Re: Concertlina II: Full Circle

MitchAlsup1 wrote:

Thomas Koenig wrote:
 

Terje Mathisen <terje.mathisen@tmsw.no> schrieb:

This is partly due to programming languages that applies lifetimes to variables, so that an index register which is defined in the
scaffolding
>
of the loop (i.e. for (i = 0; i < limit; i++) {}) is invisible as soon as the loop terminates.

 

This makes things more clear to anybody reading the code (and
unambiguous to the compiler).  However, lifetime analysis has
also become very good, and if the value is not used afterwards,
I expect no difference in practice.

 When one writes::
      for( uint64_t i = 0; i < max; i++ )
 the lifetime of i is explicit--it terminates with the loop.
 

Without such a restriction, there are many times when it would be very natural to inspect the index in order to determine if this was a normal
>
(counting) exit, or an early exit due to some internal test.

 

Hmm... do you mean for the programmer, or for the compiler?

This is probably my asm background shining trough:
All asm loops have the counting register available directly after loop exit, until it is reused. When I want to do the same in C I just have to define the variable before the loop starts, instead of inside the ().
Terje
--
- <Terje.Mathisen at tmsw.no>
"almost all programming can be viewed as an exercise in caching"