* Copyright: (c) 1998-2004 Universit\81ät Karlsruhe
* Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
*/
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#ifdef HAVE_ALLOCA_H
+#include <alloca.h>
+#endif
+#ifdef HAVE_MALLOC_H
+#include <malloc.h>
+#endif
+#ifdef HAVE_STRING_H
+# include <string.h>
+#endif
+
# include "irnode_t.h"
# include "irgraph_t.h"
# include "irmode_t.h"
# include "iropt_dbg.h"
# include "irflag_t.h"
# include "array.h"
-# include "firmstat.h"
+# include "irhooks.h"
+# include "opt_polymorphy.h"
+
+#ifdef DO_CACHEOPT
+#include "cacheopt/cachesim.h"
+#endif
#undef IMAX
#define IMAX(a,b) ((a) > (b) ? (a) : (b))
int 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 */
+ 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 */
} ldst_info_t;
/**
return 0;
}
+#define get_irn_out_n(node) (unsigned)get_irn_link(node)
+#define set_irn_out_n(node, n) set_irn_link(adr, (void *)(n))
+
/**
* walker, collects all Load/Store/Proj nodes
*
*/
static void collect_nodes(ir_node *node, void *env)
{
+ ir_op *op = get_irn_op(node);
ir_node *pred;
ldst_info_t *ldst_info;
walk_env_t *wenv = env;
- if (get_irn_op(node) == op_Proj) {
+ if (op == op_Proj) {
+ ir_node *adr;
+ ir_op *op;
+
pred = get_Proj_pred(node);
+ op = get_irn_op(pred);
+
+ if (op == op_Load) {
+ ldst_info = get_ldst_info(pred, wenv);
+
+ wenv->changes |= update_projs(ldst_info, node);
+
+ if ((ldst_info->flags & LDST_VISITED) == 0) {
+ adr = get_Load_ptr(pred);
+ set_irn_out_n(adr, get_irn_out_n(adr) + 1);
- if (get_irn_op(pred) == op_Load || get_irn_op(pred) == op_Store) {
+ ldst_info->flags |= LDST_VISITED;
+ }
+ }
+ else if (op == op_Store) {
ldst_info = get_ldst_info(pred, wenv);
wenv->changes |= update_projs(ldst_info, node);
+
+ if ((ldst_info->flags & LDST_VISITED) == 0) {
+ adr = get_Store_ptr(pred);
+ set_irn_out_n(adr, get_irn_out_n(adr) + 1);
+
+ ldst_info->flags |= LDST_VISITED;
+ }
}
}
- else if (get_irn_op(node) == op_Block) { /* check, if it's an exception block */
+ else if (op == op_Block) { /* check, if it's an exception block */
int i, n;
for (i = 0, n = get_Block_n_cfgpreds(node); i < n; ++i) {
}
}
+/**
+ * Returns an entity if the address ptr points to a constant one.
+ */
+static entity *find_constant_entity(ir_node *ptr)
+{
+ for (;;) {
+ ir_op *op = get_irn_op(ptr);
+
+ if (op == op_SymConst && (get_SymConst_kind(ptr) == symconst_addr_ent)) {
+ return get_SymConst_entity(ptr);
+ }
+ else if (op == op_Sel) {
+ entity *ent = get_Sel_entity(ptr);
+ type *tp = get_entity_owner(ent);
+
+ /* Do not fiddle about polymorphy. */
+ if (is_Class_type(get_entity_owner(ent)) &&
+ ((get_entity_n_overwrites(ent) != 0) ||
+ (get_entity_n_overwrittenby(ent) != 0) ) )
+ return NULL;
+
+ if (variability_constant == get_entity_variability(ent))
+ return ent;
+
+ if (is_Array_type(tp)) {
+ /* check bounds */
+ int i, n;
+
+ for (i = 0, n = get_Sel_n_indexs(ptr); i < n; ++i) {
+ ir_node *bound;
+ tarval *tlower, *tupper;
+ ir_node *index = get_Sel_index(ptr, i);
+ tarval *tv = computed_value(index);
+
+ /* check if the index is constant */
+ if (tv == tarval_bad)
+ return NULL;
+
+ bound = get_array_lower_bound(tp, i);
+ tlower = computed_value(bound);
+ bound = get_array_upper_bound(tp, i);
+ tupper = computed_value(bound);
+
+ if (tlower == tarval_bad || tupper == tarval_bad)
+ return NULL;
+
+ if (tarval_cmp(tv, tlower) & pn_Cmp_Lt)
+ return NULL;
+ if (tarval_cmp(tupper, tv) & pn_Cmp_Lt)
+ return NULL;
+
+ /* ok, bounds check finished */
+ }
+ }
+
+ /* try next */
+ ptr = get_Sel_ptr(ptr);
+ }
+ else
+ return NULL;
+ }
+}
+
+static long get_Sel_array_index_long(ir_node *n, int dim) {
+ ir_node *index = get_Sel_index(n, dim);
+ assert(get_irn_op(index) == op_Const);
+ return get_tarval_long(get_Const_tarval(index));
+}
+
+static compound_graph_path *rec_get_accessed_path(ir_node *ptr, int depth) {
+ compound_graph_path *res = NULL;
+ entity *root, *field;
+ int path_len, pos;
+
+ if (get_irn_op(ptr) == op_SymConst) {
+ assert(get_SymConst_kind(ptr) == symconst_addr_ent);
+ root = get_SymConst_entity(ptr);
+ res = (depth == 0) ? NULL : new_compound_graph_path(get_entity_type(root), depth);
+ }
+ else {
+ assert(get_irn_op(ptr) == op_Sel);
+ res = rec_get_accessed_path(get_Sel_ptr(ptr), depth+1);
+ field = get_Sel_entity(ptr);
+ path_len = get_compound_graph_path_length(res);
+ pos = path_len - depth - 1;
+ set_compound_graph_path_node(res, pos, field);
+ if (is_Array_type(get_entity_owner(field))) {
+ assert(get_Sel_n_indexs(ptr) == 1 && "multi dim arrays not implemented");
+ set_compound_graph_path_array_index(res, pos, get_Sel_array_index_long(ptr, 0));
+ }
+ }
+ return res;
+}
+
+
+/** Returns an access path or NULL. The access path is only
+ * valid, if the graph is in phase_high and _no_ address computation is used. */
+static compound_graph_path *get_accessed_path(ir_node *ptr) {
+ return rec_get_accessed_path(ptr, 0);
+}
+
/**
* optimize a Load
*/
{
ldst_info_t *info = get_irn_link(load);
ir_mode *load_mode = get_Load_mode(load);
- ir_node *pred, *mem, *ptr;
+ ir_node *pred, *mem, *ptr, *new_node;
+ entity *ent;
int res = 0;
+ /* the address of the load to be optimized */
+ ptr = get_Load_ptr(load);
+
+ /*
+ * Check if we can remove the exception form a Load:
+ * this can be done, if the address is from an Sel(Alloc) and
+ * the Sel type is a subtype of the alloc type.
+ *
+ * This optimizes some often used OO constructs,
+ * like x = new O; x->t;
+ */
+ if (info->projs[pn_Load_X_except]) {
+ if (get_irn_op(ptr) == op_Sel) {
+ ir_node *mem = get_Sel_mem(ptr);
+
+ if (get_irn_op(skip_Proj(mem)) == op_Alloc) {
+ /* ok, check the types */
+ entity *ent = get_Sel_entity(ptr);
+ type *s_type = get_entity_type(ent);
+ type *a_type = get_Alloc_type(mem);
+
+ if (is_subclass_of(s_type, a_type)) {
+ /* ok, condition met: there can't be an exception because
+ * alloc guarantees that enough memory was allocated */
+
+ exchange(info->projs[pn_Load_X_except], new_Bad());
+ info->projs[pn_Load_X_except] = NULL;
+ }
+ }
+ }
+ else if ((get_irn_op(skip_Proj(ptr)) == op_Alloc) ||
+ ((get_irn_op(ptr) == op_Cast) && (get_irn_op(skip_Proj(get_Cast_op(ptr))) == op_Alloc))) {
+ /* simple case: a direct load after an Alloc. Firm Alloc throw
+ * an exception in case of out-of-memory. So, there is no way for an
+ * exception in this load.
+ * This code is constructed by the "exception lowering" in the Jack compiler.
+ */
+ exchange(info->projs[pn_Load_X_except], new_Bad());
+ info->projs[pn_Load_X_except] = NULL;
+ }
+ }
+
/* do NOT touch volatile loads for now */
if (get_Load_volatility(load) == volatility_is_volatile)
return 0;
return 1;
}
- /* the address of the load to be optimized */
- ptr = get_Load_ptr(load);
-
- /* the mem of the load. Must still be returned after optimization */
+ /* the mem of the Load. Must still be returned after optimization */
mem = get_Load_mem(load);
- if ((get_irn_opcode(ptr) == iro_SymConst) && (get_SymConst_kind(ptr) == symconst_addr_ent)) {
- entity *ent = get_SymConst_entity(ptr);
-
- assert(mode_is_reference(get_irn_mode(ptr)));
+ /* Load from a constant polymorphic field, where we can resolve
+ polymorphy. */
+ new_node = transform_node_Load(load);
+ if (new_node != load) {
+ if (info->projs[pn_Load_M]) {
+ exchange(info->projs[pn_Load_M], mem);
+ info->projs[pn_Load_M] = NULL;
+ }
+ if (info->projs[pn_Load_X_except]) {
+ exchange(info->projs[pn_Load_X_except], new_Bad());
+ info->projs[pn_Load_X_except] = NULL;
+ }
+ if (info->projs[pn_Load_res])
+ exchange(info->projs[pn_Load_res], new_node);
+ return 1;
+ }
+ /* check if we can determine the entity that will be loaded */
+ ent = find_constant_entity(ptr);
+ if (ent) {
if ((allocation_static == get_entity_allocation(ent)) &&
(visibility_external_allocated != get_entity_visibility(ent))) {
/* a static allocation that is not external: there should be NO exception
}
if (variability_constant == get_entity_variability(ent)
- && is_atomic_entity(ent)) { /* Might not be atomic after
- lowering of Sels. In this
- case we could also load, but
- it's more complicated. */
+ && is_atomic_entity(ent)) {
+ /* Might not be atomic after
+ lowering of Sels. In this
+ case we could also load, but
+ it's more complicated. */
/* more simpler case: we load the content of a constant value:
* replace it by the constant itself
*/
exchange(info->projs[pn_Load_M], mem);
/* no result :-) */
- if (info->projs[pn_Load_res])
- exchange(info->projs[pn_Load_res], copy_const_value(get_atomic_ent_value(ent)));
+ if (info->projs[pn_Load_res]) {
+ if (is_atomic_entity(ent)) {
+ ir_node *c = copy_const_value(get_atomic_ent_value(ent));
- return 1;
+ DBG_OPT_RC(load, c);
+ exchange(info->projs[pn_Load_res], c);
+
+ return 1;
+ }
+ }
+ }
+ else if (variability_constant == get_entity_variability(ent)) {
+ compound_graph_path *path;
+ /*
+ printf(">>>>>>>>>>>>> Found access to constant entity %s in function %s\n", get_entity_name(ent),
+ get_entity_name(get_irg_entity(current_ir_graph)));
+ printf(" load: "); DDMN(load);
+ printf(" ptr: "); DDMN(ptr);
+ */
+ path = get_accessed_path(ptr);
+ if (path) {
+ ir_node *c;
+
+ assert(is_proper_compound_graph_path(path, get_compound_graph_path_length(path)-1));
+ c = get_compound_ent_value_by_path(ent, path);
+
+ /* printf(" cons: "); DDMN(c); */
+
+ if (info->projs[pn_Load_M])
+ exchange(info->projs[pn_Load_M], mem);
+ if (info->projs[pn_Load_res])
+ exchange(info->projs[pn_Load_res], copy_const_value(c));
+ /*
+ {
+ int j;
+ for (j = 0; j < get_compound_graph_path_length(path); ++j) {
+ entity *node = get_compound_graph_path_node(path, j);
+ fprintf(stdout, ".%s", get_entity_name(node));
+ if (is_Array_type(get_entity_owner(node)))
+ fprintf(stdout, "[%d]", get_compound_graph_path_array_index(path, j));
+ }
+ printf("\n");
+ }
+ */
+ } else {
+ /* We can not determine a correct access path. E.g., in jack, we load
+ a byte from an object to generate an exception. Happens in test program
+ Reflectiontest.
+ printf(">>>>>>>>>>>>> Found access to constant entity %s in function %s\n", get_entity_name(ent),
+ get_entity_name(get_irg_entity(current_ir_graph)));
+ printf(" load: "); DDMN(load);
+ printf(" ptr: "); DDMN(ptr);
+ if (get_irn_op(ptr) == op_SymConst &&
+ get_SymConst_kind(ptr) == symconst_addr_ent) { printf(" "); DDMEO(get_SymConst_entity(ptr)); }
+ printf("cannot optimize.\n");
+ */
+ }
}
/* we changed the irg, but try further */
}
}
+ /* Check, if the address of this load is used more than once.
+ * If not, this load cannot be removed in any case. */
+ if (get_irn_out_n(ptr) <= 1)
+ return 0;
+
/* follow the memory chain as long as there are only Loads */
for (pred = skip_Proj(mem); ; pred = skip_Proj(get_Load_mem(pred))) {
ldst_info_t *pred_info = get_irn_link(pred);
/*
- * a load immediately after a store -- a read after write.
- * We may remove the Load, if both load & Store does not have an exception handler
+ * a Load immediately after a Store -- a read after write.
+ * We may remove the Load, if both Load & Store does not have an exception handler
* OR they are in the same block. In the latter case the Load cannot
* throw an exception when the previous Store was quiet.
*
* Why we need to check for Store Exc? If the Store cannot be executed (ROM)
* the exception handler might simply jump into the load block :-(
* We could make it a little bit better if we would know that the exception
- * handler of teh Store jumps directly to the end...
+ * handler of the Store jumps directly to the end...
*/
if ((!pred_info->projs[pn_Store_X_except] && !info->projs[pn_Load_X_except]) ||
get_nodes_block(load) == get_nodes_block(pred)) {
- DBG_OPT_RAW(pred, load);
+ DBG_OPT_RAW(load, pred);
exchange( info->projs[pn_Load_res], get_Store_value(pred) );
if (info->projs[pn_Load_M])
else if (get_irn_op(pred) == op_Load && get_Load_ptr(pred) == ptr &&
get_Load_mode(pred) == load_mode) {
/*
- * a load after a load -- a read after read.
+ * a Load after a Load -- a read after read.
* We may remove the second Load, if it does not have an exception handler
* OR they are in the same block. In the later case the Load cannot
* throw an exception when the previous Load was quiet.
*
- * Here, there is no need to check if the previos load has an exception hander because
+ * Here, there is no need to check if the previos Load has an exception hander because
* they would have exact the same exception...
*/
if (! info->projs[pn_Load_X_except] || get_nodes_block(load) == get_nodes_block(pred)) {
ldst_info_t *pred_info = get_irn_link(pred);
- DBG_OPT_RAR(pred, load);
+ DBG_OPT_RAR(load, pred);
if (pred_info->projs[pn_Load_res]) {
/* we need a data proj from the previous load for this optimization */
}
}
- /* follow only load chains */
+ /* follow only Load chains */
if (get_irn_op(pred) != op_Load)
break;
}
* is possible *(type1 *)p = a; *(type2 *)p = b ...
*/
- block = get_nodes_block(store);
ptr = get_Store_ptr(store);
+
+ /* Check, if the address of this load is used more than once.
+ * If not, this load cannot be removed in any case. */
+ if (get_irn_out_n(ptr) <= 1)
+ return 0;
+
+ block = get_nodes_block(store);
mem = get_Store_mem(store);
value = get_Store_value(store);
-
mode = get_irn_mode(value);
/* follow the memory chain as long as there are only Loads */
if (get_irn_op(pred) == op_Store && get_Store_ptr(pred) == ptr &&
get_nodes_block(pred) == block && 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 block -- 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 ???
else if (get_irn_op(pred) == op_Load && get_Load_ptr(pred) == ptr &&
value == pred_info->projs[pn_Load_res]) {
/*
- * a store of a value after a load -- a write after read.
+ * 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.
*/
if (! info->projs[pn_Store_X_except]) {
- DBG_OPT_WAR(pred, store);
+ DBG_OPT_WAR(store, pred);
exchange( info->projs[pn_Store_M], mem );
return 1;
}
}
- /* follow only load chains */
+ /* follow only Load chains */
if (get_irn_op(pred) != op_Load)
break;
}
{
walk_env_t *wenv = env;
int i, n;
- ir_node *store, *ptr, *block, *phiM, *phiD, *exc, *projM;
+ ir_node *store, *old_store, *ptr, *block, *phiM, *phiD, *exc, *projM;
ir_mode *mode;
ir_node **inM, **inD;
int *idx;
return 0;
store = skip_Proj(get_Phi_pred(phi, 0));
+ old_store = store;
if (get_irn_op(store) != op_Store)
return 0;
/* fourth step: create the Store */
store = new_rd_Store(db, current_ir_graph, block, phiM, ptr, phiD);
+#ifdef DO_CACHEOPT
+ co_set_irn_name(store, co_get_irn_ident(old_store));
+#endif
+
projM = new_rd_Proj(NULL, current_ir_graph, block, store, mode_M, pn_Store_M);
info = get_ldst_info(store, wenv);
projects / libfirm / blobdiff