Re: [ros-dev] CRT source code issue

[Aleksey Bragin]

Yes, the whole issue is at pushing operands to stack, performing well-
documented assembly instructions to perform the asked action (div,
mul, shl, shr, etc), and handling some special, though obvious, cases
(like if you do a shl of some longlong number by more than 64 bits,
you always end up with 0, there is no need to call math instructions
in order to compute this).
I will let you know results when I speak with SDL.
WBR,
Aleksey Bragin.
On Aug 4, 2007, at 8:52 PM, Daniel Hazelton wrote:
>   On Saturday 04 August 2007 12:28:09 Aleksey Bragin
> wrote:
>  I can't see where that file has anything to do with the functions
>  (e.g:
>  sqrt()/alldiv()) that Betov claims are duplicated. (I've gone
>  through that
>  file and can't find any single place where it does any more math than
>  controlled bit-shifts. No advanced math or anything.)
>  While there might be similar code, for, say, memory barriers, that
>  codes
>  construction would be dictated by the specification of the target
>  machine
>  (and, to some extent, the OS). If the code for sqrt/alldiv is the same
>  between SDL/ROS I don't see a problem - they are both GNU projects
>  and "cross
>  pollination" like that is legal.
>  Whats more is that, while assembly is abstract enough to let some
>  things be
>  done in more than one way, most of the more complex functionality -
>  like math
>  algorithms - are so limited in the possibilities of variation that
>  I can
>  easily see two unconnected people arriving at the exact same
>  solution. QED:
>  Even if the code appears identical (except for things like variable
>  names,
>  et. al) there is a compelling reason for it and it does not mean
>  the code has
>  been copied in any way, shape or form. (And if you look at the ROS
>  commit
>  history I'm sure the code in question existed before MS released
>  the SSCLI2.0
>  source. Which means that the code can't be an "illegal use of MS
>  property" -
>  it was around before said property was available).
>  ...Okay, enough of this outsider sticking his neck out. I've said
>  enough and
>  it's time to disappear and wait for a really usable version of ROS
>  to hit.
>  (though I have compared it to XP under Qemu and ROS rocks!)
>  DRH