable" (see Stroustrup, page 232) ?
- Filter_Cache: Faire des benchs, et une test-suite qui soit raisonnable.
  Hum, rajouter un bool<6F>en pour calculer le cache seulement sur demande ?
  (<28>a <20>vite de le faire inutilement pour les variables interm<72>diaires,
  mais <20>a prend un chouia plus de place... mais en comparaison du reste...)
- Replace CGAL_IA_MAX_DOUBLE by standard DBL_MAX in <cfloat>, if portable
  (add a test).  Not possible for CGAL_IA_MIN_DOUBLE, since DBL_MIN is the
  _normalized_ minimum.
? See the C++ Standard numeric_limits<>, section 18.2.
? See ISO C99 and http://http.cs.berkeley.edu/~fateman/fp98/korenF/node3.html.
- "C9x FP unordered compares":
  +  /* ISO C99 IEEE Unordered compares.  */
  +  builtin_function ("__builtin_isgreater", default_function_type,
  +                   BUILT_IN_ISGREATER, BUILT_IN_NORMAL, NULL_PTR);
  +  builtin_function ("__builtin_isgreaterequal", default_function_type,
  +                   BUILT_IN_ISGREATEREQUAL, BUILT_IN_NORMAL, NULL_PTR);
  +  builtin_function ("__builtin_isless", default_function_type,
  +                   BUILT_IN_ISLESS, BUILT_IN_NORMAL, NULL_PTR);
  +  builtin_function ("__builtin_islessequal", default_function_type,
  +                   BUILT_IN_ISLESSEQUAL, BUILT_IN_NORMAL, NULL_PTR);
  +  builtin_function ("__builtin_islessgreater", default_function_type,
  +                   BUILT_IN_ISLESSGREATER, BUILT_IN_NORMAL, NULL_PTR);
  +  builtin_function ("__builtin_isunordered", default_function_type,
  +                   BUILT_IN_ISUNORDERED, BUILT_IN_NORMAL, NULL_PTR);
  [voir le draft C99 ce que c'est]
? SUN: Add "-Wa,-xarch=v8plus" to fix the following "error":
  /usr/ccs/bin/as: "/var/tmp/ccBHnU0T.s", line 861: warning: 3 instructions
  required between ldfsr and next FBfcc; nops inserted

Concerning the script:
----------------------
- Produce separate files for declarations and definitions (=> libCGAL).
- Make it output a test file for each predicate ?

Concerning the doc:
-------------------
- Documentation seriously needs to be updated before the next public release !
- Use the new doc format.
- In the 2.0 HTML doc, my enums are indexed twice.
  probably a cc_manual compliance bug from me.
  Idem, my fct to_double(Ia) is not the same as the others...
- add a pointer to my MISC'99 paper.
- DOCUMENT the new boolean template parameter, the script, the static filters,
  Lazy_exact_nt<> ...

Concerning the test-suite:
--------------------------
- Check it with GCOV again before the next public release.
- Make a more extensive test-suite for the filtered predicates.
  The script could output information to test them generically somehow.
- Test NaN propagation.  Comparisons with these should throw the exception...
  Check that they are correctly propagated (by min(), max(), even operator*...)