/* Dead store elimination
- Copyright (C) 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+ Copyright (C) 2004, 2005, 2006, 2007, 2008 Free Software Foundation,
+ Inc.
This file is part of GCC.
#include "tree-dump.h"
#include "domwalk.h"
#include "flags.h"
-#include "hashtab.h"
-#include "sbitmap.h"
/* This file implements dead store elimination.
relationship between dead store and redundant load elimination. In
fact, they are the same transformation applied to different views of
the CFG. */
-
-/* Given an aggregate, this records the parts of it which have been
- stored into. */
-struct aggregate_vardecl_d
-{
- /* The aggregate. */
- tree decl;
-
- /* Some aggregates are too big for us to handle or never get stored
- to as a whole. If this field is TRUE, we don't care about this
- aggregate. */
- bool ignore;
-
- /* Number of parts in the whole. */
- unsigned nparts;
-
- /* A bitmap of parts of the aggregate that have been set. If part N
- of an aggregate has been stored to, bit N should be on. */
- sbitmap parts_set;
-};
struct dse_global_data
{
that we want to record, set the bit corresponding to the statement's
unique ID in this bitmap. */
bitmap stores;
-
- /* A hash table containing the parts of an aggregate which have been
- stored to. */
- htab_t aggregate_vardecl;
};
/* We allocate a bitmap-per-block for stores which are encountered
bool);
static void dse_optimize_stmt (struct dom_walk_data *,
basic_block,
- block_stmt_iterator);
+ gimple_stmt_iterator);
static void dse_record_phis (struct dom_walk_data *, basic_block);
static void dse_finalize_block (struct dom_walk_data *, basic_block);
static void record_voperand_set (bitmap, bitmap *, unsigned int);
-static void dse_record_partial_aggregate_store (tree, struct dse_global_data *);
-
-static unsigned max_stmt_uid; /* Maximal uid of a statement. Uids to phi
- nodes are assigned using the versions of
- ssa names they define. */
/* Returns uid of statement STMT. */
static unsigned
-get_stmt_uid (tree stmt)
+get_stmt_uid (gimple stmt)
{
- if (TREE_CODE (stmt) == PHI_NODE)
- return SSA_NAME_VERSION (PHI_RESULT (stmt)) + max_stmt_uid;
+ if (gimple_code (stmt) == GIMPLE_PHI)
+ return SSA_NAME_VERSION (gimple_phi_result (stmt))
+ + gimple_stmt_max_uid (cfun);
- return stmt_ann (stmt)->uid;
+ return gimple_uid (stmt);
}
/* Set bit UID in bitmaps GLOBAL and *LOCAL, creating *LOCAL as needed. */
{
struct address_walk_data *walk_data = (struct address_walk_data *) data;
tree expr = *expr_p;
- tree def_stmt;
+ gimple def_stmt;
basic_block def_bb;
if (TREE_CODE (expr) != SSA_NAME)
return NULL_TREE;
def_stmt = SSA_NAME_DEF_STMT (expr);
- def_bb = bb_for_stmt (def_stmt);
+ def_bb = gimple_bb (def_stmt);
/* DEF_STMT must dominate both stores. So if it is in the same
basic block as one, it does not post-dominate that store. */
|| !dominated_by_p (CDI_POST_DOMINATORS, walk_data->store2_bb,
def_bb))
/* Return non-NULL to stop the walk. */
- return def_stmt;
+ return *expr_p;
}
return NULL_TREE;
might be modified after STORE1, before control reaches STORE2. */
static bool
-memory_address_same (tree store1, tree store2)
+memory_address_same (gimple store1, gimple store2)
{
struct address_walk_data walk_data;
- walk_data.store1_bb = bb_for_stmt (store1);
- walk_data.store2_bb = bb_for_stmt (store2);
+ walk_data.store1_bb = gimple_bb (store1);
+ walk_data.store2_bb = gimple_bb (store2);
- return (walk_tree (&GIMPLE_STMT_OPERAND (store1, 0), memory_ssa_name_same,
+ return (walk_tree (gimple_assign_lhs_ptr (store1), memory_ssa_name_same,
&walk_data, NULL)
== NULL);
}
-/* Return the use stmt for the lhs of STMT following the virtual
- def-use chains. Returns the MODIFY_EXPR stmt which lhs is equal to
- the lhs of STMT or NULL_TREE if no such stmt can be found. */
-static tree
-get_use_of_stmt_lhs (tree stmt,
- use_operand_p * first_use_p,
- use_operand_p * use_p, tree * use_stmt)
-{
- tree usevar, lhs;
- def_operand_p def_p;
+/* Return true if there is a stmt that kills the lhs of STMT and is in the
+ virtual def-use chain of STMT without a use in between the kill and STMT.
+ Returns false if no such stmt is found.
+ *FIRST_USE_P is set to the first use of the single virtual def of
+ STMT. *USE_P is set to the vop killed by *USE_STMT. */
- if (TREE_CODE (stmt) != GIMPLE_MODIFY_STMT)
- return NULL_TREE;
+static bool
+get_kill_of_stmt_lhs (gimple stmt,
+ use_operand_p * first_use_p,
+ use_operand_p * use_p, gimple * use_stmt)
+{
+ tree lhs;
- lhs = GIMPLE_STMT_OPERAND (stmt, 0);
+ gcc_assert (is_gimple_assign (stmt));
- /* The stmt must have a single VDEF. */
- def_p = SINGLE_SSA_DEF_OPERAND (stmt, SSA_OP_VDEF);
- if (def_p == NULL_DEF_OPERAND_P)
- return NULL_TREE;
-
- if (!has_single_use (DEF_FROM_PTR (def_p)))
- return NULL_TREE;
- /* Get the immediate use of the def. */
- single_imm_use (DEF_FROM_PTR (def_p), use_p, use_stmt);
- gcc_assert (*use_p != NULL_USE_OPERAND_P);
- first_use_p = use_p;
- if (TREE_CODE (*use_stmt) != GIMPLE_MODIFY_STMT)
- return NULL_TREE;
+ lhs = gimple_assign_lhs (stmt);
+ /* We now walk the chain of single uses of the single VDEFs.
+ We succeeded finding a kill if the lhs of the use stmt is
+ equal to the original lhs. We can keep walking to the next
+ use if there are no possible uses of the original lhs in
+ the stmt. */
do
{
- /* Look at the use stmt and see if it's LHS matches
- stmt's lhs SSA_NAME. */
- def_p = SINGLE_SSA_DEF_OPERAND (*use_stmt, SSA_OP_VDEF);
+ tree use_lhs;
+ def_operand_p def_p;
+
+ /* The stmt must have a single VDEF. */
+ def_p = SINGLE_SSA_DEF_OPERAND (stmt, SSA_OP_VDEF);
if (def_p == NULL_DEF_OPERAND_P)
- return NULL_TREE;
+ return false;
- usevar = GIMPLE_STMT_OPERAND (*use_stmt, 0);
- if (operand_equal_p (usevar, lhs, 0))
- return *use_stmt;
+ /* Get the single immediate use of the def. */
+ if (!single_imm_use (DEF_FROM_PTR (def_p), first_use_p, &stmt))
+ return false;
+ first_use_p = use_p;
- if (!has_single_use (DEF_FROM_PTR (def_p)))
- return NULL_TREE;
- single_imm_use (DEF_FROM_PTR (def_p), use_p, use_stmt);
- gcc_assert (*use_p != NULL_USE_OPERAND_P);
- if (TREE_CODE (*use_stmt) != GIMPLE_MODIFY_STMT)
- return NULL_TREE;
+ /* If there are possible hidden uses, give up. */
+ if (!gimple_assign_single_p (stmt)
+ || (TREE_CODE (gimple_assign_rhs1 (stmt)) != SSA_NAME
+ && !is_gimple_min_invariant (gimple_assign_rhs1 (stmt))))
+ return false;
+
+ /* If the use stmts lhs matches the original lhs we have
+ found the kill, otherwise continue walking. */
+ use_lhs = gimple_assign_lhs (stmt);
+ if (operand_equal_p (use_lhs, lhs, 0))
+ {
+ *use_stmt = stmt;
+ return true;
+ }
}
while (1);
-
- return NULL_TREE;
}
/* A helper of dse_optimize_stmt.
- Given a GIMPLE_MODIFY_STMT in STMT, check that each VDEF has one
+ Given a GIMPLE_ASSIGN in STMT, check that each VDEF has one
use, and that one use is another VDEF clobbering the first one.
Return TRUE if the above conditions are met, otherwise FALSE. */
static bool
-dse_possible_dead_store_p (tree stmt,
+dse_possible_dead_store_p (gimple stmt,
use_operand_p *first_use_p,
use_operand_p *use_p,
- tree *use_stmt,
+ gimple *use_stmt,
struct dse_global_data *dse_gd,
struct dse_block_local_data *bd)
{
bool fail = false;
def_operand_p var1;
vuse_vec_p vv;
- tree defvar = NULL_TREE, temp;
+ tree defvar = NULL_TREE;
tree prev_defvar = NULL_TREE;
- stmt_ann_t ann = stmt_ann (stmt);
+ gimple temp;
/* We want to verify that each virtual definition in STMT has
precisely one use and that all the virtual definitions are
gcc_assert (*use_p != NULL_USE_OPERAND_P);
*first_use_p = *use_p;
+ /* ??? If we hit a GIMPLE_PHI we could skip to the PHI_RESULT uses.
+ Don't bother to do that for now. */
+ if (gimple_code (temp) == GIMPLE_PHI)
+ {
+ fail = true;
+ break;
+ }
+
/* In the case of memory partitions, we may get:
# MPT.764_162 = VDEF <MPT.764_161(D)>
So we must make sure we're talking about the same LHS.
*/
- if (TREE_CODE (temp) == GIMPLE_MODIFY_STMT)
+ if (is_gimple_assign (temp))
{
- tree base1 = get_base_address (GIMPLE_STMT_OPERAND (stmt, 0));
- tree base2 = get_base_address (GIMPLE_STMT_OPERAND (temp, 0));
+ tree base1 = get_base_address (gimple_assign_lhs (stmt));
+ tree base2 = get_base_address (gimple_assign_lhs (temp));
while (base1 && INDIRECT_REF_P (base1))
base1 = TREE_OPERAND (base1, 0);
}
else if (temp != *use_stmt)
{
- /* The immediate use and the previously found immediate use
- must be the same, except... if they're uses of different
- parts of the whole. */
- if (TREE_CODE (defvar) == SSA_NAME
- && TREE_CODE (SSA_NAME_VAR (defvar)) == STRUCT_FIELD_TAG
- && TREE_CODE (prev_defvar) == SSA_NAME
- && TREE_CODE (SSA_NAME_VAR (prev_defvar)) == STRUCT_FIELD_TAG
- && (SFT_PARENT_VAR (SSA_NAME_VAR (defvar))
- == SFT_PARENT_VAR (SSA_NAME_VAR (prev_defvar))))
- ;
- else
- {
- fail = true;
- break;
- }
+ fail = true;
+ break;
}
}
if (fail)
{
- record_voperand_set (dse_gd->stores, &bd->stores, ann->uid);
- dse_record_partial_aggregate_store (stmt, dse_gd);
+ record_voperand_set (dse_gd->stores, &bd->stores, gimple_uid (stmt));
return false;
}
- /* Skip through any PHI nodes we have already seen if the PHI
- represents the only use of this store.
-
- Note this does not handle the case where the store has
- multiple VDEFs which all reach a set of PHI nodes in the same block. */
- while (*use_p != NULL_USE_OPERAND_P
- && TREE_CODE (*use_stmt) == PHI_NODE
- && bitmap_bit_p (dse_gd->stores, get_stmt_uid (*use_stmt)))
- {
- /* A PHI node can both define and use the same SSA_NAME if
- the PHI is at the top of a loop and the PHI_RESULT is
- a loop invariant and copies have not been fully propagated.
-
- The safe thing to do is exit assuming no optimization is
- possible. */
- if (SSA_NAME_DEF_STMT (PHI_RESULT (*use_stmt)) == *use_stmt)
- return false;
-
- /* Skip past this PHI and loop again in case we had a PHI
- chain. */
- single_imm_use (PHI_RESULT (*use_stmt), use_p, use_stmt);
- }
-
return true;
}
-/* Given a DECL, return its AGGREGATE_VARDECL_D entry. If no entry is
- found and INSERT is TRUE, add a new entry. */
-
-static struct aggregate_vardecl_d *
-get_aggregate_vardecl (tree decl, struct dse_global_data *dse_gd, bool insert)
-{
- struct aggregate_vardecl_d av, *av_p;
- void **slot;
-
- av.decl = decl;
- slot = htab_find_slot (dse_gd->aggregate_vardecl, &av, insert ? INSERT : NO_INSERT);
-
-
- /* Not found, and we don't want to insert. */
- if (slot == NULL)
- return NULL;
-
- /* Create new entry. */
- if (*slot == NULL)
- {
- av_p = XNEW (struct aggregate_vardecl_d);
- av_p->decl = decl;
-
- /* Record how many parts the whole has. */
- if (TREE_CODE (TREE_TYPE (decl)) == COMPLEX_TYPE)
- av_p->nparts = 2;
- else if (TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE)
- {
- tree fields;
-
- /* Count the number of fields. */
- fields = TYPE_FIELDS (TREE_TYPE (decl));
- av_p->nparts = 0;
- while (fields)
- {
- av_p->nparts++;
- fields = TREE_CHAIN (fields);
- }
- }
- else
- abort ();
-
- av_p->ignore = true;
- av_p->parts_set = sbitmap_alloc (HOST_BITS_PER_LONG);
- sbitmap_zero (av_p->parts_set);
- *slot = av_p;
- }
- else
- av_p = (struct aggregate_vardecl_d *) *slot;
-
- return av_p;
-}
-
-
-/* If STMT is a partial store into an aggregate, record which part got set. */
-
-static void
-dse_record_partial_aggregate_store (tree stmt, struct dse_global_data *dse_gd)
-{
- tree lhs, decl;
- enum tree_code code;
- struct aggregate_vardecl_d *av_p;
- int part;
-
- gcc_assert (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT);
-
- lhs = GIMPLE_STMT_OPERAND (stmt, 0);
- code = TREE_CODE (lhs);
- if (code != IMAGPART_EXPR
- && code != REALPART_EXPR
- && code != COMPONENT_REF)
- return;
- decl = TREE_OPERAND (lhs, 0);
- /* Early bail on things like nested COMPONENT_REFs. */
- if (TREE_CODE (decl) != VAR_DECL)
- return;
- /* Early bail on unions. */
- if (code == COMPONENT_REF
- && TREE_CODE (TREE_TYPE (TREE_OPERAND (lhs, 0))) != RECORD_TYPE)
- return;
-
- av_p = get_aggregate_vardecl (decl, dse_gd, /*insert=*/false);
- /* Run away, this isn't an aggregate we care about. */
- if (!av_p || av_p->ignore)
- return;
-
- switch (code)
- {
- case IMAGPART_EXPR:
- part = 0;
- break;
- case REALPART_EXPR:
- part = 1;
- break;
- case COMPONENT_REF:
- {
- tree orig_field, fields;
- tree record_type = TREE_TYPE (TREE_OPERAND (lhs, 0));
-
- /* Get FIELD_DECL. */
- orig_field = TREE_OPERAND (lhs, 1);
-
- /* FIXME: Eeech, do this more efficiently. Perhaps
- calculate bit/byte offsets. */
- part = -1;
- fields = TYPE_FIELDS (record_type);
- while (fields)
- {
- ++part;
- if (fields == orig_field)
- break;
- fields = TREE_CHAIN (fields);
- }
- gcc_assert (part >= 0);
- }
- break;
- default:
- return;
- }
-
- /* Record which part was set. */
- SET_BIT (av_p->parts_set, part);
-}
-
-
-/* Return TRUE if all parts in an AGGREGATE_VARDECL have been set. */
-
-static inline bool
-dse_whole_aggregate_clobbered_p (struct aggregate_vardecl_d *av_p)
-{
- unsigned int i;
- sbitmap_iterator sbi;
- int nbits_set = 0;
-
- /* Count the number of partial stores (bits set). */
- EXECUTE_IF_SET_IN_SBITMAP (av_p->parts_set, 0, i, sbi)
- nbits_set++;
- return ((unsigned) nbits_set == av_p->nparts);
-}
-
-
-/* Return TRUE if STMT is a store into a whole aggregate whose parts we
- have already seen and recorded. */
-
-static bool
-dse_partial_kill_p (tree stmt, struct dse_global_data *dse_gd)
-{
- tree decl;
- struct aggregate_vardecl_d *av_p;
-
- /* Make sure this is a store into the whole. */
- if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT)
- {
- enum tree_code code;
-
- decl = GIMPLE_STMT_OPERAND (stmt, 0);
- code = TREE_CODE (TREE_TYPE (decl));
-
- if (code != COMPLEX_TYPE && code != RECORD_TYPE)
- return false;
-
- if (TREE_CODE (decl) != VAR_DECL)
- return false;
- }
- else
- return false;
-
- av_p = get_aggregate_vardecl (decl, dse_gd, /*insert=*/false);
- gcc_assert (av_p != NULL);
-
- return dse_whole_aggregate_clobbered_p (av_p);
-}
-
-
/* Attempt to eliminate dead stores in the statement referenced by BSI.
A dead store is a store into a memory location which will later be
static void
dse_optimize_stmt (struct dom_walk_data *walk_data,
basic_block bb ATTRIBUTE_UNUSED,
- block_stmt_iterator bsi)
+ gimple_stmt_iterator gsi)
{
struct dse_block_local_data *bd
= (struct dse_block_local_data *)
VEC_last (void_p, walk_data->block_data_stack);
struct dse_global_data *dse_gd
= (struct dse_global_data *) walk_data->global_data;
- tree stmt = bsi_stmt (bsi);
- stmt_ann_t ann = stmt_ann (stmt);
+ gimple stmt = gsi_stmt (gsi);
/* If this statement has no virtual defs, then there is nothing
to do. */
if (ZERO_SSA_OPERANDS (stmt, SSA_OP_VDEF))
return;
- /* We know we have virtual definitions. If this is a GIMPLE_MODIFY_STMT
+ /* We know we have virtual definitions. If this is a GIMPLE_ASSIGN
that's not also a function call, then record it into our table. */
- if (get_call_expr_in (stmt))
+ if (is_gimple_call (stmt) && gimple_call_fndecl (stmt))
return;
- if (ann->has_volatile_ops)
+ if (gimple_has_volatile_ops (stmt))
return;
- if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT)
+ if (is_gimple_assign (stmt))
{
use_operand_p first_use_p = NULL_USE_OPERAND_P;
use_operand_p use_p = NULL;
- tree use_stmt;
+ gimple use_stmt;
- if (!dse_possible_dead_store_p (stmt, &first_use_p, &use_p, &use_stmt,
+ if (!dse_possible_dead_store_p (stmt, &first_use_p, &use_p, &use_stmt,
dse_gd, bd))
return;
- /* If this is a partial store into an aggregate, record it. */
- dse_record_partial_aggregate_store (stmt, dse_gd);
-
+ /* If we have precisely one immediate use at this point, then we may
+ have found redundant store. Make sure that the stores are to
+ the same memory location. This includes checking that any
+ SSA-form variables in the address will have the same values. */
if (use_p != NULL_USE_OPERAND_P
&& bitmap_bit_p (dse_gd->stores, get_stmt_uid (use_stmt))
- && (!operand_equal_p (GIMPLE_STMT_OPERAND (stmt, 0),
- GIMPLE_STMT_OPERAND (use_stmt, 0), 0)
- && !dse_partial_kill_p (stmt, dse_gd))
+ && !operand_equal_p (gimple_assign_lhs (stmt),
+ gimple_assign_lhs (use_stmt), 0)
&& memory_address_same (stmt, use_stmt))
{
/* If we have precisely one immediate use at this point, but
the stores are not to the same memory location then walk the
virtual def-use chain to get the stmt which stores to that same
memory location. */
- if (get_use_of_stmt_lhs (stmt, &first_use_p, &use_p, &use_stmt) ==
- NULL_TREE)
+ if (!get_kill_of_stmt_lhs (stmt, &first_use_p, &use_p, &use_stmt))
{
- record_voperand_set (dse_gd->stores, &bd->stores, ann->uid);
+ record_voperand_set (dse_gd->stores, &bd->stores,
+ gimple_uid (stmt));
return;
}
}
memory location, then we may have found redundant store. */
if (use_p != NULL_USE_OPERAND_P
&& bitmap_bit_p (dse_gd->stores, get_stmt_uid (use_stmt))
- && (operand_equal_p (GIMPLE_STMT_OPERAND (stmt, 0),
- GIMPLE_STMT_OPERAND (use_stmt, 0), 0)
- || dse_partial_kill_p (stmt, dse_gd))
+ && operand_equal_p (gimple_assign_lhs (stmt),
+ gimple_assign_lhs (use_stmt), 0)
&& memory_address_same (stmt, use_stmt))
{
ssa_op_iter op_iter;
vuse_vec_p vv;
tree stmt_lhs;
+ /* If use_stmt is or might be a nop assignment, e.g. for
+ struct { ... } S a, b, *p; ...
+ b = a; b = b;
+ or
+ b = a; b = *p; where p might be &b,
+ or
+ *p = a; *p = b; where p might be &b,
+ or
+ *p = *u; *p = *v; where p might be v, then USE_STMT
+ acts as a use as well as definition, so store in STMT
+ is not dead. */
+ if (gimple_loaded_syms (use_stmt)
+ && bitmap_intersect_p (gimple_loaded_syms (use_stmt),
+ gimple_stored_syms (use_stmt)))
+ {
+ record_voperand_set (dse_gd->stores, &bd->stores,
+ gimple_uid (stmt));
+ return;
+ }
+
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, " Deleted dead store '");
- print_generic_expr (dump_file, bsi_stmt (bsi), dump_flags);
+ print_gimple_stmt (dump_file, gsi_stmt (gsi), dump_flags, 0);
fprintf (dump_file, "'\n");
}
stmt_lhs = USE_FROM_PTR (first_use_p);
FOR_EACH_SSA_VDEF_OPERAND (var1, vv, stmt, op_iter)
{
- tree usevar, temp;
+ tree usevar;
+ gimple temp;
single_imm_use (DEF_FROM_PTR (var1), &use_p, &temp);
gcc_assert (VUSE_VECT_NUM_ELEM (*vv) == 1);
}
/* Remove the dead store. */
- bsi_remove (&bsi, true);
+ gsi_remove (&gsi, true);
/* And release any SSA_NAMEs set in this statement back to the
SSA_NAME manager. */
release_defs (stmt);
}
- record_voperand_set (dse_gd->stores, &bd->stores, ann->uid);
+ record_voperand_set (dse_gd->stores, &bd->stores, gimple_uid (stmt));
}
}
VEC_last (void_p, walk_data->block_data_stack);
struct dse_global_data *dse_gd
= (struct dse_global_data *) walk_data->global_data;
- tree phi;
+ gimple phi;
+ gimple_stmt_iterator gsi;
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
- if (!is_gimple_reg (PHI_RESULT (phi)))
- record_voperand_set (dse_gd->stores,
- &bd->stores,
- get_stmt_uid (phi));
+ for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ phi = gsi_stmt (gsi);
+ if (!is_gimple_reg (gimple_phi_result (phi)))
+ record_voperand_set (dse_gd->stores, &bd->stores, get_stmt_uid (phi));
+ }
}
static void
}
}
-
-/* Hashing and equality functions for AGGREGATE_VARDECL. */
-
-static hashval_t
-aggregate_vardecl_hash (const void *p)
-{
- return htab_hash_pointer
- ((const void *)((const struct aggregate_vardecl_d *)p)->decl);
-}
-
-static int
-aggregate_vardecl_eq (const void *p1, const void *p2)
-{
- return ((const struct aggregate_vardecl_d *)p1)->decl
- == ((const struct aggregate_vardecl_d *)p2)->decl;
-}
-
-
-/* Free memory allocated by one entry in AGGREGATE_VARDECL. */
-
-static void
-aggregate_vardecl_free (void *p)
-{
- struct aggregate_vardecl_d *entry = (struct aggregate_vardecl_d *) p;
- sbitmap_free (entry->parts_set);
- free (entry);
-}
-
-
-/* Return true if STMT is a store into an entire aggregate. */
-
-static bool
-aggregate_whole_store_p (tree stmt)
-{
- if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT)
- {
- tree lhs = GIMPLE_STMT_OPERAND (stmt, 0);
- enum tree_code code = TREE_CODE (TREE_TYPE (lhs));
-
- if (code == COMPLEX_TYPE || code == RECORD_TYPE)
- return true;
- }
- return false;
-}
-
-
/* Main entry point. */
static unsigned int
{
struct dom_walk_data walk_data;
struct dse_global_data dse_gd;
- basic_block bb;
-
- dse_gd.aggregate_vardecl =
- htab_create (37, aggregate_vardecl_hash,
- aggregate_vardecl_eq, aggregate_vardecl_free);
-
- max_stmt_uid = 0;
- FOR_EACH_BB (bb)
- {
- block_stmt_iterator bsi;
-
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
- {
- tree stmt = bsi_stmt (bsi);
- /* Record aggregates which have been stored into as a whole. */
- if (aggregate_whole_store_p (stmt))
- {
- tree lhs = GIMPLE_STMT_OPERAND (stmt, 0);
- if (TREE_CODE (lhs) == VAR_DECL)
- {
- struct aggregate_vardecl_d *av_p;
-
- av_p = get_aggregate_vardecl (lhs, &dse_gd, /*insert=*/true);
- av_p->ignore = false;
-
- /* Ignore aggregates with too many parts. */
- if (av_p->nparts > HOST_BITS_PER_LONG)
- av_p->ignore = true;
- }
- }
-
- /* Create a UID for each statement in the function.
- Ordering of the UIDs is not important for this pass. */
- stmt_ann (stmt)->uid = max_stmt_uid++;
- }
- }
+ renumber_gimple_stmt_uids ();
/* We might consider making this a property of each pass so that it
can be [re]computed on an as-needed basis. Particularly since
/* This is the main hash table for the dead store elimination pass. */
dse_gd.stores = BITMAP_ALLOC (NULL);
-
walk_data.global_data = &dse_gd;
/* Initialize the dominator walker. */
/* Finalize the dominator walker. */
fini_walk_dominator_tree (&walk_data);
- /* Release unneeded data. */
+ /* Release the main bitmap. */
BITMAP_FREE (dse_gd.stores);
- htab_delete (dse_gd.aggregate_vardecl);
/* For now, just wipe the post-dominator information. */
free_dominance_info (CDI_POST_DOMINATORS);
return flag_tree_dse != 0;
}
-struct tree_opt_pass pass_dse = {
+struct gimple_opt_pass pass_dse =
+{
+ {
+ GIMPLE_PASS,
"dse", /* name */
gate_dse, /* gate */
tree_ssa_dse, /* execute */
0, /* todo_flags_start */
TODO_dump_func
| TODO_ggc_collect
- | TODO_verify_ssa, /* todo_flags_finish */
- 0 /* letter */
+ | TODO_verify_ssa /* todo_flags_finish */
+ }
};
/* A very simple dead store pass eliminating write only local variables.
static unsigned int
execute_simple_dse (void)
{
- block_stmt_iterator bsi;
+ gimple_stmt_iterator gsi;
basic_block bb;
bitmap variables_loaded = BITMAP_ALLOC (NULL);
unsigned int todo = 0;
/* Collect into VARIABLES LOADED all variables that are read in function
body. */
FOR_EACH_BB (bb)
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
- if (LOADED_SYMS (bsi_stmt (bsi)))
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+
+ if (gimple_loaded_syms (gsi_stmt (gsi)))
bitmap_ior_into (variables_loaded,
- LOADED_SYMS (bsi_stmt (bsi)));
+ gimple_loaded_syms (gsi_stmt (gsi)));
- /* Look for statements writting into the write only variables.
+ /* Look for statements writing into the write only variables.
And try to remove them. */
FOR_EACH_BB (bb)
- for (bsi = bsi_start (bb); !bsi_end_p (bsi);)
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi);)
{
- tree stmt = bsi_stmt (bsi), op;
+ gimple stmt = gsi_stmt (gsi);
+ tree op;
bool removed = false;
ssa_op_iter iter;
- if (STORED_SYMS (stmt) && TREE_CODE (stmt) == GIMPLE_MODIFY_STMT
- && TREE_CODE (stmt) != RETURN_EXPR
- && !bitmap_intersect_p (STORED_SYMS (stmt), variables_loaded))
+ if (gimple_stored_syms (stmt)
+ && !bitmap_empty_p (gimple_stored_syms (stmt))
+ && (is_gimple_assign (stmt)
+ || (is_gimple_call (stmt)
+ && gimple_call_lhs (stmt)))
+ && !bitmap_intersect_p (gimple_stored_syms (stmt), variables_loaded))
{
unsigned int i;
bitmap_iterator bi;
from removing them as dead. The flag thus has no use for us
and we need to look into all operands. */
- EXECUTE_IF_SET_IN_BITMAP (STORED_SYMS (stmt), 0, i, bi)
+ EXECUTE_IF_SET_IN_BITMAP (gimple_stored_syms (stmt), 0, i, bi)
{
tree var = referenced_var_lookup (i);
if (TREE_ADDRESSABLE (var)
dead = false;
}
- if (dead && LOADED_SYMS (stmt))
- EXECUTE_IF_SET_IN_BITMAP (LOADED_SYMS (stmt), 0, i, bi)
+ if (dead && gimple_loaded_syms (stmt))
+ EXECUTE_IF_SET_IN_BITMAP (gimple_loaded_syms (stmt), 0, i, bi)
if (TREE_THIS_VOLATILE (referenced_var_lookup (i)))
dead = false;
if (TREE_THIS_VOLATILE (op))
dead = false;
- /* Look for possible occurence var = indirect_ref (...) where
+ /* Look for possible occurrence var = indirect_ref (...) where
indirect_ref itself is volatile. */
- if (dead && TREE_THIS_VOLATILE (GIMPLE_STMT_OPERAND (stmt, 1)))
+ if (dead && is_gimple_assign (stmt)
+ && TREE_THIS_VOLATILE (gimple_assign_rhs1 (stmt)))
dead = false;
if (dead)
{
- tree call = get_call_expr_in (stmt);
-
/* When LHS of var = call (); is dead, simplify it into
call (); saving one operand. */
- if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT
- && call
- && TREE_SIDE_EFFECTS (call))
+ if (is_gimple_call (stmt)
+ && gimple_has_side_effects (stmt))
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "Deleted LHS of call: ");
- print_generic_stmt (dump_file, stmt, TDF_SLIM);
+ print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
fprintf (dump_file, "\n");
}
- push_stmt_changes (bsi_stmt_ptr (bsi));
- TREE_BLOCK (call) = TREE_BLOCK (stmt);
- bsi_replace (&bsi, call, false);
- maybe_clean_or_replace_eh_stmt (stmt, call);
- mark_symbols_for_renaming (call);
- pop_stmt_changes (bsi_stmt_ptr (bsi));
+ push_stmt_changes (gsi_stmt_ptr (&gsi));
+ gimple_call_set_lhs (stmt, NULL);
+ pop_stmt_changes (gsi_stmt_ptr (&gsi));
}
else
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, " Deleted dead store '");
- print_generic_expr (dump_file, stmt, dump_flags);
+ print_gimple_stmt (dump_file, stmt, 0, dump_flags);
fprintf (dump_file, "'\n");
}
removed = true;
- bsi_remove (&bsi, true);
+ gsi_remove (&gsi, true);
todo |= TODO_cleanup_cfg;
}
todo |= TODO_remove_unused_locals | TODO_ggc_collect;
}
}
if (!removed)
- bsi_next (&bsi);
+ gsi_next (&gsi);
}
BITMAP_FREE (variables_loaded);
return todo;
}
-struct tree_opt_pass pass_simple_dse =
+struct gimple_opt_pass pass_simple_dse =
{
+ {
+ GIMPLE_PASS,
"sdse", /* name */
NULL, /* gate */
execute_simple_dse, /* execute */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- TODO_dump_func, /* todo_flags_finish */
- 0 /* letter */
+ TODO_dump_func /* todo_flags_finish */
+ }
};
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