Performance, for(int i...) vs for(i...)

[Georg-Johann Lay]

David Brown schrieb:
> On 26/08/12 20:41, Tim Prince wrote:
>> On 8/26/2012 1:56 PM, Georg-Johann Lay wrote:
>>> Tim Prince schrieb:
>>>> On 08/26/2012 11:30 AM, lab@kayohamid.net wrote:
>>>>> Hello, I like performance, and until last month i follow what I see
>>>>> on the web to do better coding for performance, like:
>>>>>
>>>>> - Avoid i++, use ++i and so on.
>>>>>
>>>>> But now i'm using the assembly (-S) code generated to see if
>>>>> somethings is correct, and today i'm investigating this:
>>>>>
>>>>> int i;
>>>>> for(i = 0;....);
>>>>>
>>>>> vs
>>>>>
>>>>> for(int i = 0;...);
>>>>
>>>> [...] It's probably important to continue to handle the declaration
>>>> outside the scope well, as that version is required for C source code
>>>> by Microsoft compilers, even VS2012.
>>>> I have had occasion to wish that people didn't rely on non-standard
>>>> maybe Microsoft is right in forbidding both incorrect and correct C++
>>>> usage in C code.
>>>
>>> It's all vanilla C99, no C++ is needed for that.
>>>
>>> Just activate that language standard in your C compiler ;-)
>>>
>>> Johann
>>>
>> Nothing wrong with maintaining compatibility with a widely marketed
>> compiler, even if gcc does the job better.
> 
> Are you suggesting that people who use gcc should limit themselves and 
> the quality of the code they write because some other manufacturer makes 
> a half-hearted C compiler that they hope no one will ever use?  MS 
> supports C++ (with their own additions), C# and VB (their own 
> proprietary languages) - they haven't supported C properly for something 
> like a decade.
> 
> If you want to use MS tools, that's fine - but use the tools they 
> actually recommend you use.  And if you want to write C, use a real C 
> compiler.
> 
> There are many features of C99 that are good additions to making C a 
> better language, and you should use them when writing C code.

Oh, embarrassing.  I never used that "widely marketed compiler" and just
thought that support for a common C standard that is 13 years old now
is a matter of course...

Sorry for the noise.

Johann