initial copyb lowerer

[r17989]

ir/lower/lower_copyb.c

+/*
+ * Copyright (C) 1995-2007 University of Karlsruhe.  All right reserved.
+ *
+ * This file is part of libFirm.
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE.
+ */
+
+/**
+ * @file
+ * @brief   Lower small CopyB nodes into a series of Load/store
+ * @author  Michael Beck
+ * @version $Id$
+ */
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include "ircons.h"
+#include "lowering.h"
+#include "irprog_t.h"
+#include "irnode_t.h"
+#include "type_t.h"
+#include "irtools.h"
+
+typedef struct copyb_env {
+	ir_node *next;      /**< link to the next one */
+} copyb_env;
+
+
+typedef struct walker_env {
+	struct obstack obst;      /**< temporary space */
+	int            max_size;
+	ir_node        *list;     /**< list of CopyB nodes. */
+} walker_env;
+
+/**
+ * Build a graph that copies an entity of type tp from src to tgt
+ */
+static ir_node *build_copy_graph(dbg_info *dbg, ir_node *blk, ir_node *mem, ir_node *src, ir_node *tgt, ir_type *tp) {
+	int i, n;
+
+	if (is_Array_type(tp)) {
+		assert(0);
+	} else {
+		for (i = 0, n = get_compound_n_members(tp); i < n; ++i) {
+			ir_entity *ent  = get_compound_member(tp, i);
+			ir_node *s      = new_d_simpleSel(dbg, mem, src, ent);
+			ir_node *d      = new_d_simpleSel(dbg, mem, tgt, ent);
+			ir_type *ent_tp = get_entity_type(ent);
+
+			if (is_atomic_type(ent_tp)) {
+				ir_mode *mode = get_type_mode(ent_tp);
+				ir_node *irn  = new_rd_Load(dbg, current_ir_graph, blk, mem, s, mode);
+				ir_node *res  = new_r_Proj(current_ir_graph, blk, irn, mode, pn_Load_res);
+
+				mem = new_r_Proj(current_ir_graph, blk, irn, mode_M, pn_Load_M);
+				irn = new_rd_Store(dbg, current_ir_graph, blk, mem, d, res);
+				mem = new_r_Proj(current_ir_graph, blk, irn, mode_M, pn_Store_M);
+			} else {
+				mem = build_copy_graph(dbg, blk, mem, s, d, ent_tp);
+			}
+		}
+	}
+	return mem;
+}
+
+/**
+ * Walker: lower small CopyB nodes.
+ */
+static void lower_copyb_nodes(ir_node *irn, void *ctx) {
+	ir_type    *tp;
+	int        size;
+	walker_env *env = ctx;
+
+	if (! is_CopyB(irn))
+		return;
+
+	tp = get_CopyB_type(irn);
+	if (get_type_state(tp) != layout_fixed)
+		return;
+
+	size = get_type_size_bytes(tp);
+	if (size > env->max_size)
+		return;
+
+	/* for now, we can only handle Struct's */
+	if (is_Struct_type(tp)) {
+		irn = build_copy_graph(get_irn_dbg_info(irn), get_nodes_block(irn), get_CopyB_mem(irn), get_CopyB_src(irn), get_CopyB_dst(irn), tp);
+	}
+}
+
+/**
+ * Lower CopyB nodes of size smaller that max_size into Loads/Stores
+ */
+void lower_CopyB(int max_size) {
+	walker_env env;
+	int        i;
+
+	obstack_init(&env.obst);
+	env.max_size = max_size;
+	env.list     = NULL;
+	for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
+		irg_walk_graph(get_irp_irg(i), firm_clear_link, lower_copyb_nodes, NULL);
+	}
+}