edge
ssa_redirect_edge (edge e, basic_block dest)
{
tree phi;
tree list = NULL, *last = &list;
tree src, dst, node;
/* Remove the appropriate PHI arguments in E's destination block. */
for (phi = phi_nodes (e->dest); phi; phi = PHI_CHAIN (phi))
{
if (PHI_ARG_DEF (phi, e->dest_idx) == NULL_TREE)
continue;
src = PHI_ARG_DEF (phi, e->dest_idx);
dst = PHI_RESULT (phi);
node = build_tree_list (dst, src);
*last = node;
last = &TREE_CHAIN (node);
}
e = redirect_edge_succ_nodup (e, dest);
PENDING_STMT (e) = list;
return e;
}
void
flush_pending_stmts (edge e)
{
tree phi, arg;
if (!PENDING_STMT (e))
return;
for (phi = phi_nodes (e->dest), arg = PENDING_STMT (e);
phi;
phi = PHI_CHAIN (phi), arg = TREE_CHAIN (arg))
{
tree def = TREE_VALUE (arg);
add_phi_arg (phi, def, e);
}
PENDING_STMT (e) = NULL;
}
void
gsi_commit_one_edge_insert (edge e, basic_block *new_bb)
{
if (new_bb)
*new_bb = NULL;
if (PENDING_STMT (e))
{
gimple_stmt_iterator gsi;
gimple_seq seq = PENDING_STMT (e);
bool ins_after;
PENDING_STMT (e) = NULL;
ins_after = gimple_find_edge_insert_loc (e, &gsi, new_bb);
update_call_edge_frequencies (gimple_seq_first (seq), gsi.bb);
if (ins_after)
gsi_insert_seq_after (&gsi, seq, GSI_NEW_STMT);
else
gsi_insert_seq_before (&gsi, seq, GSI_NEW_STMT);
}
}
basic_block
gsi_insert_seq_on_edge_immediate (edge e, gimple_seq stmts)
{
gimple_stmt_iterator gsi;
basic_block new_bb = NULL;
bool ins_after;
gcc_assert (!PENDING_STMT (e));
ins_after = gimple_find_edge_insert_loc (e, &gsi, &new_bb);
update_call_edge_frequencies (gimple_seq_first (stmts), gsi.bb);
if (ins_after)
gsi_insert_seq_after (&gsi, stmts, GSI_NEW_STMT);
else
gsi_insert_seq_before (&gsi, stmts, GSI_NEW_STMT);
return new_bb;
}
basic_block
gsi_insert_on_edge_immediate (edge e, gimple stmt)
{
gimple_stmt_iterator gsi;
struct gimple_seq_node_d node;
basic_block new_bb = NULL;
bool ins_after;
gcc_assert (!PENDING_STMT (e));
ins_after = gimple_find_edge_insert_loc (e, &gsi, &new_bb);
node.stmt = stmt;
node.prev = node.next = NULL;
update_call_edge_frequencies (&node, gsi.bb);
if (ins_after)
gsi_insert_after (&gsi, stmt, GSI_NEW_STMT);
else
gsi_insert_before (&gsi, stmt, GSI_NEW_STMT);
return new_bb;
}
static void
eliminate_tail_call (struct tailcall *t)
{
tree param, rslt;
gimple stmt, call;
tree arg;
size_t idx;
basic_block bb, first;
edge e;
gimple phi;
gimple_stmt_iterator gsi;
gimple orig_stmt;
stmt = orig_stmt = gsi_stmt (t->call_gsi);
bb = gsi_bb (t->call_gsi);
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "Eliminated tail recursion in bb %d : ",
bb->index);
print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
fprintf (dump_file, "\n");
}
gcc_assert (is_gimple_call (stmt));
first = single_succ (ENTRY_BLOCK_PTR_FOR_FN (cfun));
/* Remove the code after call_gsi that will become unreachable. The
possibly unreachable code in other blocks is removed later in
cfg cleanup. */
gsi = t->call_gsi;
gsi_next (&gsi);
while (!gsi_end_p (gsi))
{
gimple t = gsi_stmt (gsi);
/* Do not remove the return statement, so that redirect_edge_and_branch
sees how the block ends. */
if (gimple_code (t) == GIMPLE_RETURN)
break;
gsi_remove (&gsi, true);
release_defs (t);
}
/* Number of executions of function has reduced by the tailcall. */
e = single_succ_edge (gsi_bb (t->call_gsi));
decrease_profile (EXIT_BLOCK_PTR_FOR_FN (cfun), e->count, EDGE_FREQUENCY (e));
decrease_profile (ENTRY_BLOCK_PTR_FOR_FN (cfun), e->count,
EDGE_FREQUENCY (e));
if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun))
decrease_profile (e->dest, e->count, EDGE_FREQUENCY (e));
/* Replace the call by a jump to the start of function. */
e = redirect_edge_and_branch (single_succ_edge (gsi_bb (t->call_gsi)),
first);
gcc_assert (e);
PENDING_STMT (e) = NULL;
/* Add phi node entries for arguments. The ordering of the phi nodes should
be the same as the ordering of the arguments. */
for (param = DECL_ARGUMENTS (current_function_decl),
idx = 0, gsi = gsi_start_phis (first);
param;
param = DECL_CHAIN (param), idx++)
{
if (!arg_needs_copy_p (param))
continue;
arg = gimple_call_arg (stmt, idx);
phi = gsi_stmt (gsi);
gcc_assert (param == SSA_NAME_VAR (PHI_RESULT (phi)));
add_phi_arg (phi, arg, e, gimple_location (stmt));
gsi_next (&gsi);
}
/* Update the values of accumulators. */
adjust_accumulator_values (t->call_gsi, t->mult, t->add, e);
call = gsi_stmt (t->call_gsi);
rslt = gimple_call_lhs (call);
if (rslt != NULL_TREE)
{
/* Result of the call will no longer be defined. So adjust the
SSA_NAME_DEF_STMT accordingly. */
SSA_NAME_DEF_STMT (rslt) = gimple_build_nop ();
}
gsi_remove (&t->call_gsi, true);
release_defs (call);
}
gimple_stmt_iterator
gsi_start_edge (edge e)
{
return gsi_start (PENDING_STMT (e));
}
void
gsi_insert_seq_on_edge (edge e, gimple_seq seq)
{
gimple_seq_add_seq (&PENDING_STMT (e), seq);
}
void
gsi_insert_on_edge (edge e, gimple *stmt)
{
gimple_seq_add_stmt (&PENDING_STMT (e), stmt);
}