[Bug fortran/69742] New: ICE with -O3 and ASSOCIATE containing repeated expression

["mrestelli at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69742

            Bug ID: 69742
           Summary: ICE with -O3 and ASSOCIATE containing repeated
                    expression
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mrestelli at gmail dot com
  Target Milestone: ---

This code produces and internal compiler error when compiled with -O3.
It seems that the problem is the appearance of the same expression
twice inside the associate construct. The code compiles and runs
without optimization.


program p
 implicit none
 integer, allocatable :: i(:), j

  allocate( i(5) )
  i = (/( j , j=1,5 )/)

  ! The ICE appears when "size(i)" is used twice in associate
  associate( i5 => i(size(i):size(i)) ) ! this gives ICE
  !associate( i5 => i(size(2*i):size(i)) ) ! this works
  i5 = 2
  end associate

  write(*,*) i
end program p



$ gfortran -O3 test.f90 -o test
test.f90:11:0:

   i5 = 2

internal compiler error: in gimplify_var_or_parm_decl, bei gimplify.c:1840
0x86e434 gimplify_var_or_parm_decl
        gcc/gimplify.c:1840
0x872051 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        gcc/gimplify.c:10595
0x8719cc gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        gcc/gimplify.c:10455
0x87b680 gimplify_modify_expr
        gcc/gimplify.c:4709
0x872210 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        gcc/gimplify.c:10162
0x874c46 gimplify_stmt(tree_node**, gimple**)
        gcc/gimplify.c:5642
0x87339b gimplify_statement_list
        gcc/gimplify.c:1526
0x87339b gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        gcc/gimplify.c:10579
0x874c46 gimplify_stmt(tree_node**, gimple**)
        gcc/gimplify.c:5642
0x8756bd gimplify_bind_expr
        gcc/gimplify.c:1142
0x871d42 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        gcc/gimplify.c:10361
0x874c46 gimplify_stmt(tree_node**, gimple**)
        gcc/gimplify.c:5642
0x87339b gimplify_statement_list
        gcc/gimplify.c:1526
0x87339b gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        gcc/gimplify.c:10579
0x874c46 gimplify_stmt(tree_node**, gimple**)
        gcc/gimplify.c:5642
0x872952 gimplify_and_add(tree_node*, gimple**)
        gcc/gimplify.c:425
0x872952 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        gcc/gimplify.c:10501
0x874c46 gimplify_stmt(tree_node**, gimple**)
        gcc/gimplify.c:5642
0x8756bd gimplify_bind_expr
        gcc/gimplify.c:1142
0x871d42 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        gcc/gimplify.c:10361



$ gfortran --version
GNU Fortran (GCC) 6.0.0 20160209 (experimental)