[Bug fortran/93791] New: [9/10 Regression] ICE in can_represent_integral_type_p, at real.c:5426

[gscfq@t-online.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93791

            Bug ID: 93791
           Summary: [9/10 Regression] ICE in
                    can_represent_integral_type_p, at real.c:5426
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gscfq@t-online.de
  Target Milestone: ---

Changed between 20181007 and 20181014, at -O1+ :


$ cat z1.f90
program p
   implicit none
   if ( f(1.0) > 0.0 ) stop
contains
   real function f(x)
      real, intent(in) :: x
      f = g !()
   end
   real function g()
      g = 2.0
   end
end


$ cat z2.f90
program p
   implicit none
   if ( f() > 0.0 ) stop
contains
   real function f(x)
      real, optional :: x
      f = g !()
   end
   real function g()
      g = 2.0
   end
end


$ cat z3.f90
program p
   implicit none
   call s
contains
   subroutine s
      real :: x
      x = g !()
      if ( x > 0.0 ) stop
   end
   real function g()
      g = 2.0
   end
end


$ gfortran-8 -c z1.f90 -O2
$
$ gfortran-10-20200216 -c z1.f90 -O2
during GIMPLE pass: forwprop
z1.f90:3:0:

    3 |    if ( f(1.0) > 0.0 ) stop
      |
internal compiler error: in can_represent_integral_type_p, at real.c:5422
0xb21e3f format_helper::can_represent_integral_type_p(tree_node*) const
        ../../gcc/real.c:5422
0xf9a48c gimple_simplify_161
        .../gcc/gimple-match.c:9568
0xfb10d8 gimple_simplify_GT_EXPR
        .../gcc/gimple-match.c:78553
0x100250d gimple_simplify
        .../gcc/gimple-match.c:110777
0x1003f6b gimple_resimplify2
        ../../gcc/gimple-match-head.c:318
0x1022644 gimple_simplify(gimple*, gimple_match_op*, gimple**, tree_node*
(*)(tree_node*), tree_node* (*)(tree_node*))
        ../../gcc/gimple-match-head.c:1081
0x92b049 fold_stmt_1
        ../../gcc/gimple-fold.c:5075
0xca5f5e execute
        ../../gcc/tree-ssa-forwprop.c:3025


Side note : detected with reversed order, i.e. define g first.