Another variant without index, but shifts with different modes.
[libfirm] / ir / ana / irconsconfirm.c
index 0ef2c4d..03c2149 100644 (file)
 #include "iredges_t.h"
 #include "irgwalk.h"
 #include "irprintf.h"
+#include "irgopt.h"
 #include "irtools.h"
+#include "array_t.h"
 
 /**
  * Walker environment.
  */
 typedef struct _env_t {
-  unsigned num_confirms;  /**< number of inserted Confirm nodes */
-  unsigned num_consts;    /**< number of constants placed */
-  unsigned num_eq;        /**< number of equalities placed */
+       unsigned num_confirms;  /**< number of inserted Confirm nodes */
+       unsigned num_consts;    /**< number of constants placed */
+       unsigned num_eq;        /**< number of equalities placed */
 } env_t;
 
 /**
@@ -57,11 +59,12 @@ typedef struct _env_t {
  * This handles correctly Phi nodes.
  */
 static ir_node *get_effective_use_block(ir_node *node, int pos) {
-       /* the effective use of a Phi is in its predecessor block */
-       if (is_Phi(node))
-               return get_nodes_block(get_irn_n(node, pos));
-       else
-               return get_nodes_block(node);
+       if (is_Phi(node)) {
+               /* the effective use of a Phi argument is in its predecessor block */
+               node = get_nodes_block(node);
+               return get_Block_cfgpred_block(node, pos);
+       }
+       return get_nodes_block(node);
 }
 
 /**
@@ -113,6 +116,115 @@ static void handle_case(ir_node *block, ir_node *irn, long nr, env_t *env) {
        }
 }  /* handle_case */
 
+/**
+ * Handle a mode_b input of Cond nodes.
+ *
+ * @param block     the block which is entered by the branch
+ * @param selector  the mode_b node expressing the branch condition
+ * @param pnc       the true/false condition branch
+ * @param env       statistical environment
+ */
+static void handle_modeb(ir_node *block, ir_node *selector, pn_Cond pnc, env_t *env) {
+       ir_node *cond, *old, *cond_block = NULL, *other_blk = NULL, *con = NULL;
+       ir_node *c_b = NULL, *c_o = NULL;
+       const ir_edge_t *edge, *next;
+
+       for (edge = get_irn_out_edge_first(selector); edge; edge = next) {
+               ir_node *user     = get_edge_src_irn(edge);
+               int     pos       = get_edge_src_pos(edge);
+               ir_node *user_blk = get_effective_use_block(user, pos);
+
+               next = get_irn_out_edge_next(selector, edge);
+               if (block_dominates(block, user_blk)) {
+                       /*
+                        * Ok, we found a usage of selector in a block
+                        * dominated by the branch block.
+                        * We can replace the input with true/false.
+                        */
+                       if (con == NULL) {
+                               con = new_Const(mode_b, pnc == pn_Cond_true ? tarval_b_true : tarval_b_false);
+                       }
+                       old = get_irn_n(user, pos);
+                       set_irn_n(user, pos, con);
+                       DBG_OPT_CONFIRM_C(old, con);
+
+                       // ir_printf("2 Replacing input %d of node %n with %n\n", pos, user, con);
+
+                       env->num_consts += 1;
+               } else {
+                       int i, n;
+
+                       /* get the other block */
+                       if (other_blk == NULL) {
+                               /* we have already tested, that block has only ONE Cond predecessor */
+                               cond = get_Proj_pred(get_Block_cfgpred(block, 0));
+                               cond_block = get_nodes_block(cond);
+                               foreach_out_edge(cond, edge) {
+                                       ir_node *proj = get_edge_src_irn(edge);
+                                       if (get_Proj_proj(proj) == (long)pnc)
+                                               continue;
+                                       edge = get_irn_out_edge_first(proj);
+                                       other_blk = get_edge_src_irn(edge);
+                                       break;
+                               }
+                               assert(other_blk);
+
+                               /*
+                                * Note the special case here: if block is a then, there might be no else
+                                * block. In that case the other_block is the user_blk itself and pred_block
+                                * is the cond_block ...
+                                *
+                                * Best would be to introduce a block here, removing this critical edge.
+                                * For some reasons I cannot repair dominance here, so I have to remove
+                                * ALL critical edges...
+                                * FIXME: This should not be needed if we could repair dominance ...
+                                */
+                       }
+
+                       n = get_Block_n_cfgpreds(user_blk);
+
+                       /*
+                        * We have found a user in a non-dominated block:
+                        * check, if all its block predecessors are dominated.
+                        * If yes, place a Phi.
+                        */
+                       for (i = n - 1; i >= 0; --i) {
+                               ir_node *pred_blk = get_Block_cfgpred_block(user_blk, i);
+
+                               if (!block_dominates(block, pred_blk) &&
+                                   !block_dominates(other_blk, pred_blk)) {
+                                       /* can't do anything */
+                                       break;
+                               }
+                       }
+                       if (i < 0) {
+                               ir_node *phi, **in;
+
+                               NEW_ARR_A(ir_node *, in, n);
+                               /* ok, ALL predecessors are either dominated by block OR other block */
+                               if (c_b == NULL) {
+                                       ir_node *c_true  = new_Const(mode_b, tarval_b_true);
+                                       ir_node *c_false = new_Const(mode_b, tarval_b_false);
+                                       c_b = new_r_Confirm(current_ir_graph, cond_block, selector,
+                                               pnc == pn_Cond_true ? c_true : c_false, pn_Cmp_Eq);
+                                       c_o = new_r_Confirm(current_ir_graph, cond_block, selector,
+                                               pnc == pn_Cond_false ? c_true : c_false, pn_Cmp_Eq);
+                               }
+                               for (i = n - 1; i >= 0; --i) {
+                                       ir_node *pred_blk = get_Block_cfgpred_block(user_blk, i);
+
+                                       if (block_dominates(block, pred_blk))
+                                               in[i] = c_b;
+                                       else
+                                               in[i] = c_o;
+                               }
+                               phi = new_r_Phi(current_ir_graph, user_blk, n, in, mode_b);
+                               set_irn_n(user, pos, phi);
+                       }
+               }
+       }
+}
+
 /**
  * Handle an IF-branch.
  *
@@ -129,7 +241,7 @@ static void handle_if(ir_node *block, ir_node *cmp, pn_Cmp pnc, env_t *env) {
        const ir_edge_t *edge, *next;
 
        /* Beware of Bads */
-       if (is_Bad(left) ||is_Bad(right))
+       if (is_Bad(left) || is_Bad(right))
                return;
 
        op = get_irn_op(left);
@@ -253,11 +365,11 @@ static void insert_Confirm(ir_node *block, void *env) {
                return;
 
        proj = get_Block_cfgpred(block, 0);
-       if (get_irn_op(proj) != op_Proj)
+       if (! is_Proj(proj))
                return;
 
        cond = get_Proj_pred(proj);
-       if (get_irn_op(cond) != op_Cond)
+       if (! is_Cond(cond))
                return;
 
        selector = get_Cond_selector(cond);
@@ -267,12 +379,14 @@ static void insert_Confirm(ir_node *block, void *env) {
                ir_node *cmp;
                pn_Cmp pnc;
 
+               handle_modeb(block, selector, get_Proj_proj(proj), env);
+
                /* this should be an IF, check this */
-               if (get_irn_op(selector) != op_Proj)
+               if (! is_Proj(selector))
                        return;
 
                cmp = get_Proj_pred(selector);
-               if (get_irn_op(cmp) != op_Cmp)
+               if (! is_Cmp(cmp))
                        return;
 
                pnc = get_Proj_proj(selector);
@@ -302,6 +416,8 @@ void construct_confirms(ir_graph *irg) {
        env_t env;
        int edges_active = edges_activated(irg);
 
+       remove_critical_cf_edges(irg);
+
        /* we need dominance info */
        assure_doms(irg);
 
@@ -339,12 +455,13 @@ void construct_confirms(ir_graph *irg) {
                edges_deactivate(irg);
 }  /* construct_confirms */
 
+#if 0
 /**
  * Post-walker: Remove Confirm nodes
  */
 static void rem_Confirm(ir_node *n, void *env) {
        (void) env;
-       if (get_irn_op(n) == op_Confirm) {
+       if (is_Confirm(n)) {
                ir_node *value = get_Confirm_value(n);
                if (value != n)
                        exchange(n, value);
@@ -357,10 +474,12 @@ static void rem_Confirm(ir_node *n, void *env) {
                }
        }
 }  /* rem_Confirm */
+#endif
 
 /*
  * Remove all Confirm nodes from a graph.
  */
 void remove_confirms(ir_graph *irg) {
-       irg_walk_graph(irg, NULL, rem_Confirm, NULL);
+       set_opt_remove_confirm(1);
+       optimize_graph_df(irg);
 }  /* remove_confirms */