Error 799

My apologies if this is a silly error, but I am getting an unusual error message for the following code at line 3; the first executable statement:

FTN95/Win32 Ver. 6.35.0 *** Error 799: Compiler failure - unexpected type for tree argument

!  program to test
!
      integer*4 n
      real*8    mb
      real*8, allocatable, dimension(:,:) ::  a, b, c
!

      do n = 100, 2100, 500
!
        mb = n*n*3. / (2.**17)
        write (*,fmt='(a,i5,f8.2,a)') ' Test ',n, mb,' mb'
        allocate ( a(n,n) )
        allocate ( b(n,n) )
        allocate ( c(n,n) )
        write (*,*) 'Align A', mod (loc(a), 32)
        write (*,*) 'Align B', mod (loc(b), 32)
        write (*,*) 'Align C', mod (loc(c), 32)
!
        call Vec_Add_Test (n, a, b)
        call Vec_Sub_Test (n, a, b, c)

        deallocate ( c )
        deallocate ( b )
        deallocate ( a )

      end do
!
      write (*,*) 'End'
      end          

I can't see what I have done wrong !!

John

It runs without error for me, using version 7.00 (32 bit windows).

David, I have now tested it on FTN95 Ver 6.10.0 It works ok if I use /check but if I use /debug, /opt or no option I get error ( no 799) ?? Similar for the following example, which also successfully fixes the variable alignment problem, when compiled with /check ??

!  program to test 
! 
      integer*4 n, m, ka, kb, kc
      real*8    mb 
      real*8, allocatable, dimension(:,:) ::  a, b, c 
! 
      do n = 100, 2100, 500 
! 
        m  = n+1
        mb = n*m*3. / (2.**17) 
        write (*,fmt='(a,i5,f8.2,a)') ' Test ',n, mb,' mb' 
        allocate ( a(n,m) ) 
        allocate ( b(n,m) ) 
        allocate ( c(n,m) ) 
        write (*,*) 'Align A', mod (loc(a), 32) 
        write (*,*) 'Align B', mod (loc(b), 32) 
        write (*,*) 'Align C', mod (loc(c), 32) 
! 
        ka = 1 + ( 32 - mod (loc(a), 32) ) / 8
        kb = 1 + ( 32 - mod (loc(b), 32) ) / 8
        kc = 1 + ( 32 - mod (loc(c), 32) ) / 8
!
        call Vec_Sub_Test (n, a(ka,1), b(kb,1), c(kc,1) ) 

        deallocate ( c ) 
        deallocate ( b ) 
        deallocate ( a ) 

      end do 
! 
      write (*,*) 'End' 
      end

      subroutine Vec_Sub_Test (n, a, b, c ) 
      integer*4 :: n
      real*8    :: a(n,n), b(n,n), c(n,n) 
!
        write (*,*) 'Align A', mod (loc(a), 32) 
        write (*,*) 'Align B', mod (loc(b), 32) 
        write (*,*) 'Align C', mod (loc(c), 32) 
      end

I see. It looks like a bug then.

I'd like to know what a 'tree argument' is. I'm not aware of using these.

John

There aren't any 'Tree arguments' in Fortran.

This is an internal compiler error. I suspect that a tree argument is related to the Abstract Syntax Tree used by the compiler. See

http://en.wikipedia.org/wiki/Abstract_syntax_tree

Will have to see what Paul makes of the error.

I have now logged this for investigation.

Edit: I have found a simplified version of the error plus a work-around that identifies the problem is using LOC inside MOD. It appears to me that LOC is being treated differently from other PURE functions, such as INT in the expanded example.

integer*4 function align_32a (a) 
  integer*4 a, la
  la = loc (a)
  align_32a = mod (la, 32) 
end 
integer*4 function angle (deg_val)
  real*8 deg_val
  angle = mod ( int (deg_val), 360)
end
integer*4 function align_32 (a)
  integer*4 a
  align_32 = mod (loc (a), 32)
end

John

Thanks

This bug has been fixed for the next release.

Paul,

Thanks for fixing this. I suppose that FTN95 no longer has tree arguments.

John

The error report was equivalent to 'Internal compiler error'. An internal compiler tree had become corrupted.