Inherent code performance advantages of D over C?

[Timon Gehr]

On 12/08/2013 09:42 PM, Walter Bright wrote:
> On 12/8/2013 12:06 PM, Timon Gehr wrote:
>> On 12/08/2013 07:53 PM, Walter Bright wrote:
>>> On 12/8/2013 2:13 AM, Araq wrote:
>>>> From this list only (7) is a valid point. All the others can be
>>>> trivially dealt
>>>> with whole program optimization (1,2,3)
>>>
>>> If it's trivial, it's not happening. (1) would require solving the
>>> halting problem.  ...
>>
>> No it would not. If all you need to do is catching up with D, just
>> infer where
>> immutability qualifiers should go. This is decidable (the search space is
>> finite). Of course, an analysis of this style could infer more
>> fine-grained
>> global aliasing information anyway.
>
> I don't believe it is remotely correct that any amount of static
> analysis will determine where a pointer points to,
> just as it won't tell you what value the variable 'i' has in it.

?

Static analysis will tell you where a pointer might point to (more 
importantly, it may exclude aliasing) and what values the variable 'i' 
might have in it. How precise this information is hinges on the details 
of the analysis and the program it is applied on. I'm just saying that 
this may be more precise than what 'immutable' qualifiers give you 
(since those are quite easy to infer, given the program, and alias 
analysis may be non-trivial.)