sparc: be more conservative when moving memops around

[libfirm] / ir / opt / ldstopt.c

diff --git a/ir/opt/ldstopt.c b/ir/opt/ldstopt.c
index 3667f26..ff447f7 100644 (file)
--- a/ir/opt/ldstopt.c
+++ b/ir/opt/ldstopt.c
@@ -165,9 +165,6 @@ static unsigned update_exc(ldst_info_t *info, ir_node *block, int pos)
        return 0;
 }  /* update_exc */
 
-/** Return the number of uses of an address node */
-#define get_irn_n_uses(adr)     get_irn_n_edges(adr)
-
 /**
  * walker, collects all Load/Store/Proj nodes
  *
@@ -1046,7 +1043,7 @@ static unsigned optimize_load(ir_node *load)
 
        /* Check, if the address of this load is used more than once.
         * If not, more load cannot be removed in any case. */
-       if (get_irn_n_uses(ptr) <= 1 && get_irn_n_uses(get_base_and_offset(ptr, &dummy)) <= 1)
+       if (get_irn_n_edges(ptr) <= 1 && get_irn_n_edges(get_base_and_offset(ptr, &dummy)) <= 1)
                return res;
 
        /*
@@ -1278,7 +1275,7 @@ static unsigned optimize_store(ir_node *store)
 
        /* Check, if the address of this Store is used more than once.
         * If not, this Store cannot be removed in any case. */
-       if (get_irn_n_uses(ptr) <= 1)
+       if (get_irn_n_edges(ptr) <= 1)
                return 0;
 
        mem = get_Store_mem(store);
@@ -1289,6 +1286,22 @@ static unsigned optimize_store(ir_node *store)
        return follow_Mem_chain_for_Store(store, skip_Proj(mem));
 }  /* optimize_store */
 
+/* check if a node has more than one real user. Keepalive edges do not count as
+ * real users */
+static bool has_multiple_users(const ir_node *node)
+{
+       unsigned real_users = 0;
+       foreach_out_edge(node, edge) {
+               ir_node *user = get_edge_src_irn(edge);
+               if (is_End(user))
+                       continue;
+               ++real_users;
+               if (real_users > 1)
+                       return true;
+       }
+       return false;
+}
+
 /**
  * walker, optimizes Phi after Stores to identical places:
  * Does the following optimization:
@@ -1333,7 +1346,7 @@ static unsigned optimize_phi(ir_node *phi, walk_env_t *wenv)
 
        /* must be only one user */
        projM = get_Phi_pred(phi, 0);
-       if (get_irn_n_edges(projM) != 1)
+       if (has_multiple_users(projM))
                return 0;
 
        store = skip_Proj(projM);
@@ -1364,7 +1377,7 @@ static unsigned optimize_phi(ir_node *phi, walk_env_t *wenv)
        for (i = 1; i < n; ++i) {
                ir_node *pred = get_Phi_pred(phi, i);
 
-               if (get_irn_n_edges(pred) != 1)
+               if (has_multiple_users(pred))
                        return 0;
 
                pred = skip_Proj(pred);
@@ -1487,6 +1500,44 @@ static unsigned optimize_phi(ir_node *phi, walk_env_t *wenv)
        return res | DF_CHANGED;
 }  /* optimize_phi */
 
+static int optimize_conv_load(ir_node *conv)
+{
+       ir_node *op = get_Conv_op(conv);
+       if (!is_Proj(op))
+               return 0;
+       if (has_multiple_users(op))
+               return 0;
+       /* shrink mode of load if possible. */
+       ir_node *load = get_Proj_pred(op);
+       if (!is_Load(load))
+               return 0;
+
+       /* only do it if we are the only user (otherwise the risk is too
+        * great that we end up with 2 loads instead of one). */
+       ir_mode *mode      = get_irn_mode(conv);
+       ir_mode *load_mode = get_Load_mode(load);
+       int      bits_diff
+               = get_mode_size_bits(load_mode) - get_mode_size_bits(mode);
+       if (mode_is_float(load_mode) || mode_is_float(mode) || bits_diff < 0)
+           return 0;
+
+       if (be_get_backend_param()->byte_order_big_endian) {
+               if (bits_diff % 8 != 0)
+                       return 0;
+               ir_graph *irg   = get_irn_irg(conv);
+               ir_node  *ptr   = get_Load_ptr(load);
+               ir_mode  *mode  = get_irn_mode(ptr);
+               ir_node  *delta = new_r_Const_long(irg, mode, bits_diff/8);
+               ir_node  *block = get_nodes_block(load);
+               ir_node  *add   = new_r_Add(block, ptr, delta, mode);
+               set_Load_ptr(load, add);
+       }
+       set_Load_mode(load, mode);
+       set_irn_mode(op, mode);
+       exchange(conv, op);
+       return DF_CHANGED;
+}
+
 /**
  * walker, do the optimizations
  */
@@ -1508,6 +1559,10 @@ static void do_load_store_optimize(ir_node *n, void *env)
                wenv->changes |= optimize_phi(n, wenv);
                break;
 
+       case iro_Conv:
+               wenv->changes |= optimize_conv_load(n);
+               break;
+
        default:
                break;
        }
@@ -1545,7 +1600,7 @@ typedef struct loop_env {
 */
 static node_entry *get_irn_ne(ir_node *irn, loop_env *env)
 {
-       node_entry *e = (node_entry*)ir_nodehashmap_get(&env->map, irn);
+       node_entry *e = ir_nodehashmap_get(node_entry, &env->map, irn);
 
        if (e == NULL) {
                e = OALLOC(&env->obst, node_entry);
@@ -1746,7 +1801,7 @@ static void move_loads_out_of_loops(scc *pscc, loop_env *env)
                                        } else {
                                                irn = new_rd_Load(db, pred, get_Phi_pred(phi, pos), ptr, load_mode, cons_none);
                                                entry.load = irn;
-                                               set_insert(avail_entry_t, avail, &entry, sizeof(entry), hash_cache_entry(&entry));
+                                               (void)set_insert(avail_entry_t, avail, &entry, sizeof(entry), hash_cache_entry(&entry));
                                                DB((dbg, LEVEL_1, "  Created %+F in %+F\n", irn, pred));
                                        }
                                        pe->load = irn;