+/*
+ * Copyright (C) 1995-2008 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 restarting SSA construction for values.
+ * @author Michael Beck
+ * @version $Id$
+ */
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include "ircons_t.h"
+#include "irgraph_t.h"
+#include "irnode_t.h"
+#include "irgwalk.h"
+
+typedef struct walk_env_t {
+ int n_loc; /**< Number of newly allocated locations. */
+} walk_env;
+
+/**
+ * Post-walker: prepare the graph nodes for new SSA construction cycle by allocation
+ * new arrays.
+ */
+static void prepare_nodes(ir_node *irn, void *ctx) {
+ walk_env *env = ctx;
+
+ switch (get_irn_opcode(irn)) {
+ case iro_Block:
+ /* reset mature flag */
+ irn->attr.block.is_matured = 0;
+ irn->attr.block.graph_arr = NEW_ARR_D(ir_node *, current_ir_graph->obst,
+ current_ir_graph->n_loc);
+ memset(irn->attr.block.graph_arr, 0, sizeof(ir_node *) * current_ir_graph->n_loc);
+ irn->attr.block.phis = NULL;
+ break;
+#if PRECISE_EXC_CONTEXT
+ /* note that the frag array must be cleared first, else firm_alloc_frag_arr()
+ will not allocate new memory. */
+ case iro_Quot:
+ irn->attr.except.frag_arr = NULL;
+ firm_alloc_frag_arr(irn, op_Quot, &irn->attr.except.frag_arr);
+ break;
+ case iro_DivMod:
+ irn->attr.except.frag_arr = NULL;
+ firm_alloc_frag_arr(irn, op_DivMod, &irn->attr.except.frag_arr);
+ break;
+ case iro_Div:
+ irn->attr.except.frag_arr = NULL;
+ firm_alloc_frag_arr(irn, op_Div, &irn->attr.except.frag_arr);
+ break;
+ case iro_Mod:
+ irn->attr.except.frag_arr = NULL;
+ firm_alloc_frag_arr(irn, op_Mod, &irn->attr.except.frag_arr);
+ break;
+ case iro_Call:
+ irn->attr.call.exc.frag_arr = NULL;
+ firm_alloc_frag_arr(irn, op_Call, &irn->attr.call.exc.frag_arr);
+ break;
+ case iro_Load:
+ irn->attr.load.exc.frag_arr = NULL;
+ firm_alloc_frag_arr(irn, op_Load, &irn->attr.load.exc.frag_arr);
+ break;
+ case iro_Store:
+ irn->attr.store.exc.frag_arr = NULL;
+ firm_alloc_frag_arr(irn, op_Store, &irn->attr.store.exc.frag_arr);
+ break;
+ case iro_Alloc:
+ irn->attr.alloc.exc.frag_arr = NULL;
+ firm_alloc_frag_arr(irn, op_Alloc, &irn->attr.alloc.exc.frag_arr);
+ break;
+ case iro_CopyB:
+ irn->attr.copyb.exc.frag_arr = NULL;
+ firm_alloc_frag_arr(irn, op_CopyB, &irn->attr.copyb.exc.frag_arr);
+ break;
+ case iro_Raise:
+ irn->attr.bound.exc.frag_arr = NULL;
+ firm_alloc_frag_arr(irn, op_Bound, &irn->attr.bound.exc.frag_arr);
+ break;
+#endif
+ default:
+ ;
+ }
+}
+
+/*
+ * Restarts SSA construction on the given graph with n_loc
+ * new values.
+ *
+ * @param irg the graph on which the SSA construction is restarted
+ * @param n_loc number of new variables
+ *
+ * After this function is complete, the graph is in phase_building
+ * again and set_value()/get_value() and mature_block() can be used
+ * to construct new values.
+ */
+void ssa_cons_start(ir_graph *irg, int n_loc) {
+ walk_env env;
+
+ /* for now we support only phase_high graphs */
+ assert(irg->phase_state == phase_high);
+
+ /* reset the phase to phase building: some optimization might depend on it */
+ set_irg_phase_state(irg, phase_building);
+
+ irg_set_nloc(irg, n_loc);
+
+ /*
+ * Note: we could try to reuse existing frag arrays, but it does not
+ * seems worth to do this. First, we have to check if they really exists and
+ * then clear them. We do not expect SSA construction is used often.
+ */
+ irg_walk_graph(irg, NULL, prepare_nodes, &env);
+}
+
+/**
+ * mature all immature Blocks.
+ */
+static void finish_block(ir_node *block, void *env) {
+ if (!get_Block_matured(block))
+ mature_immBlock(block);
+}
+
+/*
+ * Finalize the (restarted) SSA construction. Matures all blocks that are
+ * not matured yet and reset the graph state to phase_high.
+ */
+void ssa_cons_finish(ir_graph *irg) {
+ irg_block_walk_graph(irg, NULL, finish_block, NULL);
+ irg_finalize_cons(irg);
+}