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Subject: Re: Ichbiah 2022 compiler mode
Date: Sat, 21 Dec 2024 18:19:12 +0100
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On 21.12.24 09:14, Randy Brukardt wrote:

>> Note that :
>> 1. I have no statistics, but it seems to me that there is more variables
>> than constants in my code.
> 
> But how many of them *have* to be variables vs. the number that just are
> because it is easier? I know I have a number of the latter.
> 
>> 2. I say "Useless" from my coder point of view, I dont know if it simplify
>> the work for compiler or tools implementers.
> 
> Constants do help the compiler generate better code, although a lot of the
> benefits can be gained also by working harder. (That's what C compilers do,
> after all.)

What are some compilers offering today? That is, can they find declarations
of variables that could be constants, if so instructed?
I am seeing some warnings about non-initialized variables for a meaningless
mock-up, but not much else.  Ada, C++, Java.
(Maybe there are options that I have missed. Or an analysis of a whole
program yields more.)

function testc (b : Boolean) return Integer is
    package P is
      x : Integer;
    end;
begin
   if b then
      P.x := 42;
   end if;
   return P.x;
end testc;

int testc(bool b) {
    struct {
      int x;
    } P;
    if (b) {
      P.x = 42;
    }
    return P.x;
}

class testc {
   class P {
     int x;
   }
   P P;
   int $(boolean b) {
     if (b) {
        P.x = 42;
     }
     return P.x;
   }
}