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[src/trunk]: src/gnu/dist/gcc From the egcs development tree:
details: https://anonhg.NetBSD.org/src/rev/362895a23615
branches: trunk
changeset: 475010:362895a23615
user: mycroft <mycroft%NetBSD.org@localhost>
date: Thu Jul 29 09:09:18 1999 +0000
description:
>From the egcs development tree:
Fix problems with autoincrement/autodecrement caused by changes to the way
memcpy() calls are generated between egcs 1.1.1 and 1.1.2.
diffstat:
gnu/dist/gcc/expr.c | 186 +++++++++++++++++++++++++++++++++------------------
1 files changed, 121 insertions(+), 65 deletions(-)
diffs (223 lines):
diff -r 30a13e8b582b -r 362895a23615 gnu/dist/gcc/expr.c
--- a/gnu/dist/gcc/expr.c Thu Jul 29 08:58:46 1999 +0000
+++ b/gnu/dist/gcc/expr.c Thu Jul 29 09:09:18 1999 +0000
@@ -1694,6 +1694,37 @@
}
}
+ /* X, Y, or SIZE may have been passed through protect_from_queue.
+
+ It is unsafe to save the value generated by protect_from_queue
+ and reuse it later. Consider what happens if emit_queue is
+ called before the return value from protect_from_queue is used.
+
+ Expansion of the CALL_EXPR below will call emit_queue before
+ we are finished emitting RTL for argument setup. So if we are
+ not careful we could get the wrong value for an argument.
+
+ To avoid this problem we go ahead and emit code to copy X, Y &
+ SIZE into new pseudos. We can then place those new pseudos
+ into an RTL_EXPR and use them later, even after a call to
+ emit_queue.
+
+ Note this is not strictly needed for library calls since they
+ do not call emit_queue before loading their arguments. However,
+ we may need to have library calls call emit_queue in the future
+ since failing to do so could cause problems for targets which
+ define SMALL_REGISTER_CLASSES and pass arguments in registers. */
+ x = copy_to_mode_reg (Pmode, XEXP (x, 0));
+ y = copy_to_mode_reg (Pmode, XEXP (y, 0));
+
+#ifdef TARGET_MEM_FUNCTIONS
+ size = copy_to_mode_reg (TYPE_MODE (sizetype), size);
+#else
+ size = convert_to_mode (TYPE_MODE (integer_type_node), size,
+ TREE_UNSIGNED (integer_type_node));
+ size = copy_to_mode_reg (TYPE_MODE (integer_type_node), size);
+#endif
+
#ifdef TARGET_MEM_FUNCTIONS
/* It is incorrect to use the libcall calling conventions to call
memcpy in this context.
@@ -1732,12 +1763,10 @@
the last is a size_t byte count for the copy. */
arg_list
= build_tree_list (NULL_TREE,
- make_tree (build_pointer_type (void_type_node),
- XEXP (x, 0)));
+ make_tree (build_pointer_type (void_type_node), x));
TREE_CHAIN (arg_list)
= build_tree_list (NULL_TREE,
- make_tree (build_pointer_type (void_type_node),
- XEXP (y, 0)));
+ make_tree (build_pointer_type (void_type_node), y));
TREE_CHAIN (TREE_CHAIN (arg_list))
= build_tree_list (NULL_TREE, make_tree (sizetype, size));
TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (arg_list))) = NULL_TREE;
@@ -1751,8 +1780,7 @@
retval = expand_expr (call_expr, NULL_RTX, VOIDmode, 0);
#else
emit_library_call (bcopy_libfunc, 0,
- VOIDmode, 3, XEXP (y, 0), Pmode,
- XEXP (x, 0), Pmode,
+ VOIDmode, 3, y, Pmode, x, Pmode,
convert_to_mode (TYPE_MODE (integer_type_node), size,
TREE_UNSIGNED (integer_type_node)),
TYPE_MODE (integer_type_node));
@@ -2330,69 +2358,97 @@
}
}
+ /* OBJECT or SIZE may have been passed through protect_from_queue.
+
+ It is unsafe to save the value generated by protect_from_queue
+ and reuse it later. Consider what happens if emit_queue is
+ called before the return value from protect_from_queue is used.
+
+ Expansion of the CALL_EXPR below will call emit_queue before
+ we are finished emitting RTL for argument setup. So if we are
+ not careful we could get the wrong value for an argument.
+
+ To avoid this problem we go ahead and emit code to copy OBJECT
+ and SIZE into new pseudos. We can then place those new pseudos
+ into an RTL_EXPR and use them later, even after a call to
+ emit_queue.
+
+ Note this is not strictly needed for library calls since they
+ do not call emit_queue before loading their arguments. However,
+ we may need to have library calls call emit_queue in the future
+ since failing to do so could cause problems for targets which
+ define SMALL_REGISTER_CLASSES and pass arguments in registers. */
+ object = copy_to_mode_reg (Pmode, XEXP (object, 0));
+
+#ifdef TARGET_MEM_FUNCTIONS
+ size = copy_to_mode_reg (TYPE_MODE (sizetype), size);
+#else
+ size = convert_to_mode (TYPE_MODE (integer_type_node), size,
+ TREE_UNSIGNED (integer_type_node));
+ size = copy_to_mode_reg (TYPE_MODE (integer_type_node), size);
+#endif
+
#ifdef TARGET_MEM_FUNCTIONS
- /* It is incorrect to use the libcall calling conventions to call
- memset in this context.
-
- This could be a user call to memset and the user may wish to
- examine the return value from memset.
-
- For targets where libcalls and normal calls have different conventions
- for returning pointers, we could end up generating incorrect code.
-
- So instead of using a libcall sequence we build up a suitable
- CALL_EXPR and expand the call in the normal fashion. */
- if (fn == NULL_TREE)
- {
- tree fntype;
-
- /* This was copied from except.c, I don't know if all this is
- necessary in this context or not. */
- fn = get_identifier ("memset");
- push_obstacks_nochange ();
- end_temporary_allocation ();
- fntype = build_pointer_type (void_type_node);
- fntype = build_function_type (fntype, NULL_TREE);
- fn = build_decl (FUNCTION_DECL, fn, fntype);
- DECL_EXTERNAL (fn) = 1;
- TREE_PUBLIC (fn) = 1;
- DECL_ARTIFICIAL (fn) = 1;
- make_decl_rtl (fn, NULL_PTR, 1);
- assemble_external (fn);
- pop_obstacks ();
- }
-
- /* We need to make an argument list for the function call.
-
- memset has three arguments, the first is a void * addresses, the
- second a integer with the initialization value, the last is a size_t
- byte count for the copy. */
- arg_list
- = build_tree_list (NULL_TREE,
- make_tree (build_pointer_type (void_type_node),
- XEXP (object, 0)));
- TREE_CHAIN (arg_list)
- = build_tree_list (NULL_TREE,
- make_tree (integer_type_node, const0_rtx));
- TREE_CHAIN (TREE_CHAIN (arg_list))
- = build_tree_list (NULL_TREE, make_tree (sizetype, size));
- TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (arg_list))) = NULL_TREE;
-
- /* Now we have to build up the CALL_EXPR itself. */
- call_expr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (fn)), fn);
- call_expr = build (CALL_EXPR, TREE_TYPE (TREE_TYPE (fn)),
- call_expr, arg_list, NULL_TREE);
- TREE_SIDE_EFFECTS (call_expr) = 1;
-
- retval = expand_expr (call_expr, NULL_RTX, VOIDmode, 0);
+ /* It is incorrect to use the libcall calling conventions to call
+ memset in this context.
+
+ This could be a user call to memset and the user may wish to
+ examine the return value from memset.
+
+ For targets where libcalls and normal calls have different
+ conventions for returning pointers, we could end up generating
+ incorrect code.
+
+ So instead of using a libcall sequence we build up a suitable
+ CALL_EXPR and expand the call in the normal fashion. */
+ if (fn == NULL_TREE)
+ {
+ tree fntype;
+
+ /* This was copied from except.c, I don't know if all this is
+ necessary in this context or not. */
+ fn = get_identifier ("memset");
+ push_obstacks_nochange ();
+ end_temporary_allocation ();
+ fntype = build_pointer_type (void_type_node);
+ fntype = build_function_type (fntype, NULL_TREE);
+ fn = build_decl (FUNCTION_DECL, fn, fntype);
+ DECL_EXTERNAL (fn) = 1;
+ TREE_PUBLIC (fn) = 1;
+ DECL_ARTIFICIAL (fn) = 1;
+ make_decl_rtl (fn, NULL_PTR, 1);
+ assemble_external (fn);
+ pop_obstacks ();
+ }
+
+ /* We need to make an argument list for the function call.
+
+ memset has three arguments, the first is a void * addresses, the
+ second a integer with the initialization value, the last is a
+ size_t byte count for the copy. */
+ arg_list
+ = build_tree_list (NULL_TREE,
+ make_tree (build_pointer_type (void_type_node),
+ object));
+ TREE_CHAIN (arg_list)
+ = build_tree_list (NULL_TREE,
+ make_tree (integer_type_node, const0_rtx));
+ TREE_CHAIN (TREE_CHAIN (arg_list))
+ = build_tree_list (NULL_TREE, make_tree (sizetype, size));
+ TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (arg_list))) = NULL_TREE;
+
+ /* Now we have to build up the CALL_EXPR itself. */
+ call_expr = build1 (ADDR_EXPR,
+ build_pointer_type (TREE_TYPE (fn)), fn);
+ call_expr = build (CALL_EXPR, TREE_TYPE (TREE_TYPE (fn)),
+ call_expr, arg_list, NULL_TREE);
+ TREE_SIDE_EFFECTS (call_expr) = 1;
+
+ retval = expand_expr (call_expr, NULL_RTX, VOIDmode, 0);
#else
emit_library_call (bzero_libfunc, 0,
- VOIDmode, 2,
- XEXP (object, 0), Pmode,
- convert_to_mode
- (TYPE_MODE (integer_type_node), size,
- TREE_UNSIGNED (integer_type_node)),
+ VOIDmode, 2, object, Pmode, size,
TYPE_MODE (integer_type_node));
#endif
}
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