Re: max-stack-var-size

[canqun at nudt dot edu dot cn]

Paul Brook <paul@nowt.org>:

> On Friday 07 November 2003 7:58 am, canqun@nudt.edu.cn
wrote:
> > It seems that recursive function is the only case that
> > its local variables should be placed on stack. Is it
> > true? If so, add an extra condition to avoid such case
> > will let it work.
> >
> > +   /* Keep variables larger than max-stack-var-size
> > off stack.  */
> > +   if (!(sym->ns->proc_name->attr.recursive)
> >         && !gfc_can_put_var_on_stack (DECL_SIZE_UNIT
> > (decl)))
> > +     TREE_STATIC (decl) = 1;
> 
> This would be fine, preferably accompanied by a testcase.
> 
> Paul
> 
> 

I attached a test program for this case. Is it OK to
apply the patch and commit the testcase ?

Canqun Yang

! Program to test the stack variable size limit.
program stack
   call sub1
   call sub2 (1)
contains

   ! Local variables larger than 32768 in byte size shall be placed in static
   ! storage area, while others be put on stack by default.
   subroutine sub1
      real a, b(32768/4), c(32768/4+1) 
      integer m, n(1024,4), k(1024,1024)
      a = 10.0
      b = 20.0
      c = 30.0
      m = 10
      n = 20
      k = 30
      if ((a .ne. 10.0).or.(b(1) .ne. 20.0).or.(c(1) .ne. 30.0)) call abort
      if ((m .ne. 10).or.(n(256,4) .ne. 20).or.(k(1,1024) .ne. 30)) call abort
   end     

   ! Local variables defined in recursive subroutine are always put on stack.
   recursive subroutine sub2 (n)
      real a (32769)
      a (1) = 42
      if (n .ge. 1) call sub2 (n-1)
      if (a(1) .ne. 42) call abort
      a (1) = 0
   end
end