+ codec_env_t env;
+ int res;
+
+ env.buf = buf;
+ env.curr_id = 1; /* 0 is used for special purpose */
+ env.options = status->options;
+ env.dmp = NULL;
+
+ if (env.options & OPT_ENC_DAG)
+ env.id_set = new_set(addr_cmp, 32);
+ else
+ env.id_set = NULL;
+
+ /* encode options if any */
+ if (env.options) {
+ put_tag(buf, VLC_TAG_OPTION);
+ put_code(buf, env.options);
+ }
+
+ res = _encode_node(node, max_depth, &env);
+
+ if (env.options & OPT_ENC_DAG)
+ del_set(env.id_set);
+
+ return max_depth - res;
+}
+
+/**
+ * decode an IR-node, recursive walker
+ */
+static void _decode_node(unsigned parent, int position, codec_env_t *env)
+{
+ unsigned code;
+ unsigned op_code;
+ unsigned mode_code = 0;
+ long iconst;
+ void *attr = NULL;
+
+ code = next_tag(env->buf);
+ if (code == VLC_TAG_REF) { /* it's a REF */
+ code = get_code(env->buf);
+
+ /* dump the edge */
+ if (parent) {
+ int edge_mode = 0;
+ /*
+ * the mode of a Firm edge can be either computed from its target or
+ * from its source and position. We must take the second approach because
+ * we dont know the target here, it's a ref.
+ */
+ pattern_dump_edge(env->dmp, code, parent, position, edge_mode);
+ }
+
+ /* dump the node ref */
+ pattern_dump_ref(env->dmp, code);
+
+ return;
+ }
+
+ /* get the opcode */
+ op_code = get_code(env->buf);
+
+ /* get the mode if encoded */
+ if (env->options & OPT_WITH_MODE) {
+ if (next_tag(env->buf) != VLC_TAG_EMPTY) {
+ mode_code = get_code(env->buf);
+ }
+ }
+
+ /* check, if a ICONST attribute is given */
+ if (next_tag(env->buf) == VLC_TAG_ICONST) {
+ iconst = get_code(env->buf);
+ attr = &iconst;
+ }
+
+ /* dump the edge */
+ if (parent) {
+ int edge_mode = 0;
+
+ /*
+ * the mode of a Firm edge can be either computed from its target or
+ * from its source and position. We take the second approach because
+ * we need it anyway for ref's.
+ */
+ pattern_dump_edge(env->dmp, env->curr_id, parent, position, edge_mode);
+ }
+
+ /* dump the node */
+ parent = env->curr_id;
+ pattern_dump_node(env->dmp, parent, op_code, mode_code, attr);
+
+ /* ok, we have a new ID */
+ ++env->curr_id;
+
+ code = next_tag(env->buf);
+ if (code != VLC_TAG_END) {
+ /* more info, do recursion */
+ int i, preds;
+
+ preds = get_code(env->buf);
+ if (preds > 0) {
+ pattern_start_children(env->dmp, parent);
+ for (i = 0; i < preds; ++i) {
+ _decode_node(parent, i, env);
+ }
+ pattern_finish_children(env->dmp, parent);
+ }
+ }
+}
+
+/**
+ * decode an IR-node
+ */
+static void decode_node(BYTE *b, unsigned len, pattern_dumper_t *dump)
+{
+ codec_env_t env;
+ CODE_BUFFER buf;
+ unsigned code, options = 0;
+
+ init_buf(&buf, b, len);
+
+ env.buf = &buf;
+ env.curr_id = 1; /* 0 is used for special purpose */
+ env.dmp = dump;
+
+ /* decode options */
+ code = next_tag(&buf);
+ if (code == VLC_TAG_OPTION) {
+ options = get_code(&buf);
+ }
+ env.options = options;
+
+ _decode_node(0, 0, &env);
+}
+
+/**
+ * the environment for the pattern calculation
+ */
+typedef struct _pattern_env {
+ int max_depth; /**< maximum depth for pattern generation */
+} pattern_env_t;
+
+/**
+ * Returns the associates pattern_entry_t for a CODE_BUF
+ *
+ * @param buf the code buffer
+ * @param set the hash table containing all pattern entries
+ */
+static pattern_entry_t *pattern_get_entry(CODE_BUFFER *buf, pset *set)
+{
+ pattern_entry_t *key, *elem;
+ unsigned len = buf_lenght(buf);
+ unsigned hash;
+
+ key = obstack_alloc(&status->obst, sizeof(*key) + len - 1);
+ assert(key);
+
+ key->len = len;
+ memcpy(key->buf, buf_content(buf), len);
+
+ hash = buf_hash(buf);
+
+ elem = pset_find(set, key, hash);
+ if (elem) {
+ obstack_free(&status->obst, key);
+ return elem;
+ }
+
+ cnt_clr(&key->count);
+ return pset_insert(set, key, hash);
+}
+
+/**
+ * count a pattern
+ */
+static void count_pattern(CODE_BUFFER *buf, int depth) {
+ pattern_entry_t *entry;
+
+ /* ignore single node pattern (i.e. constants) */
+ if (depth > 1) {
+ entry = pattern_get_entry(buf, status->pattern_hash);
+
+ /* increase count */
+ cnt_inc(&entry->count);
+ }
+}
+
+/**
+ * pre-walker for nodes pattern calculation
+ */
+static void calc_nodes_pattern(ir_node *node, void *ctx)
+{
+ BYTE buffer[1024];
+ pattern_env_t *env = ctx;
+ CODE_BUFFER buf;
+ int depth;
+
+ init_buf(&buf, buffer, sizeof(buffer));
+ depth = encode_node(node, &buf, env->max_depth);
+
+ count_pattern(&buf, depth);
+}
+
+/**
+ * output the collected pattern
+ */
+static void pattern_output(void)
+{
+ pattern_entry_t *entry;
+ pattern_entry_t **pattern_arr;
+ pattern_dumper_t *dump;
+ int i, count = pset_count(status->pattern_hash);
+
+ printf("\n%d pattern detected\n", count);
+
+ if (count <= 0)
+ return;
+
+ /* creates a dumper */
+ dump = new_vcg_dumper("pattern.vcg", 100);
+
+ pattern_arr = xmalloc(sizeof(*pattern_arr) * count);
+ for (i = 0, entry = pset_first(status->pattern_hash);
+ entry && i < count;
+ entry = pset_next(status->pattern_hash), ++i) {
+ pattern_arr[i] = entry;
+ }
+ assert(count == i);
+ count = i;
+
+ /* sort it */
+ qsort(pattern_arr, count, sizeof(*pattern_arr), pattern_count_cmp);
+
+ for (i = 0; i < count; ++i) {
+ entry = pattern_arr[i];
+ if (entry->count.cnt[0] < status->bound)
+ continue;
+
+ /* dump a pattern */
+ pattern_dump_new_pattern(dump, &entry->count);
+ decode_node(entry->buf, entry->len, dump);
+ pattern_dump_finish_pattern(dump);
+ }
+
+ /* destroy it */
+ pattern_end(dump);
+}
+
+/*
+ * calculates the pattern history
+ */
+void stat_calc_pattern_history(ir_graph *irg)
+{
+ pattern_env_t env;
+
+ if (! status->enable)
+ return;
+
+ /* do NOT count the const code IRG */
+ if (irg == get_const_code_irg())
+ return;
+
+ env.max_depth = 5;
+ irg_walk_graph(irg, calc_nodes_pattern, NULL, &env);
+}
+
+/*
+ * initializes the pattern history
+ */
+void stat_init_pattern_history(int enable)
+{
+ status->enable = enable;
+ if (! enable)
+ return;
+
+ status->bound = 10;
+ status->options = OPT_WITH_MODE | OPT_ENC_DAG | OPT_WITH_ICONST;
+
+ obstack_init(&status->obst);
+
+ /* create the hash-table */
+ status->pattern_hash = new_pset(pattern_cmp, 8);
+}
+
+/*
+ * finishes the pattern history
+ */
+void stat_finish_pattern_history(void)
+{
+ if (! status->enable)
+ return;
+
+ pattern_output();
+
+ del_pset(status->pattern_hash);
+ obstack_free(&status->obst, NULL);
+
+ status->enable = 0;