-/******************************************************************************
- _____ _____ _____ _
- / ____/ ____| /\ | __ \ | |
- | (___| (___ / \ ______| | | | ___ ___| |_ _ __
- \___ \\___ \ / /\ \______| | | |/ _ \/ __| __| '__|
- ____) |___) / ____ \ | |__| | __/\__ \ |_| |
- |_____/_____/_/ \_\ |_____/ \___||___/\__|_|
-
- *****************************************************************************/
-
-#define mark_as_done(irn, pos) set_irn_link(irn, INT_TO_PTR(pos+1))
-#define has_been_done(irn, pos) (PTR_TO_INT(get_irn_link(irn)) > pos)
-
-/**
- * Insert a copy for the argument of @p start_phi found at position @p pos.
- * Also searches a phi-loop of arbitrary length to detect and resolve
- * the class of phi-swap-problems. To search for a loop recursion is used.
- *
- * 1) Simplest case (phi with a non-phi arg):
- * A single copy is inserted.
- *
- * 2) Phi chain (phi (with phi-arg)* with non=phi arg):
- * Several copies are placed, each after returning from recursion.
- *
- * 3) Phi-loop:
- * On detection a loop breaker is inserted, which is a copy of the start_phi.
- * This copy then pretends beeing the argumnent of the last phi.
- * Now case 2) can be used.
- *
- * The values of @p start_phi and @p pos never change during recursion.
- *
- * @p raenv Environment with all the stuff needed
- * @p start_phi Phi node to process
- * @p pos Argument position to insert copy/copies for
- * @p curr_phi Phi node currently processed during recursion. Equals start_phi on initial call
- *
- * @return NULL If no copy is necessary
- * NULL If the phi has already been processed at this pos
- * Link field is used to keep track of processed positions
- * In all other cases the ir_node *copy which was placed is returned.
- */
-static ir_node *insert_copies(be_raext_env_t *raenv, ir_node *start_phi, int pos, ir_node *curr_phi) {
- ir_node *arg = get_irn_n(curr_phi, pos);
- ir_node *arg_blk = get_nodes_block(arg);
- ir_node *pred_blk = get_Block_cfgpred_block(get_nodes_block(curr_phi), pos);
- ir_node *curr_cpy, *last_cpy;
-
- assert(is_Phi(start_phi) && is_Phi(curr_phi));
-
- if (has_been_done(start_phi, pos))
- return NULL;
-
- /* In case this is a 'normal' phi we insert at the
- * end of the pred block before cf nodes */
- last_cpy = sched_skip(pred_blk, 0, sched_skip_cf_predicator, raenv->aenv);
- last_cpy = sched_next(last_cpy);
-
- /* If we detect a loop stop recursion. */
- if (arg == start_phi) {
- ir_node *loop_breaker;
- if (start_phi == curr_phi) {
- /* Phi directly uses itself. No copy necessary */
- return NULL;
- }
-
- /* At least 2 phis are involved */
- /* Insert a loop breaking copy (an additional variable T) */
- loop_breaker = be_new_Copy(raenv->cls, raenv->irg, pred_blk, start_phi);
- sched_add_before(last_cpy, loop_breaker);
-
- arg = loop_breaker;
- }
-
- /* If arg is a phi in the same block we have to continue search */
- if (is_Phi(arg) && arg_blk == get_nodes_block(start_phi))
- last_cpy = insert_copies(raenv, start_phi, pos, arg);
-
- /* Insert copy of argument (may be the loop-breaker) */
- curr_cpy = be_new_Copy(raenv->cls, raenv->irg, pred_blk, arg);
- set_irn_n(curr_phi, pos, curr_cpy);
- mark_as_done(curr_phi, pos);
- sched_add_before(last_cpy, curr_cpy);
- return curr_cpy;
-}
-
-
-/**
- * Perform simple SSA-destruction with copies.
- * The order of processing _must_ be
- * for all positions {
- * for all phis {
- * doit
- * }
- * }
- * else the magic to keep track of processed phi-positions will fail in
- * function 'insert_copies'
- */
-static void ssa_destr_simple_walker(ir_node *blk, void *env) {
- be_raext_env_t *raenv = env;
- int pos, max;
- ir_node *phi;
-
- /* for all argument positions of the phis */
- for (pos=0, max=get_irn_arity(blk); pos<max; ++pos) {
-
- /* for all phi nodes (which are scheduled first) */
- sched_foreach(blk, phi) {
- if (!is_Phi(phi))
- break;
-
- if (arch_irn_is(raenv->aenv, phi, ignore))
- continue;
-
- raenv->cls = arch_get_irn_reg_class(raenv->aenv, phi, -1);
- insert_copies(raenv, phi, pos, phi);
- }
- }
-}
-
-
-static void ssa_destr_simple(be_raext_env_t *raenv) {
- be_clear_links(raenv->irg);
- irg_block_walk_graph(raenv->irg, ssa_destr_simple_walker, NULL, raenv);
-}
-
-
-static void ssa_destr_rastello(be_raext_env_t *raenv) {
- assert(0 && "NYI");
- exit(0xDeadBeef);
- /*
- phi_class_compute(raenv->irg);
- irg_block_walk_graph(irg, ssa_destr_rastello, NULL, &raenv);
- */
-}
-
-/******************************************************************************
- __ __ _ ___ __ __
- \ \ / / | | |__ \ \ \ / /
- \ \ / /_ _| |___ ) | \ \ / /_ _ _ __ ___
- \ \/ / _` | / __| / / \ \/ / _` | '__/ __|
- \ / (_| | \__ \ / /_ \ / (_| | | \__ \
- \/ \__,_|_|___/ |____| \/ \__,_|_| |___/
- *****************************************************************************/
-
-/**
- * This struct maps a variable (nr) to the values belonging to this variable
- */
-struct _var_info_t {
- int var_nr; /* the key */
- pset *values; /* the ssa-values belonging to this variable */
-};
-
-#define SET_REMOVED -1
-
-/**
- * The link field of an irn points to the var_info struct
- * representing the corresponding variable.
- */
-#define set_var_info(irn, vi) set_irn_link(irn, vi)
-#define get_var_info(irn) ((var_info_t *)get_irn_link(irn))
-
-#define HASH_VAR_NR(var_nr) var_nr
-
-static int compare_var_infos(const void *e1, const void *e2, size_t size) {
- const var_info_t *v1 = e1;
- const var_info_t *v2 = e2;
-
- if (v1->var_nr == SET_REMOVED || v2->var_nr == SET_REMOVED)
- return 1;
-
- return v1->var_nr != v2->var_nr;
-}
-
-static INLINE var_info_t *var_find(set *vars, int var_nr) {
- var_info_t vi;
- vi.var_nr = var_nr;
-
- return set_find(vars, &vi, sizeof(vi), HASH_VAR_NR(var_nr));
-}
-
-static INLINE var_info_t *var_find_or_insert(set *vars, int var_nr) {
- var_info_t vi, *found;
- memset(&vi, 0, sizeof(vi));
- vi.var_nr = var_nr;
-
- found = set_insert(vars, &vi, sizeof(vi), HASH_VAR_NR(var_nr));
-
- if (!found->values)
- found->values = pset_new_ptr(1);
-
- return found;
-}
-
-/**
- * Adds a value to a variable. Sets all pointers accordingly.
- */
-static INLINE var_info_t *var_add_value(be_raext_env_t *raenv, int var_nr, ir_node *irn) {
- var_info_t *vi = var_find_or_insert(raenv->vars, var_nr);
-
- /* var 2 value mapping */
- pset_insert_ptr(vi->values, irn);
-
- /* value 2 var mapping */
- set_var_info(irn, vi);
-
- return vi;
-}
-
-static INLINE pset *get_var_values(be_raext_env_t *raenv, int var_nr) {
- var_info_t *vi = var_find(raenv->vars, var_nr);
- assert(vi && "Variable does not exist");
- return vi->values;
-}
-
-/**
- * Define variables (numbers) for all SSA-values.
- * All values in a phi class get assigned the same variable name.
- * The link field maps values to the var-name
- */
-static void values_to_vars(ir_node *irn, void *env) {
- be_raext_env_t *raenv = env;
- int nr;
- pset *vals;
-
- if(arch_get_irn_reg_class(raenv->aenv, irn, -1) == NULL)
- return;
-
- vals = get_phi_class(irn);
-
- if (vals) {
- nr = get_irn_node_nr(get_first_phi(vals));
- } else {
- /* not a phi class member, value == var */
- nr = get_irn_node_nr(irn);
- vals = pset_new_ptr(1);
- pset_insert_ptr(vals, irn);
- }
-
- /* values <--> var mapping */
- pset_foreach(vals, irn) {
- DBG((raenv->dbg, 0, "Var %d contains %+F\n", nr, irn));
- var_add_value(raenv, nr, irn);
- }
-}