[Bug tree-optimization/101373] PRE hoists trapping instructions over possibly throwing calls

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101373

--- Comment #3 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> Eric, is it possible to write an equivalent testcase in Ada?

procedure P is

  function Foo (J : Integer) return Integer;
  pragma Machine_Attribute (Foo, "const");
  pragma Machine_Attribute (Foo, "noipa");

  function Foo (J : Integer) return Integer is
  begin
    if J /= 0 then
      raise Constraint_Error;
    end if;
    return 0;
  end;

  function Bar (A : access Integer; N : Integer) return Integer;
  pragma Machine_Attribute (Bar, "noipa");

  function Bar (A : access Integer; N : Integer) return Integer is
    Ret : Integer := 0;
  begin
    if N /= 0 then
      Ret := Foo (N);
      Ret := A.all;
    end if;
    Ret := Ret + A.all;
    return Ret;
  end;

  V : Integer;
  pragma Volatile (V);

begin
  V := Bar (null, 1);
exception
  when Constraint_Error => null;
end;

compiled with -O2 -gnatp, but I cannot have the load hoisted in this case.