DEBUG_ONLY(static firm_dbg_module_t *dbg);
-
/**
* Add the new predecessor x to node node, which is either a Block or a Phi
*/
n = get_irn_arity(node);
NEW_ARR_A(ir_node*, ins, n + 1);
- for (i = 0; i < n; i++) ins[i] = get_irn_n(node, i);
+ for (i = 0; i < n; i++)
+ ins[i] = get_irn_n(node, i);
ins[n] = x;
set_irn_in(node, n + 1, ins);
}
if (is_Block(node)) {
pred = get_nodes_block(pred);
- ir_fprintf(stderr, "Exchaning %+F with %+F\n", node, pred);
- //set_irn_in(node, get_irn_arity(pred), get_irn_in(pred) + 1);
- //exchange(node, pred);
edges_reroute(node, pred, current_ir_graph);
} else {
exchange(node, pred);
int i;
NEW_ARR_A(ir_node*, ins, n - 1);
- for (i = 0; i < j; i++) ins[i] = get_irn_n(node, i);
- for (i++; i < n; i++) ins[i - 1] = get_irn_n(node, i);
+ for (i = 0; i < j; i++)
+ ins[i] = get_irn_n(node, i);
+ for (i++; i < n; i++)
+ ins[i - 1] = get_irn_n(node, i);
+
set_irn_in(node, n - 1, ins);
return 0;
}
/**
* Given a set of values this function constructs SSA-form for all users of the
- * values (the user are determined through the out-edges of the values).
+ * values (the user are determined through the out-edges of the values). Uses
+ * the irn_visited flags. Works without using the dominance tree.
*/
static void construct_ssa(ir_node * const *blocks, ir_node * const *vals, int n_vals)
{
}
}
+static void split_critical_edge(ir_node *block, int pos) {
+ ir_graph *irg = get_irn_irg(block);
+ ir_node *in[1];
+ ir_node *new_block;
+ ir_node *new_jmp;
-#if 0
-/**
- * Compare node compares two Const nodes
- * Returns true if this direction is taken
- */
-static int handle_const_const(ir_node* cnst_left, cnst_right, pn_Cmp pnc)
-{
- // TODO
+ in[0] = get_Block_cfgpred(block, pos);
+ new_block = new_r_Block(irg, 1, in);
+ new_jmp = new_r_Jmp(irg, new_block);
+ set_Block_cfgpred(block, pos, new_jmp);
}
-#endif
+typedef struct _condeval_env_t {
+ ir_node *true_block;
+ pn_Cmp pnc;
+ ir_node *cnst;
+ int visited_nr;
-/**
- *
- */
-static int handle_phi_const(ir_node* block, ir_node* cond_block, ir_node* phi, ir_node* cnst, pn_Cmp pnc)
-{
- int changed = 0;
- ir_graph *irg;
- tarval* tv_cnst;
- int n_phi;
- int j;
+ ir_node *cnst_pred; /**< the block before the constant */
+ int cnst_pos; /**< the pos to the constant block (needed to kill that edge later) */
+} condeval_env_t;
- tv_cnst = get_Const_tarval(cnst);
- n_phi = get_Phi_n_preds(phi);
- for (j = 0; j < n_phi; j++) {
- const ir_edge_t *edge, *next;
- ir_node *pred;
- ir_node *pred_block;
- tarval *tv_phi;
- pn_Cmp cmp_val;
-
- pred = get_Phi_pred(phi, j);
- // TODO handle Phi cascades
- if (!is_Const(pred))
+static void copy_and_fix(ir_node *block, ir_node *copy_block, int j, const condeval_env_t *env) {
+ const ir_edge_t *edge;
+
+ /* Look at all nodes in the cond_block and copy them into pred */
+ foreach_out_edge(block, edge) {
+ ir_node *node = get_edge_src_irn(edge);
+ ir_node *copy;
+
+ /* ignore control flow */
+ if (get_irn_mode(node) == mode_X)
continue;
- tv_phi = get_Const_tarval(pred);
+ /* we can evaluate Phis right now, all other nodes get copied */
+ if (is_Phi(node)) {
+ copy = get_Phi_pred(node, j);
+ } else {
+ copy = exact_copy(node);
+ set_nodes_block(copy, copy_block);
+ }
+
+ set_irn_link(node, copy);
+ set_irn_visited(node, env->visited_nr);
+
+ /* we might hit values in blocks that have already been processed by a
+ * recursive find_phi_with_const call */
+ assert(get_irn_visited(copy) <= env->visited_nr);
+ if(get_irn_visited(copy) >= env->visited_nr) {
+ ir_node *prev_copy = get_irn_link(copy);
+ if(prev_copy != NULL)
+ set_irn_link(node, prev_copy);
+ }
+ }
- cmp_val = tarval_cmp(tv_phi, tv_cnst);
- if (cmp_val == pn_Cmp_False) continue;
- if ((cmp_val & pnc) != cmp_val) continue;
+ /* fix data-flow (and reconstruct SSA if needed) */
+ foreach_out_edge(block, edge) {
+ ir_node *vals[2];
+ ir_node *blocks[2];
+
+ ir_node *node = get_edge_src_irn(edge);
+
+ if (get_irn_mode(node) == mode_X)
+ continue;
+
+ blocks[0] = block;
+ vals[0] = node;
+ blocks[1] = copy_block;
+ vals[1] = get_irn_link(node);
+ construct_ssa(blocks, vals, 2);
+ }
+}
+
+static int eval_cmp(pn_Cmp pnc, tarval *tv1, tarval *tv2) {
+ pn_Cmp cmp_result = tarval_cmp(tv1, tv2);
+
+ // does the compare evaluate to true?
+ if(cmp_result == pn_Cmp_False)
+ return 0;
+ if((cmp_result & pnc) != cmp_result)
+ return 0;
+
+ return 1;
+}
+
+static ir_node *find_phi_with_const(ir_node *jump, ir_node *value, condeval_env_t *env) {
+ ir_node *block = get_nodes_block(jump);
+
+ if(irn_visited(value))
+ return NULL;
+ mark_irn_visited(value);
+
+ if(is_Const(value)) {
+ tarval *tv_const = get_Const_tarval(env->cnst);
+ tarval *tv = get_Const_tarval(value);
+
+ if(!eval_cmp(env->pnc, tv, tv_const))
+ return NULL;
DB((
dbg, LEVEL_1,
- "> Found condition evaluation candidate %+F->%+F predecessor %d\n",
- block, cond_block, j
+ "> Found condition evaluation candidate %+F->%+F\n",
+ env->true_block, block
));
- add_pred(block, get_Block_cfgpred(cond_block, j));
- // split critical edges
- /*if(get_irn_arity(block) == 2)*/ {
- ir_node *in[1];
- ir_node *new_block;
- ir_node *new_jmp;
-
- in[0] = get_Block_cfgpred(block, 0);
- new_block = new_r_Block(current_ir_graph, 1, in);
- new_jmp = new_r_Jmp(current_ir_graph, new_block);
- set_Block_cfgpred(block, 0, new_jmp);
- }
+ // adjust true_block to point directly towards our jump
+ add_pred(env->true_block, jump);
- pred_block = get_Block_cfgpred_block(cond_block, j);
+ split_critical_edge(env->true_block, 0);
- /* Look at all nodes in the cond_block and copy them into pred */
- foreach_out_edge(cond_block, edge) {
- ir_node *node = get_edge_src_irn(edge);
- ir_node *copy;
+ // we need a bigger visited nr when going back
+ env->visited_nr++;
- // ignore these as SSA construction would fail on ProjX
- if (is_Proj(node) && get_irn_mode(node) == mode_X)
- continue;
+ return block;
+ }
- // we can evaluate Phis right now, all other nodes get copied
- if (is_Phi(node)) {
- copy = get_Phi_pred(node, j);
- } else {
- copy = exact_copy(node);
- set_nodes_block(copy, pred_block);
- }
+ if(is_Phi(value)) {
+ int i, arity;
- set_irn_link(node, copy);
- }
+ // the phi has to be in the same block as the jump
+ if(get_nodes_block(value) != block)
+ return NULL;
- /* fix data-flow (and reconstruct SSA if needed) */
- foreach_out_edge(cond_block, edge) {
- ir_node *vals[2];
- ir_node *blocks[2];
+ arity = get_irn_arity(value);
+ for(i = 0; i < arity; ++i) {
+ ir_node *copy_block;
+ ir_node *phi_pred = get_Phi_pred(value, i);
+ ir_node *cfgpred = get_Block_cfgpred(block, i);
- ir_node *node = get_edge_src_irn(edge);
- assert(get_nodes_block(node) == cond_block);
- if (is_Proj(node) && get_irn_mode(node) == mode_X)
+ copy_block = find_phi_with_const(cfgpred, phi_pred, env);
+ if(copy_block == NULL)
continue;
- blocks[0] = cond_block;
- vals[0] = node;
- blocks[1] = pred_block;
- vals[1] = get_irn_link(node);
- construct_ssa(blocks, vals, 2);
- }
+ /* copy duplicated nodes in copy_block and fix SSA */
+ copy_and_fix(block, copy_block, i, env);
- /* shorten phis */
- foreach_out_edge_safe(cond_block, edge, next) {
- ir_node *node = get_edge_src_irn(edge);
+ if(copy_block == get_nodes_block(cfgpred)) {
+ env->cnst_pred = block;
+ env->cnst_pos = i;
+ }
- if(is_Phi(node))
- remove_pred(node, j);
+ // return now as we can't process more possibilities in 1 run
+ return copy_block;
}
-
- changed = 1;
- remove_pred(cond_block, j);
-#if 0
- if (remove_pred(cond_block, j))
- break;
- // the phi got shortened
- n_phi--;
- j--;
-#endif
- break;
}
- if (changed) {
- irg = get_irn_irg(block);
- set_irg_doms_inconsistent(irg);
- set_irg_extblk_inconsistent(irg);
- set_irg_loopinfo_inconsistent(irg);
- }
- return changed;
+ return NULL;
}
/**
- * Block-walker:
+ * Block-walker: searchs for the following construct
+ *
+ * Const or Phi with constants
+ * |
+ * Cmp
+ * |
+ * Cond
+ * /
+ * ProjX
+ * /
+ * Block
*/
-static void cond_eval(ir_node* block, void* env)
+static void cond_eval(ir_node* block, void* data)
{
- int n_block;
- int i;
+ condeval_env_t env;
+ int *changed = data;
+ ir_graph *irg = current_ir_graph;
+ ir_node *copy_block;
+ ir_node *pred;
+ ir_node *projx;
+ ir_node *cond;
+ ir_node *cmp;
+ ir_node *left;
+ ir_node *right;
+ ir_node *cond_block;
+ pn_Cmp pnc;
+
+ if(get_Block_n_cfgpreds(block) != 1)
+ return;
+
+ projx = get_Block_cfgpred(block, 0);
+ if (!is_Proj(projx))
+ return;
+ assert(get_irn_mode(projx) == mode_X);
+
+ cond = get_Proj_pred(projx);
+ if (!is_Cond(cond))
+ return;
+
+ pred = get_Cond_selector(cond);
+ // TODO handle switches
+ if (get_irn_mode(pred) != mode_b)
+ return;
+ if (!is_Proj(pred))
+ return;
+ pnc = get_Proj_proj(pred);
+
+ cmp = get_Proj_pred(pred);
+ assert(is_Cmp(cmp));
+
+ left = get_Cmp_left(cmp);
+ right = get_Cmp_right(cmp);
+ assert(get_irn_mode(left) == get_irn_mode(right));
+
+ /* we assume that the cond_block is the true case */
+ if (get_Proj_proj(projx) == pn_Cond_false) {
+ pnc = get_negated_pnc(pnc, get_irn_mode(left));
+ }
- n_block = get_Block_n_cfgpreds(block);
- for (i = 0; i < n_block; i++) {
- ir_node* pred;
- ir_node* projx;
- ir_node* cond;
- ir_node* cmp;
- ir_node* left;
- ir_node* right;
- ir_node* cond_block;
- pn_Cmp pnc;
-
- pred = get_Block_cfgpred(block, i);
- if (!is_Proj(pred)) continue;
- projx = pred;
-
- pred = get_Proj_pred(projx);
- if (!is_Cond(pred)) continue;
- cond = pred;
-
- pred = get_Cond_selector(cond);
- // TODO handle switches
- if (get_irn_mode(pred) != mode_b) continue;
- assert(is_Proj(pred));
- pnc = get_Proj_proj(pred);
-
- cmp = get_Proj_pred(pred);
- assert(is_Cmp(cmp));
-
- left = get_Cmp_left(cmp);
- right = get_Cmp_right(cmp);
- assert(get_irn_mode(left) == get_irn_mode(right));
-
- if (get_Proj_proj(projx) == 0) {
- pnc = get_negated_pnc(pnc, get_irn_mode(left));
- }
+ /* we assume that the constant is on the right side, swap left/right
+ * if needed */
+ if(is_Const(left)) {
+ ir_node *t = left;
+ left = right;
+ right = t;
-#if 0 // TODO implement
- if (is_Const(left) && is_Const(right)) {
- if (!handle_const_const()) {
- n_block--;
- i--;
- }
- continue;
- }
-#endif
- cond_block = get_nodes_block(cond);
- if (is_Phi(left) && is_Const(right)) {
- if (get_nodes_block(left) != cond_block) continue;
- handle_phi_const(block, cond_block, left, right, pnc);
- continue;
- }
- if (is_Const(left) && is_Phi(right)) {
- if (get_nodes_block(right) != cond_block) continue;
- handle_phi_const(block, cond_block, right, left, get_inversed_pnc(pnc));
- continue;
+ pnc = get_inversed_pnc(pnc);
+ }
+
+ if(!is_Const(right))
+ return;
+
+ cond_block = get_nodes_block(cond);
+
+ // special case: comparing a constant with a constant
+ if(is_Const(left)) {
+ tarval *tv1 = get_Const_tarval(left);
+ tarval *tv2 = get_Const_tarval(right);
+ if(eval_cmp(pnc, tv1, tv2)) {
+ ir_node *jmp = new_r_Jmp(irg, cond_block);
+ set_Block_cfgpred(block, 0, jmp);
+ } else {
+ set_Block_cfgpred(block, 0, new_Bad());
}
-#if 0
- if (is_Phi(left) && is_Phi(right)) {
- // TODO implement
+ *changed = 1;
+ set_irg_doms_inconsistent(irg);
+ set_irg_extblk_inconsistent(irg);
+ set_irg_loopinfo_inconsistent(irg);
+ } else {
+ if(get_nodes_block(left) != cond_block)
+ return;
+
+ // (recursively) look if a pred of a phi is a constant
+ env.true_block = block;
+ env.pnc = pnc;
+ env.cnst = right;
+ inc_irg_visited(current_ir_graph);
+ env.visited_nr = get_irg_visited(irg);
+
+ copy_block = find_phi_with_const(projx, left, &env);
+
+ if(copy_block != NULL) {
+ /* we have to remove the edge towards the pred as the pred now
+ * jumps into the true_block. We also have to shorten phis
+ * in our block because of this */
+ const ir_edge_t *edge, *next;
+
+ /* shorten phis */
+ foreach_out_edge_safe(env.cnst_pred, edge, next) {
+ ir_node *node = get_edge_src_irn(edge);
+
+ if(is_Phi(node))
+ remove_pred(node, env.cnst_pos);
+ }
+
+ remove_pred(env.cnst_pred, env.cnst_pos);
+
+ // the graph is changed now
+ *changed = 1;
+ set_irg_doms_inconsistent(irg);
+ set_irg_extblk_inconsistent(irg);
+ set_irg_loopinfo_inconsistent(irg);
}
-#endif
}
}
-
void opt_cond_eval(ir_graph* irg)
{
+ int changed;
+
FIRM_DBG_REGISTER(dbg, "firm.opt.condeval");
- firm_dbg_set_mask(dbg, SET_LEVEL_5);
+ //firm_dbg_set_mask(dbg, SET_LEVEL_5);
DB((dbg, LEVEL_1, "===> Performing condition evaluation on %+F\n", irg));
- if(edges_activated(irg))
- edges_deactivate(irg);
edges_assure(irg);
remove_critical_cf_edges(irg);
normalize_proj_nodes(irg);
- irg_block_walk_graph(irg, cond_eval, NULL, NULL);
-#if 0
- irg_block_walk_graph(irg, NULL, cond_eval, NULL);
- irg_block_walk_graph(irg, NULL, cond_eval, NULL);
- irg_block_walk_graph(irg, NULL, cond_eval, NULL);
-#endif
+ do {
+ changed = 0;
+ irg_block_walk_graph(irg, cond_eval, NULL, &changed);
+ } while(changed);
}