sweep failed to find exact end of memory

tim Rowledge tim at rowledge.org
Wed Feb 21 19:10:45 UTC 2007


On 21-Feb-07, at 10:58 AM, Avi Bryant wrote:

> On 2/21/07, tim Rowledge <tim at rowledge.org> wrote:
>
>> It's an old issue; look up assorted reports of problems with > 2Gb
>> pointers. The VM code is mostly written under the assumption that
>> singed integers suffice for pointers and we really need to fix that.
>> It's an issue of available time.
>
> Do you have an estimate, hopefully under 1 million euros, of what it
> would take to fix this?

That's a distressingly difficult question to answer. I bet there are  
some nasty hacks one could do that would 'fix' it on the basis of  
forcing the C compiler to do signed-unsigned conversions but... I  
never trust a C compiler. Aside from Slang code there are of course  
the primitives and platform code that would be indirectly affected,  
if only at the level of "I have change this decl to stop an oodleplex  
of compiler warnings obscuring a real problem". There's also a  
boatload of VMMaker patches needing proper integration anyway and it  
would stupid not to do them as well.

I'd love to say, "oh a week" but long experience suggests that the  
truth is normally "double the digits and up the unit" so probably  
'two months' is higher in the truthiness scale.

tim
--
tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
Strange OpCodes: BH: Branch and Hang





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