+/*
+ * bechordal_common.c
+ *
+ * Created on: Nov 11, 2009
+ * Author: bersch
+ */
+
+#include "config.h"
+#include "debug.h"
+
+#include "iredges.h"
+#include "bitset.h"
+
+#include "bechordal.h"
+#include "bechordal_t.h"
+#include "beirgmod.h"
+#include "beinsn_t.h"
+#include "besched.h"
+#include "bestatevent.h"
+#include "benode.h"
+#include "bemodule.h"
+#include "belive.h"
+#include "belive_t.h"
+#include "fourcc.h"
+
+DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
+
+/* Make a fourcc for border checking. */
+#define BORDER_FOURCC FOURCC('B', 'O', 'R', 'D')
+
+
+/**
+ * Check, if an irn is of the register class currently under processing.
+ * @param env The chordal environment.
+ * @param irn The node.
+ * @return 1, if the node is of that register class, 0 if not.
+ */
+inline int has_reg_class(const be_chordal_env_t *env, const ir_node *irn)
+{
+ return arch_irn_consider_in_reg_alloc(env->cls, irn);
+}
+
+/**
+ * Add an interval border to the list of a block's list
+ * of interval border.
+ * @note You always have to create the use before the def.
+ * @param env The environment.
+ * @param head The list head to enqueue the borders.
+ * @param irn The node (value) the border belongs to.
+ * @param pressure The pressure at this point in time.
+ * @param step A time step for the border.
+ * @param is_def Is the border a use or a def.
+ * @return The created border.
+ */
+static inline border_t *border_add(be_chordal_env_t *env, struct list_head *head,
+ ir_node *irn, unsigned step, unsigned pressure,
+ unsigned is_def, unsigned is_real)
+{
+ border_t *b;
+
+ if (!is_def) {
+ border_t *def;
+
+ b = OALLOC(env->obst, border_t);
+
+ /* also allocate the def and tie it to the use. */
+ def = OALLOCZ(env->obst, border_t);
+ b->other_end = def;
+ def->other_end = b;
+
+ /*
+ * Set the link field of the irn to the def.
+ * This strongly relies on the fact, that the use is always
+ * made before the def.
+ */
+ set_irn_link(irn, def);
+
+ DEBUG_ONLY(b->magic = BORDER_FOURCC);
+ DEBUG_ONLY(def->magic = BORDER_FOURCC);
+ } else {
+ /*
+ * If the def is encountered, the use was made and so was the
+ * the def node (see the code above). It was placed into the
+ * link field of the irn, so we can get it there.
+ */
+ b = get_irn_link(irn);
+
+ DEBUG_ONLY(assert(b && b->magic == BORDER_FOURCC && "Illegal border encountered"));
+ }
+
+ b->pressure = pressure;
+ b->is_def = is_def;
+ b->is_real = is_real;
+ b->irn = irn;
+ b->step = step;
+ list_add_tail(&b->list, head);
+ DBG((dbg, LEVEL_5, "\t\t%s adding %+F, step: %d\n", is_def ? "def" : "use", irn, step));
+
+
+ return b;
+}
+
+/**
+ * Annotate the register pressure to the nodes and compute
+ * the liveness intervals.
+ * @param block The block to do it for.
+ * @param env_ptr The environment.
+ */
+void pressure(ir_node *block, void *env_ptr)
+{
+/* Convenience macro for a def */
+#define border_def(irn, step, real) \
+ border_add(env, head, irn, step, pressure--, 1, real)
+
+/* Convenience macro for a use */
+#define border_use(irn, step, real) \
+ border_add(env, head, irn, step, ++pressure, 0, real)
+
+ be_chordal_env_t *env = env_ptr;
+ bitset_t *live = bitset_malloc(get_irg_last_idx(env->irg));
+ ir_node *irn;
+ be_lv_t *lv = env->birg->lv;
+
+ int i, n;
+ bitset_pos_t elm;
+ unsigned step = 0;
+ unsigned pressure = 0;
+ struct list_head *head;
+
+ bitset_clear_all(live);
+
+ /* Set up the border list in the block info */
+ head = OALLOC(env->obst, struct list_head);
+ INIT_LIST_HEAD(head);
+ assert(pmap_get(env->border_heads, block) == NULL);
+ pmap_insert(env->border_heads, block, head);
+
+ /*
+ * Make final uses of all values live out of the block.
+ * They are necessary to build up real intervals.
+ */
+ be_lv_foreach(lv, block, be_lv_state_end, i) {
+ ir_node *irn = be_lv_get_irn(lv, block, i);
+ if (has_reg_class(env, irn)) {
+ DBG((dbg, LEVEL_3, "\tMaking live: %+F/%d\n", irn, get_irn_idx(irn)));
+ bitset_set(live, get_irn_idx(irn));
+ border_use(irn, step, 0);
+ }
+ }
+ ++step;
+
+ /*
+ * Determine the last uses of a value inside the block, since they are
+ * relevant for the interval borders.
+ */
+ sched_foreach_reverse(block, irn) {
+ DBG((dbg, LEVEL_1, "\tinsn: %+F, pressure: %d\n", irn, pressure));
+ DBG((dbg, LEVEL_2, "\tlive: %B\n", live));
+
+ if (get_irn_mode(irn) == mode_T) {
+ const ir_edge_t *edge;
+
+ foreach_out_edge(irn, edge) {
+ ir_node *proj = get_edge_src_irn(edge);
+
+ /*
+ * If the node defines some value, which can put into a
+ * register of the current class, make a border for it.
+ */
+ if (has_reg_class(env, proj)) {
+ int nr = get_irn_idx(proj);
+
+ bitset_clear(live, nr);
+ border_def(proj, step, 1);
+ }
+ }
+ } else {
+ /*
+ * If the node defines some value, which can put into a
+ * register of the current class, make a border for it.
+ */
+ if (has_reg_class(env, irn)) {
+ int nr = get_irn_idx(irn);
+
+ bitset_clear(live, nr);
+ border_def(irn, step, 1);
+ }
+ }
+
+ /*
+ * If the node is no phi node we can examine the uses.
+ */
+ if (!is_Phi(irn)) {
+ for (i = 0, n = get_irn_arity(irn); i < n; ++i) {
+ ir_node *op = get_irn_n(irn, i);
+
+ if (has_reg_class(env, op)) {
+ int nr = get_irn_idx(op);
+ const char *msg = "-";
+
+ if (!bitset_is_set(live, nr)) {
+ border_use(op, step, 1);
+ bitset_set(live, nr);
+ msg = "X";
+ }
+
+ DBG((dbg, LEVEL_4, "\t\t%s pos: %d, use: %+F\n", msg, i, op));
+ }
+ }
+ }
+ ++step;
+ }
+
+ bitset_foreach(live, elm) {
+ ir_node *irn = get_idx_irn(env->irg, elm);
+ if (be_is_live_in(lv, block, irn))
+ border_def(irn, step, 0);
+ }
+
+ bitset_free(live);
+}
+
+
+be_insn_t *chordal_scan_insn(be_chordal_env_t *env, ir_node *irn)
+{
+ be_insn_env_t ie;
+
+ ie.ignore_colors = env->ignore_colors;
+ ie.obst = env->obst;
+ ie.cls = env->cls;
+ return be_scan_insn(&ie, irn);
+}
+
+ir_node *pre_process_constraints(be_chordal_env_t *env, be_insn_t **the_insn)
+{
+ be_insn_t *insn = *the_insn;
+ ir_node *perm = NULL;
+ bitset_t *out_constr = bitset_alloca(env->cls->n_regs);
+ const ir_edge_t *edge;
+ int i;
+
+ assert(insn->has_constraints && "only do this for constrained nodes");
+
+ /*
+ * Collect all registers that occur in output constraints.
+ * This is necessary, since if the insn has one of these as an input constraint
+ * and the corresponding operand interferes with the insn, the operand must
+ * be copied.
+ */
+ for (i = 0; i < insn->use_start; ++i) {
+ be_operand_t *op = &insn->ops[i];
+ if (op->has_constraints)
+ bitset_or(out_constr, op->regs);
+ }
+
+ /*
+ * Make the Perm, recompute liveness and re-scan the insn since the
+ * in operands are now the Projs of the Perm.
+ */
+ perm = insert_Perm_after(env->birg, env->cls, sched_prev(insn->irn));
+
+ /* Registers are propagated by insert_Perm_after(). Clean them here! */
+ if (perm == NULL)
+ return NULL;
+
+ be_stat_ev("constr_perm", get_irn_arity(perm));
+ foreach_out_edge(perm, edge) {
+ ir_node *proj = get_edge_src_irn(edge);
+ arch_set_irn_register(proj, NULL);
+ }
+
+ /*
+ * We also have to re-build the insn since the input operands are now the Projs of
+ * the Perm. Recomputing liveness is also a good idea if a Perm is inserted, since
+ * the live sets may change.
+ */
+ obstack_free(env->obst, insn);
+ *the_insn = insn = chordal_scan_insn(env, insn->irn);
+
+ /*
+ * Copy the input constraints of the insn to the Perm as output
+ * constraints. Succeeding phases (coalescing) will need that.
+ */
+ for (i = insn->use_start; i < insn->n_ops; ++i) {
+ be_operand_t *op = &insn->ops[i];
+ ir_node *proj = op->carrier;
+ /*
+ * Note that the predecessor must not be a Proj of the Perm,
+ * since ignore-nodes are not Perm'ed.
+ */
+ if (op->has_constraints && is_Proj(proj) && get_Proj_pred(proj) == perm) {
+ be_set_constr_out(perm, get_Proj_proj(proj), op->req);
+ }
+ }
+
+ return perm;
+}
+
+void be_init_chordal_common(void)
+{
+ FIRM_DBG_REGISTER(dbg, "firm.be.chordal_common");
+}
+
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_chordal_common);