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expr.c (emit_block_move): Properly handle case where one of the block move arguments has a queued...
�
* expr.c (emit_block_move): Properly handle case where one of the
block move arguments has a queued increment or decrement.
(clear_storage): Similarly. Fix formatting goof.
From-SVN: r27822
This commit is contained in:
Jeff Law
parent
5dd2921918
commit
4bc973aedd
170
gcc/expr.c
170
gcc/expr.c
@ -1710,6 +1710,37 @@ emit_block_move (x, y, size, align)
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}
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}
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/* X, Y, or SIZE may have been passed through protect_from_queue.
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It is unsafe to save the value generated by protect_from_queue
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and reuse it later. Consider what happens if emit_queue is
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called before the return value from protect_from_queue is used.
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Expansion of the CALL_EXPR below will call emit_queue before
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we are finished emitting RTL for argument setup. So if we are
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not careful we could get the wrong value for an argument.
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To avoid this problem we go ahead and emit code to copy X, Y &
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SIZE into new pseudos. We can then place those new pseudos
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into an RTL_EXPR and use them later, even after a call to
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emit_queue.
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Note this is not strictly needed for library calls since they
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do not call emit_queue before loading their arguments. However,
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we may need to have library calls call emit_queue in the future
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since failing to do so could cause problems for targets which
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define SMALL_REGISTER_CLASSES and pass arguments in registers. */
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x = copy_to_mode_reg (Pmode, XEXP (x, 0));
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y = copy_to_mode_reg (Pmode, XEXP (y, 0));
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#ifdef TARGET_MEM_FUNCTIONS
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size = copy_to_mode_reg (TYPE_MODE (sizetype), size);
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#else
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size = convert_to_mode (TYPE_MODE (integer_type_node), size,
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TREE_UNSIGNED (integer_type_node));
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size = copy_to_reg (size);
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#endif
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#ifdef TARGET_MEM_FUNCTIONS
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/* It is incorrect to use the libcall calling conventions to call
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memcpy in this context.
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@ -1748,12 +1779,10 @@ emit_block_move (x, y, size, align)
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the last is a size_t byte count for the copy. */
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arg_list
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= build_tree_list (NULL_TREE,
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make_tree (build_pointer_type (void_type_node),
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XEXP (x, 0)));
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make_tree (build_pointer_type (void_type_node), x));
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TREE_CHAIN (arg_list)
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= build_tree_list (NULL_TREE,
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make_tree (build_pointer_type (void_type_node),
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XEXP (y, 0)));
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make_tree (build_pointer_type (void_type_node), y));
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TREE_CHAIN (TREE_CHAIN (arg_list))
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= build_tree_list (NULL_TREE, make_tree (sizetype, size));
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TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (arg_list))) = NULL_TREE;
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@ -1767,8 +1796,7 @@ emit_block_move (x, y, size, align)
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retval = expand_expr (call_expr, NULL_RTX, VOIDmode, 0);
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#else
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emit_library_call (bcopy_libfunc, 0,
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VOIDmode, 3, XEXP (y, 0), Pmode,
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XEXP (x, 0), Pmode,
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VOIDmode, 3, y, Pmode, x, Pmode
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convert_to_mode (TYPE_MODE (integer_type_node), size,
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TREE_UNSIGNED (integer_type_node)),
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TYPE_MODE (integer_type_node));
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@ -2444,69 +2472,97 @@ clear_storage (object, size, align)
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}
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}
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/* OBJECT or SIZE may have been passed through protect_from_queue.
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It is unsafe to save the value generated by protect_from_queue
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and reuse it later. Consider what happens if emit_queue is
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called before the return value from protect_from_queue is used.
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Expansion of the CALL_EXPR below will call emit_queue before
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we are finished emitting RTL for argument setup. So if we are
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not careful we could get the wrong value for an argument.
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To avoid this problem we go ahead and emit code to copy OBJECT
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and SIZE into new pseudos. We can then place those new pseudos
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into an RTL_EXPR and use them later, even after a call to
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emit_queue.
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Note this is not strictly needed for library calls since they
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do not call emit_queue before loading their arguments. However,
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we may need to have library calls call emit_queue in the future
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since failing to do so could cause problems for targets which
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define SMALL_REGISTER_CLASSES and pass arguments in registers. */
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object = copy_to_mode_reg (Pmode, XEXP (object, 0));
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#ifdef TARGET_MEM_FUNCTIONS
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/* It is incorrect to use the libcall calling conventions to call
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memset in this context.
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size = copy_to_mode_reg (TYPE_MODE (sizetype), size);
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#else
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size = convert_to_mode (TYPE_MODE (integer_type_node), size,
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TREE_UNSIGNED (integer_type_node));
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size = copy_to_reg (size);
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#endif
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This could be a user call to memset and the user may wish to
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examine the return value from memset.
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For targets where libcalls and normal calls have different conventions
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for returning pointers, we could end up generating incorrect code.
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#ifdef TARGET_MEM_FUNCTIONS
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/* It is incorrect to use the libcall calling conventions to call
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memset in this context.
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So instead of using a libcall sequence we build up a suitable
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CALL_EXPR and expand the call in the normal fashion. */
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if (fn == NULL_TREE)
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{
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tree fntype;
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This could be a user call to memset and the user may wish to
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examine the return value from memset.
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/* This was copied from except.c, I don't know if all this is
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necessary in this context or not. */
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fn = get_identifier ("memset");
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push_obstacks_nochange ();
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end_temporary_allocation ();
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fntype = build_pointer_type (void_type_node);
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fntype = build_function_type (fntype, NULL_TREE);
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fn = build_decl (FUNCTION_DECL, fn, fntype);
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DECL_EXTERNAL (fn) = 1;
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TREE_PUBLIC (fn) = 1;
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DECL_ARTIFICIAL (fn) = 1;
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make_decl_rtl (fn, NULL_PTR, 1);
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assemble_external (fn);
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pop_obstacks ();
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}
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For targets where libcalls and normal calls have different
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conventions for returning pointers, we could end up generating
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incorrect code.
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/* We need to make an argument list for the function call.
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So instead of using a libcall sequence we build up a suitable
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CALL_EXPR and expand the call in the normal fashion. */
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if (fn == NULL_TREE)
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{
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tree fntype;
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memset has three arguments, the first is a void * addresses, the
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second a integer with the initialization value, the last is a size_t
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byte count for the copy. */
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arg_list
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= build_tree_list (NULL_TREE,
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make_tree (build_pointer_type (void_type_node),
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XEXP (object, 0)));
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TREE_CHAIN (arg_list)
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= build_tree_list (NULL_TREE,
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make_tree (integer_type_node, const0_rtx));
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TREE_CHAIN (TREE_CHAIN (arg_list))
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= build_tree_list (NULL_TREE, make_tree (sizetype, size));
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TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (arg_list))) = NULL_TREE;
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/* This was copied from except.c, I don't know if all this is
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necessary in this context or not. */
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fn = get_identifier ("memset");
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push_obstacks_nochange ();
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end_temporary_allocation ();
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fntype = build_pointer_type (void_type_node);
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fntype = build_function_type (fntype, NULL_TREE);
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fn = build_decl (FUNCTION_DECL, fn, fntype);
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DECL_EXTERNAL (fn) = 1;
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TREE_PUBLIC (fn) = 1;
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DECL_ARTIFICIAL (fn) = 1;
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make_decl_rtl (fn, NULL_PTR, 1);
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assemble_external (fn);
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pop_obstacks ();
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}
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/* Now we have to build up the CALL_EXPR itself. */
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call_expr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (fn)), fn);
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call_expr = build (CALL_EXPR, TREE_TYPE (TREE_TYPE (fn)),
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call_expr, arg_list, NULL_TREE);
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TREE_SIDE_EFFECTS (call_expr) = 1;
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/* We need to make an argument list for the function call.
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retval = expand_expr (call_expr, NULL_RTX, VOIDmode, 0);
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memset has three arguments, the first is a void * addresses, the
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second a integer with the initialization value, the last is a
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size_t byte count for the copy. */
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arg_list
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= build_tree_list (NULL_TREE,
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make_tree (build_pointer_type (void_type_node),
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object));
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TREE_CHAIN (arg_list)
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= build_tree_list (NULL_TREE,
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make_tree (integer_type_node, const0_rtx));
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TREE_CHAIN (TREE_CHAIN (arg_list))
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= build_tree_list (NULL_TREE, make_tree (sizetype, size));
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TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (arg_list))) = NULL_TREE;
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/* Now we have to build up the CALL_EXPR itself. */
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call_expr = build1 (ADDR_EXPR,
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build_pointer_type (TREE_TYPE (fn)), fn);
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call_expr = build (CALL_EXPR, TREE_TYPE (TREE_TYPE (fn)),
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call_expr, arg_list, NULL_TREE);
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TREE_SIDE_EFFECTS (call_expr) = 1;
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retval = expand_expr (call_expr, NULL_RTX, VOIDmode, 0);
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#else
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emit_library_call (bzero_libfunc, 0,
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VOIDmode, 2,
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XEXP (object, 0), Pmode,
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convert_to_mode
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(TYPE_MODE (integer_type_node), size,
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TREE_UNSIGNED (integer_type_node)),
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VOIDmode, 2, object, Pmode, size
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TYPE_MODE (integer_type_node));
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#endif
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}
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