/*
- * Copyright (C) 1995-2007 University of Karlsruhe. All right reserved.
+ * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
*
* This file is part of libFirm.
*
#undef IMAX
#define IMAX(a,b) ((a) > (b) ? (a) : (b))
-#define MAX_PROJ IMAX(pn_Load_max, pn_Store_max)
+#define MAX_PROJ IMAX(IMAX(pn_Load_max, pn_Store_max), pn_Call_max)
enum changes_t {
DF_CHANGED = 1, /**< data flow changed */
unsigned changes; /**< a bitmask of graph changes */
} walk_env_t;
-/**
- * flags for Load/Store
- */
-enum ldst_flags_t {
- LDST_VISITED = 1 /**< if set, this Load/Store is already visited */
-};
-
/** A Load/Store info. */
typedef struct _ldst_info_t {
ir_node *projs[MAX_PROJ]; /**< list of Proj's of this node */
ir_node *exc_block; /**< the exception block if available */
int exc_idx; /**< predecessor index in the exception block */
- unsigned flags; /**< flags */
unsigned visited; /**< visited counter for breaking loops */
} ldst_info_t;
*/
static void collect_nodes(ir_node *node, void *env)
{
- ir_op *op = get_irn_op(node);
+ ir_opcode opcode = get_irn_opcode(node);
ir_node *pred, *blk, *pred_blk;
ldst_info_t *ldst_info;
walk_env_t *wenv = env;
- if (op == op_Proj) {
- ir_node *adr;
- ir_op *op;
-
- pred = get_Proj_pred(node);
- op = get_irn_op(pred);
+ if (opcode == iro_Proj) {
+ pred = get_Proj_pred(node);
+ opcode = get_irn_opcode(pred);
- if (op == op_Load) {
+ if (opcode == iro_Load || opcode == iro_Store || opcode == iro_Call) {
ldst_info = get_ldst_info(pred, &wenv->obst);
wenv->changes |= update_projs(ldst_info, node);
- if ((ldst_info->flags & LDST_VISITED) == 0) {
- adr = get_Load_ptr(pred);
- ldst_info->flags |= LDST_VISITED;
- }
-
/*
* Place the Proj's to the same block as the
* predecessor Load. This is always ok and prevents
wenv->changes |= DF_CHANGED;
set_nodes_block(node, pred_blk);
}
- } else if (op == op_Store) {
- ldst_info = get_ldst_info(pred, &wenv->obst);
-
- wenv->changes |= update_projs(ldst_info, node);
-
- if ((ldst_info->flags & LDST_VISITED) == 0) {
- adr = get_Store_ptr(pred);
- ldst_info->flags |= LDST_VISITED;
- }
-
- /*
- * Place the Proj's to the same block as the
- * predecessor Store. This is always ok and prevents
- * "non-SSA" form after optimizations if the Proj
- * is in a wrong block.
- */
- blk = get_nodes_block(node);
- pred_blk = get_nodes_block(pred);
- if (blk != pred_blk) {
- wenv->changes |= DF_CHANGED;
- set_nodes_block(node, pred_blk);
- }
}
- } else if (op == op_Block) {
+ } else if (opcode == iro_Block) {
int i;
for (i = get_Block_n_cfgpreds(node) - 1; i >= 0; --i) {
else if (is_irn_forking(pred))
bl_info->flags |= BLOCK_HAS_COND;
- if (is_exc && (get_irn_op(pred) == op_Load || get_irn_op(pred) == op_Store)) {
+ opcode = get_irn_opcode(pred);
+ if (is_exc && (opcode == iro_Load || opcode == iro_Store || opcode == iro_Call)) {
ldst_info = get_ldst_info(pred, &wenv->obst);
wenv->changes |= update_exc(ldst_info, node, i);
exchange(info->projs[pn_Load_M], mem);
if (info->projs[pn_Load_X_regular])
exchange(info->projs[pn_Load_X_regular], new_r_Jmp(current_ir_graph, get_nodes_block(load)));
- exchange(load, new_Bad());
+ kill_node(load);
reduce_adr_usage(ptr);
}
} /* handle_load_update */
} /* can_use_stored_value */
/**
- * Follow the memory chain as long as there are only Loads
- * and alias free Stores and try to replace current Load or Store
- * by a previous ones.
+ * Check whether a Call is at least pure, ie. does only read memory.
+ */
+static unsigned is_Call_pure(ir_node *call) {
+ ir_type *call_tp = get_Call_type(call);
+ unsigned prop = get_method_additional_properties(call_tp);
+
+ /* check first the call type */
+ if ((prop & (mtp_property_const|mtp_property_pure)) == 0) {
+ /* try the called entity */
+ ir_node *ptr = get_Call_ptr(call);
+
+ if (is_Global(ptr)) {
+ ir_entity *ent = get_Global_entity(ptr);
+
+ prop = get_entity_additional_properties(ent);
+ }
+ }
+ return (prop & (mtp_property_const|mtp_property_pure)) != 0;
+} /* is_Call_pure */
+
+/**
+ * Follow the memory chain as long as there are only Loads,
+ * alias free Stores, and constant Calls and try to replace the
+ * current Load by a previous ones.
* Note that in unreachable loops it might happen that we reach
* load again, as well as we can fall into a cycle.
* We break such cycles using a special visited flag.
if (info->projs[pn_Load_res])
exchange(info->projs[pn_Load_res], value);
- exchange(load, new_Bad());
+ kill_node(load);
reduce_adr_usage(ptr);
return res | DF_CHANGED;
}
res |= CF_CHANGED;
}
- exchange(load, new_Bad());
+ kill_node(load);
reduce_adr_usage(ptr);
return res |= DF_CHANGED;
}
get_irn_mode(get_Store_value(pred)),
ptr, load_mode);
/* if the might be an alias, we cannot pass this Store */
- if (rel != no_alias)
+ if (rel != ir_no_alias)
break;
pred = skip_Proj(get_Store_mem(pred));
- } else if (get_irn_op(pred) == op_Load) {
+ } else if (is_Load(pred)) {
pred = skip_Proj(get_Load_mem(pred));
+ } else if (is_Call(pred)) {
+ if (is_Call_pure(pred)) {
+ /* The called graph is at least pure, so there are no Store's
+ in it. We can handle it like a Load and skip it. */
+ pred = skip_Proj(get_Call_mem(pred));
+ } else {
+ /* there might be Store's in the graph, stop here */
+ break;
+ }
} else {
/* follow only Load chains */
break;
for (i = get_Sync_n_preds(pred) - 1; i >= 0; --i) {
res |= follow_Mem_chain(load, skip_Proj(get_Sync_pred(pred, i)));
if (res)
- break;
+ return res;
}
}
exchange(info->projs[pn_Load_X_regular], new_r_Jmp(current_ir_graph, get_nodes_block(load)));
res |= CF_CHANGED;
}
- exchange(load, new_Bad());
+ kill_node(load);
reduce_adr_usage(ptr);
return res | DF_CHANGED;
}
if (info->projs[pn_Load_res])
exchange(info->projs[pn_Load_res], new_node);
- exchange(load, new_Bad());
+ kill_node(load);
reduce_adr_usage(ptr);
return res | DF_CHANGED;
}
res |= DF_CHANGED;
}
}
- exchange(load, new_Bad());
+ kill_node(load);
reduce_adr_usage(ptr);
return res;
} else {
compound_graph_path *path = get_accessed_path(ptr);
- if (path) {
+ if (path && !ent->has_initializer) {
ir_node *c;
assert(is_proper_compound_graph_path(path, get_compound_graph_path_length(path)-1));
exchange(info->projs[pn_Load_res], copy_const_value(get_irn_dbg_info(load), c));
res |= DF_CHANGED;
}
- exchange(load, new_Bad());
+ kill_node(load);
reduce_adr_usage(ptr);
return res;
} else {
get_nodes_MacroBlock(pred) == mblk &&
is_completely_overwritten(get_irn_mode(get_Store_value(pred)), mode)) {
/*
- * a Store after a Store in the same block -- a write after write.
+ * a Store after a Store in the same MacroBlock -- a write after write.
* We may remove the first Store, if it does not have an exception handler.
*
* TODO: What, if both have the same exception handler ???
if (get_Store_volatility(pred) != volatility_is_volatile && !pred_info->projs[pn_Store_X_except]) {
DBG_OPT_WAW(pred, store);
exchange(pred_info->projs[pn_Store_M], get_Store_mem(pred));
- exchange(pred, new_Bad());
+ kill_node(pred);
reduce_adr_usage(ptr);
return DF_CHANGED;
}
} else if (is_Load(pred) && get_Load_ptr(pred) == ptr &&
value == pred_info->projs[pn_Load_res]) {
/*
- * a Store of a value after a Load -- a write after read.
- * We may remove the second Store, if it does not have an exception handler.
+ * a Store of a value just loaded from the same address
+ * -- a write after read.
+ * We may remove the Store, if it does not have an exception
+ * handler.
*/
if (! info->projs[pn_Store_X_except]) {
DBG_OPT_WAR(store, pred);
exchange(info->projs[pn_Store_M], mem);
- exchange(store, new_Bad());
+ kill_node(store);
reduce_adr_usage(ptr);
return DF_CHANGED;
}
get_irn_mode(get_Store_value(pred)),
ptr, mode);
/* if the might be an alias, we cannot pass this Store */
- if (rel != no_alias)
+ if (rel != ir_no_alias)
break;
pred = skip_Proj(get_Store_mem(pred));
} else if (get_irn_op(pred) == op_Load) {
+ ir_alias_relation rel = get_alias_relation(
+ current_ir_graph, get_Load_ptr(pred), get_Load_mode(pred),
+ ptr, mode);
+ if (rel != ir_no_alias)
+ break;
+
pred = skip_Proj(get_Load_mem(pred));
} else {
/* follow only Load chains */
/* follow the memory chain as long as there are only Loads */
INC_MASTER();
+
return follow_Mem_chain_for_Store(store, skip_Proj(mem));
} /* optimize_store */
case iro_Phi:
wenv->changes |= optimize_phi(n, wenv);
+ break;
default:
;
};
/**
- * Move loops out of loops if possible
+ * Move loops out of loops if possible.
+ *
+ * @param pscc the loop described by an SCC
+ * @param env the loop environment
*/
-static void move_loads_in_loops(scc *pscc, loop_env *env) {
+static void move_loads_out_of_loops(scc *pscc, loop_env *env) {
ir_node *phi, *load, *next, *other, *next_other;
ir_entity *ent;
int j;
if (info->projs[pn_Load_res] == NULL || info->projs[pn_Load_X_regular] != NULL || info->projs[pn_Load_X_except] != NULL)
continue;
- /* for now, we can only handle Load(SymConst) */
- if (! is_SymConst(ptr) || get_SymConst_kind(ptr) != symconst_addr_ent)
+ /* for now, we can only handle Load(Global) */
+ if (! is_Global(ptr))
continue;
- ent = get_SymConst_entity(ptr);
+ ent = get_Global_entity(ptr);
load_mode = get_Load_mode(load);
for (other = pscc->head; other != NULL; other = next_other) {
node_entry *ne = get_irn_ne(other, env);
get_irn_mode(get_Store_value(other)),
ptr, load_mode);
/* if the might be an alias, we cannot pass this Store */
- if (rel != no_alias)
+ if (rel != ir_no_alias)
break;
}
+ /* only pure Calls are allowed here, so ignore them */
}
if (other == NULL) {
ldst_info_t *ninfo;
}
}
}
-} /* move_loads_in_loops */
+} /* move_loads_out_of_loops */
/**
* Process a loop SCC.
next = e->next;
switch (get_irn_opcode(irn)) {
case iro_Call:
+ if (is_Call_pure(irn)) {
+ /* pure calls can be treated like loads */
+ only_phi = 0;
+ break;
+ }
+ /* non-pure calls must be handle like may-alias Stores */
+ goto fail;
case iro_CopyB:
- /* cannot handle Calls or CopyB yet */
+ /* cannot handle CopyB yet */
goto fail;
case iro_Load:
process = 1;
}
DB((dbg, LEVEL_2, "\n"));
- move_loads_in_loops(pscc, env);
+ move_loads_out_of_loops(pscc, env);
fail:
;
for (i = get_Block_n_cfgpreds(endblk) - 1; i >= 0; --i) {
ir_node *pred = get_Block_cfgpred(endblk, i);
+ pred = skip_Proj(pred);
if (is_Return(pred))
dfs(get_Return_mem(pred), env);
else if (is_Raise(pred))
/**
* Initialize new phase data. We do this always explicit, so return NULL here
*/
-static void *init_loop_data(ir_phase *ph, ir_node *irn, void *data) {
+static void *init_loop_data(ir_phase *ph, const ir_node *irn, void *data) {
(void)ph;
(void)irn;
(void)data;
assert(get_irg_pinned(irg) != op_pin_state_floats &&
"LoadStore optimization needs pinned graph");
- if (! get_opt_redundant_loadstore())
- return;
-
/* we need landing pads */
remove_critical_cf_edges(irg);
projects / libfirm / blobdiff