Re: Ada bootstrap failure due to loop optimization and builtin_stack_alloc

[Zdenek Dvorak <rakdver at atrey dot karlin dot mff dot cuni dot cz>]

Hello,

> Send me the code again?  
> 
> > In the mail you responded to I have outlined two possible approaches to
> > fixing this; I have both basically done, so I am just waiting on what
> > will people consider better (or whether someone will not have a better
> > idea how to solve the problem).
> > 
> Perhaps #1.  But I think neither, the address of that variable is not
> invariant, so it shouldn't be lifted out of the loop.  But I lost track
> of the original test case, so I'm not convinced I'm making any sense.

the loop looks like


while (...)
  {
    builtin_stack_alloc (&array, size);

    arraystart_1 = &array;

    use (*arraystart_1);
  }

Since there is no USE nor VUSE operand on the arraystart_1 = &array;
statement, loop invariant motion decides that it is invariant inside the
loop and moves it out, which is wrong.

Zdenek