/*
- * Project: libFIRM
- * File name: ir/opt/ldstopt.c
- * Purpose: load store optimizations
- * Author: Michael Beck
- * Created:
- * CVS-ID: $Id$
- * Copyright: (c) 1998-2004 Universit\81ät Karlsruhe
- * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
+ * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
+ *
+ * This file is part of libFirm.
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE.
*/
-#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
+/**
+ * @file
+ * @brief Load/Store optimizations.
+ * @author Michael Beck
+ * @version $Id$
+ */
+#include "config.h"
+#include <string.h>
+
+#include "iroptimize.h"
#include "irnode_t.h"
#include "irgraph_t.h"
#include "irmode_t.h"
#include "dbginfo_t.h"
#include "iropt_dbg.h"
#include "irflag_t.h"
-#include "array.h"
+#include "array_t.h"
#include "irhooks.h"
#include "iredges.h"
#include "irtools.h"
#include "opt_polymorphy.h"
+#include "irmemory.h"
+#include "irphase_t.h"
+#include "irgopt.h"
+#include "set.h"
+#include "debug.h"
+
+/** The debug handle. */
+DEBUG_ONLY(static firm_dbg_module_t *dbg;)
#ifdef DO_CACHEOPT
#include "cacheopt/cachesim.h"
#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 */
- CF_CHANGED = 2, /**< control flow changed */
+ DF_CHANGED = 1, /**< data flow changed */
+ CF_CHANGED = 2, /**< control flow changed */
};
/**
* walker environment
*/
typedef struct _walk_env_t {
- struct obstack obst; /**< list of all stores */
- unsigned changes; /**< a bitmask of graph changes */
+ struct obstack obst; /**< list of all stores */
+ 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 */
+ 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 visited; /**< visited counter for breaking loops */
} ldst_info_t;
/**
* flags for control flow.
*/
enum block_flags_t {
- BLOCK_HAS_COND = 1, /**< Block has conditional control flow */
- BLOCK_HAS_EXC = 2 /**< Block has exceptional control flow */
+ BLOCK_HAS_COND = 1, /**< Block has conditional control flow */
+ BLOCK_HAS_EXC = 2 /**< Block has exceptional control flow */
};
/**
* a Block info.
*/
typedef struct _block_info_t {
- unsigned flags; /**< flags for the block */
+ unsigned flags; /**< flags for the block */
} block_info_t;
/** the master visited flag for loop detection. */
/**
* get the Load/Store info of a node
*/
-static ldst_info_t *get_ldst_info(ir_node *node, walk_env_t *env) {
- ldst_info_t *info = get_irn_link(node);
-
- if (! info) {
- info = obstack_alloc(&env->obst, sizeof(*info));
+static ldst_info_t *get_ldst_info(ir_node *node, struct obstack *obst) {
+ ldst_info_t *info = get_irn_link(node);
- memset(info, 0, sizeof(*info));
-
- set_irn_link(node, info);
- }
- return info;
-}
+ if (! info) {
+ info = obstack_alloc(obst, sizeof(*info));
+ memset(info, 0, sizeof(*info));
+ set_irn_link(node, info);
+ }
+ return info;
+} /* get_ldst_info */
/**
* get the Block info of a node
*/
-static block_info_t *get_block_info(ir_node *node, walk_env_t *env)
-{
- block_info_t *info = get_irn_link(node);
-
- if (! info) {
- info = obstack_alloc(&env->obst, sizeof(*info));
+static block_info_t *get_block_info(ir_node *node, struct obstack *obst) {
+ block_info_t *info = get_irn_link(node);
- memset(info, 0, sizeof(*info));
-
- set_irn_link(node, info);
- }
- return info;
-}
+ if (! info) {
+ info = obstack_alloc(obst, sizeof(*info));
+ memset(info, 0, sizeof(*info));
+ set_irn_link(node, info);
+ }
+ return info;
+} /* get_block_info */
/**
* update the projection info for a Load/Store
*/
static unsigned update_projs(ldst_info_t *info, ir_node *proj)
{
- long nr = get_Proj_proj(proj);
-
- assert(0 <= nr && nr <= MAX_PROJ && "Wrong proj from LoadStore");
-
- if (info->projs[nr]) {
- /* there is already one, do CSE */
- exchange(proj, info->projs[nr]);
- return DF_CHANGED;
- }
- else {
- info->projs[nr] = proj;
- return 0;
- }
-}
+ long nr = get_Proj_proj(proj);
+
+ assert(0 <= nr && nr <= MAX_PROJ && "Wrong proj from LoadStore");
+
+ if (info->projs[nr]) {
+ /* there is already one, do CSE */
+ exchange(proj, info->projs[nr]);
+ return DF_CHANGED;
+ }
+ else {
+ info->projs[nr] = proj;
+ return 0;
+ }
+} /* update_projs */
/**
* update the exception block info for a Load/Store node.
*/
static unsigned update_exc(ldst_info_t *info, ir_node *block, int pos)
{
- assert(info->exc_block == NULL && "more than one exception block found");
+ assert(info->exc_block == NULL && "more than one exception block found");
- info->exc_block = block;
- info->exc_idx = pos;
- return 0;
-}
+ info->exc_block = block;
+ info->exc_idx = 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)
*/
static void collect_nodes(ir_node *node, void *env)
{
- ir_op *op = get_irn_op(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 (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);
- ldst_info->flags |= LDST_VISITED;
- }
-
- /*
- * Place the Proj's to the same block as the
- * predecessor Load. 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_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);
- 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) { /* check, if it's an exception block */
- int i;
-
- for (i = get_Block_n_cfgpreds(node) - 1; i >= 0; --i) {
- ir_node *pred_block;
- block_info_t *bl_info;
-
- pred = skip_Proj(get_Block_cfgpred(node, i));
-
- /* ignore Bad predecessors, they will be removed later */
- if (is_Bad(pred))
- continue;
-
- pred_block = get_nodes_block(pred);
- bl_info = get_block_info(pred_block, wenv);
-
- if (is_fragile_op(pred))
- bl_info->flags |= BLOCK_HAS_EXC;
- else if (is_irn_forking(pred))
- bl_info->flags |= BLOCK_HAS_COND;
-
- if (get_irn_op(pred) == op_Load || get_irn_op(pred) == op_Store) {
- ldst_info = get_ldst_info(pred, wenv);
-
- wenv->changes |= update_exc(ldst_info, node, i);
- }
- }
- }
-}
+ ir_opcode opcode = get_irn_opcode(node);
+ ir_node *pred, *blk, *pred_blk;
+ ldst_info_t *ldst_info;
+ walk_env_t *wenv = env;
+
+ if (opcode == iro_Proj) {
+ pred = get_Proj_pred(node);
+ opcode = get_irn_opcode(pred);
+
+ 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);
+
+ /*
+ * Place the Proj's to the same block as the
+ * predecessor Load. 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 (opcode == iro_Block) {
+ int i;
+
+ for (i = get_Block_n_cfgpreds(node) - 1; i >= 0; --i) {
+ ir_node *pred_block, *proj;
+ block_info_t *bl_info;
+ int is_exc = 0;
+
+ pred = proj = get_Block_cfgpred(node, i);
+
+ if (is_Proj(proj)) {
+ pred = get_Proj_pred(proj);
+ is_exc = get_Proj_proj(proj) == pn_Generic_X_except;
+ }
+
+ /* ignore Bad predecessors, they will be removed later */
+ if (is_Bad(pred))
+ continue;
+
+ pred_block = get_nodes_block(pred);
+ bl_info = get_block_info(pred_block, &wenv->obst);
+
+ if (is_fragile_op(pred) && is_exc)
+ bl_info->flags |= BLOCK_HAS_EXC;
+ else if (is_irn_forking(pred))
+ bl_info->flags |= BLOCK_HAS_COND;
+
+ 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);
+ }
+ }
+ }
+} /* collect_nodes */
/**
* Returns an entity if the address ptr points to a constant one.
+ *
+ * @param ptr the address
+ *
+ * @return an entity or NULL
*/
-static entity *find_constant_entity(ir_node *ptr)
+static ir_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);
- ir_type *tp = get_entity_owner(ent);
-
- /* Do not fiddle with polymorphism. */
- 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;
- }
-}
+ for (;;) {
+ if (is_SymConst(ptr) && get_SymConst_kind(ptr) == symconst_addr_ent) {
+ return get_SymConst_entity(ptr);
+ } else if (is_Sel(ptr)) {
+ ir_entity *ent = get_Sel_entity(ptr);
+ ir_type *tp = get_entity_owner(ent);
+
+ /* Do not fiddle with polymorphism. */
+ if (is_Class_type(get_entity_owner(ent)) &&
+ ((get_entity_n_overwrites(ent) != 0) ||
+ (get_entity_n_overwrittenby(ent) != 0) ) )
+ return NULL;
+
+ 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 */
+ }
+ }
+
+ if (variability_constant == get_entity_variability(ent))
+ return ent;
+
+ /* try next */
+ ptr = get_Sel_ptr(ptr);
+ } else if (is_Add(ptr)) {
+ ir_node *l = get_Add_left(ptr);
+ ir_node *r = get_Add_right(ptr);
+
+ if (get_irn_mode(l) == get_irn_mode(ptr) && is_Const(r))
+ ptr = l;
+ else if (get_irn_mode(r) == get_irn_mode(ptr) && is_Const(l))
+ ptr = r;
+ else
+ return NULL;
+
+ /* for now, we support only one addition, reassoc should fold all others */
+ if (! is_SymConst(ptr) && !is_Sel(ptr))
+ return NULL;
+ } else if (is_Sub(ptr)) {
+ ir_node *l = get_Sub_left(ptr);
+ ir_node *r = get_Sub_right(ptr);
+
+ if (get_irn_mode(l) == get_irn_mode(ptr) && is_Const(r))
+ ptr = l;
+ else
+ return NULL;
+ /* for now, we support only one substraction, reassoc should fold all others */
+ if (! is_SymConst(ptr) && !is_Sel(ptr))
+ return NULL;
+ } else
+ return NULL;
+ }
+} /* find_constant_entity */
/**
* Return the Selection index of a Sel node from dimension n
*/
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));
-}
+ ir_node *index = get_Sel_index(n, dim);
+ assert(is_Const(index));
+ return get_tarval_long(get_Const_tarval(index));
+} /* get_Sel_array_index_long */
/**
* Returns the accessed component graph path for an
* of the address
*/
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) {
- /* a SymConst. If the depth is 0, this is an access to a global
- * entity and we don't need a component path, else we know
- * at least it's length.
- */
- 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);
- /* it's a Sel, go up until we find the root */
- res = rec_get_accessed_path(get_Sel_ptr(ptr), depth+1);
-
- /* fill up the step in the path at the current position */
- 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;
-}
+ compound_graph_path *res = NULL;
+ ir_entity *root, *field, *ent;
+ int path_len, pos, idx;
+ tarval *tv;
+ ir_type *tp;
+
+ if (is_SymConst(ptr)) {
+ /* a SymConst. If the depth is 0, this is an access to a global
+ * entity and we don't need a component path, else we know
+ * at least its length.
+ */
+ 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 if (is_Sel(ptr)) {
+ /* it's a Sel, go up until we find the root */
+ res = rec_get_accessed_path(get_Sel_ptr(ptr), depth+1);
+ if (res == NULL)
+ return NULL;
+
+ /* fill up the step in the path at the current position */
+ 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));
+ }
+ } else if (is_Add(ptr)) {
+ ir_node *l = get_Add_left(ptr);
+ ir_node *r = get_Add_right(ptr);
+ ir_mode *mode = get_irn_mode(ptr);
+ tarval *tmp;
+
+ if (is_Const(r) && get_irn_mode(l) == mode) {
+ ptr = l;
+ tv = get_Const_tarval(r);
+ } else {
+ ptr = r;
+ tv = get_Const_tarval(l);
+ }
+ptr_arith:
+ mode = get_tarval_mode(tv);
+ tmp = tv;
+
+ /* ptr must be a Sel or a SymConst, this was checked in find_constant_entity() */
+ if (is_Sel(ptr)) {
+ field = get_Sel_entity(ptr);
+ } else {
+ field = get_SymConst_entity(ptr);
+ }
+ idx = 0;
+ for (ent = field;;) {
+ unsigned size;
+ tarval *sz, *tv_index, *tlower, *tupper;
+ ir_node *bound;
+
+ tp = get_entity_type(ent);
+ if (! is_Array_type(tp))
+ break;
+ ent = get_array_element_entity(tp);
+ size = get_type_size_bytes(get_entity_type(ent));
+ sz = new_tarval_from_long(size, mode);
+
+ tv_index = tarval_div(tmp, sz);
+ tmp = tarval_mod(tmp, sz);
+
+ if (tv_index == tarval_bad || tmp == tarval_bad)
+ return NULL;
+
+ assert(get_array_n_dimensions(tp) == 1 && "multiarrays not implemented");
+ bound = get_array_lower_bound(tp, 0);
+ tlower = computed_value(bound);
+ bound = get_array_upper_bound(tp, 0);
+ tupper = computed_value(bound);
+
+ if (tlower == tarval_bad || tupper == tarval_bad)
+ return NULL;
+
+ if (tarval_cmp(tv_index, tlower) & pn_Cmp_Lt)
+ return NULL;
+ if (tarval_cmp(tupper, tv_index) & pn_Cmp_Lt)
+ return NULL;
+
+ /* ok, bounds check finished */
+ ++idx;
+ }
+ if (! tarval_is_null(tmp)) {
+ /* access to some struct/union member */
+ return NULL;
+ }
+
+ /* should be at least ONE array */
+ if (idx == 0)
+ return NULL;
+
+ res = rec_get_accessed_path(ptr, depth + idx);
+ if (res == NULL)
+ return NULL;
+
+ path_len = get_compound_graph_path_length(res);
+ pos = path_len - depth - idx;
+
+ for (ent = field;;) {
+ unsigned size;
+ tarval *sz, *tv_index;
+ long index;
+
+ tp = get_entity_type(ent);
+ if (! is_Array_type(tp))
+ break;
+ ent = get_array_element_entity(tp);
+ set_compound_graph_path_node(res, pos, ent);
+
+ size = get_type_size_bytes(get_entity_type(ent));
+ sz = new_tarval_from_long(size, mode);
+
+ tv_index = tarval_div(tv, sz);
+ tv = tarval_mod(tv, sz);
+
+ /* worked above, should work again */
+ assert(tv_index != tarval_bad && tv != tarval_bad);
+
+ /* bounds already checked above */
+ index = get_tarval_long(tv_index);
+ set_compound_graph_path_array_index(res, pos, index);
+ ++pos;
+ }
+ } else if (is_Sub(ptr)) {
+ ir_node *l = get_Sub_left(ptr);
+ ir_node *r = get_Sub_right(ptr);
+
+ ptr = l;
+ tv = get_Const_tarval(r);
+ tv = tarval_neg(tv);
+ goto ptr_arith;
+ }
+ return res;
+} /* rec_get_accessed_path */
-/** 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.
+/**
+ * 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);
+ compound_graph_path *gr = rec_get_accessed_path(ptr, 0);
+ return gr;
+} /* get_accessed_path */
+
+typedef struct path_entry {
+ ir_entity *ent;
+ struct path_entry *next;
+ long index;
+} path_entry;
+
+static ir_node *rec_find_compound_ent_value(ir_node *ptr, path_entry *next) {
+ path_entry entry, *p;
+ ir_entity *ent, *field;
+ ir_initializer_t *initializer;
+ tarval *tv;
+ ir_type *tp;
+ unsigned n;
+
+ entry.next = next;
+ if (is_SymConst(ptr)) {
+ /* found the root */
+ ent = get_SymConst_entity(ptr);
+ initializer = get_entity_initializer(ent);
+ for (p = next; p != NULL;) {
+ if (initializer->kind != IR_INITIALIZER_COMPOUND)
+ return NULL;
+ n = get_initializer_compound_n_entries(initializer);
+ tp = get_entity_type(ent);
+
+ if (is_Array_type(tp)) {
+ ent = get_array_element_entity(tp);
+ if (ent != p->ent) {
+ /* a missing [0] */
+ if (0 >= n)
+ return NULL;
+ initializer = get_initializer_compound_value(initializer, 0);
+ continue;
+ }
+ }
+ if (p->index >= (int) n)
+ return NULL;
+ initializer = get_initializer_compound_value(initializer, p->index);
+
+ ent = p->ent;
+ p = p->next;
+ }
+ tp = get_entity_type(ent);
+ while (is_Array_type(tp)) {
+ ent = get_array_element_entity(tp);
+ tp = get_entity_type(ent);
+ /* a missing [0] */
+ n = get_initializer_compound_n_entries(initializer);
+ if (0 >= n)
+ return NULL;
+ initializer = get_initializer_compound_value(initializer, 0);
+ }
+
+ switch (initializer->kind) {
+ case IR_INITIALIZER_CONST:
+ return get_initializer_const_value(initializer);
+ case IR_INITIALIZER_TARVAL:
+ case IR_INITIALIZER_NULL:
+ default:
+ return NULL;
+ }
+ } else if (is_Sel(ptr)) {
+ entry.ent = field = get_Sel_entity(ptr);
+ tp = get_entity_owner(field);
+ if (is_Array_type(tp)) {
+ assert(get_Sel_n_indexs(ptr) == 1 && "multi dim arrays not implemented");
+ entry.index = get_Sel_array_index_long(ptr, 0) - get_array_lower_bound_int(tp, 0);
+ } else {
+ int i, n_members = get_compound_n_members(tp);
+ for (i = 0; i < n_members; ++i) {
+ if (get_compound_member(tp, i) == field)
+ break;
+ }
+ if (i >= n_members) {
+ /* not found: should NOT happen */
+ return NULL;
+ }
+ entry.index = i;
+ }
+ return rec_find_compound_ent_value(get_Sel_ptr(ptr), &entry);
+ } else if (is_Add(ptr)) {
+ ir_node *l = get_Add_left(ptr);
+ ir_node *r = get_Add_right(ptr);
+ ir_mode *mode;
+ unsigned pos;
+
+ if (is_Const(r)) {
+ ptr = l;
+ tv = get_Const_tarval(r);
+ } else {
+ ptr = r;
+ tv = get_Const_tarval(l);
+ }
+ptr_arith:
+ mode = get_tarval_mode(tv);
+
+ /* ptr must be a Sel or a SymConst, this was checked in find_constant_entity() */
+ if (is_Sel(ptr)) {
+ field = get_Sel_entity(ptr);
+ } else {
+ field = get_SymConst_entity(ptr);
+ }
+
+ /* count needed entries */
+ pos = 0;
+ for (ent = field;;) {
+ tp = get_entity_type(ent);
+ if (! is_Array_type(tp))
+ break;
+ ent = get_array_element_entity(tp);
+ ++pos;
+ }
+ /* should be at least ONE entry */
+ if (pos == 0)
+ return NULL;
+
+ /* allocate the right number of entries */
+ NEW_ARR_A(path_entry, p, pos);
+
+ /* fill them up */
+ pos = 0;
+ for (ent = field;;) {
+ unsigned size;
+ tarval *sz, *tv_index, *tlower, *tupper;
+ long index;
+ ir_node *bound;
+
+ tp = get_entity_type(ent);
+ if (! is_Array_type(tp))
+ break;
+ ent = get_array_element_entity(tp);
+ p[pos].ent = ent;
+ p[pos].next = &p[pos + 1];
+
+ size = get_type_size_bytes(get_entity_type(ent));
+ sz = new_tarval_from_long(size, mode);
+
+ tv_index = tarval_div(tv, sz);
+ tv = tarval_mod(tv, sz);
+
+ if (tv_index == tarval_bad || tv == tarval_bad)
+ return NULL;
+
+ assert(get_array_n_dimensions(tp) == 1 && "multiarrays not implemented");
+ bound = get_array_lower_bound(tp, 0);
+ tlower = computed_value(bound);
+ bound = get_array_upper_bound(tp, 0);
+ tupper = computed_value(bound);
+
+ if (tlower == tarval_bad || tupper == tarval_bad)
+ return NULL;
+
+ if (tarval_cmp(tv_index, tlower) & pn_Cmp_Lt)
+ return NULL;
+ if (tarval_cmp(tupper, tv_index) & pn_Cmp_Lt)
+ return NULL;
+
+ /* ok, bounds check finished */
+ index = get_tarval_long(tv_index);
+ p[pos].index = index;
+ ++pos;
+ }
+ if (! tarval_is_null(tv)) {
+ /* hmm, wrong access */
+ return NULL;
+ }
+ p[pos - 1].next = next;
+ return rec_find_compound_ent_value(ptr, p);
+ } else if (is_Sub(ptr)) {
+ ir_node *l = get_Sub_left(ptr);
+ ir_node *r = get_Sub_right(ptr);
+
+ ptr = l;
+ tv = get_Const_tarval(r);
+ tv = tarval_neg(tv);
+ goto ptr_arith;
+ }
+ return NULL;
+}
+
+static ir_node *find_compound_ent_value(ir_node *ptr) {
+ return rec_find_compound_ent_value(ptr, NULL);
}
/* forward */
static void reduce_adr_usage(ir_node *ptr);
/**
- * Update a Load that may lost it's usage.
+ * Update a Load that may have lost its users.
*/
static void handle_load_update(ir_node *load) {
- ldst_info_t *info = get_irn_link(load);
+ ldst_info_t *info = get_irn_link(load);
- /* do NOT touch volatile loads for now */
- if (get_Load_volatility(load) == volatility_is_volatile)
- return;
+ /* do NOT touch volatile loads for now */
+ if (get_Load_volatility(load) == volatility_is_volatile)
+ return;
- if (! info->projs[pn_Load_res] && ! info->projs[pn_Load_X_except]) {
- ir_node *ptr = get_Load_ptr(load);
- ir_node *mem = get_Load_mem(load);
+ if (! info->projs[pn_Load_res] && ! info->projs[pn_Load_X_except]) {
+ ir_node *ptr = get_Load_ptr(load);
+ ir_node *mem = get_Load_mem(load);
- /* a Load which value is neither used nor exception checked, remove it */
- exchange(info->projs[pn_Load_M], mem);
- exchange(load, new_Bad());
- reduce_adr_usage(ptr);
- }
-}
+ /* a Load whose value is neither used nor exception checked, remove it */
+ exchange(info->projs[pn_Load_M], mem);
+ if (info->projs[pn_Load_X_regular])
+ exchange(info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load)));
+ kill_node(load);
+ reduce_adr_usage(ptr);
+ }
+} /* handle_load_update */
/**
- * A Use of an address node is vanished. Check if this was a Proj
+ * A use of an address node has vanished. Check if this was a Proj
* node and update the counters.
*/
static void reduce_adr_usage(ir_node *ptr) {
- if (is_Proj(ptr)) {
- if (get_irn_n_edges(ptr) <= 0) {
- /* this Proj is dead now */
- ir_node *pred = get_Proj_pred(ptr);
- opcode code = get_irn_opcode(pred);
-
- if (code == iro_Load) {
- ldst_info_t *info = get_irn_link(pred);
- info->projs[get_Proj_proj(ptr)] = NULL;
-
- /* this node lost it's result proj, handle that */
- handle_load_update(pred);
- }
- }
- }
+ if (is_Proj(ptr)) {
+ if (get_irn_n_edges(ptr) <= 0) {
+ /* this Proj is dead now */
+ ir_node *pred = get_Proj_pred(ptr);
+
+ if (is_Load(pred)) {
+ ldst_info_t *info = get_irn_link(pred);
+ info->projs[get_Proj_proj(ptr)] = NULL;
+
+ /* this node lost its result proj, handle that */
+ handle_load_update(pred);
+ }
+ }
+ }
+} /* reduce_adr_usage */
+
+/**
+ * Check, if an already existing value of mode old_mode can be converted
+ * into the needed one new_mode without loss.
+ */
+static int can_use_stored_value(ir_mode *old_mode, ir_mode *new_mode) {
+ if (old_mode == new_mode)
+ return 1;
+
+ /* if both modes are two-complement ones, we can always convert the
+ Stored value into the needed one. */
+ if (get_mode_size_bits(old_mode) >= get_mode_size_bits(new_mode) &&
+ get_mode_arithmetic(old_mode) == irma_twos_complement &&
+ get_mode_arithmetic(new_mode) == irma_twos_complement)
+ return 1;
+ return 0;
+} /* can_use_stored_value */
+
+/**
+ * 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 */
+
+static ir_node *get_base_and_offset(ir_node *ptr, long *pOffset)
+{
+ ir_mode *mode = get_irn_mode(ptr);
+ long offset = 0;
+
+ /* TODO: long might not be enough, we should probably use some tarval thingy... */
+ for (;;) {
+ if (is_Add(ptr)) {
+ ir_node *l = get_Add_left(ptr);
+ ir_node *r = get_Add_right(ptr);
+
+ if (get_irn_mode(l) != mode || !is_Const(r))
+ break;
+
+ offset += get_tarval_long(get_Const_tarval(r));
+ ptr = l;
+ } else if (is_Sub(ptr)) {
+ ir_node *l = get_Sub_left(ptr);
+ ir_node *r = get_Sub_right(ptr);
+
+ if (get_irn_mode(l) != mode || !is_Const(r))
+ break;
+
+ offset -= get_tarval_long(get_Const_tarval(r));
+ ptr = l;
+ } else if (is_Sel(ptr)) {
+ ir_entity *ent = get_Sel_entity(ptr);
+ ir_type *tp = get_entity_owner(ent);
+
+ if (is_Array_type(tp)) {
+ int size;
+ ir_node *index;
+
+ /* only one dimensional arrays yet */
+ if (get_Sel_n_indexs(ptr) != 1)
+ break;
+ index = get_Sel_index(ptr, 0);
+ if (! is_Const(index))
+ break;
+
+ tp = get_entity_type(ent);
+ if (get_type_state(tp) != layout_fixed)
+ break;
+
+ size = get_type_size_bytes(tp);
+ offset += size * get_tarval_long(get_Const_tarval(index));
+ } else {
+ if (get_type_state(tp) != layout_fixed)
+ break;
+ offset += get_entity_offset(ent);
+ }
+ ptr = get_Sel_ptr(ptr);
+ } else
+ break;
+ }
+
+ *pOffset = offset;
+ return ptr;
+}
+
+static int try_load_after_store(ir_node *load,
+ ir_node *load_base_ptr, long load_offset, ir_node *store)
+{
+ ldst_info_t *info;
+ ir_node *store_ptr = get_Store_ptr(store);
+ long store_offset;
+ ir_node *store_base_ptr = get_base_and_offset(store_ptr, &store_offset);
+ ir_node *store_value;
+ ir_mode *store_mode;
+ ir_node *load_ptr;
+ ir_mode *load_mode;
+ long load_mode_len;
+ long store_mode_len;
+ long delta;
+ int res;
+
+ if (load_base_ptr != store_base_ptr)
+ return 0;
+
+ load_mode = get_Load_mode(load);
+ load_mode_len = get_mode_size_bytes(load_mode);
+ store_mode = get_irn_mode(get_Store_value(store));
+ store_mode_len = get_mode_size_bytes(store_mode);
+ delta = load_offset - store_offset;
+ store_value = get_Store_value(store);
+
+ if (delta != 0 || store_mode != load_mode) {
+ if (delta < 0 || delta + load_mode_len > store_mode_len)
+ return 0;
+
+ if (get_mode_arithmetic(store_mode) != irma_twos_complement ||
+ get_mode_arithmetic(load_mode) != irma_twos_complement)
+ return 0;
+
+
+ /* produce a shift to adjust offset delta */
+ if (delta > 0) {
+ ir_node *cnst;
+
+ /* FIXME: only true for little endian */
+ cnst = new_Const_long(mode_Iu, delta * 8);
+ store_value = new_r_Shr(get_nodes_block(load),
+ store_value, cnst, store_mode);
+ }
+
+ /* add an convert if needed */
+ if (store_mode != load_mode) {
+ store_value = new_r_Conv(get_nodes_block(load), store_value, load_mode);
+ }
+ }
+
+ DBG_OPT_RAW(load, store_value);
+
+ info = get_irn_link(load);
+ if (info->projs[pn_Load_M])
+ exchange(info->projs[pn_Load_M], get_Load_mem(load));
+
+ res = 0;
+ /* no exception */
+ if (info->projs[pn_Load_X_except]) {
+ exchange( info->projs[pn_Load_X_except], new_Bad());
+ res |= CF_CHANGED;
+ }
+ if (info->projs[pn_Load_X_regular]) {
+ exchange( info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load)));
+ res |= CF_CHANGED;
+ }
+
+ if (info->projs[pn_Load_res])
+ exchange(info->projs[pn_Load_res], store_value);
+
+ load_ptr = get_Load_ptr(load);
+ kill_node(load);
+ reduce_adr_usage(load_ptr);
+ return res | DF_CHANGED;
}
/**
- * Follow the memory chain as long as there are only Loads
- * and try to replace current Load or Store by a previous one.
+ * 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.
*
* INC_MASTER() must be called before dive into
*/
-static unsigned follow_Load_chain(ir_node *load, ir_node *curr) {
- unsigned res = 0;
- ldst_info_t *info = get_irn_link(load);
- ir_node *pred;
- ir_node *ptr = get_Load_ptr(load);
- ir_node *mem = get_Load_mem(load);
- ir_mode *load_mode = get_Load_mode(load);
-
- for (pred = curr; load != pred; pred = skip_Proj(get_Load_mem(pred))) {
- ldst_info_t *pred_info = get_irn_link(pred);
-
- /*
- * BEWARE: one might think that checking the modes is useless, because
- * if the pointers are identical, they refer to the same object.
- * This is only true in strong typed languages, not in C were the following
- * is possible a = *(ir_type1 *)p; b = *(ir_type2 *)p ...
- */
-
- if (get_irn_op(pred) == op_Store && get_Store_ptr(pred) == ptr &&
- get_irn_mode(get_Store_value(pred)) == load_mode) {
- /*
- * 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 Exception? 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 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)) {
- ir_node *value = get_Store_value(pred);
-
- DBG_OPT_RAW(load, value);
- if (info->projs[pn_Load_M])
- exchange(info->projs[pn_Load_M], mem);
-
- /* no exception */
- if (info->projs[pn_Load_X_except]) {
- exchange( info->projs[pn_Load_X_except], new_Bad());
- res |= CF_CHANGED;
- }
-
- if (info->projs[pn_Load_res])
- exchange(info->projs[pn_Load_res], value);
-
- exchange(load, new_Bad());
- reduce_adr_usage(ptr);
- return res | DF_CHANGED;
- }
- }
- 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.
- * 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 previous 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)) {
- DBG_OPT_RAR(load, pred);
-
- if (pred_info->projs[pn_Load_res]) {
- /* we need a data proj from the previous load for this optimization */
- if (info->projs[pn_Load_res])
- exchange(info->projs[pn_Load_res], pred_info->projs[pn_Load_res]);
-
- if (info->projs[pn_Load_M])
- exchange(info->projs[pn_Load_M], mem);
- }
- else {
- if (info->projs[pn_Load_res]) {
- set_Proj_pred(info->projs[pn_Load_res], pred);
- set_nodes_block(info->projs[pn_Load_res], get_nodes_block(pred));
- pred_info->projs[pn_Load_res] = info->projs[pn_Load_res];
- }
- if (info->projs[pn_Load_M]) {
- /* Actually, this if should not be necessary. Construct the Loads
- properly!!! */
- exchange(info->projs[pn_Load_M], mem);
- }
- }
-
- /* no exception */
- if (info->projs[pn_Load_X_except]) {
- exchange(info->projs[pn_Load_X_except], new_Bad());
- res |= CF_CHANGED;
- }
-
- exchange(load, new_Bad());
- reduce_adr_usage(ptr);
- return res |= DF_CHANGED;
- }
- }
-
- /* follow only Load chains */
- if (get_irn_op(pred) != op_Load)
- break;
-
- /* check for cycles */
- if (NODE_VISITED(pred_info))
- break;
- MARK_NODE(pred_info);
- }
-
- if (get_irn_op(pred) == op_Sync) {
- int i;
-
- /* handle all Sync predecessors */
- for (i = get_Sync_n_preds(pred) - 1; i >= 0; --i) {
- res |= follow_Load_chain(load, skip_Proj(get_Sync_pred(pred, i)));
- if (res)
- break;
- }
- }
-
- return res;
-}
+static unsigned follow_Mem_chain(ir_node *load, ir_node *curr) {
+ unsigned res = 0;
+ ldst_info_t *info = get_irn_link(load);
+ ir_node *pred;
+ ir_node *ptr = get_Load_ptr(load);
+ ir_node *mem = get_Load_mem(load);
+ ir_mode *load_mode = get_Load_mode(load);
+
+ for (pred = curr; load != 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 OR they are in the same MacroBlock. In the latter
+ * case the Load cannot throw an exception when the previous Store was
+ * quiet.
+ *
+ * Why we need to check for Store Exception? If the Store cannot
+ * be executed (ROM) the exception handler might simply jump into
+ * the load MacroBlock :-(
+ * We could make it a little bit better if we would know that the
+ * exception handler of the Store jumps directly to the end...
+ */
+ if (is_Store(pred) && ((pred_info->projs[pn_Store_X_except] == NULL
+ && info->projs[pn_Load_X_except] == NULL)
+ || get_nodes_MacroBlock(load) == get_nodes_MacroBlock(pred)))
+ {
+ long load_offset;
+ ir_node *base_ptr = get_base_and_offset(ptr, &load_offset);
+ int changes = try_load_after_store(load, base_ptr, load_offset, pred);
+
+ if (changes != 0)
+ return res | changes;
+ } else if (is_Load(pred) && get_Load_ptr(pred) == ptr &&
+ can_use_stored_value(get_Load_mode(pred), load_mode)) {
+ /*
+ * 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 MacroBlock. 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 previous Load has an exception
+ * hander because they would have exact the same exception...
+ */
+ if (info->projs[pn_Load_X_except] == NULL || get_nodes_MacroBlock(load) == get_nodes_MacroBlock(pred)) {
+ ir_node *value;
+
+ DBG_OPT_RAR(load, pred);
+
+ /* the result is used */
+ if (info->projs[pn_Load_res]) {
+ if (pred_info->projs[pn_Load_res] == NULL) {
+ /* create a new Proj again */
+ pred_info->projs[pn_Load_res] = new_r_Proj(get_nodes_block(pred), pred, get_Load_mode(pred), pn_Load_res);
+ }
+ value = pred_info->projs[pn_Load_res];
+
+ /* add an convert if needed */
+ if (get_Load_mode(pred) != load_mode) {
+ value = new_r_Conv(get_nodes_block(load), value, load_mode);
+ }
+
+ exchange(info->projs[pn_Load_res], value);
+ }
+
+ if (info->projs[pn_Load_M])
+ exchange(info->projs[pn_Load_M], mem);
+
+ /* no exception */
+ if (info->projs[pn_Load_X_except]) {
+ exchange(info->projs[pn_Load_X_except], new_Bad());
+ res |= CF_CHANGED;
+ }
+ if (info->projs[pn_Load_X_regular]) {
+ exchange( info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load)));
+ res |= CF_CHANGED;
+ }
+
+ kill_node(load);
+ reduce_adr_usage(ptr);
+ return res |= DF_CHANGED;
+ }
+ }
+
+ if (is_Store(pred)) {
+ /* check if we can pass through this store */
+ ir_alias_relation rel = get_alias_relation(
+ current_ir_graph,
+ get_Store_ptr(pred),
+ get_irn_mode(get_Store_value(pred)),
+ ptr, load_mode);
+ /* if the might be an alias, we cannot pass this Store */
+ if (rel != ir_no_alias)
+ break;
+ pred = skip_Proj(get_Store_mem(pred));
+ } 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;
+ }
+
+ /* check for cycles */
+ if (NODE_VISITED(pred_info))
+ break;
+ MARK_NODE(pred_info);
+ }
+
+ if (is_Sync(pred)) {
+ int i;
+
+ /* handle all Sync predecessors */
+ 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)
+ return res;
+ }
+ }
+
+ return res;
+} /* follow_Mem_chain */
+
+/*
+ * Check if we can replace the load by a given const from
+ * the const code irg.
+ */
+ir_node *can_replace_load_by_const(const ir_node *load, ir_node *c) {
+ ir_mode *c_mode = get_irn_mode(c);
+ ir_mode *l_mode = get_Load_mode(load);
+ ir_node *res = NULL;
+
+ if (c_mode != l_mode) {
+ /* check, if the mode matches OR can be easily converted info */
+ if (is_reinterpret_cast(c_mode, l_mode)) {
+ /* we can safely cast */
+ dbg_info *dbg = get_irn_dbg_info(load);
+ ir_node *block = get_nodes_block(load);
+
+ /* copy the value from the const code irg and cast it */
+ res = copy_const_value(dbg, c);
+ res = new_rd_Conv(dbg, block, res, l_mode);
+ }
+ } else {
+ /* copy the value from the const code irg */
+ res = copy_const_value(get_irn_dbg_info(load), c);
+ }
+ return res;
+} /* can_replace_load_by_const */
/**
* optimize a Load
+ *
+ * @param load the Load node
*/
static unsigned optimize_load(ir_node *load)
{
- ldst_info_t *info = get_irn_link(load);
- ir_mode *load_mode = get_Load_mode(load);
- ir_node *mem, *ptr, *new_node;
- entity *ent;
- unsigned res = 0;
-
- /* do NOT touch volatile loads for now */
- if (get_Load_volatility(load) == volatility_is_volatile)
- return 0;
-
- /* the address of the load to be optimized */
- ptr = get_Load_ptr(load);
-
- /*
- * Check if we can remove the exception from a Load:
- * This can be done, if the address is from an Sel(Alloc) and
- * the Sel type is a subtype of the allocated type.
- *
- * This optimizes some often used OO constructs,
- * like x = new O; x->t;
- */
- if (info->projs[pn_Load_X_except]) {
- if (is_Sel(ptr)) {
- 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);
- ir_type *s_type = get_entity_type(ent);
- ir_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;
- res |= CF_CHANGED;
- }
- }
- }
- 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;
- res |= CF_CHANGED;
- }
- }
-
- /* the mem of the Load. Must still be returned after optimization */
- mem = get_Load_mem(load);
-
- if (! info->projs[pn_Load_res] && ! info->projs[pn_Load_X_except]) {
- /* a Load which value is neither used nor exception checked, remove it */
- exchange(info->projs[pn_Load_M], mem);
-
- exchange(load, new_Bad());
- reduce_adr_usage(ptr);
- return res | DF_CHANGED;
- }
-
- /* Load from a constant polymorphic field, where we can resolve
- polymorphism. */
- 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);
-
- exchange(load, new_Bad());
- reduce_adr_usage(ptr);
- return res | DF_CHANGED;
- }
-
- /* 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
- * when loading. */
-
- /* no exception, clear the info field as it might be checked later again */
- if (info->projs[pn_Load_X_except]) {
- exchange(info->projs[pn_Load_X_except], new_Bad());
- info->projs[pn_Load_X_except] = NULL;
- res |= CF_CHANGED;
- }
-
- 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. */
- /* more simpler case: we load the content of a constant value:
- * replace it by the constant itself
- */
-
- /* no memory */
- if (info->projs[pn_Load_M]) {
- exchange(info->projs[pn_Load_M], mem);
- res |= DF_CHANGED;
- }
- /* no result :-) */
- if (info->projs[pn_Load_res]) {
- if (is_atomic_entity(ent)) {
- ir_node *c = copy_const_value(get_irn_dbg_info(load), get_atomic_ent_value(ent));
-
- DBG_OPT_RC(load, c);
- exchange(info->projs[pn_Load_res], c);
- res |= DF_CHANGED;
- }
- }
- exchange(load, new_Bad());
- reduce_adr_usage(ptr);
- return res;
- }
- else if (variability_constant == get_entity_variability(ent)) {
- compound_graph_path *path = get_accessed_path(ptr);
-
- if (path) {
- ir_node *c;
-
- assert(is_proper_compound_graph_path(path, get_compound_graph_path_length(path)-1));
- /*
- {
- 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");
- }
- */
-
- c = get_compound_ent_value_by_path(ent, path);
- free_compound_graph_path(path);
-
- /* printf(" cons: "); DDMN(c); */
-
- if (info->projs[pn_Load_M]) {
- exchange(info->projs[pn_Load_M], mem);
- res |= DF_CHANGED;
- }
- if (info->projs[pn_Load_res]) {
- exchange(info->projs[pn_Load_res], copy_const_value(get_irn_dbg_info(load), c));
- res |= DF_CHANGED;
- }
- exchange(load, new_Bad());
- reduce_adr_usage(ptr);
- return res;
- }
- 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);
- */
- }
- }
- }
- }
-
- /* 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_n_uses(ptr) <= 1)
- return res;
-
- /*
- * follow the memory chain as long as there are only Loads
- * and try to replace current Load or Store by a previous one.
- * 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.
- */
- INC_MASTER();
- res = follow_Load_chain(load, skip_Proj(mem));
- return res;
-}
+ ldst_info_t *info = get_irn_link(load);
+ ir_node *mem, *ptr, *value;
+ ir_entity *ent;
+ long dummy;
+ unsigned res = 0;
+
+ /* do NOT touch volatile loads for now */
+ if (get_Load_volatility(load) == volatility_is_volatile)
+ return 0;
+
+ /* the address of the load to be optimized */
+ ptr = get_Load_ptr(load);
+
+ /*
+ * Check if we can remove the exception from a Load:
+ * This can be done, if the address is from an Sel(Alloc) and
+ * the Sel type is a subtype of the allocated type.
+ *
+ * This optimizes some often used OO constructs,
+ * like x = new O; x->t;
+ */
+ if (info->projs[pn_Load_X_except]) {
+ ir_node *addr = ptr;
+
+ /* find base address */
+ while (is_Sel(addr))
+ addr = get_Sel_ptr(addr);
+ if (is_Alloc(skip_Proj(skip_Cast(addr)))) {
+ /* 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;
+ exchange(info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load)));
+ info->projs[pn_Load_X_regular] = NULL;
+ res |= CF_CHANGED;
+ }
+ }
+
+ /* The mem of the Load. Must still be returned after optimization. */
+ mem = get_Load_mem(load);
+
+ if (! info->projs[pn_Load_res] && ! info->projs[pn_Load_X_except]) {
+ /* a Load which value is neither used nor exception checked, remove it */
+ exchange(info->projs[pn_Load_M], mem);
+
+ if (info->projs[pn_Load_X_regular]) {
+ /* should not happen, but if it does, remove it */
+ exchange(info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load)));
+ res |= CF_CHANGED;
+ }
+ kill_node(load);
+ reduce_adr_usage(ptr);
+ return res | DF_CHANGED;
+ }
+
+ /* Load from a constant polymorphic field, where we can resolve
+ polymorphism. */
+ value = transform_polymorph_Load(load);
+ if (value == load) {
+ value = NULL;
+ /* check if we can determine the entity that will be loaded */
+ ent = find_constant_entity(ptr);
+ if (ent != NULL &&
+ 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
+ * when loading even if we cannot replace the load itself. */
+
+ /* no exception, clear the info field as it might be checked later again */
+ if (info->projs[pn_Load_X_except]) {
+ exchange(info->projs[pn_Load_X_except], new_Bad());
+ info->projs[pn_Load_X_except] = NULL;
+ res |= CF_CHANGED;
+ }
+ if (info->projs[pn_Load_X_regular]) {
+ exchange(info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load)));
+ info->projs[pn_Load_X_regular] = NULL;
+ res |= CF_CHANGED;
+ }
+
+ if (variability_constant == get_entity_variability(ent)) {
+ if (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 */
+ value = get_atomic_ent_value(ent);
+ } else if (ent->has_initializer) {
+ /* new style initializer */
+ value = find_compound_ent_value(ptr);
+ } else {
+ /* old style initializer */
+ compound_graph_path *path = get_accessed_path(ptr);
+
+ if (path != NULL) {
+ assert(is_proper_compound_graph_path(path, get_compound_graph_path_length(path)-1));
+
+ value = get_compound_ent_value_by_path(ent, path);
+ DB((dbg, LEVEL_1, " Constant access at %F%F resulted in %+F\n", ent, path, value));
+ free_compound_graph_path(path);
+ }
+ }
+ if (value != NULL)
+ value = can_replace_load_by_const(load, value);
+ }
+ }
+ }
+ if (value != NULL) {
+ /* we completely replace the load by this value */
+ if (info->projs[pn_Load_X_except]) {
+ exchange(info->projs[pn_Load_X_except], new_Bad());
+ info->projs[pn_Load_X_except] = NULL;
+ res |= CF_CHANGED;
+ }
+ if (info->projs[pn_Load_X_regular]) {
+ exchange(info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load)));
+ info->projs[pn_Load_X_regular] = NULL;
+ res |= CF_CHANGED;
+ }
+ if (info->projs[pn_Load_M]) {
+ exchange(info->projs[pn_Load_M], mem);
+ res |= DF_CHANGED;
+ }
+ if (info->projs[pn_Load_res]) {
+ exchange(info->projs[pn_Load_res], value);
+ res |= DF_CHANGED;
+ }
+ kill_node(load);
+ reduce_adr_usage(ptr);
+ return res;
+ }
+
+ /* 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)
+ return res;
+
+ /*
+ * follow the memory chain as long as there are only Loads
+ * and try to replace current Load or Store by a previous one.
+ * 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.
+ */
+ INC_MASTER();
+ res = follow_Mem_chain(load, skip_Proj(mem));
+ return res;
+} /* optimize_load */
/**
- * follow the memory chain as long as there are only Loads.
- *
- * INC_MASTER() must be called before dive into
+ * Check whether a value of mode new_mode would completely overwrite a value
+ * of mode old_mode in memory.
*/
-static unsigned follow_Load_chain_for_Store(ir_node *store, ir_node *curr) {
- unsigned res = 0;
- ldst_info_t *info = get_irn_link(store);
- ir_node *pred;
- ir_node *ptr = get_Store_ptr(store);
- ir_node *mem = get_Store_mem(store);
- ir_node *value = get_Store_value(store);
- ir_mode *mode = get_irn_mode(value);
- ir_node *block = get_nodes_block(store);
-
- for (pred = curr; pred != store; pred = skip_Proj(get_Load_mem(pred))) {
- ldst_info_t *pred_info = get_irn_link(pred);
-
- /*
- * BEWARE: one might think that checking the modes is useless, because
- * if the pointers are identical, they refer to the same object.
- * This is only true in strong typed languages, not is C were the following
- * is possible *(ir_type1 *)p = a; *(ir_type2 *)p = b ...
- */
- 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.
- * 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());
- reduce_adr_usage(ptr);
- return DF_CHANGED;
- }
- }
- 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.
- * We may remove the second 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());
- reduce_adr_usage(ptr);
- return DF_CHANGED;
- }
- }
-
- /* follow only Load chains */
- if (get_irn_op(pred) != op_Load)
- break;
-
- /* check for cycles */
- if (NODE_VISITED(pred_info))
- break;
- MARK_NODE(pred_info);
- }
-
- if (get_irn_op(pred) == op_Sync) {
- int i;
-
- /* handle all Sync predecessors */
- for (i = get_Sync_n_preds(pred) - 1; i >= 0; --i) {
- res |= follow_Load_chain_for_Store(store, skip_Proj(get_Sync_pred(pred, i)));
- if (res)
- break;
- }
- }
- return res;
-}
+static int is_completely_overwritten(ir_mode *old_mode, ir_mode *new_mode)
+{
+ return get_mode_size_bits(new_mode) >= get_mode_size_bits(old_mode);
+} /* is_completely_overwritten */
/**
- * optimize a Store
+ * Check whether small is a part of large (starting at same address).
*/
-static unsigned optimize_store(ir_node *store)
+static int is_partially_same(ir_node *small, ir_node *large)
{
- ldst_info_t *info = get_irn_link(store);
- ir_node *ptr, *mem;
-
- if (get_Store_volatility(store) == volatility_is_volatile)
- return 0;
-
- ptr = get_Store_ptr(store);
+ ir_mode *sm = get_irn_mode(small);
+ ir_mode *lm = get_irn_mode(large);
- /* 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_n_uses(ptr) <= 1)
- return 0;
+ /* FIXME: Check endianness */
+ return is_Conv(small) && get_Conv_op(small) == large
+ && get_mode_size_bytes(sm) < get_mode_size_bytes(lm)
+ && get_mode_arithmetic(sm) == irma_twos_complement
+ && get_mode_arithmetic(lm) == irma_twos_complement;
+} /* is_partially_same */
- mem = get_Store_mem(store);
-
- /* follow the memory chain as long as there are only Loads */
- INC_MASTER();
- return follow_Load_chain_for_Store(store, skip_Proj(mem));
+/**
+ * follow the memory chain as long as there are only Loads and alias free Stores.
+ *
+ * INC_MASTER() must be called before dive into
+ */
+static unsigned follow_Mem_chain_for_Store(ir_node *store, ir_node *curr) {
+ unsigned res = 0;
+ ldst_info_t *info = get_irn_link(store);
+ ir_node *pred;
+ ir_node *ptr = get_Store_ptr(store);
+ ir_node *mem = get_Store_mem(store);
+ ir_node *value = get_Store_value(store);
+ ir_mode *mode = get_irn_mode(value);
+ ir_node *block = get_nodes_block(store);
+ ir_node *mblk = get_Block_MacroBlock(block);
+
+ for (pred = curr; pred != store;) {
+ ldst_info_t *pred_info = get_irn_link(pred);
+
+ /*
+ * BEWARE: one might think that checking the modes is useless, because
+ * if the pointers are identical, they refer to the same object.
+ * This is only true in strong typed languages, not is C were the following
+ * is possible *(ir_type1 *)p = a; *(ir_type2 *)p = b ...
+ * However, if the size of the mode that is written is bigger or equal the
+ * size of the old one, the old value is completely overwritten and can be
+ * killed ...
+ */
+ if (is_Store(pred) && get_Store_ptr(pred) == ptr &&
+ get_nodes_MacroBlock(pred) == mblk) {
+ /*
+ * a Store after a Store in the same MacroBlock -- a write after write.
+ */
+
+ /*
+ * We may remove the first Store, if the old value is completely
+ * overwritten or the old value is a part of the new value,
+ * and 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]) {
+ ir_node *predvalue = get_Store_value(pred);
+ ir_mode *predmode = get_irn_mode(predvalue);
+
+ if(is_completely_overwritten(predmode, mode)
+ || is_partially_same(predvalue, value)) {
+ DBG_OPT_WAW(pred, store);
+ exchange(pred_info->projs[pn_Store_M], get_Store_mem(pred));
+ kill_node(pred);
+ reduce_adr_usage(ptr);
+ return DF_CHANGED;
+ }
+ }
+
+ /*
+ * We may remove the Store, if the old value already contains
+ * the new value, and if it does not have an exception handler.
+ *
+ * TODO: What, if both have the same exception handler ???
+ */
+ if (get_Store_volatility(store) != volatility_is_volatile
+ && !info->projs[pn_Store_X_except]) {
+ ir_node *predvalue = get_Store_value(pred);
+
+ if(is_partially_same(value, predvalue)) {
+ DBG_OPT_WAW(pred, store);
+ exchange(info->projs[pn_Store_M], mem);
+ kill_node(store);
+ 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 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);
+ kill_node(store);
+ reduce_adr_usage(ptr);
+ return DF_CHANGED;
+ }
+ }
+
+ if (is_Store(pred)) {
+ /* check if we can pass through this store */
+ ir_alias_relation rel = get_alias_relation(
+ current_ir_graph,
+ get_Store_ptr(pred),
+ get_irn_mode(get_Store_value(pred)),
+ ptr, mode);
+ /* if the might be an alias, we cannot pass this Store */
+ if (rel != ir_no_alias)
+ break;
+ pred = skip_Proj(get_Store_mem(pred));
+ } else if (is_Load(pred)) {
+ 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 */
+ break;
+ }
+
+ /* check for cycles */
+ if (NODE_VISITED(pred_info))
+ break;
+ MARK_NODE(pred_info);
+ }
+
+ if (is_Sync(pred)) {
+ int i;
+
+ /* handle all Sync predecessors */
+ for (i = get_Sync_n_preds(pred) - 1; i >= 0; --i) {
+ res |= follow_Mem_chain_for_Store(store, skip_Proj(get_Sync_pred(pred, i)));
+ if (res)
+ break;
+ }
+ }
+ return res;
+} /* follow_Mem_chain_for_Store */
+
+/** find entity used as base for an address calculation */
+static ir_entity *find_entity(ir_node *ptr)
+{
+ switch(get_irn_opcode(ptr)) {
+ case iro_SymConst:
+ return get_SymConst_entity(ptr);
+ case iro_Sel: {
+ ir_node *pred = get_Sel_ptr(ptr);
+ if (get_irg_frame(get_irn_irg(ptr)) == pred)
+ return get_Sel_entity(ptr);
+
+ return find_entity(pred);
+ }
+ case iro_Sub:
+ case iro_Add: {
+ ir_node *left = get_binop_left(ptr);
+ ir_node *right;
+ if (mode_is_reference(get_irn_mode(left)))
+ return find_entity(left);
+ right = get_binop_right(ptr);
+ if (mode_is_reference(get_irn_mode(right)))
+ return find_entity(right);
+ return NULL;
+ }
+ default:
+ return NULL;
+ }
}
+/**
+ * optimize a Store
+ *
+ * @param store the Store node
+ */
+static unsigned optimize_store(ir_node *store) {
+ ir_node *ptr;
+ ir_node *mem;
+ ir_entity *entity;
+
+ if (get_Store_volatility(store) == volatility_is_volatile)
+ return 0;
+
+ ptr = get_Store_ptr(store);
+ entity = find_entity(ptr);
+
+ /* a store to an entity which is never read is unnecessary */
+ if (entity != NULL && !(get_entity_usage(entity) & ir_usage_read)) {
+ ldst_info_t *info = get_irn_link(store);
+ if (info->projs[pn_Store_X_except] == NULL) {
+ DB((dbg, LEVEL_1, " Killing useless %+F to never read entity %+F\n", store, entity));
+ exchange(info->projs[pn_Store_M], get_Store_mem(store));
+ kill_node(store);
+ reduce_adr_usage(ptr);
+ return DF_CHANGED;
+ }
+ }
+
+ /* 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)
+ return 0;
+
+ mem = get_Store_mem(store);
+
+ /* 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 */
+
/**
* walker, optimizes Phi after Stores to identical places:
* Does the following optimization:
*
* val1 val2 val3 val1 val2 val3
* | | | \ | /
- * Str Str Str \ | /
+ * Store Store Store \ | /
* \ | / PhiData
* \ | / |
- * \ | / Str
+ * \ | / Store
* PhiM
*
* @endverbatim
*/
static unsigned optimize_phi(ir_node *phi, walk_env_t *wenv)
{
- int i, n;
- ir_node *store, *old_store, *ptr, *block, *phiM, *phiD, *exc, *projM;
- ir_mode *mode;
- ir_node **inM, **inD;
- int *idx;
- dbg_info *db = NULL;
- ldst_info_t *info;
- block_info_t *bl_info;
- unsigned res = 0;
-
- /* Must be a memory Phi */
- if (get_irn_mode(phi) != mode_M)
- return 0;
-
- n = get_Phi_n_preds(phi);
- if (n <= 0)
- return 0;
-
- store = skip_Proj(get_Phi_pred(phi, 0));
- old_store = store;
- if (get_irn_op(store) != op_Store)
- return 0;
-
- /* abort on dead blocks */
- if (is_Block_dead(get_nodes_block(store)))
- return 0;
-
- /* check if the block has only one successor */
- bl_info = get_irn_link(get_nodes_block(store));
- if (bl_info->flags)
- return 0;
-
- /* this is the address of the store */
- ptr = get_Store_ptr(store);
- mode = get_irn_mode(get_Store_value(store));
- info = get_irn_link(store);
- exc = info->exc_block;
-
- for (i = 1; i < n; ++i) {
- ir_node *pred = skip_Proj(get_Phi_pred(phi, i));
-
- if (get_irn_op(pred) != op_Store)
- return 0;
-
- if (ptr != get_Store_ptr(pred) || mode != get_irn_mode(get_Store_value(pred)))
- return 0;
-
- info = get_irn_link(pred);
-
- /* check, if all stores have the same exception flow */
- if (exc != info->exc_block)
- return 0;
-
- /* abort on dead blocks */
- if (is_Block_dead(get_nodes_block(store)))
- return 0;
-
- /* check if the block has only one successor */
- bl_info = get_irn_link(get_nodes_block(store));
- if (bl_info->flags)
- return 0;
- }
-
- /*
- * ok, when we are here, we found all predecessors of a Phi that
- * are Stores to the same address and size. That means whatever
- * we do before we enter the block of the Phi, we do a Store.
- * So, we can move the Store to the current block:
- *
- * val1 val2 val3 val1 val2 val3
- * | | | \ | /
- * | Str | | Str | | Str | \ | /
- * \ | / PhiData
- * \ | / |
- * \ | / Str
- * PhiM
- *
- * Is only allowed if the predecessor blocks have only one successor.
- */
-
- /* first step: collect all inputs */
- NEW_ARR_A(ir_node *, inM, n);
- NEW_ARR_A(ir_node *, inD, n);
- NEW_ARR_A(int, idx, n);
-
- for (i = 0; i < n; ++i) {
- ir_node *pred = skip_Proj(get_Phi_pred(phi, i));
- info = get_irn_link(pred);
-
- inM[i] = get_Store_mem(pred);
- inD[i] = get_Store_value(pred);
- idx[i] = info->exc_idx;
-
- /* Should we here replace the Proj after the Store by
- * the Store's memory? Would be save but should not be needed,
- * because we checked that all pred blocks have only one
- * control flow successor.
- */
- }
- block = get_nodes_block(phi);
-
- /* second step: create a new memory Phi */
- phiM = new_rd_Phi(get_irn_dbg_info(phi), current_ir_graph, block, n, inM, mode_M);
-
- /* third step: create a new data Phi */
- phiD = new_rd_Phi(get_irn_dbg_info(phi), current_ir_graph, block, n, inD, mode);
-
- /* fourth step: create the Store */
- store = new_rd_Store(db, current_ir_graph, block, phiM, ptr, phiD);
+ int i, n;
+ ir_node *store, *old_store, *ptr, *block, *phi_block, *phiM, *phiD, *exc, *projM;
+ ir_mode *mode;
+ ir_node **inM, **inD, **projMs;
+ int *idx;
+ dbg_info *db = NULL;
+ ldst_info_t *info;
+ block_info_t *bl_info;
+ unsigned res = 0;
+
+ /* Must be a memory Phi */
+ if (get_irn_mode(phi) != mode_M)
+ return 0;
+
+ n = get_Phi_n_preds(phi);
+ if (n <= 0)
+ return 0;
+
+ /* must be only one user */
+ projM = get_Phi_pred(phi, 0);
+ if (get_irn_n_edges(projM) != 1)
+ return 0;
+
+ store = skip_Proj(projM);
+ old_store = store;
+ if (!is_Store(store))
+ return 0;
+
+ block = get_nodes_block(store);
+
+ /* abort on dead blocks */
+ if (is_Block_dead(block))
+ return 0;
+
+ /* check if the block is post dominated by Phi-block
+ and has no exception exit */
+ bl_info = get_irn_link(block);
+ if (bl_info->flags & BLOCK_HAS_EXC)
+ return 0;
+
+ phi_block = get_nodes_block(phi);
+ if (! block_strictly_postdominates(phi_block, block))
+ return 0;
+
+ /* this is the address of the store */
+ ptr = get_Store_ptr(store);
+ mode = get_irn_mode(get_Store_value(store));
+ info = get_irn_link(store);
+ exc = info->exc_block;
+
+ for (i = 1; i < n; ++i) {
+ ir_node *pred = get_Phi_pred(phi, i);
+
+ if (get_irn_n_edges(pred) != 1)
+ return 0;
+
+ pred = skip_Proj(pred);
+ if (!is_Store(pred))
+ return 0;
+
+ if (ptr != get_Store_ptr(pred) || mode != get_irn_mode(get_Store_value(pred)))
+ return 0;
+
+ info = get_irn_link(pred);
+
+ /* check, if all stores have the same exception flow */
+ if (exc != info->exc_block)
+ return 0;
+
+ /* abort on dead blocks */
+ block = get_nodes_block(pred);
+ if (is_Block_dead(block))
+ return 0;
+
+ /* check if the block is post dominated by Phi-block
+ and has no exception exit. Note that block must be different from
+ Phi-block, else we would move a Store from end End of a block to its
+ Start... */
+ bl_info = get_irn_link(block);
+ if (bl_info->flags & BLOCK_HAS_EXC)
+ return 0;
+ if (block == phi_block || ! block_postdominates(phi_block, block))
+ return 0;
+ }
+
+ /*
+ * ok, when we are here, we found all predecessors of a Phi that
+ * are Stores to the same address and size. That means whatever
+ * we do before we enter the block of the Phi, we do a Store.
+ * So, we can move the Store to the current block:
+ *
+ * val1 val2 val3 val1 val2 val3
+ * | | | \ | /
+ * | Str | | Str | | Str | \ | /
+ * \ | / PhiData
+ * \ | / |
+ * \ | / Str
+ * PhiM
+ *
+ * Is only allowed if the predecessor blocks have only one successor.
+ */
+
+ NEW_ARR_A(ir_node *, projMs, n);
+ NEW_ARR_A(ir_node *, inM, n);
+ NEW_ARR_A(ir_node *, inD, n);
+ NEW_ARR_A(int, idx, n);
+
+ /* Prepare: Collect all Store nodes. We must do this
+ first because we otherwise may loose a store when exchanging its
+ memory Proj.
+ */
+ for (i = n - 1; i >= 0; --i) {
+ ir_node *store;
+
+ projMs[i] = get_Phi_pred(phi, i);
+ assert(is_Proj(projMs[i]));
+
+ store = get_Proj_pred(projMs[i]);
+ info = get_irn_link(store);
+
+ inM[i] = get_Store_mem(store);
+ inD[i] = get_Store_value(store);
+ idx[i] = info->exc_idx;
+ }
+ block = get_nodes_block(phi);
+
+ /* second step: create a new memory Phi */
+ phiM = new_rd_Phi(get_irn_dbg_info(phi), block, n, inM, mode_M);
+
+ /* third step: create a new data Phi */
+ phiD = new_rd_Phi(get_irn_dbg_info(phi), block, n, inD, mode);
+
+ /* rewire memory and kill the node */
+ for (i = n - 1; i >= 0; --i) {
+ ir_node *proj = projMs[i];
+
+ if(is_Proj(proj)) {
+ ir_node *store = get_Proj_pred(proj);
+ exchange(proj, inM[i]);
+ kill_node(store);
+ }
+ }
+
+ /* fourth step: create the Store */
+ store = new_rd_Store(db, block, phiM, ptr, phiD, 0);
#ifdef DO_CACHEOPT
- co_set_irn_name(store, co_get_irn_ident(old_store));
+ 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);
+ projM = new_rd_Proj(NULL, block, store, mode_M, pn_Store_M);
- info = get_ldst_info(store, wenv);
- info->projs[pn_Store_M] = projM;
+ info = get_ldst_info(store, &wenv->obst);
+ info->projs[pn_Store_M] = projM;
- /* fifths step: repair exception flow */
- if (exc) {
- ir_node *projX = new_rd_Proj(NULL, current_ir_graph, block, store, mode_X, pn_Store_X_except);
+ /* fifths step: repair exception flow */
+ if (exc) {
+ ir_node *projX = new_rd_Proj(NULL, block, store, mode_X, pn_Store_X_except);
- info->projs[pn_Store_X_except] = projX;
- info->exc_block = exc;
- info->exc_idx = idx[0];
+ info->projs[pn_Store_X_except] = projX;
+ info->exc_block = exc;
+ info->exc_idx = idx[0];
- for (i = 0; i < n; ++i) {
- set_Block_cfgpred(exc, idx[i], projX);
- }
+ for (i = 0; i < n; ++i) {
+ set_Block_cfgpred(exc, idx[i], projX);
+ }
- if (n > 1) {
- /* the exception block should be optimized as some inputs are identical now */
- }
+ if (n > 1) {
+ /* the exception block should be optimized as some inputs are identical now */
+ }
- res |= CF_CHANGED;
- }
+ res |= CF_CHANGED;
+ }
- /* sixth step: replace old Phi */
- exchange(phi, projM);
+ /* sixth step: replace old Phi */
+ exchange(phi, projM);
- return res | DF_CHANGED;
-}
+ return res | DF_CHANGED;
+} /* optimize_phi */
/**
* walker, do the optimizations
*/
-static void do_load_store_optimize(ir_node *n, void *env)
+static void do_load_store_optimize(ir_node *n, void *env) {
+ walk_env_t *wenv = env;
+
+ switch (get_irn_opcode(n)) {
+
+ case iro_Load:
+ wenv->changes |= optimize_load(n);
+ break;
+
+ case iro_Store:
+ wenv->changes |= optimize_store(n);
+ break;
+
+ case iro_Phi:
+ wenv->changes |= optimize_phi(n, wenv);
+ break;
+
+ default:
+ ;
+ }
+} /* do_load_store_optimize */
+
+/** A scc. */
+typedef struct scc {
+ ir_node *head; /**< the head of the list */
+} scc;
+
+/** A node entry. */
+typedef struct node_entry {
+ unsigned DFSnum; /**< the DFS number of this node */
+ unsigned low; /**< the low number of this node */
+ int in_stack; /**< flag, set if the node is on the stack */
+ ir_node *next; /**< link to the next node the the same scc */
+ scc *pscc; /**< the scc of this node */
+ unsigned POnum; /**< the post order number for blocks */
+} node_entry;
+
+/** A loop entry. */
+typedef struct loop_env {
+ ir_phase ph; /**< the phase object */
+ ir_node **stack; /**< the node stack */
+ int tos; /**< tos index */
+ unsigned nextDFSnum; /**< the current DFS number */
+ unsigned POnum; /**< current post order number */
+
+ unsigned changes; /**< a bitmask of graph changes */
+} loop_env;
+
+/**
+* Gets the node_entry of a node
+*/
+static node_entry *get_irn_ne(ir_node *irn, loop_env *env) {
+ ir_phase *ph = &env->ph;
+ node_entry *e = phase_get_irn_data(&env->ph, irn);
+
+ if (! e) {
+ e = phase_alloc(ph, sizeof(*e));
+ memset(e, 0, sizeof(*e));
+ phase_set_irn_data(ph, irn, e);
+ }
+ return e;
+} /* get_irn_ne */
+
+/**
+ * Push a node onto the stack.
+ *
+ * @param env the loop environment
+ * @param n the node to push
+ */
+static void push(loop_env *env, ir_node *n) {
+ node_entry *e;
+
+ if (env->tos == ARR_LEN(env->stack)) {
+ int nlen = ARR_LEN(env->stack) * 2;
+ ARR_RESIZE(ir_node *, env->stack, nlen);
+ }
+ env->stack[env->tos++] = n;
+ e = get_irn_ne(n, env);
+ e->in_stack = 1;
+} /* push */
+
+/**
+ * pop a node from the stack
+ *
+ * @param env the loop environment
+ *
+ * @return The topmost node
+ */
+static ir_node *pop(loop_env *env) {
+ ir_node *n = env->stack[--env->tos];
+ node_entry *e = get_irn_ne(n, env);
+
+ e->in_stack = 0;
+ return n;
+} /* pop */
+
+/**
+ * Check if irn is a region constant.
+ * The block or irn must strictly dominate the header block.
+ *
+ * @param irn the node to check
+ * @param header_block the header block of the induction variable
+ */
+static int is_rc(ir_node *irn, ir_node *header_block) {
+ ir_node *block = get_nodes_block(irn);
+
+ return (block != header_block) && block_dominates(block, header_block);
+} /* is_rc */
+
+typedef struct phi_entry phi_entry;
+struct phi_entry {
+ ir_node *phi; /**< A phi with a region const memory. */
+ int pos; /**< The position of the region const memory */
+ ir_node *load; /**< the newly created load for this phi */
+ phi_entry *next;
+};
+
+/**
+ * An entry in the avail set.
+ */
+typedef struct avail_entry_t {
+ ir_node *ptr; /**< the address pointer */
+ ir_mode *mode; /**< the load mode */
+ ir_node *load; /**< the associated Load */
+} avail_entry_t;
+
+/**
+ * Compare two avail entries.
+ */
+static int cmp_avail_entry(const void *elt, const void *key, size_t size) {
+ const avail_entry_t *a = elt;
+ const avail_entry_t *b = key;
+ (void) size;
+
+ return a->ptr != b->ptr || a->mode != b->mode;
+} /* cmp_avail_entry */
+
+/**
+ * Calculate the hash value of an avail entry.
+ */
+static unsigned hash_cache_entry(const avail_entry_t *entry) {
+ return get_irn_idx(entry->ptr) * 9 + HASH_PTR(entry->mode);
+} /* hash_cache_entry */
+
+/**
+ * Move loops out of loops if possible.
+ *
+ * @param pscc the loop described by an SCC
+ * @param env the loop environment
+ */
+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;
+ phi_entry *phi_list = NULL;
+ set *avail;
+
+ avail = new_set(cmp_avail_entry, 8);
+
+ /* collect all outer memories */
+ for (phi = pscc->head; phi != NULL; phi = next) {
+ node_entry *ne = get_irn_ne(phi, env);
+ next = ne->next;
+
+ /* check all memory Phi's */
+ if (! is_Phi(phi))
+ continue;
+
+ assert(get_irn_mode(phi) == mode_M && "DFS return non-memory Phi");
+
+ for (j = get_irn_arity(phi) - 1; j >= 0; --j) {
+ ir_node *pred = get_irn_n(phi, j);
+ node_entry *pe = get_irn_ne(pred, env);
+
+ if (pe->pscc != ne->pscc) {
+ /* not in the same SCC, is region const */
+ phi_entry *pe = phase_alloc(&env->ph, sizeof(*pe));
+
+ pe->phi = phi;
+ pe->pos = j;
+ pe->next = phi_list;
+ phi_list = pe;
+ }
+ }
+ }
+ /* no Phis no fun */
+ assert(phi_list != NULL && "DFS found a loop without Phi");
+
+ /* for now, we cannot handle more than one input (only reducible cf) */
+ if (phi_list->next != NULL)
+ return;
+
+ for (load = pscc->head; load; load = next) {
+ ir_mode *load_mode;
+ node_entry *ne = get_irn_ne(load, env);
+ next = ne->next;
+
+ if (is_Load(load)) {
+ ldst_info_t *info = get_irn_link(load);
+ ir_node *ptr = get_Load_ptr(load);
+
+ /* for now, we cannot handle Loads with exceptions */
+ 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 move Load(Global) */
+ if (! is_Global(ptr))
+ continue;
+ 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);
+ next_other = ne->next;
+
+ if (is_Store(other)) {
+ ir_alias_relation rel = get_alias_relation(
+ current_ir_graph,
+ get_Store_ptr(other),
+ get_irn_mode(get_Store_value(other)),
+ ptr, load_mode);
+ /* if the might be an alias, we cannot pass this Store */
+ if (rel != ir_no_alias)
+ break;
+ }
+ /* only Phis and pure Calls are allowed here, so ignore them */
+ }
+ if (other == NULL) {
+ ldst_info_t *ninfo;
+ phi_entry *pe;
+ dbg_info *db;
+
+ /* yep, no aliasing Store found, Load can be moved */
+ DB((dbg, LEVEL_1, " Found a Load that could be moved: %+F\n", load));
+
+ db = get_irn_dbg_info(load);
+ for (pe = phi_list; pe != NULL; pe = pe->next) {
+ int pos = pe->pos;
+ ir_node *phi = pe->phi;
+ ir_node *blk = get_nodes_block(phi);
+ ir_node *pred = get_Block_cfgpred_block(blk, pos);
+ ir_node *irn, *mem;
+ avail_entry_t entry, *res;
+
+ entry.ptr = ptr;
+ entry.mode = load_mode;
+ res = set_find(avail, &entry, sizeof(entry), hash_cache_entry(&entry));
+ if (res != NULL) {
+ irn = res->load;
+ } else {
+ irn = new_rd_Load(db, pred, get_Phi_pred(phi, pos), ptr, load_mode, 0);
+ entry.load = irn;
+ set_insert(avail, &entry, sizeof(entry), hash_cache_entry(&entry));
+ DB((dbg, LEVEL_1, " Created %+F in %+F\n", irn, pred));
+ }
+ pe->load = irn;
+ ninfo = get_ldst_info(irn, phase_obst(&env->ph));
+
+ ninfo->projs[pn_Load_M] = mem = new_r_Proj(pred, irn, mode_M, pn_Load_M);
+ set_Phi_pred(phi, pos, mem);
+
+ ninfo->projs[pn_Load_res] = new_r_Proj(pred, irn, load_mode, pn_Load_res);
+ }
+
+ /* now kill the old Load */
+ exchange(info->projs[pn_Load_M], get_Load_mem(load));
+ exchange(info->projs[pn_Load_res], ninfo->projs[pn_Load_res]);
+
+ env->changes |= DF_CHANGED;
+ }
+ }
+ }
+ del_set(avail);
+} /* move_loads_out_of_loops */
+
+/**
+ * Process a loop SCC.
+ *
+ * @param pscc the SCC
+ * @param env the loop environment
+ */
+static void process_loop(scc *pscc, loop_env *env) {
+ ir_node *irn, *next, *header = NULL;
+ node_entry *b, *h = NULL;
+ int j, only_phi, num_outside, process = 0;
+ ir_node *out_rc;
+
+ /* find the header block for this scc */
+ for (irn = pscc->head; irn; irn = next) {
+ node_entry *e = get_irn_ne(irn, env);
+ ir_node *block = get_nodes_block(irn);
+
+ next = e->next;
+ b = get_irn_ne(block, env);
+
+ if (header != NULL) {
+ if (h->POnum < b->POnum) {
+ header = block;
+ h = b;
+ }
+ } else {
+ header = block;
+ h = b;
+ }
+ }
+
+ /* check if this scc contains only Phi, Loads or Stores nodes */
+ only_phi = 1;
+ num_outside = 0;
+ out_rc = NULL;
+ for (irn = pscc->head; irn; irn = next) {
+ node_entry *e = get_irn_ne(irn, env);
+
+ 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 CopyB yet */
+ goto fail;
+ case iro_Load:
+ process = 1;
+ if (get_Load_volatility(irn) == volatility_is_volatile) {
+ /* cannot handle loops with volatile Loads */
+ goto fail;
+ }
+ only_phi = 0;
+ break;
+ case iro_Store:
+ if (get_Store_volatility(irn) == volatility_is_volatile) {
+ /* cannot handle loops with volatile Stores */
+ goto fail;
+ }
+ only_phi = 0;
+ break;
+ default:
+ only_phi = 0;
+ break;
+ case iro_Phi:
+ for (j = get_irn_arity(irn) - 1; j >= 0; --j) {
+ ir_node *pred = get_irn_n(irn, j);
+ node_entry *pe = get_irn_ne(pred, env);
+
+ if (pe->pscc != e->pscc) {
+ /* not in the same SCC, must be a region const */
+ if (! is_rc(pred, header)) {
+ /* not a memory loop */
+ goto fail;
+ }
+ if (out_rc == NULL) {
+ /* first region constant */
+ out_rc = pred;
+ ++num_outside;
+ } else if (out_rc != pred) {
+ /* another region constant */
+ ++num_outside;
+ }
+ }
+ }
+ break;
+ }
+ }
+ if (! process)
+ goto fail;
+
+ /* found a memory loop */
+ DB((dbg, LEVEL_2, " Found a memory loop:\n "));
+ if (only_phi && num_outside == 1) {
+ /* a phi cycle with only one real predecessor can be collapsed */
+ DB((dbg, LEVEL_2, " Found an USELESS Phi cycle:\n "));
+
+ for (irn = pscc->head; irn; irn = next) {
+ node_entry *e = get_irn_ne(irn, env);
+ next = e->next;
+ exchange(irn, out_rc);
+ }
+ env->changes |= DF_CHANGED;
+ return;
+ }
+
+#ifdef DEBUG_libfirm
+ for (irn = pscc->head; irn; irn = next) {
+ node_entry *e = get_irn_ne(irn, env);
+ next = e->next;
+ DB((dbg, LEVEL_2, " %+F,", irn));
+ }
+ DB((dbg, LEVEL_2, "\n"));
+#endif
+ move_loads_out_of_loops(pscc, env);
+
+fail:
+ ;
+} /* process_loop */
+
+/**
+ * Process a SCC.
+ *
+ * @param pscc the SCC
+ * @param env the loop environment
+ */
+static void process_scc(scc *pscc, loop_env *env) {
+ ir_node *head = pscc->head;
+ node_entry *e = get_irn_ne(head, env);
+
+#ifdef DEBUG_libfirm
+ {
+ ir_node *irn, *next;
+
+ DB((dbg, LEVEL_4, " SCC at %p:\n ", pscc));
+ for (irn = pscc->head; irn; irn = next) {
+ node_entry *e = get_irn_ne(irn, env);
+
+ next = e->next;
+
+ DB((dbg, LEVEL_4, " %+F,", irn));
+ }
+ DB((dbg, LEVEL_4, "\n"));
+ }
+#endif
+
+ if (e->next != NULL) {
+ /* this SCC has more than one member */
+ process_loop(pscc, env);
+ }
+} /* process_scc */
+
+/**
+ * Do Tarjan's SCC algorithm and drive load/store optimization.
+ *
+ * @param irn start at this node
+ * @param env the loop environment
+ */
+static void dfs(ir_node *irn, loop_env *env)
{
- walk_env_t *wenv = env;
+ int i, n;
+ node_entry *node = get_irn_ne(irn, env);
+
+ mark_irn_visited(irn);
+
+ node->DFSnum = env->nextDFSnum++;
+ node->low = node->DFSnum;
+ push(env, irn);
+
+ /* handle preds */
+ if (is_Phi(irn) || is_Sync(irn)) {
+ n = get_irn_arity(irn);
+ for (i = 0; i < n; ++i) {
+ ir_node *pred = get_irn_n(irn, i);
+ node_entry *o = get_irn_ne(pred, env);
+
+ if (!irn_visited(pred)) {
+ dfs(pred, env);
+ node->low = MIN(node->low, o->low);
+ }
+ if (o->DFSnum < node->DFSnum && o->in_stack)
+ node->low = MIN(o->DFSnum, node->low);
+ }
+ } else if (is_fragile_op(irn)) {
+ ir_node *pred = get_fragile_op_mem(irn);
+ node_entry *o = get_irn_ne(pred, env);
+
+ if (!irn_visited(pred)) {
+ dfs(pred, env);
+ node->low = MIN(node->low, o->low);
+ }
+ if (o->DFSnum < node->DFSnum && o->in_stack)
+ node->low = MIN(o->DFSnum, node->low);
+ } else if (is_Proj(irn)) {
+ ir_node *pred = get_Proj_pred(irn);
+ node_entry *o = get_irn_ne(pred, env);
+
+ if (!irn_visited(pred)) {
+ dfs(pred, env);
+ node->low = MIN(node->low, o->low);
+ }
+ if (o->DFSnum < node->DFSnum && o->in_stack)
+ node->low = MIN(o->DFSnum, node->low);
+ }
+ else {
+ /* IGNORE predecessors */
+ }
+
+ if (node->low == node->DFSnum) {
+ scc *pscc = phase_alloc(&env->ph, sizeof(*pscc));
+ ir_node *x;
+
+ pscc->head = NULL;
+ do {
+ node_entry *e;
+
+ x = pop(env);
+ e = get_irn_ne(x, env);
+ e->pscc = pscc;
+ e->next = pscc->head;
+ pscc->head = x;
+ } while (x != irn);
+
+ process_scc(pscc, env);
+ }
+} /* dfs */
- switch (get_irn_opcode(n)) {
+/**
+ * Do the DFS on the memory edges a graph.
+ *
+ * @param irg the graph to process
+ * @param env the loop environment
+ */
+static void do_dfs(ir_graph *irg, loop_env *env) {
+ ir_graph *rem = current_ir_graph;
+ ir_node *endblk, *end;
+ int i;
+
+ current_ir_graph = irg;
+ inc_irg_visited(irg);
+
+ /* visit all memory nodes */
+ endblk = get_irg_end_block(irg);
+ 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))
+ dfs(get_Raise_mem(pred), env);
+ else if (is_fragile_op(pred))
+ dfs(get_fragile_op_mem(pred), env);
+ else {
+ assert(0 && "Unknown EndBlock predecessor");
+ }
+ }
+
+ /* visit the keep-alives */
+ end = get_irg_end(irg);
+ for (i = get_End_n_keepalives(end) - 1; i >= 0; --i) {
+ ir_node *ka = get_End_keepalive(end, i);
+
+ if (is_Phi(ka) && !irn_visited(ka))
+ dfs(ka, env);
+ }
+ current_ir_graph = rem;
+} /* do_dfs */
- case iro_Load:
- wenv->changes |= optimize_load(n);
- break;
+/**
+ * Initialize new phase data. We do this always explicit, so return NULL here
+ */
+static void *init_loop_data(ir_phase *ph, const ir_node *irn, void *data) {
+ (void)ph;
+ (void)irn;
+ (void)data;
+ return NULL;
+} /* init_loop_data */
- case iro_Store:
- wenv->changes |= optimize_store(n);
- break;
+/**
+ * Optimize Loads/Stores in loops.
+ *
+ * @param irg the graph
+ */
+static int optimize_loops(ir_graph *irg) {
+ loop_env env;
- case iro_Phi:
- wenv->changes |= optimize_phi(n, wenv);
+ env.stack = NEW_ARR_F(ir_node *, 128);
+ env.tos = 0;
+ env.nextDFSnum = 0;
+ env.POnum = 0;
+ env.changes = 0;
+ phase_init(&env.ph, "ldstopt", irg, PHASE_DEFAULT_GROWTH, init_loop_data, NULL);
- default:
- ;
- }
-}
+ /* calculate the SCC's and drive loop optimization. */
+ do_dfs(irg, &env);
+
+ DEL_ARR_F(env.stack);
+ phase_free(&env.ph);
+
+ return env.changes;
+} /* optimize_loops */
/*
* do the load store optimization
*/
-void optimize_load_store(ir_graph *irg)
-{
- walk_env_t env;
- int was_activ;
+int optimize_load_store(ir_graph *irg) {
+ walk_env_t env;
- assert(get_irg_phase_state(irg) != phase_building);
- assert(get_irg_pinned(irg) != op_pin_state_floats &&
- "LoadStore optimization needs pinned graph");
+ FIRM_DBG_REGISTER(dbg, "firm.opt.ldstopt");
- if (! get_opt_redundant_loadstore())
- return;
+ assert(get_irg_phase_state(irg) != phase_building);
+ assert(get_irg_pinned(irg) != op_pin_state_floats &&
+ "LoadStore optimization needs pinned graph");
- was_activ = edges_activated(irg);
- if (was_activ) {
- /* we need "fresh" edges */
- edges_deactivate(irg);
- }
- edges_activate(irg);
+ /* we need landing pads */
+ remove_critical_cf_edges(irg);
- obstack_init(&env.obst);
- env.changes = 0;
+ edges_assure(irg);
- /* init the links, then collect Loads/Stores/Proj's in lists */
- master_visited = 0;
- irg_walk_graph(irg, firm_clear_link, collect_nodes, &env);
+ /* for Phi optimization post-dominators are needed ... */
+ assure_postdoms(irg);
- /* now we have collected enough information, optimize */
- irg_walk_graph(irg, NULL, do_load_store_optimize, &env);
+ if (get_opt_alias_analysis()) {
+ assure_irg_entity_usage_computed(irg);
+ assure_irp_globals_entity_usage_computed();
+ }
- obstack_free(&env.obst, NULL);
+ obstack_init(&env.obst);
+ env.changes = 0;
- /* Handle graph state */
- if (env.changes) {
- if (get_irg_outs_state(irg) == outs_consistent)
- set_irg_outs_inconsistent(irg);
- }
+ /* init the links, then collect Loads/Stores/Proj's in lists */
+ master_visited = 0;
+ irg_walk_graph(irg, firm_clear_link, collect_nodes, &env);
- if (env.changes & CF_CHANGED) {
- /* is this really needed: Yes, control flow changed, block might
- have Bad() predecessors. */
- set_irg_doms_inconsistent(irg);
- }
+ /* now we have collected enough information, optimize */
+ irg_walk_graph(irg, NULL, do_load_store_optimize, &env);
- if (! was_activ)
- edges_deactivate(irg);
-}
+ env.changes |= optimize_loops(irg);
+
+ obstack_free(&env.obst, NULL);
+
+ /* Handle graph state */
+ if (env.changes) {
+ set_irg_outs_inconsistent(irg);
+ set_irg_entity_usage_state(irg, ir_entity_usage_not_computed);
+ }
+
+ if (env.changes & CF_CHANGED) {
+ /* is this really needed: Yes, control flow changed, block might
+ have Bad() predecessors. */
+ set_irg_doms_inconsistent(irg);
+ }
+ return env.changes != 0;
+} /* optimize_load_store */
+
+ir_graph_pass_t *optimize_load_store_pass(const char *name, int verify, int dump)
+{
+ return def_graph_pass(name ? name : "ldst", verify, dump, optimize_load_store);
+} /* optimize_load_store_pass */
projects / libfirm / blobdiff