Beispiel #1
0
tree
gfc_build_array_ref (tree base, tree offset, tree decl)
{
  tree type = TREE_TYPE (base);
  tree tmp;

  gcc_assert (TREE_CODE (type) == ARRAY_TYPE);
  type = TREE_TYPE (type);

  if (DECL_P (base))
    TREE_ADDRESSABLE (base) = 1;

  /* Strip NON_LVALUE_EXPR nodes.  */
  STRIP_TYPE_NOPS (offset);

  /* If the array reference is to a pointer, whose target contains a
     subreference, use the span that is stored with the backend decl
     and reference the element with pointer arithmetic.  */
  if (decl && (TREE_CODE (decl) == FIELD_DECL
		 || TREE_CODE (decl) == VAR_DECL
		 || TREE_CODE (decl) == PARM_DECL)
	&& GFC_DECL_SUBREF_ARRAY_P (decl)
	&& !integer_zerop (GFC_DECL_SPAN(decl)))
    {
      offset = fold_build2_loc (input_location, MULT_EXPR,
				gfc_array_index_type,
				offset, GFC_DECL_SPAN(decl));
      tmp = gfc_build_addr_expr (pvoid_type_node, base);
      tmp = fold_build2_loc (input_location, POINTER_PLUS_EXPR,
			     pvoid_type_node, tmp,
			     fold_convert (sizetype, offset));
      tmp = fold_convert (build_pointer_type (type), tmp);
      if (!TYPE_STRING_FLAG (type))
	tmp = build_fold_indirect_ref_loc (input_location, tmp);
      return tmp;
    }
  else
    /* Otherwise use a straightforward array reference.  */
    return build4_loc (input_location, ARRAY_REF, type, base, offset,
		       NULL_TREE, NULL_TREE);
}
Beispiel #2
0
tree
convert (tree type, tree expr)
{
  tree e = expr;
  enum tree_code code = TREE_CODE (type);
  const char *invalid_conv_diag;
  tree ret;
  location_t loc = EXPR_LOCATION (expr);

  if (type == error_mark_node
      || expr == error_mark_node
      || TREE_TYPE (expr) == error_mark_node)
    return error_mark_node;

  if ((invalid_conv_diag
       = targetm.invalid_conversion (TREE_TYPE (expr), type)))
    {
      error (invalid_conv_diag);
      return error_mark_node;
    }

  if (type == TREE_TYPE (expr))
    return expr;
  ret = targetm.convert_to_type (type, expr);
  if (ret)
      return ret;

  STRIP_TYPE_NOPS (e);

  if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (expr))
      && (TREE_CODE (TREE_TYPE (expr)) != COMPLEX_TYPE
	  || TREE_CODE (e) == COMPLEX_EXPR))
    return fold_convert_loc (loc, type, expr);
  if (TREE_CODE (TREE_TYPE (expr)) == ERROR_MARK)
    return error_mark_node;
  if (TREE_CODE (TREE_TYPE (expr)) == VOID_TYPE)
    {
      error ("void value not ignored as it ought to be");
      return error_mark_node;
    }

  switch (code)
    {
    case VOID_TYPE:
      return fold_convert_loc (loc, type, e);

    case INTEGER_TYPE:
    case ENUMERAL_TYPE:
      ret = convert_to_integer (type, e);
      goto maybe_fold;

    case BOOLEAN_TYPE:
      return fold_convert_loc
	(loc, type, c_objc_common_truthvalue_conversion (input_location, expr));

    case POINTER_TYPE:
    case REFERENCE_TYPE:
      ret = convert_to_pointer (type, e);
      goto maybe_fold;

    case REAL_TYPE:
      ret = convert_to_real (type, e);
      goto maybe_fold;

    case FIXED_POINT_TYPE:
      ret = convert_to_fixed (type, e);
      goto maybe_fold;

    case COMPLEX_TYPE:
      /* If converting from COMPLEX_TYPE to a different COMPLEX_TYPE
	 and e is not COMPLEX_EXPR, convert_to_complex uses save_expr,
	 but for the C FE c_save_expr needs to be called instead.  */
      if (TREE_CODE (TREE_TYPE (e)) == COMPLEX_TYPE)
	{
	  if (TREE_CODE (e) != COMPLEX_EXPR)
	    {
	      tree subtype = TREE_TYPE (type);
	      tree elt_type = TREE_TYPE (TREE_TYPE (e));

	      if (in_late_binary_op)
		e = save_expr (e);
	      else
		e = c_save_expr (e);
	      ret
		= fold_build2_loc (loc, COMPLEX_EXPR, type,
				   convert (subtype,
					    fold_build1 (REALPART_EXPR,
							 elt_type, e)),
				   convert (subtype,
					    fold_build1 (IMAGPART_EXPR,
							 elt_type, e)));
	      goto maybe_fold;
	    }
	}
      ret = convert_to_complex (type, e);
      goto maybe_fold;

    case VECTOR_TYPE:
      ret = convert_to_vector (type, e);
      goto maybe_fold;

    case RECORD_TYPE:
    case UNION_TYPE:
      if (lang_hooks.types_compatible_p (type, TREE_TYPE (expr)))
	return e;
      break;

    default:
      break;

    maybe_fold:
      if (TREE_CODE (ret) != C_MAYBE_CONST_EXPR)
	ret = fold (ret);
      return ret;
    }

  error ("conversion to non-scalar type requested");
  return error_mark_node;
}
Beispiel #3
0
tree
convert (tree type, tree expr)
{
  tree e = expr;
  enum tree_code code = TREE_CODE (type);
  const char *invalid_conv_diag;
  tree ret;
  location_t loc = EXPR_LOCATION (expr);

  if (type == error_mark_node
      || expr == error_mark_node
      || TREE_TYPE (expr) == error_mark_node)
    return error_mark_node;

  if ((invalid_conv_diag
       = targetm.invalid_conversion (TREE_TYPE (expr), type)))
    {
      error (invalid_conv_diag);
      return error_mark_node;
    }

  if (type == TREE_TYPE (expr))
    return expr;
  ret = targetm.convert_to_type (type, expr);
  if (ret)
      return ret;

  STRIP_TYPE_NOPS (e);

  if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (expr)))
    return fold_convert_loc (loc, type, expr);
  if (TREE_CODE (TREE_TYPE (expr)) == ERROR_MARK)
    return error_mark_node;
  if (TREE_CODE (TREE_TYPE (expr)) == VOID_TYPE)
    {
      error ("void value not ignored as it ought to be");
      return error_mark_node;
    }

  switch (code)
    {
    case VOID_TYPE:
      return fold_convert_loc (loc, type, e);

    case INTEGER_TYPE:
    case ENUMERAL_TYPE:
      ret = convert_to_integer (type, e);
      goto maybe_fold;

    case BOOLEAN_TYPE:
      return fold_convert_loc
	(loc, type, c_objc_common_truthvalue_conversion (input_location, expr));

    case POINTER_TYPE:
    case REFERENCE_TYPE:
      ret = convert_to_pointer (type, e);
      goto maybe_fold;

    case REAL_TYPE:
      ret = convert_to_real (type, e);
      goto maybe_fold;

    case FIXED_POINT_TYPE:
      ret = convert_to_fixed (type, e);
      goto maybe_fold;

    case COMPLEX_TYPE:
      ret = convert_to_complex (type, e);
      goto maybe_fold;

    case VECTOR_TYPE:
      ret = convert_to_vector (type, e);
      goto maybe_fold;

    case RECORD_TYPE:
    case UNION_TYPE:
      if (lang_hooks.types_compatible_p (type, TREE_TYPE (expr)))
	return e;
      break;

    default:
      break;

    maybe_fold:
      if (TREE_CODE (ret) != C_MAYBE_CONST_EXPR)
	ret = fold (ret);
      return ret;
    }

  error ("conversion to non-scalar type requested");
  return error_mark_node;
}
Beispiel #4
0
tree
gfc_build_array_ref (tree base, tree offset, tree decl)
{
  tree type = TREE_TYPE (base);
  tree tmp;
  tree span;

  if (GFC_ARRAY_TYPE_P (type) && GFC_TYPE_ARRAY_RANK (type) == 0)
    {
      gcc_assert (GFC_TYPE_ARRAY_CORANK (type) > 0);

      return fold_convert (TYPE_MAIN_VARIANT (type), base);
    }

  /* Scalar coarray, there is nothing to do.  */
  if (TREE_CODE (type) != ARRAY_TYPE)
    {
      gcc_assert (decl == NULL_TREE);
      gcc_assert (integer_zerop (offset));
      return base;
    }

  type = TREE_TYPE (type);

  if (DECL_P (base))
    TREE_ADDRESSABLE (base) = 1;

  /* Strip NON_LVALUE_EXPR nodes.  */
  STRIP_TYPE_NOPS (offset);

  /* If the array reference is to a pointer, whose target contains a
     subreference, use the span that is stored with the backend decl
     and reference the element with pointer arithmetic.  */
  if (decl && (TREE_CODE (decl) == FIELD_DECL
		 || TREE_CODE (decl) == VAR_DECL
		 || TREE_CODE (decl) == PARM_DECL)
	&& ((GFC_DECL_SUBREF_ARRAY_P (decl)
	      && !integer_zerop (GFC_DECL_SPAN(decl)))
	   || GFC_DECL_CLASS (decl)))
    {
      if (GFC_DECL_CLASS (decl))
	{
	  /* Allow for dummy arguments and other good things.  */
	  if (POINTER_TYPE_P (TREE_TYPE (decl)))
	    decl = build_fold_indirect_ref_loc (input_location, decl);

	  /* Check if '_data' is an array descriptor. If it is not,
	     the array must be one of the components of the class object,
	     so return a normal array reference.  */
	  if (!GFC_DESCRIPTOR_TYPE_P (TREE_TYPE (gfc_class_data_get (decl))))
	    return build4_loc (input_location, ARRAY_REF, type, base,
			       offset, NULL_TREE, NULL_TREE);

	  span = gfc_vtable_size_get (decl);
	}
      else if (GFC_DECL_SUBREF_ARRAY_P (decl))
	span = GFC_DECL_SPAN(decl);
      else
	gcc_unreachable ();

      offset = fold_build2_loc (input_location, MULT_EXPR,
				gfc_array_index_type,
				offset, span);
      tmp = gfc_build_addr_expr (pvoid_type_node, base);
      tmp = fold_build_pointer_plus_loc (input_location, tmp, offset);
      tmp = fold_convert (build_pointer_type (type), tmp);
      if (!TYPE_STRING_FLAG (type))
	tmp = build_fold_indirect_ref_loc (input_location, tmp);
      return tmp;
    }
  else
    /* Otherwise use a straightforward array reference.  */
    return build4_loc (input_location, ARRAY_REF, type, base, offset,
		       NULL_TREE, NULL_TREE);
}
Beispiel #5
0
tree
convert (tree type, tree expr)
{
  tree e = expr;
  enum tree_code code = TREE_CODE (type);
  const char *invalid_conv_diag;
  tree ret;
  location_t loc = EXPR_LOCATION (expr);

  if (type == error_mark_node
      || error_operand_p (expr))
    return error_mark_node;

  if ((invalid_conv_diag
       = targetm.invalid_conversion (TREE_TYPE (expr), type)))
    {
      error (invalid_conv_diag);
      return error_mark_node;
    }

  if (type == TREE_TYPE (expr))
    return expr;
  ret = targetm.convert_to_type (type, expr);
  if (ret)
      return ret;

  STRIP_TYPE_NOPS (e);

  if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (expr))
      && (TREE_CODE (TREE_TYPE (expr)) != COMPLEX_TYPE
	  || TREE_CODE (e) == COMPLEX_EXPR))
    return fold_convert_loc (loc, type, expr);
  if (TREE_CODE (TREE_TYPE (expr)) == ERROR_MARK)
    return error_mark_node;
  if (TREE_CODE (TREE_TYPE (expr)) == VOID_TYPE)
    {
      error ("void value not ignored as it ought to be");
      return error_mark_node;
    }

  switch (code)
    {
    case VOID_TYPE:
      return fold_convert_loc (loc, type, e);

    case INTEGER_TYPE:
    case ENUMERAL_TYPE:
      if (flag_sanitize & SANITIZE_FLOAT_CAST
	  && TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
	  && COMPLETE_TYPE_P (type)
	  && current_function_decl != NULL_TREE
	  && !lookup_attribute ("no_sanitize_undefined",
				DECL_ATTRIBUTES (current_function_decl)))
	{
	  tree arg;
	  if (in_late_binary_op)
	    {
	      expr = save_expr (expr);
	      arg = expr;
	    }
	  else
	    {
	      expr = c_save_expr (expr);
	      arg = c_fully_fold (expr, false, NULL);
	    }
	  tree check = ubsan_instrument_float_cast (loc, type, expr, arg);
	  expr = fold_build1 (FIX_TRUNC_EXPR, type, expr);
	  if (check == NULL)
	    return expr;
	  return fold_build2 (COMPOUND_EXPR, TREE_TYPE (expr), check, expr);
	}
      ret = convert_to_integer (type, e);
      goto maybe_fold;

    case BOOLEAN_TYPE:
      return fold_convert_loc
	(loc, type, c_objc_common_truthvalue_conversion (input_location, expr));

    case POINTER_TYPE:
    case REFERENCE_TYPE:
      ret = convert_to_pointer (type, e);
      goto maybe_fold;

    case REAL_TYPE:
      ret = convert_to_real (type, e);
      goto maybe_fold;

    case FIXED_POINT_TYPE:
      ret = convert_to_fixed (type, e);
      goto maybe_fold;

    case COMPLEX_TYPE:
      /* If converting from COMPLEX_TYPE to a different COMPLEX_TYPE
	 and e is not COMPLEX_EXPR, convert_to_complex uses save_expr,
	 but for the C FE c_save_expr needs to be called instead.  */
      if (TREE_CODE (TREE_TYPE (e)) == COMPLEX_TYPE)
	{
	  if (TREE_CODE (e) != COMPLEX_EXPR)
	    {
	      tree subtype = TREE_TYPE (type);
	      tree elt_type = TREE_TYPE (TREE_TYPE (e));

	      if (in_late_binary_op)
		e = save_expr (e);
	      else
		e = c_save_expr (e);
	      ret
		= fold_build2_loc (loc, COMPLEX_EXPR, type,
				   convert (subtype,
					    fold_build1 (REALPART_EXPR,
							 elt_type, e)),
				   convert (subtype,
					    fold_build1 (IMAGPART_EXPR,
							 elt_type, e)));
	      goto maybe_fold;
	    }
	}
      ret = convert_to_complex (type, e);
      goto maybe_fold;

    case VECTOR_TYPE:
      ret = convert_to_vector (type, e);
      goto maybe_fold;

    case RECORD_TYPE:
    case UNION_TYPE:
      if (lang_hooks.types_compatible_p (type, TREE_TYPE (expr)))
	return e;
      break;

    default:
      break;

    maybe_fold:
      if (TREE_CODE (ret) != C_MAYBE_CONST_EXPR)
	ret = fold (ret);
      return ret;
    }

  error ("conversion to non-scalar type requested");
  return error_mark_node;
}
Beispiel #6
0
static tree
c_fully_fold_internal (tree expr, bool in_init, bool *maybe_const_operands,
		       bool *maybe_const_itself, bool for_int_const)
{
  tree ret = expr;
  enum tree_code code = TREE_CODE (expr);
  enum tree_code_class kind = TREE_CODE_CLASS (code);
  location_t loc = EXPR_LOCATION (expr);
  tree op0, op1, op2, op3;
  tree orig_op0, orig_op1, orig_op2;
  bool op0_const = true, op1_const = true, op2_const = true;
  bool op0_const_self = true, op1_const_self = true, op2_const_self = true;
  bool nowarning = TREE_NO_WARNING (expr);
  bool unused_p;
  source_range old_range;

  /* Constants, declarations, statements, errors, SAVE_EXPRs and
     anything else not counted as an expression cannot usefully be
     folded further at this point.  */
  if (!IS_EXPR_CODE_CLASS (kind)
      || kind == tcc_statement
      || code == SAVE_EXPR)
    return expr;

  if (IS_EXPR_CODE_CLASS (kind))
    old_range = EXPR_LOCATION_RANGE (expr);

  /* Operands of variable-length expressions (function calls) have
     already been folded, as have __builtin_* function calls, and such
     expressions cannot occur in constant expressions.  */
  if (kind == tcc_vl_exp)
    {
      *maybe_const_operands = false;
      ret = fold (expr);
      goto out;
    }

  if (code == C_MAYBE_CONST_EXPR)
    {
      tree pre = C_MAYBE_CONST_EXPR_PRE (expr);
      tree inner = C_MAYBE_CONST_EXPR_EXPR (expr);
      if (C_MAYBE_CONST_EXPR_NON_CONST (expr))
	*maybe_const_operands = false;
      if (C_MAYBE_CONST_EXPR_INT_OPERANDS (expr))
	{
	  *maybe_const_itself = false;
	  inner = c_fully_fold_internal (inner, in_init, maybe_const_operands,
					 maybe_const_itself, true);
	}
      if (pre && !in_init)
	ret = build2 (COMPOUND_EXPR, TREE_TYPE (expr), pre, inner);
      else
	ret = inner;
      goto out;
    }

  /* Assignment, increment, decrement, function call and comma
     operators, and statement expressions, cannot occur in constant
     expressions if evaluated / outside of sizeof.  (Function calls
     were handled above, though VA_ARG_EXPR is treated like a function
     call here, and statement expressions are handled through
     C_MAYBE_CONST_EXPR to avoid folding inside them.)  */
  switch (code)
    {
    case MODIFY_EXPR:
    case PREDECREMENT_EXPR:
    case PREINCREMENT_EXPR:
    case POSTDECREMENT_EXPR:
    case POSTINCREMENT_EXPR:
    case COMPOUND_EXPR:
      *maybe_const_operands = false;
      break;

    case VA_ARG_EXPR:
    case TARGET_EXPR:
    case BIND_EXPR:
    case OBJ_TYPE_REF:
      *maybe_const_operands = false;
      ret = fold (expr);
      goto out;

    default:
      break;
    }

  /* Fold individual tree codes as appropriate.  */
  switch (code)
    {
    case COMPOUND_LITERAL_EXPR:
      /* Any non-constancy will have been marked in a containing
	 C_MAYBE_CONST_EXPR; there is no more folding to do here.  */
      goto out;

    case COMPONENT_REF:
      orig_op0 = op0 = TREE_OPERAND (expr, 0);
      op1 = TREE_OPERAND (expr, 1);
      op2 = TREE_OPERAND (expr, 2);
      op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
				   maybe_const_itself, for_int_const);
      STRIP_TYPE_NOPS (op0);
      if (op0 != orig_op0)
	ret = build3 (COMPONENT_REF, TREE_TYPE (expr), op0, op1, op2);
      if (ret != expr)
	{
	  TREE_READONLY (ret) = TREE_READONLY (expr);
	  TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (expr);
	}
      goto out;

    case ARRAY_REF:
      orig_op0 = op0 = TREE_OPERAND (expr, 0);
      orig_op1 = op1 = TREE_OPERAND (expr, 1);
      op2 = TREE_OPERAND (expr, 2);
      op3 = TREE_OPERAND (expr, 3);
      op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
				   maybe_const_itself, for_int_const);
      STRIP_TYPE_NOPS (op0);
      op1 = c_fully_fold_internal (op1, in_init, maybe_const_operands,
				   maybe_const_itself, for_int_const);
      STRIP_TYPE_NOPS (op1);
      op1 = decl_constant_value_for_optimization (op1);
      if (op0 != orig_op0 || op1 != orig_op1)
	ret = build4 (ARRAY_REF, TREE_TYPE (expr), op0, op1, op2, op3);
      if (ret != expr)
	{
	  TREE_READONLY (ret) = TREE_READONLY (expr);
	  TREE_SIDE_EFFECTS (ret) = TREE_SIDE_EFFECTS (expr);
	  TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (expr);
	}
      ret = fold (ret);
      goto out;

    case COMPOUND_EXPR:
    case MODIFY_EXPR:
    case PREDECREMENT_EXPR:
    case PREINCREMENT_EXPR:
    case POSTDECREMENT_EXPR:
    case POSTINCREMENT_EXPR:
    case PLUS_EXPR:
    case MINUS_EXPR:
    case MULT_EXPR:
    case POINTER_PLUS_EXPR:
    case TRUNC_DIV_EXPR:
    case CEIL_DIV_EXPR:
    case FLOOR_DIV_EXPR:
    case TRUNC_MOD_EXPR:
    case RDIV_EXPR:
    case EXACT_DIV_EXPR:
    case LSHIFT_EXPR:
    case RSHIFT_EXPR:
    case BIT_IOR_EXPR:
    case BIT_XOR_EXPR:
    case BIT_AND_EXPR:
    case LT_EXPR:
    case LE_EXPR:
    case GT_EXPR:
    case GE_EXPR:
    case EQ_EXPR:
    case NE_EXPR:
    case COMPLEX_EXPR:
    case TRUTH_AND_EXPR:
    case TRUTH_OR_EXPR:
    case TRUTH_XOR_EXPR:
    case UNORDERED_EXPR:
    case ORDERED_EXPR:
    case UNLT_EXPR:
    case UNLE_EXPR:
    case UNGT_EXPR:
    case UNGE_EXPR:
    case UNEQ_EXPR:
      /* Binary operations evaluating both arguments (increment and
	 decrement are binary internally in GCC).  */
      orig_op0 = op0 = TREE_OPERAND (expr, 0);
      orig_op1 = op1 = TREE_OPERAND (expr, 1);
      op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
				   maybe_const_itself, for_int_const);
      STRIP_TYPE_NOPS (op0);
      if (code != MODIFY_EXPR
	  && code != PREDECREMENT_EXPR
	  && code != PREINCREMENT_EXPR
	  && code != POSTDECREMENT_EXPR
	  && code != POSTINCREMENT_EXPR)
	op0 = decl_constant_value_for_optimization (op0);
      /* The RHS of a MODIFY_EXPR was fully folded when building that
	 expression for the sake of conversion warnings.  */
      if (code != MODIFY_EXPR)
	op1 = c_fully_fold_internal (op1, in_init, maybe_const_operands,
				     maybe_const_itself, for_int_const);
      STRIP_TYPE_NOPS (op1);
      op1 = decl_constant_value_for_optimization (op1);

      if (for_int_const && (TREE_CODE (op0) != INTEGER_CST
			    || TREE_CODE (op1) != INTEGER_CST))
	goto out;

      if (op0 != orig_op0 || op1 != orig_op1 || in_init)
	ret = in_init
	  ? fold_build2_initializer_loc (loc, code, TREE_TYPE (expr), op0, op1)
	  : fold_build2_loc (loc, code, TREE_TYPE (expr), op0, op1);
      else
	ret = fold (expr);
      if (TREE_OVERFLOW_P (ret)
	  && !TREE_OVERFLOW_P (op0)
	  && !TREE_OVERFLOW_P (op1))
	overflow_warning (EXPR_LOC_OR_LOC (expr, input_location), ret);
      if (code == LSHIFT_EXPR
	  && TREE_CODE (orig_op0) != INTEGER_CST
	  && TREE_CODE (TREE_TYPE (orig_op0)) == INTEGER_TYPE
	  && TREE_CODE (op0) == INTEGER_CST
	  && c_inhibit_evaluation_warnings == 0
	  && tree_int_cst_sgn (op0) < 0)
	warning_at (loc, OPT_Wshift_negative_value,
		    "left shift of negative value");
      if ((code == LSHIFT_EXPR || code == RSHIFT_EXPR)
	  && TREE_CODE (orig_op1) != INTEGER_CST
	  && TREE_CODE (op1) == INTEGER_CST
	  && (TREE_CODE (TREE_TYPE (orig_op0)) == INTEGER_TYPE
	      || TREE_CODE (TREE_TYPE (orig_op0)) == FIXED_POINT_TYPE)
	  && TREE_CODE (TREE_TYPE (orig_op1)) == INTEGER_TYPE
	  && c_inhibit_evaluation_warnings == 0)
	{
	  if (tree_int_cst_sgn (op1) < 0)
	    warning_at (loc, OPT_Wshift_count_negative,
			(code == LSHIFT_EXPR
			 ? G_("left shift count is negative")
			 : G_("right shift count is negative")));
	  else if (compare_tree_int (op1,
				     TYPE_PRECISION (TREE_TYPE (orig_op0)))
		   >= 0)
	    warning_at (loc, OPT_Wshift_count_overflow,
			(code == LSHIFT_EXPR
			 ? G_("left shift count >= width of type")
			 : G_("right shift count >= width of type")));
	}
      if (code == LSHIFT_EXPR
	  /* If either OP0 has been folded to INTEGER_CST...  */
	  && ((TREE_CODE (orig_op0) != INTEGER_CST
	       && TREE_CODE (TREE_TYPE (orig_op0)) == INTEGER_TYPE
	       && TREE_CODE (op0) == INTEGER_CST)
	      /* ...or if OP1 has been folded to INTEGER_CST...  */
	      || (TREE_CODE (orig_op1) != INTEGER_CST
		  && TREE_CODE (TREE_TYPE (orig_op1)) == INTEGER_TYPE
		  && TREE_CODE (op1) == INTEGER_CST))
	  && c_inhibit_evaluation_warnings == 0)
	/* ...then maybe we can detect an overflow.  */
	maybe_warn_shift_overflow (loc, op0, op1);
      if ((code == TRUNC_DIV_EXPR
	   || code == CEIL_DIV_EXPR
	   || code == FLOOR_DIV_EXPR
	   || code == EXACT_DIV_EXPR
	   || code == TRUNC_MOD_EXPR)
	  && TREE_CODE (orig_op1) != INTEGER_CST
	  && TREE_CODE (op1) == INTEGER_CST
	  && (TREE_CODE (TREE_TYPE (orig_op0)) == INTEGER_TYPE
	      || TREE_CODE (TREE_TYPE (orig_op0)) == FIXED_POINT_TYPE)
	  && TREE_CODE (TREE_TYPE (orig_op1)) == INTEGER_TYPE)
	warn_for_div_by_zero (loc, op1);
      goto out;

    case INDIRECT_REF:
    case FIX_TRUNC_EXPR:
    case FLOAT_EXPR:
    CASE_CONVERT:
    case ADDR_SPACE_CONVERT_EXPR:
    case VIEW_CONVERT_EXPR:
    case NON_LVALUE_EXPR:
    case NEGATE_EXPR:
    case BIT_NOT_EXPR:
    case TRUTH_NOT_EXPR:
    case ADDR_EXPR:
    case CONJ_EXPR:
    case REALPART_EXPR:
    case IMAGPART_EXPR:
      /* Unary operations.  */
      orig_op0 = op0 = TREE_OPERAND (expr, 0);
      op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
				   maybe_const_itself, for_int_const);
      STRIP_TYPE_NOPS (op0);
      if (code != ADDR_EXPR && code != REALPART_EXPR && code != IMAGPART_EXPR)
	op0 = decl_constant_value_for_optimization (op0);

      if (for_int_const && TREE_CODE (op0) != INTEGER_CST)
	goto out;

      /* ??? Cope with user tricks that amount to offsetof.  The middle-end is
	 not prepared to deal with them if they occur in initializers.  */
      if (op0 != orig_op0
	  && code == ADDR_EXPR
	  && (op1 = get_base_address (op0)) != NULL_TREE
	  && INDIRECT_REF_P (op1)
	  && TREE_CONSTANT (TREE_OPERAND (op1, 0)))
	ret = fold_convert_loc (loc, TREE_TYPE (expr), fold_offsetof_1 (op0));
      else if (op0 != orig_op0 || in_init)
	ret = in_init
	  ? fold_build1_initializer_loc (loc, code, TREE_TYPE (expr), op0)
	  : fold_build1_loc (loc, code, TREE_TYPE (expr), op0);
      else
	ret = fold (expr);
      if (code == INDIRECT_REF
	  && ret != expr
	  && INDIRECT_REF_P (ret))
	{
	  TREE_READONLY (ret) = TREE_READONLY (expr);
	  TREE_SIDE_EFFECTS (ret) = TREE_SIDE_EFFECTS (expr);
	  TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (expr);
	}
      switch (code)
	{
	case FIX_TRUNC_EXPR:
	case FLOAT_EXPR:
	CASE_CONVERT:
	  /* Don't warn about explicit conversions.  We will already
	     have warned about suspect implicit conversions.  */
	  break;

	default:
	  if (TREE_OVERFLOW_P (ret) && !TREE_OVERFLOW_P (op0))
	    overflow_warning (EXPR_LOCATION (expr), ret);
	  break;
	}
      goto out;

    case TRUTH_ANDIF_EXPR:
    case TRUTH_ORIF_EXPR:
      /* Binary operations not necessarily evaluating both
	 arguments.  */
      orig_op0 = op0 = TREE_OPERAND (expr, 0);
      orig_op1 = op1 = TREE_OPERAND (expr, 1);
      op0 = c_fully_fold_internal (op0, in_init, &op0_const, &op0_const_self,
				   for_int_const);
      STRIP_TYPE_NOPS (op0);

      unused_p = (op0 == (code == TRUTH_ANDIF_EXPR
			  ? truthvalue_false_node
			  : truthvalue_true_node));
      c_disable_warnings (unused_p);
      op1 = c_fully_fold_internal (op1, in_init, &op1_const, &op1_const_self,
				   for_int_const);
      STRIP_TYPE_NOPS (op1);
      c_enable_warnings (unused_p);

      if (for_int_const
	  && (TREE_CODE (op0) != INTEGER_CST
	      /* Require OP1 be an INTEGER_CST only if it's evaluated.  */
	      || (!unused_p && TREE_CODE (op1) != INTEGER_CST)))
	goto out;

      if (op0 != orig_op0 || op1 != orig_op1 || in_init)
	ret = in_init
	  ? fold_build2_initializer_loc (loc, code, TREE_TYPE (expr), op0, op1)
	  : fold_build2_loc (loc, code, TREE_TYPE (expr), op0, op1);
      else
	ret = fold (expr);
      *maybe_const_operands &= op0_const;
      *maybe_const_itself &= op0_const_self;
      if (!(flag_isoc99
	    && op0_const
	    && op0_const_self
	    && (code == TRUTH_ANDIF_EXPR
		? op0 == truthvalue_false_node
		: op0 == truthvalue_true_node)))
	*maybe_const_operands &= op1_const;
      if (!(op0_const
	    && op0_const_self
	    && (code == TRUTH_ANDIF_EXPR
		? op0 == truthvalue_false_node
		: op0 == truthvalue_true_node)))
	*maybe_const_itself &= op1_const_self;
      goto out;

    case COND_EXPR:
      orig_op0 = op0 = TREE_OPERAND (expr, 0);
      orig_op1 = op1 = TREE_OPERAND (expr, 1);
      orig_op2 = op2 = TREE_OPERAND (expr, 2);
      op0 = c_fully_fold_internal (op0, in_init, &op0_const, &op0_const_self,
				   for_int_const);

      STRIP_TYPE_NOPS (op0);
      c_disable_warnings (op0 == truthvalue_false_node);
      op1 = c_fully_fold_internal (op1, in_init, &op1_const, &op1_const_self,
				   for_int_const);
      STRIP_TYPE_NOPS (op1);
      c_enable_warnings (op0 == truthvalue_false_node);

      c_disable_warnings (op0 == truthvalue_true_node);
      op2 = c_fully_fold_internal (op2, in_init, &op2_const, &op2_const_self,
				   for_int_const);
      STRIP_TYPE_NOPS (op2);
      c_enable_warnings (op0 == truthvalue_true_node);

      if (for_int_const
	  && (TREE_CODE (op0) != INTEGER_CST
	      /* Only the evaluated operand must be an INTEGER_CST.  */
	      || (op0 == truthvalue_true_node
		  ? TREE_CODE (op1) != INTEGER_CST
		  : TREE_CODE (op2) != INTEGER_CST)))
	goto out;

      if (op0 != orig_op0 || op1 != orig_op1 || op2 != orig_op2)
	ret = fold_build3_loc (loc, code, TREE_TYPE (expr), op0, op1, op2);
      else
	ret = fold (expr);
      *maybe_const_operands &= op0_const;
      *maybe_const_itself &= op0_const_self;
      if (!(flag_isoc99
	    && op0_const
	    && op0_const_self
	    && op0 == truthvalue_false_node))
	*maybe_const_operands &= op1_const;
      if (!(op0_const
	    && op0_const_self
	    && op0 == truthvalue_false_node))
	*maybe_const_itself &= op1_const_self;
      if (!(flag_isoc99
	    && op0_const
	    && op0_const_self
	    && op0 == truthvalue_true_node))
	*maybe_const_operands &= op2_const;
      if (!(op0_const
	    && op0_const_self
	    && op0 == truthvalue_true_node))
	*maybe_const_itself &= op2_const_self;
      goto out;

    case VEC_COND_EXPR:
      orig_op0 = op0 = TREE_OPERAND (expr, 0);
      orig_op1 = op1 = TREE_OPERAND (expr, 1);
      orig_op2 = op2 = TREE_OPERAND (expr, 2);
      op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
				   maybe_const_itself, for_int_const);
      STRIP_TYPE_NOPS (op0);
      op1 = c_fully_fold_internal (op1, in_init, maybe_const_operands,
				   maybe_const_itself, for_int_const);
      STRIP_TYPE_NOPS (op1);
      op2 = c_fully_fold_internal (op2, in_init, maybe_const_operands,
				   maybe_const_itself, for_int_const);
      STRIP_TYPE_NOPS (op2);

      if (op0 != orig_op0 || op1 != orig_op1 || op2 != orig_op2)
	ret = fold_build3_loc (loc, code, TREE_TYPE (expr), op0, op1, op2);
      else
	ret = fold (expr);
      goto out;

    case EXCESS_PRECISION_EXPR:
      /* Each case where an operand with excess precision may be
	 encountered must remove the EXCESS_PRECISION_EXPR around
	 inner operands and possibly put one around the whole
	 expression or possibly convert to the semantic type (which
	 c_fully_fold does); we cannot tell at this stage which is
	 appropriate in any particular case.  */
      gcc_unreachable ();

    default:
      /* Various codes may appear through folding built-in functions
	 and their arguments.  */
      goto out;
    }

 out:
  /* Some folding may introduce NON_LVALUE_EXPRs; all lvalue checks
     have been done by this point, so remove them again.  */
  nowarning |= TREE_NO_WARNING (ret);
  STRIP_TYPE_NOPS (ret);
  if (nowarning && !TREE_NO_WARNING (ret))
    {
      if (!CAN_HAVE_LOCATION_P (ret))
	ret = build1 (NOP_EXPR, TREE_TYPE (ret), ret);
      TREE_NO_WARNING (ret) = 1;
    }
  if (ret != expr)
    {
      protected_set_expr_location (ret, loc);
      if (IS_EXPR_CODE_CLASS (kind))
	set_source_range (ret, old_range.m_start, old_range.m_finish);
    }
  return ret;
}