static tree
maybe_get_single_definition (tree t)
{
if (TREE_CODE (t) == SSA_NAME)
{
gimple g = SSA_NAME_DEF_STMT (t);
if (gimple_assign_single_p (g))
return gimple_assign_rhs1 (g);
}
return NULL_TREE;
}
static enum ssa_prop_result
copy_prop_visit_stmt (gimple stmt, edge *taken_edge_p, tree *result_p)
{
enum ssa_prop_result retval;
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "\nVisiting statement:\n");
print_gimple_stmt (dump_file, stmt, 0, dump_flags);
fprintf (dump_file, "\n");
}
if (gimple_assign_single_p (stmt)
&& TREE_CODE (gimple_assign_lhs (stmt)) == SSA_NAME
&& (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
|| is_gimple_min_invariant (gimple_assign_rhs1 (stmt))))
{
/* If the statement is a copy assignment, evaluate its RHS to
see if the lattice value of its output has changed. */
retval = copy_prop_visit_assignment (stmt, result_p);
}
else if (gimple_code (stmt) == GIMPLE_COND)
{
/* See if we can determine which edge goes out of a conditional
jump. */
retval = copy_prop_visit_cond_stmt (stmt, taken_edge_p);
}
else
retval = SSA_PROP_VARYING;
if (retval == SSA_PROP_VARYING)
{
tree def;
ssa_op_iter i;
/* Any other kind of statement is not interesting for constant
propagation and, therefore, not worth simulating. */
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "No interesting values produced.\n");
/* The assignment is not a copy operation. Don't visit this
statement again and mark all the definitions in the statement
to be copies of nothing. */
FOR_EACH_SSA_TREE_OPERAND (def, stmt, i, SSA_OP_ALL_DEFS)
set_copy_of_val (def, def);
}
return retval;
}
static tree
lhs_of_dominating_assert (tree op, basic_block bb, gimple stmt)
{
imm_use_iterator imm_iter;
gimple use_stmt;
use_operand_p use_p;
FOR_EACH_IMM_USE_FAST (use_p, imm_iter, op)
{
use_stmt = USE_STMT (use_p);
if (use_stmt != stmt
&& gimple_assign_single_p (use_stmt)
&& TREE_CODE (gimple_assign_rhs1 (use_stmt)) == ASSERT_EXPR
&& TREE_OPERAND (gimple_assign_rhs1 (use_stmt), 0) == op
&& dominated_by_p (CDI_DOMINATORS, bb, gimple_bb (use_stmt)))
{
return gimple_assign_lhs (use_stmt);
}
}
static tree
get_real_ref_rhs (tree expr)
{
switch (TREE_CODE (expr))
{
case SSA_NAME:
{
/* Given a self-assign statement, say foo.x = foo.x,
the IR (after SSA) looks like:
D.1797_14 = foo.x;
foo.x ={v} D.1797_14;
So if the rhs EXPR is an SSA_NAME of a temp variable,
e.g. D.1797_14, we need to grab the rhs of its SSA def
statement (i.e. foo.x). */
tree vdecl = SSA_NAME_VAR (expr);
if ((!vdecl || DECL_ARTIFICIAL (vdecl))
&& !gimple_nop_p (SSA_NAME_DEF_STMT (expr)))
{
gimple def_stmt = SSA_NAME_DEF_STMT (expr);
/* We are only interested in an assignment with a single
rhs operand because if it is not, the original assignment
will not possibly be a self-assignment. */
if (gimple_assign_single_p (def_stmt))
return get_real_ref_rhs (gimple_assign_rhs1 (def_stmt));
else
return NULL_TREE;
}
else
return vdecl;
}
case VAR_DECL:
case PARM_DECL:
case FIELD_DECL:
case COMPONENT_REF:
case MEM_REF:
case ARRAY_REF:
return expr;
default:
return NULL_TREE;
}
}
bool
may_propagate_copy_into_stmt (gimple dest, tree orig)
{
tree type_d;
tree type_o;
/* If the statement is a switch or a single-rhs assignment,
then the expression to be replaced by the propagation may
be an SSA_NAME. Fortunately, there is an explicit tree
for the expression, so we delegate to may_propagate_copy. */
if (gimple_assign_single_p (dest))
return may_propagate_copy (gimple_assign_rhs1 (dest), orig);
else if (gimple_code (dest) == GIMPLE_SWITCH)
return may_propagate_copy (gimple_switch_index (dest), orig);
/* In other cases, the expression is not materialized, so there
is no destination to pass to may_propagate_copy. On the other
hand, the expression cannot be an SSA_NAME, so the analysis
is much simpler. */
if (TREE_CODE (orig) == SSA_NAME
&& (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (orig)
|| TREE_CODE (SSA_NAME_VAR (orig)) == MEMORY_PARTITION_TAG))
return false;
if (is_gimple_assign (dest))
type_d = TREE_TYPE (gimple_assign_lhs (dest));
else if (gimple_code (dest) == GIMPLE_COND)
type_d = boolean_type_node;
else if (is_gimple_call (dest)
&& gimple_call_lhs (dest) != NULL_TREE)
type_d = TREE_TYPE (gimple_call_lhs (dest));
else
gcc_unreachable ();
type_o = TREE_TYPE (orig);
if (!useless_type_conversion_p (type_d, type_o))
return false;
return true;
}
static void
warn_self_assign (gimple stmt)
{
tree rhs, lhs;
/* Check assigment statement. */
if (gimple_assign_single_p (stmt))
{
rhs = get_real_ref_rhs (gimple_assign_rhs1 (stmt));
if (!rhs)
return;
lhs = gimple_assign_lhs (stmt);
if (TREE_CODE (lhs) == SSA_NAME)
{
lhs = SSA_NAME_VAR (lhs);
if (!lhs || DECL_ARTIFICIAL (lhs))
return;
}
compare_and_warn (stmt, lhs, rhs);
}
/* Check overloaded operator '=' (if enabled). */
else if (check_operator_eq && is_gimple_call (stmt))
{
tree fdecl = gimple_call_fndecl (stmt);
if (fdecl && (DECL_NAME (fdecl) == maybe_get_identifier ("operator=")))
{
/* If 'operator=' takes reference operands, the arguments will be
ADDR_EXPR trees. In this case, just remove the address-taken
operator before we compare the lhs and rhs. */
lhs = gimple_call_arg (stmt, 0);
if (TREE_CODE (lhs) == ADDR_EXPR)
lhs = TREE_OPERAND (lhs, 0);
rhs = gimple_call_arg (stmt, 1);
if (TREE_CODE (rhs) == ADDR_EXPR)
rhs = TREE_OPERAND (rhs, 0);
compare_and_warn (stmt, lhs, rhs);
}
}
}
static bool
can_propagate_from (gimple def_stmt)
{
use_operand_p use_p;
ssa_op_iter iter;
gcc_assert (is_gimple_assign (def_stmt));
/* If the rhs has side-effects we cannot propagate from it. */
if (gimple_has_volatile_ops (def_stmt))
return false;
/* If the rhs is a load we cannot propagate from it. */
if (TREE_CODE_CLASS (gimple_assign_rhs_code (def_stmt)) == tcc_reference
|| TREE_CODE_CLASS (gimple_assign_rhs_code (def_stmt)) == tcc_declaration)
return false;
/* Constants can be always propagated. */
if (gimple_assign_single_p (def_stmt)
&& is_gimple_min_invariant (gimple_assign_rhs1 (def_stmt)))
return true;
/* We cannot propagate ssa names that occur in abnormal phi nodes. */
FOR_EACH_SSA_USE_OPERAND (use_p, def_stmt, iter, SSA_OP_USE)
if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (USE_FROM_PTR (use_p)))
return false;
/* If the definition is a conversion of a pointer to a function type,
then we can not apply optimizations as some targets require
function pointers to be canonicalized and in this case this
optimization could eliminate a necessary canonicalization. */
if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt)))
{
tree rhs = gimple_assign_rhs1 (def_stmt);
if (POINTER_TYPE_P (TREE_TYPE (rhs))
&& TREE_CODE (TREE_TYPE (TREE_TYPE (rhs))) == FUNCTION_TYPE)
return false;
}
return true;
}
void
propagate_tree_value_into_stmt (gimple_stmt_iterator *gsi, tree val)
{
gimple stmt = gsi_stmt (*gsi);
if (is_gimple_assign (stmt))
{
tree expr = NULL_TREE;
if (gimple_assign_single_p (stmt))
expr = gimple_assign_rhs1 (stmt);
propagate_tree_value (&expr, val);
gimple_assign_set_rhs_from_tree (gsi, expr);
stmt = gsi_stmt (*gsi);
}
else if (gimple_code (stmt) == GIMPLE_COND)
{
tree lhs = NULL_TREE;
tree rhs = fold_convert (TREE_TYPE (val), integer_zero_node);
propagate_tree_value (&lhs, val);
gimple_cond_set_code (stmt, NE_EXPR);
gimple_cond_set_lhs (stmt, lhs);
gimple_cond_set_rhs (stmt, rhs);
}
else if (is_gimple_call (stmt)
&& gimple_call_lhs (stmt) != NULL_TREE)
{
gimple new_stmt;
tree expr = NULL_TREE;
propagate_tree_value (&expr, val);
new_stmt = gimple_build_assign (gimple_call_lhs (stmt), expr);
copy_virtual_operands (new_stmt, stmt);
move_ssa_defining_stmt_for_defs (new_stmt, stmt);
gsi_replace (gsi, new_stmt, false);
}
else if (gimple_code (stmt) == GIMPLE_SWITCH)
propagate_tree_value (gimple_switch_index_ptr (stmt), val);
else
gcc_unreachable ();
}
void
propagate_tree_value_into_stmt (gimple_stmt_iterator *gsi, tree val)
{
gimple stmt = gsi_stmt (*gsi);
if (is_gimple_assign (stmt))
{
tree expr = NULL_TREE;
if (gimple_assign_single_p (stmt))
expr = gimple_assign_rhs1 (stmt);
propagate_tree_value (&expr, val);
gimple_assign_set_rhs_from_tree (gsi, expr);
}
else if (gimple_code (stmt) == GIMPLE_COND)
{
tree lhs = NULL_TREE;
tree rhs = build_zero_cst (TREE_TYPE (val));
propagate_tree_value (&lhs, val);
gimple_cond_set_code (stmt, NE_EXPR);
gimple_cond_set_lhs (stmt, lhs);
gimple_cond_set_rhs (stmt, rhs);
}
else if (is_gimple_call (stmt)
&& gimple_call_lhs (stmt) != NULL_TREE)
{
tree expr = NULL_TREE;
bool res;
propagate_tree_value (&expr, val);
res = update_call_from_tree (gsi, expr);
gcc_assert (res);
}
else if (gimple_code (stmt) == GIMPLE_SWITCH)
propagate_tree_value (gimple_switch_index_ptr (stmt), val);
else
gcc_unreachable ();
}
static tree
get_non_ssa_expr (tree expr)
{
if (!expr)
return NULL_TREE;
switch (TREE_CODE (expr))
{
case VAR_DECL:
case PARM_DECL:
case FIELD_DECL:
{
if (DECL_NAME (expr))
return expr;
else
return NULL_TREE;
}
case COMPONENT_REF:
{
tree base, orig_base = TREE_OPERAND (expr, 0);
tree component, orig_component = TREE_OPERAND (expr, 1);
base = get_non_ssa_expr (orig_base);
if (!base)
return NULL_TREE;
component = get_non_ssa_expr (orig_component);
if (!component)
return NULL_TREE;
/* If either BASE or COMPONENT is converted, build a new
component reference tree. */
if (base != orig_base || component != orig_component)
return build3 (COMPONENT_REF, TREE_TYPE (component),
base, component, NULL_TREE);
else
return expr;
}
case MEM_REF:
{
tree orig_base = TREE_OPERAND (expr, 0);
if (TREE_CODE (orig_base) == SSA_NAME)
{
tree base = get_non_ssa_expr (orig_base);
if (!base)
return NULL_TREE;
return fold_build2 (MEM_REF, TREE_TYPE (expr),
base, TREE_OPERAND (expr, 1));
}
return expr;
}
case ARRAY_REF:
{
tree array, orig_array = TREE_OPERAND (expr, 0);
tree index, orig_index = TREE_OPERAND (expr, 1);
array = get_non_ssa_expr (orig_array);
if (!array)
return NULL_TREE;
index = get_non_ssa_expr (orig_index);
if (!index)
return NULL_TREE;
/* If either ARRAY or INDEX is converted, build a new array
reference tree. */
if (array != orig_array || index != orig_index)
return build4 (ARRAY_REF, TREE_TYPE (expr), array, index,
TREE_OPERAND (expr, 2), TREE_OPERAND (expr, 3));
else
return expr;
}
case SSA_NAME:
{
tree vdecl = SSA_NAME_VAR (expr);
if ((!vdecl || DECL_ARTIFICIAL (vdecl))
&& !gimple_nop_p (SSA_NAME_DEF_STMT (expr)))
{
gimple def_stmt = SSA_NAME_DEF_STMT (expr);
if (gimple_assign_single_p (def_stmt))
vdecl = gimple_assign_rhs1 (def_stmt);
}
return get_non_ssa_expr (vdecl);
}
case INTEGER_CST:
return expr;
default:
/* Return NULL_TREE for any other kind of tree nodes. */
return NULL_TREE;
}
}
tree
avail_exprs_stack::lookup_avail_expr (gimple *stmt, bool insert, bool tbaa_p)
{
expr_hash_elt **slot;
tree lhs;
/* Get LHS of phi, assignment, or call; else NULL_TREE. */
if (gimple_code (stmt) == GIMPLE_PHI)
lhs = gimple_phi_result (stmt);
else
lhs = gimple_get_lhs (stmt);
class expr_hash_elt element (stmt, lhs);
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "LKUP ");
element.print (dump_file);
}
/* Don't bother remembering constant assignments and copy operations.
Constants and copy operations are handled by the constant/copy propagator
in optimize_stmt. */
if (element.expr()->kind == EXPR_SINGLE
&& (TREE_CODE (element.expr()->ops.single.rhs) == SSA_NAME
|| is_gimple_min_invariant (element.expr()->ops.single.rhs)))
return NULL_TREE;
/* Finally try to find the expression in the main expression hash table. */
slot = m_avail_exprs->find_slot (&element, (insert ? INSERT : NO_INSERT));
if (slot == NULL)
{
return NULL_TREE;
}
else if (*slot == NULL)
{
class expr_hash_elt *element2 = new expr_hash_elt (element);
*slot = element2;
record_expr (element2, NULL, '2');
return NULL_TREE;
}
/* If we found a redundant memory operation do an alias walk to
check if we can re-use it. */
if (gimple_vuse (stmt) != (*slot)->vop ())
{
tree vuse1 = (*slot)->vop ();
tree vuse2 = gimple_vuse (stmt);
/* If we have a load of a register and a candidate in the
hash with vuse1 then try to reach its stmt by walking
up the virtual use-def chain using walk_non_aliased_vuses.
But don't do this when removing expressions from the hash. */
ao_ref ref;
if (!(vuse1 && vuse2
&& gimple_assign_single_p (stmt)
&& TREE_CODE (gimple_assign_lhs (stmt)) == SSA_NAME
&& (ao_ref_init (&ref, gimple_assign_rhs1 (stmt)),
ref.base_alias_set = ref.ref_alias_set = tbaa_p ? -1 : 0, true)
&& walk_non_aliased_vuses (&ref, vuse2,
vuse_eq, NULL, NULL, vuse1) != NULL))
{
if (insert)
{
class expr_hash_elt *element2 = new expr_hash_elt (element);
/* Insert the expr into the hash by replacing the current
entry and recording the value to restore in the
avail_exprs_stack. */
record_expr (element2, *slot, '2');
*slot = element2;
}
return NULL_TREE;
}
}
/* Extract the LHS of the assignment so that it can be used as the current
definition of another variable. */
lhs = (*slot)->lhs ();
/* Valueize the result. */
if (TREE_CODE (lhs) == SSA_NAME)
{
tree tem = SSA_NAME_VALUE (lhs);
if (tem)
lhs = tem;
}
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "FIND: ");
print_generic_expr (dump_file, lhs, 0);
fprintf (dump_file, "\n");
}
return lhs;
}
