[Bug fortran/21027] New: Triple call to _gfortran_runtime_error with -fbounds-check

[tkoenig at gcc dot gnu dot org]

$ cat bounds-check.f90
program main
  integer, parameter :: n=10
  integer :: m,i
  integer a(n), b(n)
  call foo(a,m)
  do i=1,m
    b(i) = a(i)*a(i)
  end do
  print *,b(1:m)
end program main

subroutine foo(a)
  integer a(10)
  a = 2
  m = 12
end subroutine foo
$ gfortran -fbounds-check -fdump-tree-optimized -O2 -S bounds-check.f90

gets me (from the .t71.optimized file):

bb 0>:
  foo (&a, &m);
  D.474 = m;
  if (D.474 > 0) goto <L38>; else goto <L10>;

<L38>:;
  ivtmp.19 = 0;

<L0>:;
  if (__builtin_expect (ivtmp.19 > 9, 0) != 0) goto <L2>; else goto <L7>;

<L2>:;
  _gfortran_runtime_error ("Array reference out of bounds", "bounds-check.f90",
5);
  _gfortran_runtime_error ("Array reference out of bounds", "bounds-check.f90",
5);
  _gfortran_runtime_error ("Array reference out of bounds", "bounds-check.f90",
5);

<L7>:;
  D.499 = *&a[ivtmp.19];
  *&b[ivtmp.19] = D.499 * D.499;
  ivtmp.19 = ivtmp.19 + 1;
  if ((<unnamed type>) D.474 == ivtmp.19) goto <L10>; else goto <L0>;

which is still present in the assembly code:

.L16:
        movl    $5, %ecx
        movl    $.LC0, %edx
        movl    %ecx, 8(%esp)
        movl    %edx, 4(%esp)
        movl    $.LC1, (%esp)
        call    _gfortran_runtime_error
        movl    $5, %eax
        movl    %eax, 8(%esp)
        movl    $.LC0, %eax
        movl    %eax, 4(%esp)
        movl    $.LC1, (%esp)
        call    _gfortran_runtime_error
        movl    $5, %eax
        movl    %eax, 8(%esp)
        movl    $.LC0, %eax
        movl    %eax, 4(%esp)
        movl    $.LC1, (%esp)
        call    _gfortran_runtime_error
        jmp     .L5

Maybe it would help if _gfortran_runtime_error was marked
as non-returning.

-- 
           Summary: Triple call to _gfortran_runtime_error with -fbounds-
                    check
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P2
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: tkoenig at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21027