cleanup space generation logic and make it more robust for union constructs
[libfirm] / ir / opt / opt_inline.c
index 9f88455..b12e7ef 100644 (file)
@@ -838,8 +838,30 @@ int inline_method(ir_node *call, ir_graph *called_graph) {
        ent = get_irg_entity(called_graph);
 
        /* Do not inline variadic functions. */
-       if (get_method_variadicity(get_entity_type(ent)) == variadicity_variadic)
-               return 0;
+       if (get_method_variadicity(get_entity_type(ent)) == variadicity_variadic) {
+               /* Arg, KR functions are marked as variadic one's, so check further */
+               ir_type *mtp     = get_entity_type(ent);
+               ir_type *ctp     = get_Call_type(call);
+               int     n_params = get_method_n_params(mtp);
+               int     i;
+
+               /* This is too strong, but probably ok. Function calls with a wrong number of
+                  parameters should not be inlined. */
+               if (n_params != get_method_n_params(ctp))
+                       return 0;
+
+               /* check types: for K&R calls, this was not done by the compiler. Again, this is
+                  too strong, but ok for now. */
+               for (i = n_params - 1; i >= 0; --i) {
+                       ir_type *param_tp = get_method_param_type(mtp, i);
+                       ir_type *arg_tp   = get_method_param_type(ctp, i);
+
+                       if (param_tp != arg_tp)
+                               return 0;
+               }
+               DB((dbg, LEVEL_1, "Inlining allowed for variadic function %+F\n", called_graph));
+               /* types match, fine: when the frame is access, the inliner stops at can_inline() */
+       }
 
        assert(get_method_n_params(get_entity_type(ent)) ==
               get_method_n_params(get_Call_type(call)));
@@ -864,7 +886,7 @@ int inline_method(ir_node *call, ir_graph *called_graph) {
        rem = current_ir_graph;
        current_ir_graph = irg;
 
-       DB((dbg, SET_LEVEL_1, "Inlining %+F(%+F) into %+F\n", call, called_graph, irg));
+       DB((dbg, LEVEL_1, "Inlining %+F(%+F) into %+F\n", call, called_graph, irg));
 
        /* --  Turn off optimizations, this can cause problems when allocating new nodes. -- */
        rem_opt = get_opt_optimize();
@@ -914,7 +936,6 @@ int inline_method(ir_node *call, ir_graph *called_graph) {
        in[pn_Start_X_initial_exec]   = new_Jmp();
        in[pn_Start_M]                = get_Call_mem(call);
        in[pn_Start_P_frame_base]     = get_irg_frame(irg);
-       in[pn_Start_P_globals]        = get_irg_globals(irg);
        in[pn_Start_P_tls]            = get_irg_tls(irg);
        in[pn_Start_T_args]           = new_Tuple(get_Call_n_params(call), get_Call_param_arr(call));
        /* in[pn_Start_P_value_arg_base] = ??? */
@@ -1169,10 +1190,10 @@ static struct obstack  temp_obst;
 /** Represents a possible inlinable call in a graph. */
 typedef struct _call_entry call_entry;
 struct _call_entry {
-       ir_node    *call;   /**< the Call */
-       ir_graph   *callee; /**< the callee called here */
-       call_entry *next;   /**< for linking the next one */
-       unsigned   weight;  /**< the weight of the call */
+       ir_node    *call;      /**< the Call node */
+       ir_graph   *callee;    /**< the callee IR-graph called here */
+       call_entry *next;      /**< for linking the next one */
+       int        loop_depth; /**< the loop depth of this call */
 };
 
 /**
@@ -1213,10 +1234,10 @@ static void collect_calls(ir_node *call, void *env) {
                        /* The Call node calls a locally defined method.  Remember to inline. */
                        inline_env_t *ienv  = env;
                        call_entry   *entry = obstack_alloc(&ienv->obst, sizeof(*entry));
-                       entry->call   = call;
-                       entry->callee = called_irg;
-                       entry->next   = NULL;
-                       entry->weight = 0;
+                       entry->call       = call;
+                       entry->callee     = called_irg;
+                       entry->next       = NULL;
+                       entry->loop_depth = 0;
 
                        if (ienv->tail == NULL)
                                ienv->head = entry;
@@ -1276,14 +1297,15 @@ typedef struct {
        int n_nodes;             /**< Number of nodes in graph except Id, Tuple, Proj, Start, End. */
        int n_blocks;            /**< Number of Blocks in graph without Start and End block. */
        int n_nodes_orig;        /**< for statistics */
-       call_entry *call_head;   /**< The head of the list of all call nodes in this graph. */
-       call_entry *call_tail;   /**< The tail of the list of all call nodes in this graph .*/
        int n_call_nodes;        /**< Number of Call nodes in the graph. */
        int n_call_nodes_orig;   /**< for statistics */
        int n_callers;           /**< Number of known graphs that call this graphs. */
        int n_callers_orig;      /**< for statistics */
        unsigned got_inline:1;   /**< Set, if at least one call inside this graph was inlined. */
        unsigned local_vars:1;   /**< Set, if a inlined function gets the address of an inlined variable. */
+       unsigned recursive:1;    /**< Set, if this function is self recursive. */
+       call_entry *call_head;   /**< The head of the list of all call nodes in this graph. */
+       call_entry *call_tail;   /**< The tail of the list of all call nodes in this graph .*/
        unsigned *local_weights; /**< Once allocated, the beneficial weight for transmitting local addresses. */
 } inline_irg_env;
 
@@ -1303,14 +1325,16 @@ static inline_irg_env *alloc_inline_irg_env(void) {
        env->n_callers_orig    = 0;
        env->got_inline        = 0;
        env->local_vars        = 0;
+       env->recursive         = 0;
        env->local_weights     = NULL;
        return env;
 }
 
 typedef struct walker_env {
-       inline_irg_env *x;    /**< the inline environment */
-       char ignore_runtime;  /**< the ignore runtime flag */
-       char ignore_callers;  /**< if set, do change callers data */
+       inline_irg_env *x;     /**< the inline environment */
+       call_entry *last_call; /**< points to the last inserted call */
+       char ignore_runtime;   /**< the ignore runtime flag */
+       char ignore_callers;   /**< if set, do change callers data */
 } wenv_t;
 
 /**
@@ -1360,17 +1384,44 @@ static void collect_calls2(ir_node *call, void *ctx) {
                        ++callee_env->n_callers;
                        ++callee_env->n_callers_orig;
                }
+               if (callee == current_ir_graph)
+                       x->recursive = 1;
 
                /* link it in the list of possible inlinable entries */
                entry = obstack_alloc(&temp_obst, sizeof(*entry));
-               entry->call   = call;
-               entry->callee = callee;
-               entry->next   = NULL;
-               if (x->call_tail == NULL)
+               entry->call       = call;
+               entry->callee     = callee;
+               entry->next       = NULL;
+               entry->loop_depth = get_irn_loop(get_nodes_block(call))->depth;
+
+               /* note: we use call_tail here as a pointer to the last inserted */
+               if (x->call_head == NULL) {
                        x->call_head = entry;
-               else
-                       x->call_tail->next = entry;
-               x->call_tail = entry;
+               } else {
+                       if (entry->loop_depth == env->last_call->loop_depth) {
+                               /* same depth as the last one, enqueue after it */
+                               entry->next          = env->last_call->next;
+                               env->last_call->next = entry;
+                       } else if (entry->loop_depth > x->call_head->loop_depth) {
+                               /* put first */
+                               entry->next  = x->call_head;
+                               x->call_head = entry;
+                       } else {
+                               /* search the insertion point */
+                               call_entry *p;
+
+                               for (p = x->call_head; p->next != NULL; p = p->next)
+                                       if (entry->loop_depth > p->next->loop_depth)
+                                               break;
+                               entry->next = p->next;
+                               p->next     = entry;
+                       }
+               }
+               env->last_call = entry;
+               if (entry->next == NULL) {
+                       /* keep tail up to date */
+                       x->call_tail = entry;
+               }
        }
 }
 
@@ -1403,14 +1454,46 @@ static void append_call_list(inline_irg_env *dst, call_entry *src) {
           in the link field. */
        for (entry = src; entry != NULL; entry = entry->next) {
                nentry = obstack_alloc(&temp_obst, sizeof(*nentry));
-               nentry->call   = get_irn_link(entry->call);
-               nentry->callee = entry->callee;
-               nentry->next   = NULL;
+               nentry->call         = get_irn_link(entry->call);
+               nentry->callee       = entry->callee;
+               nentry->next         = NULL;
+               nentry->loop_depth   = entry->loop_depth;
                dst->call_tail->next = nentry;
                dst->call_tail       = nentry;
        }
 }
 
+/**
+ * Add the nodes of the list src in front to the nodes of the list dst.
+ */
+static call_entry *replace_entry_by_call_list(call_entry *dst, call_entry *src) {
+       call_entry *entry, *nentry, *head, *tail;
+
+       /* Note that the src list points to Call nodes in the inlined graph, but
+          we need Call nodes in our graph. Luckily the inliner leaves this information
+          in the link field. */
+       head = tail = NULL;
+       for (entry = src; entry != NULL; entry = entry->next) {
+               nentry = obstack_alloc(&temp_obst, sizeof(*nentry));
+               nentry->call         = get_irn_link(entry->call);
+               nentry->callee       = entry->callee;
+               nentry->next         = NULL;
+               nentry->loop_depth   = entry->loop_depth + dst->loop_depth;
+               if (head == NULL)
+                       head = nentry;
+               else
+                       tail->next = nentry;
+               tail = nentry;
+       }
+       /* skip the head of dst */
+       if (head != NULL) {
+               tail->next = dst->next;
+       } else {
+               head = dst->next;
+       }
+       return head;
+}
+
 /*
  * Inlines small leave methods at call sites where the called address comes
  * from a Const node that references the entity representing the called
@@ -1451,6 +1534,7 @@ void inline_leave_functions(int maxsize, int leavesize, int size, int ignore_run
                assert(get_irg_phase_state(irg) != phase_building);
                free_callee_info(irg);
 
+               assure_cf_loop(irg);
                wenv.x = get_irg_link(irg);
                irg_walk_graph(irg, NULL, collect_calls2, &wenv);
        }
@@ -1563,6 +1647,7 @@ void inline_leave_functions(int maxsize, int leavesize, int size, int ignore_run
                                        callee_env = alloc_inline_irg_env();
                                        set_irg_link(copy, callee_env);
 
+                                       assure_cf_loop(copy);
                                        wenv.x              = callee_env;
                                        wenv.ignore_callers = 1;
                                        irg_walk_graph(copy, NULL, collect_calls2, &wenv);
@@ -1629,7 +1714,7 @@ void inline_leave_functions(int maxsize, int leavesize, int size, int ignore_run
                        optimize_cf(irg);
                }
                if (env->got_inline || (env->n_callers_orig != env->n_callers)) {
-                       DB((dbg, SET_LEVEL_1, "Nodes:%3d ->%3d, calls:%3d ->%3d, callers:%3d ->%3d, -- %s\n",
+                       DB((dbg, LEVEL_1, "Nodes:%3d ->%3d, calls:%3d ->%3d, callers:%3d ->%3d, -- %s\n",
                        env->n_nodes_orig, env->n_nodes, env->n_call_nodes_orig, env->n_call_nodes,
                        env->n_callers_orig, env->n_callers,
                        get_entity_name(get_irg_entity(irg))));
@@ -1705,6 +1790,7 @@ static unsigned calc_method_local_weight(ir_node *arg) {
                                        }
                                }
                        }
+                       break;
                default:
                        /* any other node: unsupported yet or bad. */
                        return 0;
@@ -1770,7 +1856,7 @@ static int calc_inline_benefice(ir_node *call, ir_graph *callee, unsigned *local
        ir_node   *frame_ptr;
        ir_type   *mtp;
        int       weight = 0;
-       int       i, n_params;
+       int       i, n_params, all_const;
        unsigned  cc, v;
 
        inline_irg_env *curr_env, *callee_env;
@@ -1799,21 +1885,27 @@ static int calc_inline_benefice(ir_node *call, ir_graph *callee, unsigned *local
 
        /* constant parameters improve the benefice */
        frame_ptr = get_irg_frame(current_ir_graph);
+       all_const = 1;
        for (i = 0; i < n_params; ++i) {
                ir_node *param = get_Call_param(call, i);
 
-               if (is_Const(param) || is_SymConst(param))
+               if (is_Const(param))
                        weight += get_method_param_weight(ent, i);
-               else if (is_Sel(param) && get_Sel_ptr(param) == frame_ptr) {
-                       /*
-                        * An address of a local variable is transmitted. After inlining,
-                        * scalar_replacement might be able to remove the local variable,
-                        * so honor this.
-                        */
-                       v = get_method_local_adress_weight(callee, i);
-                       weight += v;
-                       if (v > 0)
-                               *local_adr = 1;
+               else {
+                       all_const = 0;
+                       if (is_SymConst(param))
+                               weight += get_method_param_weight(ent, i);
+                       else if (is_Sel(param) && get_Sel_ptr(param) == frame_ptr) {
+                               /*
+                                * An address of a local variable is transmitted. After inlining,
+                                * scalar_replacement might be able to remove the local variable,
+                                * so honor this.
+                                */
+                               v = get_method_local_adress_weight(callee, i);
+                               weight += v;
+                               if (v > 0)
+                                       *local_adr = 1;
+                       }
                }
        }
 
@@ -1830,26 +1922,48 @@ static int calc_inline_benefice(ir_node *call, ir_graph *callee, unsigned *local
 
        /* reduce the benefice if the current function is already big */
        curr_env = get_irg_link(current_ir_graph);
-       weight -= curr_env->n_nodes / 100;
+       weight -= curr_env->n_nodes / 50;
 
        /* give a bonus for functions with one block */
        if (callee_env->n_blocks == 1)
                weight = weight * 3 / 2;
 
+       /* and one for small non-recursive functions: we want them to be inlined in mostly every case */
+       else if (callee_env->n_nodes < 20 && !callee_env->recursive)
+               weight += 5000;
+
+       /* and finally for leaves: they do not increase the register pressure
+          because of callee safe registers */
+       else if (callee_env->n_call_nodes == 0)
+               weight += 25;
+
+       /*
+        * Reduce the weight for recursive function IFF not all arguments are const.
+        * inlining recursive functions is rarely good.
+        */
+       if (callee_env->recursive && !all_const)
+               weight -= 500;
+
+       /*
+        * All arguments constant is probably a good sign, give an extra bonus
+        */
+       if (all_const)
+               weight += 100;
+
        return weight;
 }
 
 /**
- * Heuristic inliner. Calculates a benifice value for every call and inlines
+ * Heuristic inliner. Calculates a benefice value for every call and inlines
  * those calls with a value higher than the threshold.
  */
-void inline_functions(int inline_threshold) {
+void inline_functions(int maxsize, int inline_threshold) {
        inline_irg_env   *env;
        int              i, n_irgs;
        ir_graph         *rem;
        int              did_inline;
        wenv_t           wenv;
-       call_entry       *entry, *tail;
+       call_entry       *curr_call, **last_call;
        const call_entry *centry;
        pmap             *copied_graphs;
        pmap_entry       *pm_entry;
@@ -1874,7 +1988,9 @@ void inline_functions(int inline_threshold) {
                assert(get_irg_phase_state(irg) != phase_building);
                free_callee_info(irg);
 
-               wenv.x = get_irg_link(irg);
+               wenv.x         = get_irg_link(irg);
+               wenv.last_call = NULL;
+               assure_cf_loop(irg);
                irg_walk_graph(irg, NULL, collect_calls2, &wenv);
        }
 
@@ -1888,30 +2004,32 @@ void inline_functions(int inline_threshold) {
                env = get_irg_link(irg);
 
                /* note that the list of possible calls is updated during the process */
-               tail = NULL;
-               for (entry = env->call_head; entry != NULL; entry = entry->next) {
+               last_call = &env->call_head;
+               for (curr_call = env->call_head; curr_call != NULL;) {
                        ir_graph   *callee;
                        pmap_entry *e;
                        int        benefice;
                        unsigned   local_adr;
 
-                       call   = entry->call;
-                       callee = entry->callee;
+                       if (env->n_nodes > maxsize) break;
 
-                       /* calculate the benifice on the original call to prevent excessive inlining */
-                       local_adr = 0;
-                       benefice = calc_inline_benefice(call, callee, &local_adr);
-                       DB((dbg, SET_LEVEL_2, "In %+F Call %+F has benefice %d\n", irg, callee, benefice));
+                       call   = curr_call->call;
+                       callee = curr_call->callee;
 
                        e = pmap_find(copied_graphs, callee);
                        if (e != NULL) {
                                /*
-                                * Remap callee if we have a copy.
-                                * FIXME: Should we do this only for recursive Calls ?
-                                */
+                               * Remap callee if we have a copy.
+                               * FIXME: Should we do this only for recursive Calls ?
+                               */
                                callee = e->value;
                        }
 
+                       /* calculate the benefice on the original call to prevent excessive inlining */
+                       local_adr = 0;
+                       benefice = calc_inline_benefice(call, callee, &local_adr);
+                       DB((dbg, LEVEL_2, "In %+F Call %+F has benefice %d\n", irg, callee, benefice));
+
                        if (benefice > -inline_threshold ||
                                (get_irg_inline_property(callee) >= irg_inline_forced)) {
                                if (current_ir_graph == callee) {
@@ -1938,6 +2056,7 @@ void inline_functions(int inline_threshold) {
                                        callee_env = alloc_inline_irg_env();
                                        set_irg_link(copy, callee_env);
 
+                                       assure_cf_loop(copy);
                                        wenv.x              = callee_env;
                                        wenv.ignore_callers = 1;
                                        irg_walk_graph(copy, NULL, collect_calls2, &wenv);
@@ -1967,34 +2086,31 @@ void inline_functions(int inline_threshold) {
                                        /* was inlined, must be recomputed */
                                        phiproj_computed = 0;
 
+                                       /* after we have inlined callee, all called methods inside callee
+                                       are now called once more */
+                                       for (centry = callee_env->call_head; centry != NULL; centry = centry->next) {
+                                               inline_irg_env *penv = get_irg_link(centry->callee);
+                                               ++penv->n_callers;
+                                       }
+
                                        /* callee was inline. Append it's call list. */
                                        env->got_inline = 1;
                                        if (local_adr)
                                                env->local_vars = 1;
                                        --env->n_call_nodes;
-                                       append_call_list(env, callee_env->call_head);
+                                       curr_call = replace_entry_by_call_list(curr_call, callee_env->call_head);
                                        env->n_call_nodes += callee_env->n_call_nodes;
                                        env->n_nodes += callee_env->n_nodes;
                                        --callee_env->n_callers;
 
-                                       /* after we have inlined callee, all called methods inside callee
-                                          are now called once more */
-                                       for (centry = callee_env->call_head; centry != NULL; centry = centry->next) {
-                                               inline_irg_env *penv = get_irg_link(centry->callee);
-                                               ++penv->n_callers;
-                                       }
-
-                                       /* remove this call from the list */
-                                       if (tail != NULL)
-                                               tail->next = entry->next;
-                                       else
-                                               env->call_head = entry->next;
+                                       /* remove the current call entry from the list */
+                                       *last_call = curr_call;
                                        continue;
                                }
                        }
-                       tail = entry;
+                       last_call = &curr_call->next;
+                       curr_call = curr_call->next;
                }
-               env->call_tail = tail;
 
                if (env->got_inline) {
                        /* this irg got calls inlined: optimize it */
@@ -2007,11 +2123,10 @@ void inline_functions(int inline_threshold) {
                                        optimize_graph_df(irg);
                                }
                        }
-
                        optimize_cf(irg);
                }
                if (env->got_inline || (env->n_callers_orig != env->n_callers)) {
-                       DB((dbg, SET_LEVEL_1, "Nodes:%3d ->%3d, calls:%3d ->%3d, callers:%3d ->%3d, -- %s\n",
+                       DB((dbg, LEVEL_1, "Nodes:%3d ->%3d, calls:%3d ->%3d, callers:%3d ->%3d, -- %s\n",
                        env->n_nodes_orig, env->n_nodes, env->n_call_nodes_orig, env->n_call_nodes,
                        env->n_callers_orig, env->n_callers,
                        get_entity_name(get_irg_entity(irg))));