--          This file is part of SmallEiffel The GNU Eiffel Compiler.
--          Copyright (C) 1994-98 LORIA - UHP - CRIN - INRIA - FRANCE
--            Dominique COLNET and Suzanne COLLIN - colnet@loria.fr 
--                       http://www.loria.fr/SmallEiffel
-- SmallEiffel is  free  software;  you can  redistribute it and/or modify it 
-- under the terms of the GNU General Public License as published by the Free
-- Software  Foundation;  either  version  2, or (at your option)  any  later 
-- version. SmallEiffel is distributed in the hope that it will be useful,but
-- WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
-- or  FITNESS FOR A PARTICULAR PURPOSE.   See the GNU General Public License 
-- for  more  details.  You  should  have  received a copy of the GNU General 
-- Public  License  along  with  SmallEiffel;  see the file COPYING.  If not,
-- write to the  Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-- Boston, MA 02111-1307, USA.
--
class CALL_INFIX_EQ
   --   
   --   Infix operator : "=".
   --   

inherit CALL_INFIX_EQ_NEQ;
   
creation make
   
feature 
   
   operator: STRING is 
      do
	 Result := us_eq;
      end;
   
   is_static: BOOLEAN is
      do
	 if target.is_void then
	    Result := is_static_eq_void(arg1);
	 elseif arg1.is_void then
	    Result := is_static_eq_void(target);
	 elseif target.is_static and then arg1.is_static then
	    Result := true;
	    if target.static_value = arg1.static_value then
	       static_value_mem := 1;
	    end;
	 end;
      end;
   
   compile_to_c is
      local
	 tt, at: TYPE;
      do
	 tt := target.result_type.run_type;
	 at := arg1.result_type.run_type;
	 if tt.is_expanded then
	    if at.is_expanded then -- ------------- Expanded/Expanded :
	       if tt.is_user_expanded then
		  cmp_user_expanded(true,tt);
	       elseif tt.is_basic_eiffel_expanded then
		  cmp_basic_eiffel_expanded(true,at,tt);
	       elseif tt.is_bit then
		  cmp_bit(true,tt);
	       else -- NATIVE_ARRAY
		  cmp_basic_ref(true);
	       end;
	    else -- ------------------------------- Expanded/Reference :
	       c2c_exp_ref(target,tt,arg1,at);
	    end;
	 elseif at.is_expanded then -- ----------- Reference/Expanded :
	    c2c_exp_ref(arg1,at,target,tt);
	 else -- ---------------------------- Reference/Reference :
	    cmp_basic_ref(true);
	 end;
      end;

feature {NONE}

   c2c_exp_ref(e: EXPRESSION; et: TYPE; r: EXPRESSION; rt: TYPE) is
      do
	 if r.is_void then
	    cpp.put_string("((");
	    e.compile_to_c;
	    cpp.put_string("),0)");
	 else
	    cpp.put_string("((");
	    e.compile_to_c;
	    cpp.put_string("),(");
	    r.compile_to_c;
	    cpp.put_string("),0)");
	 end;
      end;
   
feature {NONE}

   is_static_eq_void(e: EXPRESSION): BOOLEAN is
      local
	 rt: TYPE;
      do
	 if e.is_current then
	    Result := true;
	 elseif e.is_manifest_string then
	    Result := true;
	 elseif is_manifest_array(e) then
	    Result := true;
	 else
	    rt := e.result_type.run_type;
	    if rt.is_expanded then
	       if e.can_be_dropped then
		  Result := true;
	       end;
	    elseif e.is_static then
	       if e.static_value = 0 then
		  Result := true;
		  static_value_mem := 1;
	       end;
	    end;
	 end;
      end;

feature 

   compile_to_jvm is
      local
	 space, point1, point2: INTEGER;
	 rt: TYPE;
	 rc: RUN_CLASS;
      do
	 if target.is_void then
	    jvm_void_cmp(arg1);
	 elseif arg1.is_void then
	    jvm_void_cmp(target);
	 else
	    rt := target.result_type.smallest_ancestor(arg1.result_type);
	    space := target.compile_to_jvm_into(rt);
	    space := arg1.compile_to_jvm_into(rt);
	    if rt.is_user_expanded then
	       rc := rt.run_class;
	       jvm_standard_is_equal_aux(rc,rc.writable_attributes);
	    else
	       point1 := rt.jvm_if_x_eq;
	       code_attribute.opcode_iconst_0;
	       point2 := code_attribute.opcode_goto;
	       code_attribute.resolve_u2_branch(point1);
	       code_attribute.opcode_iconst_1;
	       code_attribute.resolve_u2_branch(point2);
	    end;
	 end;
      end;
   
   jvm_branch_if_false: INTEGER is
      do
	 Result := jvm_standard_branch_if_false;
      end;
   
   jvm_branch_if_true: INTEGER is
      do
	 Result := jvm_standard_branch_if_true;
      end;
   
feature {NONE}

   jvm_void_cmp(e: EXPRESSION) is
      local
	 rt: TYPE;
	 point1, point2: INTEGER;
	 space: INTEGER;
      do
	 rt := e.result_type.run_type;
	 if rt.is_expanded then
	    e.compile_to_jvm;
	    from
	       space := rt.jvm_stack_space;
	    until
	       space = 0
	    loop
	       code_attribute.opcode_pop;
	       space := space - 1;
	    end;
	    code_attribute.opcode_iconst_0;
	 else
	    e.compile_to_jvm;
	    point1 := code_attribute.opcode_ifnull;
	    code_attribute.opcode_iconst_0;
	    point2 := code_attribute.opcode_goto;
	    code_attribute.resolve_u2_branch(point1);
	    code_attribute.opcode_iconst_1;
	    code_attribute.resolve_u2_branch(point2);
	 end;
      end;

invariant
   
   run_feature = Void;

end -- CALL_INFIX_EQ