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Re: variable addresses on the stack

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Thiago Adams <thiago.adams@gmail.com> writes:

> I am curious with the following..
>
> void f(int i) {
>    if (i > 1)  {
>        int j ='a';       
>    }
>    if (i < 1)  {
>        int k ='b';       
>    }
> }
> When I see the assembly ouput I can see the compiler
> use the address  rbp-4 for j and rbp-8 for k
>
> Why not the same address considering that j and k don't exist 
> at the same time?
> Any reason?

Easier to just allocate more space and not keep track of variable
lifetimes.  A compiler that was optimizing for space might decide to use
the same location for both.

Likelier would be for an optimizing compiler to notice the function has
no observable behavior and optimize the whole thing away.

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variable addresses on the stack Thiago Adams <thiago.adams@gmail.com> - 2022-08-19 10:22 -0700
  Re: variable addresses on the stack Thiago Adams <thiago.adams@gmail.com> - 2022-08-19 10:27 -0700
  Re: variable addresses on the stack Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-08-19 10:59 -0700
    Re: variable addresses on the stack Thiago Adams <thiago.adams@gmail.com> - 2022-09-21 05:09 -0700
      Re: variable addresses on the stack Thiago Adams <thiago.adams@gmail.com> - 2022-09-21 05:18 -0700
        Re: variable addresses on the stack Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-09-21 15:30 -0700
      Re: variable addresses on the stack David Brown <david.brown@hesbynett.no> - 2022-09-21 15:34 +0200
      Re: variable addresses on the stack Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-09-21 15:23 -0700
  Re: variable addresses on the stack Kaz Kylheku <480-992-1380@kylheku.com> - 2022-08-19 20:58 +0000
  Re: variable addresses on the stack Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2022-08-19 15:47 -0600
  Re: variable addresses on the stack Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-08-19 18:47 -0700

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