**
** Author: Christian Schaefer
**
-** dead node elimination
-** walks one time through the whole graph and copies it into another graph,
-** so unreachable nodes will be lost.
+** Optimizations for a whole ir graph, i.e., a procedure.
*/
+# include <assert.h>
+
# include "irgopt.h"
-# include "irnode.h"
+# include "irnode_t.h"
+# include "irgraph_t.h"
# include "iropt.h"
# include "irgwalk.h"
-# include "irgraph.h"
# include "ircons.h"
+# include "misc.h"
+# include "irgmod.h"
/********************************************************************/
/* apply optimizations of iropt to all nodes. */
+/********************************************************************/
+
void
optimize_in_place_wrapper (ir_node *n, void *env) {
int i;
}
}
-
void
local_optimize_graph (ir_graph *irg) {
ir_graph *rem = current_ir_graph;
/********************************************************************/
/* Routines for dead node elimination / copying garbage collection */
/* of the obstack. */
+/********************************************************************/
-/* Remeber the new node in the old node,
- by using a field that all nodes have. */
-void *
+/* Remeber the new node in the old node by using a field all nodes have. */
+inline void
set_new_node (ir_node *old, ir_node *new)
{
- old->in[0] = new; /* Hi Chris: Benutze old->link, ich hab mich vergewissert dass
- das hier ueberschrieben werden kann, das erspaart eine
- indirektion --> schneller. */
- return old;
+ old->link = new;
}
/* Get this new node, before the old node is forgotton.*/
-ir_node *
+inline ir_node *
get_new_node (ir_node * n)
{
- ir_node *new;
- new = n->in[0];
- assert(new);
-
- return new;
+ return n->link;
}
-/* Create this node on a new obstack. */
-void
-copy_node (ir_node *n, void *env) {
- ir_node *res = NULL;
- ir_node *a = NULL;
- ir_node *b = NULL;
- int i;
-
- assert (n);
- DDMSG2(n);
- if (is_binop(n)) {
- a = get_binop_left(n);
- b = get_binop_right(n);
- } else if (is_unop(n)) {
- a = get_unop_op(n);
+/* We use the block_visited flag to mark that we have computed the
+ number of useful predecessors for this block.
+ Further we encode the new arity in this flag. Remembering the arity is
+ useful, as it saves a lot of pointer accesses. This function is called
+ for all Phi and Block nodes in a Block. */
+inline int
+compute_new_arity(ir_node *b) {
+ int i, res;
+ int irg_v, block_v;
+
+ irg_v = get_irg_block_visited(current_ir_graph);
+ block_v = get_Block_block_visited(b);
+ if (block_v >= irg_v) {
+ /* we computed the number of preds for this block and saved it in the
+ block_v flag */
+ return block_v - irg_v;
+ } else {
+ /* compute the number of good predecessors */
+ res = get_irn_arity(b);
+ for (i = 0; i < get_irn_arity(b); i++)
+ if (get_irn_opcode(get_irn_n(b, i)) == iro_Bad) res--;
+ /* save it in the flag. */
+ set_Block_block_visited(b, irg_v + res);
+ return res;
}
+}
- switch (get_irn_opcode(n)) {
- case iro_Block:
- {
- ir_node **in = get_Block_cfgpred_arr(n);
- for (i = 0; i < get_Block_n_cfgpreds(n); i++)
- set_Block_cfgpred(n, i, get_new_node(get_Block_cfgpred(n, i)));
- res = new_r_Block (current_ir_graph, get_Block_n_cfgpreds(n), in);
+/* Copies the node to the new obstack. The Ins of the new node point to
+ the predecessors on the old obstack. n->link points to the new node.
+ For Phi and Block nodes the function allocate in arrays with an arity
+ only for useful predecessors. The arity is determined by counting
+ the non-bad predecessors of the block. */
+inline void
+copy_node (ir_node *n, void *env) {
+ ir_node *nn, *block;
+ int new_arity;
+
+ if (get_irn_opcode(n) == iro_Block) {
+ block = NULL;
+ new_arity = compute_new_arity(n);
+ } else {
+ block = get_nodes_Block(n);
+ if (get_irn_opcode(n) == iro_Phi) {
+ new_arity = compute_new_arity(block);
+ } else {
+ new_arity = get_irn_arity(n);
}
- break;
- case iro_Start:
- res = new_r_Start (current_ir_graph, get_new_node(get_nodes_Block(n)));
- break;
- case iro_End:
- res = new_r_End (current_ir_graph, get_new_node(get_nodes_Block(n)));
- current_ir_graph -> end = res;
- current_ir_graph -> end_block = get_nodes_Block(res);
- break;
- case iro_Jmp:
- res = new_r_Jmp (current_ir_graph, get_new_node(get_nodes_Block(n)));
- break;
- case iro_Cond:
- DDMSG;
- res = new_r_Cond (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Cond_selector(n)));
- break;
- case iro_Return:
- {
- ir_node **in;
- in = get_Return_res_arr(n);
- for (i = 0; i < get_Return_n_res(n); i++) {
- set_Return_res(n, i, get_new_node(get_Return_res(n, i)));
+ }
+ nn = new_ir_node(current_ir_graph,
+ block,
+ get_irn_op(n),
+ get_irn_mode(n),
+ new_arity,
+ get_irn_in(n));
+ copy_attrs(n, nn);
+ set_new_node(n, nn);
+}
+
+/* Copies new predecessors of old node to new node remembered in link.
+ Spare the Bad predecessors of Phi and Block nodes. */
+inline void
+copy_preds (ir_node *n, void *env) {
+ ir_node *nn, *block/*, *on*/;
+ int i, j;
+
+ nn = get_new_node(n);
+
+ if (get_irn_opcode(n) == iro_Block) {
+ /* Don't copy Bad nodes. */
+ j = 0;
+ for (i = 0; i < get_irn_arity(n); i++)
+ if (get_irn_opcode(get_irn_n(n, i)) != iro_Bad) {
+ set_irn_n (nn, j, get_new_node(get_irn_n(n, i)));
+ j++;
}
- res = new_r_Return (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Return_mem(n)),
- get_Return_n_res(n), in);
- }
- break;
- case iro_Raise:
- res = new_r_Raise (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Raise_mem(n)),
- get_new_node(get_Raise_exo_ptr(n)));
- break;
- case iro_Const:
- res = new_r_Const (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_irn_mode(n), get_Const_tarval(n));
- break;
- case iro_SymConst:
- {
- type_or_id *value = NULL;
-
- if ((get_SymConst_kind(n)==type_tag) || (get_SymConst_kind(n)==size))
- {
-
- value = (type_or_id *) get_SymConst_type(n);
- }
- else
- {
- if (get_SymConst_kind(n)==linkage_ptr_info)
- {
- value = (type_or_id *) get_SymConst_ptrinfo(n);
- }
- }
- res = new_r_SymConst (current_ir_graph, get_new_node(get_nodes_Block(n)),
- value, get_SymConst_kind (n));
- }
- break;
- case iro_Sel:
- {
- ir_node **in = get_Sel_index_arr(n);
- for (i = 0; i < get_Sel_n_index(n); i++)
- set_Sel_index(n, i, get_new_node(get_Sel_index(n, i)));
- res = new_r_Sel (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Sel_mem(n)),
- get_new_node(get_Sel_ptr(n)), get_Sel_n_index(n),
- in, get_Sel_entity(n));
- }
- break;
- case iro_Call:
- {
- ir_node **in = get_Call_param_arr(n);
- for (i = 0; i < get_Call_arity(n); i++)
- set_Call_param(n, i, get_new_node(get_Call_param(n, i)));
- res = new_r_Call (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Call_mem(n)),
- get_new_node(get_Call_ptr(n)), get_Call_arity(n),
- in, get_Call_type (n));
- }
- break;
- case iro_Add:
- res = new_r_Add (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(a), get_new_node(b), get_irn_mode(n));
- break;
- case iro_Sub:
- {
- res = new_r_Sub (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(a), get_new_node(b), get_irn_mode(n));
- }
- break;
- case iro_Minus:
- res = new_r_Minus (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(a), get_irn_mode(n));
- break;
- case iro_Mul:
- res = new_r_Mul (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(a), get_new_node(b), get_irn_mode(n));
- break;
- case iro_Quot:
- res = new_r_Quot (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Quot_mem(n)), get_new_node(a),
- get_new_node(b));
- break;
- case iro_DivMod:
- res = new_r_DivMod (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_DivMod_mem(n)), get_new_node(a),
- get_new_node(b));
- break;
- case iro_Div:
- res = new_r_Div (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Div_mem(n)), get_new_node(a),
- get_new_node(b));
- break;
- case iro_Mod:
- res = new_r_Mod (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Mod_mem(n)), get_new_node(a),
- get_new_node(b));
- break;
- case iro_Abs:
- res = new_r_Abs (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Abs_op(n)), get_irn_mode(n));
- break;
- case iro_And:
- res = new_r_And (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(a), get_new_node(b), get_irn_mode(n));
- break;
- case iro_Or:
- res = new_r_Or (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(a), get_new_node(b), get_irn_mode(n));
- break;
- case iro_Eor:
- res = new_r_Eor (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(a), get_new_node(b), get_irn_mode(n));
- break;
- case iro_Not:
- res = new_r_Not (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Not_op(n)), get_irn_mode(n));
- break;
- case iro_Cmp:
- res = new_r_Cmp (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Cmp_left(n)),
- get_new_node(get_Cmp_right(n)));
- break;
- case iro_Shl:
- res = new_r_Shl (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Shl_left(n)),
- get_new_node(get_Shl_right(n)), get_irn_mode(n));
- break;
- case iro_Shr:
- res = new_r_Shr (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Shr_left(n)),
- get_new_node(get_Shr_right(n)), get_irn_mode(n));
- break;
- case iro_Shrs:
- res = new_r_Shrs (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Shrs_left(n)),
- get_new_node(get_Shrs_right(n)), get_irn_mode(n));
- break;
- case iro_Rot:
- res = new_r_Rot (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Rot_left(n)),
- get_new_node(get_Rot_right(n)), get_irn_mode(n));
- break;
- case iro_Conv:
- res = new_r_Conv (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Conv_op(n)),
- get_irn_mode(n));
- break;
- case iro_Phi:
- {
- ir_node **in = get_Phi_preds_arr(n);
- for (i = 0; i < get_Phi_n_preds(n); i++)
- set_Phi_pred(n, i, get_new_node(get_Phi_pred(n, i)));
- res = new_r_Phi (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_Phi_n_preds(n), in, get_irn_mode(n));
- }
- break;
- case iro_Load:
- res = new_r_Load (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Load_mem(n)),
- get_new_node(get_Load_ptr(n)));
- break;
- case iro_Store:
- res = new_r_Store (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Store_mem(n)),
- get_new_node(get_Store_ptr(n)),
- get_new_node(get_Store_value(n)));
- break;
- case iro_Alloc:
- res = new_r_Alloc (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Alloc_mem(n)),
- get_new_node(get_Alloc_size(n)),
- get_Alloc_type(n), get_Alloc_where(n));
-
- break;
- case iro_Free:
- res = new_r_Free (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Free_mem(n)),
- get_new_node(get_Free_ptr(n)),
- get_new_node(get_Free_size(n)), get_Free_type(n));
- break;
- case iro_Sync:
- {
- ir_node **in = get_Sync_preds_arr(n);
- for (i = 0; i < get_Sync_n_preds(n); i++)
- set_Sync_pred(n, i, get_new_node(get_Sync_pred(n, i)));
- res = new_r_Sync (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_Sync_n_preds(n), in);
- }
- break;
- case iro_Proj:
- res = new_r_Proj (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Proj_pred(n)), get_irn_mode(n),
- get_Proj_proj(n));
- break;
- case iro_Tuple:
- {
- ir_node **in = get_Tuple_preds_arr(n);
- for (i = 0; i < get_Tuple_n_preds(n); i++)
- set_Tuple_pred(n, i, get_new_node(get_Tuple_pred(n, i)));
- res = new_r_Tuple (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_Tuple_n_preds(n), in);
- }
- break;
- case iro_Id:
- res = new_r_Id (current_ir_graph, get_new_node(get_nodes_Block(n)),
- get_new_node(get_Id_pred(n)), get_irn_mode(n));
- break;
- case iro_Bad:
- res = new_r_Bad ();
- break;
+ /* repair the block visited flag from above misuse */
+ set_Block_block_visited(nn, 0);
+ /* Local optimization could not merge two subsequent blocks if
+ in array contained Bads. Now it's possible. *
+ on = optimize_in_place(nn);
+ if (nn != on) exchange(nn, on);*/
+ } else if (get_irn_opcode(n) == iro_Phi) {
+ /* Don't copy node if corresponding predecessor in block is Bad.
+ The Block itself should not be Bad. */
+ block = get_nodes_Block(n);
+ set_irn_n (nn, -1, get_new_node(block));
+ j = 0;
+ for (i = 0; i < get_irn_arity(n); i++)
+ if (get_irn_opcode(get_irn_n(block, i)) != iro_Bad) {
+ set_irn_n (nn, j, get_new_node(get_irn_n(n, i)));
+ j++;
+ }
+ /* Compacting the Phi's ins might generate Phis with only one
+ predecessor. *
+ if (get_irn_arity(n) == 1)
+ exchange(n, get_irn_n(n, 0)); */
+ } else {
+ for (i = -1; i < get_irn_arity(n); i++)
+ set_irn_n (nn, i, get_new_node(get_irn_n(n, i)));
}
- /* @@@ Here we could call optimize()!! */
- set_new_node(n, res);
+}
- printf(" "); DDMSG2(res);
+/* Copies the graph reachable from current_ir_graph->end to the obstack
+ in current_ir_graph.
+ Then fixes the fields in current_ir_graph containing nodes of the
+ graph. */
+void
+copy_graph () {
+ /* Not all nodes remembered in current_ir_graph might be reachable
+ from the end node. Assure their link is set to NULL so that
+ we can test whether new nodes have been computed. */
+ set_irn_link(get_irg_frame (current_ir_graph), NULL);
+ set_irn_link(get_irg_globals(current_ir_graph), NULL);
+ set_irn_link(get_irg_args (current_ir_graph), NULL);
+
+ /* we use the block walk flag for removing Bads from Blocks ins. */
+ inc_irg_block_visited(current_ir_graph);
+
+ /* copy the graph */
+ irg_walk(get_irg_end(current_ir_graph), copy_node, copy_preds, NULL);
+
+ /* fix the fields in current_ir_graph */
+ set_irg_end (current_ir_graph, get_new_node(get_irg_end(current_ir_graph)));
+ set_irg_end_block (current_ir_graph, get_new_node(get_irg_end_block(current_ir_graph)));
+ if (get_irn_link(get_irg_frame(current_ir_graph)) == NULL)
+ irg_walk(get_irg_frame(current_ir_graph), copy_node, copy_preds, NULL);
+ if (get_irn_link(get_irg_globals(current_ir_graph)) == NULL)
+ irg_walk(get_irg_globals(current_ir_graph), copy_node, copy_preds, NULL);
+ if (get_irn_link(get_irg_args(current_ir_graph)) == NULL)
+ irg_walk(get_irg_args(current_ir_graph), copy_node, copy_preds, NULL);
+ set_irg_start (current_ir_graph, get_new_node(get_irg_start(current_ir_graph)));
+ set_irg_start_block(current_ir_graph,
+ get_new_node(get_irg_start_block(current_ir_graph)));
+ set_irg_frame (current_ir_graph, get_new_node(get_irg_frame(current_ir_graph)));
+ set_irg_globals(current_ir_graph, get_new_node(get_irg_globals(current_ir_graph)));
+ set_irg_args (current_ir_graph, get_new_node(get_irg_args(current_ir_graph)));
+ if (get_irn_link(get_irg_bad(current_ir_graph)) == NULL) {
+ copy_node(get_irg_bad(current_ir_graph), NULL);
+ copy_preds(get_irg_bad(current_ir_graph), NULL);
+ }
+ set_irg_bad(current_ir_graph, get_new_node(get_irg_bad(current_ir_graph)));
}
+
/* Amroq call this emigrate() */
void
dead_node_elimination(ir_graph *irg) {
- struct obstack *graveyard_obst=NULL;
- struct obstack *rebirth_obst;
+ ir_graph *rem;
+ struct obstack *graveyard_obst = NULL;
+ struct obstack *rebirth_obst = NULL;
- ir_node *old_node, *new_node;
- ir_graph *rem = current_ir_graph;
+ /* Remember external state of current_ir_graph. */
+ rem = current_ir_graph;
current_ir_graph = irg;
- if (get_opt_dead_node_elimination()) {
+ if (get_optimize() && get_opt_dead_node_elimination()) {
/* A quiet place, where the old obstack can rest in peace,
until it will be cremated. */
current_ir_graph->obst = rebirth_obst;
obstack_init (current_ir_graph->obst);
- /*CS*/
- printf("Before starting the DEAD NODE ELIMINATION !\n");
-
- /* Copy nodes remembered in irg fields first.
- The optimization contains tests against these fields, e.g., not
- to optimize the start block away. Therefore these fields have to
- be fixed first.
- Further setting these fields in copy_node would impose additional
- tests for all nodes of a kind.
- Predict the visited flag the walker will use! */
- /* Copy the start Block node */
- old_node = irg->start_block;
- new_node = new_r_Block (current_ir_graph, 0, NULL); /* new_r_Block calls
- no optimization --> save */
- irg->start_block = new_node;
- set_new_node (old_node, new_node);
- set_irn_visited (old_node, get_irg_visited(current_ir_graph)+1);
- /* Copy the Start node */
- old_node = irg->start;
- new_node = new_r_Start (current_ir_graph, irg->start_block);
- irg->start = new_node;
- DDMSG2(new_node);
- set_new_node (old_node, new_node);
- set_irn_visited (old_node, get_irg_visited(current_ir_graph)+1);
- /* Copy the Bad node */
- old_node = irg->bad;
- new_node = new_ir_node (irg, irg->start_block, op_Bad, mode_T, 0, NULL);
- irg->bad = new_node;
- set_new_node (old_node, new_node);
- set_irn_visited (old_node, get_irg_visited(current_ir_graph)+1);
- /* Copy the Projs for the Start's results. */
- old_node = irg->frame;
- new_node = new_r_Proj (irg, irg->start_block, irg->start, mode_p, pns_frame_base);
- irg->frame = new_node;
- set_new_node (old_node, new_node);
- set_irn_visited (old_node, get_irg_visited(current_ir_graph)+1);
-
- old_node = irg->globals;
- new_node = new_r_Proj (irg, irg->start_block, irg->start, mode_p, pns_globals);
- irg->globals = new_node;
- set_new_node (old_node, new_node);
- set_irn_visited (old_node, get_irg_visited(current_ir_graph)+1);
-
- old_node = irg->args;
- new_node = new_r_Proj (irg, irg->start_block, irg->start, mode_T, pns_args);
- irg->args = new_node;
- set_new_node (old_node, new_node);
- set_irn_visited (old_node, get_irg_visited(current_ir_graph)+1);
-
- /* Walks the graph once, and at the recursive way do the copy thing.
- all reachable nodes will be copied to a new obstack. */
- irg_walk(irg->end, NULL, copy_node, NULL);
-
- /*CS*/
- printf("After the DEAD NODE ELIMINATION !\n");
+ /* Copy the graph from the old to the new obstack */
+ copy_graph();
/* Free memory from old unoptimized obstack */
- xfree (graveyard_obst);
+ obstack_free(graveyard_obst, 0); /* First empty the obstack ... */
+ xfree (graveyard_obst); /* ... then free it. */
}
current_ir_graph = rem;
projects / libfirm / blobdiff