NULL_TREE, 0));
e3 = PFN_FROM_PTRMEMFUNC (function);
- if (TYPE_SIZE (basetype) != NULL_TREE
- && ! TYPE_VIRTUAL_P (basetype))
- /* If basetype doesn't have virtual functions, don't emit code to
- handle that case. */
- e1 = e3;
- else
+ /* This used to avoid checking for virtual functions if basetype
+ has no virtual functions, according to an earlier ANSI draft.
+ With the final ISO C++ rules, such an optimization is
+ incorrect: A pointer to a derived member can be static_cast
+ to pointer-to-base-member, as long as the dynamic object
+ later has the right member. */
+
+ /* Promoting idx before saving it improves performance on RISC
+ targets. Without promoting, the first compare used
+ load-with-sign-extend, while the second used normal load then
+ shift to sign-extend. An optimizer flaw, perhaps, but it's
+ easier to make this change. */
+ idx = save_expr (default_conversion
+ (build_component_ref (function,
+ index_identifier,
+ NULL_TREE, 0)));
+ e1 = build_binary_op (GE_EXPR, idx, integer_zero_node);
+
+ /* Convert down to the right base, before using the instance. */
+ instance = convert_pointer_to_real (basetype, instance_ptr);
+ if (instance == error_mark_node && instance_ptr != error_mark_node)
+ return instance;
+
+ vtbl = convert_pointer_to (ptr_type_node, instance);
+ delta2 = DELTA2_FROM_PTRMEMFUNC (function);
+ vtbl = build
+ (PLUS_EXPR,
+ build_pointer_type (build_pointer_type (vtable_entry_type)),
+ vtbl, cp_convert (ptrdiff_type_node, delta2));
+ vtbl = build_indirect_ref (vtbl, NULL_PTR);
+ aref = build_array_ref (vtbl, build_binary_op (MINUS_EXPR,
+ idx,
+ integer_one_node));
+ if (! flag_vtable_thunks)
{
- /* Promoting idx before saving it improves performance on RISC
- targets. Without promoting, the first compare used
- load-with-sign-extend, while the second used normal load then
- shift to sign-extend. An optimizer flaw, perhaps, but it's
- easier to make this change. */
- idx = save_expr (default_conversion
- (build_component_ref (function,
- index_identifier,
- NULL_TREE, 0)));
- e1 = build_binary_op (GE_EXPR, idx, integer_zero_node);
-
- /* Convert down to the right base, before using the instance. */
- instance = convert_pointer_to_real (basetype, instance_ptr);
- if (instance == error_mark_node && instance_ptr != error_mark_node)
- return instance;
-
- vtbl = convert_pointer_to (ptr_type_node, instance);
- delta2 = DELTA2_FROM_PTRMEMFUNC (function);
- vtbl = build
+ aref = save_expr (aref);
+
+ delta = build_binary_op
(PLUS_EXPR,
- build_pointer_type (build_pointer_type (vtable_entry_type)),
- vtbl, cp_convert (ptrdiff_type_node, delta2));
- vtbl = build_indirect_ref (vtbl, NULL_PTR);
- aref = build_array_ref (vtbl, build_binary_op (MINUS_EXPR,
- idx,
- integer_one_node));
- if (! flag_vtable_thunks)
- {
- aref = save_expr (aref);
-
- delta = build_binary_op
- (PLUS_EXPR,
- build_conditional_expr (e1,
- build_component_ref (aref,
- delta_identifier,
- NULL_TREE, 0),
- integer_zero_node),
- delta);
- }
-
- if (flag_vtable_thunks)
- e2 = aref;
- else
- e2 = build_component_ref (aref, pfn_identifier, NULL_TREE, 0);
- TREE_TYPE (e2) = TREE_TYPE (e3);
- e1 = build_conditional_expr (e1, e2, e3);
-
- /* Make sure this doesn't get evaluated first inside one of the
- branches of the COND_EXPR. */
- if (TREE_CODE (instance_ptr) == SAVE_EXPR)
- e1 = build (COMPOUND_EXPR, TREE_TYPE (e1),
- instance_ptr, e1);
+ build_conditional_expr (e1,
+ build_component_ref (aref,
+ delta_identifier,
+ NULL_TREE, 0),
+ integer_zero_node),
+ delta);
}
+ if (flag_vtable_thunks)
+ e2 = aref;
+ else
+ e2 = build_component_ref (aref, pfn_identifier, NULL_TREE, 0);
+ TREE_TYPE (e2) = TREE_TYPE (e3);
+ e1 = build_conditional_expr (e1, e2, e3);
+
+ /* Make sure this doesn't get evaluated first inside one of the
+ branches of the COND_EXPR. */
+ if (TREE_CODE (instance_ptr) == SAVE_EXPR)
+ e1 = build (COMPOUND_EXPR, TREE_TYPE (e1),
+ instance_ptr, e1);
+
*instance_ptrptr = build (PLUS_EXPR, TREE_TYPE (instance_ptr),
instance_ptr, delta);