change mixins

[retard]

Tue, 16 Feb 2010 21:11:32 +0100, grauzone wrote:

> retard wrote:
>>> Granted, even if logging is disabled, the compiler will push the
>>> arguments on the stack and call logInfo().
>> 
>> This is a case where a JIT compiler wins. The code runs equally fast
>> without the call at all and with logging turned off (dynamically). In
>> languages like D, the like has to be statically turned off unless
>> compilers have any new dynamic optimizations.
> 
> Can the JIT really do this optimization? It sounds as if it'd detect
> that the variable never changes, and generate code with that fixed
> value.

It sure can recompile the code assuming that the logging policy doesn't 
change that often - in case it does change often switching the code might 
have larger overhead than testing the condition. In real life you would 
probably start the program with either logging on or off. With JIT 
compiled languages, the decision can be postponed to runtime, in D it 
probably has to be done on compile time and provide two binaries, if both 
logging and efficiency are required options. I can post a rather short 
test case in Java/Scala here, if you insist.