[Bug tree-optimization/54967] New: [4.8 Regression] ICE in check_loop_closed_ssa_use, at tree-ssa-loop-manip.c:55

["Joost.VandeVondele at mat dot ethz.ch" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54967

             Bug #: 54967
           Summary: [4.8 Regression] ICE in check_loop_closed_ssa_use, at
                    tree-ssa-loop-manip.c:55
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: Joost.VandeVondele@mat.ethz.ch


This started failing very recently on trunk :

> gfortran  -c -O2 -funroll-loops bug.f90 
bug.f90: In function âcalc_s_derivsâ:
bug.f90:1:0: internal compiler error: in check_loop_closed_ssa_use, at
tree-ssa-loop-manip.c:557
   SUBROUTINE calc_S_derivs()
 ^
0xa0cf93 check_loop_closed_ssa_use
    ../../gcc/gcc/tree-ssa-loop-manip.c:557
0xa0d591 check_loop_closed_ssa_stmt
    ../../gcc/gcc/tree-ssa-loop-manip.c:572
0xa0d591 verify_loop_closed_ssa(bool)
    ../../gcc/gcc/tree-ssa-loop-manip.c:606
0xa0d880 gimple_duplicate_loop_to_header_edge(loop*, edge_def*, unsigned int,
simple_bitmap_def*, edge_def*, vec_t<edge_def*>**, int)
    ../../gcc/gcc/tree-ssa-loop-manip.c:762
0xdbd99a try_unroll_loop_completely
    ../../gcc/gcc/tree-ssa-loop-ivcanon.c:519
0xdbd99a canonicalize_loop_induction_variables
    ../../gcc/gcc/tree-ssa-loop-ivcanon.c:666
0xdbea10 tree_unroll_loops_completely(bool, bool)
    ../../gcc/gcc/tree-ssa-loop-ivcanon.c:815

> cat bug.f90 
  SUBROUTINE calc_S_derivs()
    INTEGER, DIMENSION(6, 2)      :: c_map_mat
    INTEGER, DIMENSION(:), POINTER:: C_mat
    DO j=1,3
       DO m=j,3
          n=n+1
          c_map_mat(n,1)=j
          IF(m==j)CYCLE
          c_map_mat(n,2)=m
       END DO
    END DO
    DO m=1,6
       DO j=1,2
          IF(c_map_mat(m,j)==0)CYCLE
          CALL foo(C_mat(c_map_mat(m,j))) 
       END DO
    END DO
  END SUBROUTINE calc_S_derivs