'int' is enough for 'length' to migrate code from x86 to x64

[Andrei Alexandrescu via Digitalmars-d]

On 11/21/14 6:17 AM, Ary Borenszweig wrote:
> On 11/21/14, 5:45 AM, Walter Bright wrote:
>> On 11/21/2014 12:10 AM, bearophile wrote:
>>> Walter Bright:
>>>
>>>> All you're doing is trading 0 crossing for 0x7FFFFFFF crossing
>>>> issues, and
>>>> pretending the problems have gone away.
>>>
>>> I'm not pretending anything. I am asking in practical programming what
>>> of the
>>> two solutions leads to leas problems/bugs. So far I've seen the unsigned
>>> solution and I've seen it's highly bug-prone.
>>
>> I'm suggesting that having a bug and detecting the bug are two different
>> things. The 0-crossing bug is easier to detect, but that doesn't mean
>> that shifting the problem to 0x7FFFFFFF crossing bugs is making the bug
>> count less.
>>
>>
>>>> BTW, granted the 0x7FFFFFFF problems exhibit the bugs less often, but
>>>> paradoxically this can make the bug worse, because then it only gets
>>>> found
>>>> much, much later in supposedly tested & robust code.
>>>
>>> Is this true? Do you have some examples of buggy code?
>>
>> http://googleresearch.blogspot.com/2006/06/extra-extra-read-all-about-it-nearly.html
>>
>>
>
> "This bug can manifest itself for arrays whose length (in elements) is
> 2^30 or greater (roughly a billion elements)"
>
> How often does that happen in practice?

Every time you read a DVD image :o). I should say that in my doctoral 
work it was often the case I'd have very large arrays.

Andrei