1C PR tree-optimization/39516
2C { dg-do compile }
3C { dg-options "-O2 -ftree-loop-linear" }
4      SUBROUTINE SUB(A, B, M)
5      IMPLICIT NONE
6      DOUBLE PRECISION A(20,20), B(20)
7      INTEGER*8 I, J, K, M
8      DO I=1,M
9        DO J=1,M
10          A(I,J)=A(I,J)+1
11        END DO
12      END DO
13      DO K=1,20
14        DO I=1,M
15          DO J=1,M
16            B(I)=B(I)+A(I,J)
17          END DO
18        END DO
19      END DO
20      END SUBROUTINE
21