static bool
forwarder_block_to (basic_block bb, basic_block to_bb)
{
return empty_block_p (bb)
&& single_succ_p (bb)
&& single_succ (bb) == to_bb;
}
static bool
check_process_case (tree cs)
{
tree ldecl;
basic_block label_bb, following_bb;
edge e;
ldecl = CASE_LABEL (cs);
label_bb = label_to_block (ldecl);
e = find_edge (info.switch_bb, label_bb);
gcc_assert (e);
if (CASE_LOW (cs) == NULL_TREE)
{
/* Default branch. */
info.default_prob = e->probability;
info.default_count = e->count;
}
else
info.other_count += e->count;
if (!label_bb)
{
info.reason = " Bad case - cs BB label is NULL\n";
return false;
}
if (!single_pred_p (label_bb))
{
if (info.final_bb && info.final_bb != label_bb)
{
info.reason = " Bad case - a non-final BB has two predecessors\n";
return false; /* sth complex going on in this branch */
}
following_bb = label_bb;
}
else
{
if (!empty_block_p (label_bb))
{
info.reason = " Bad case - a non-final BB not empty\n";
return false;
}
e = single_succ_edge (label_bb);
following_bb = single_succ (label_bb);
}
if (!info.final_bb)
info.final_bb = following_bb;
else if (info.final_bb != following_bb)
{
info.reason = " Bad case - different final BB\n";
return false; /* the only successor is not common for all the branches */
}
return true;
}
static bool
minmax_replacement (basic_block cond_bb, basic_block middle_bb,
edge e0, edge e1, gimple phi,
tree arg0, tree arg1)
{
tree result, type;
gimple cond, new_stmt;
edge true_edge, false_edge;
enum tree_code cmp, minmax, ass_code;
tree smaller, larger, arg_true, arg_false;
gimple_stmt_iterator gsi, gsi_from;
type = TREE_TYPE (PHI_RESULT (phi));
/* The optimization may be unsafe due to NaNs. */
if (HONOR_NANS (TYPE_MODE (type)))
return false;
cond = last_stmt (cond_bb);
cmp = gimple_cond_code (cond);
result = PHI_RESULT (phi);
/* This transformation is only valid for order comparisons. Record which
operand is smaller/larger if the result of the comparison is true. */
if (cmp == LT_EXPR || cmp == LE_EXPR)
{
smaller = gimple_cond_lhs (cond);
larger = gimple_cond_rhs (cond);
}
else if (cmp == GT_EXPR || cmp == GE_EXPR)
{
smaller = gimple_cond_rhs (cond);
larger = gimple_cond_lhs (cond);
}
else
return false;
/* We need to know which is the true edge and which is the false
edge so that we know if have abs or negative abs. */
extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge);
/* Forward the edges over the middle basic block. */
if (true_edge->dest == middle_bb)
true_edge = EDGE_SUCC (true_edge->dest, 0);
if (false_edge->dest == middle_bb)
false_edge = EDGE_SUCC (false_edge->dest, 0);
if (true_edge == e0)
{
gcc_assert (false_edge == e1);
arg_true = arg0;
arg_false = arg1;
}
else
{
gcc_assert (false_edge == e0);
gcc_assert (true_edge == e1);
arg_true = arg1;
arg_false = arg0;
}
if (empty_block_p (middle_bb))
{
if (operand_equal_for_phi_arg_p (arg_true, smaller)
&& operand_equal_for_phi_arg_p (arg_false, larger))
{
/* Case
if (smaller < larger)
rslt = smaller;
else
rslt = larger; */
minmax = MIN_EXPR;
}
else if (operand_equal_for_phi_arg_p (arg_false, smaller)
&& operand_equal_for_phi_arg_p (arg_true, larger))
minmax = MAX_EXPR;
else
return false;
}
else
{
/* Recognize the following case, assuming d <= u:
if (a <= u)
b = MAX (a, d);
x = PHI <b, u>
This is equivalent to
b = MAX (a, d);
x = MIN (b, u); */
gimple assign = last_and_only_stmt (middle_bb);
tree lhs, op0, op1, bound;
if (!assign
|| gimple_code (assign) != GIMPLE_ASSIGN)
return false;
lhs = gimple_assign_lhs (assign);
ass_code = gimple_assign_rhs_code (assign);
if (ass_code != MAX_EXPR && ass_code != MIN_EXPR)
return false;
op0 = gimple_assign_rhs1 (assign);
op1 = gimple_assign_rhs2 (assign);
if (true_edge->src == middle_bb)
{
/* We got here if the condition is true, i.e., SMALLER < LARGER. */
if (!operand_equal_for_phi_arg_p (lhs, arg_true))
return false;
if (operand_equal_for_phi_arg_p (arg_false, larger))
{
/* Case
if (smaller < larger)
{
r' = MAX_EXPR (smaller, bound)
}
r = PHI <r', larger> --> to be turned to MIN_EXPR. */
if (ass_code != MAX_EXPR)
return false;
minmax = MIN_EXPR;
if (operand_equal_for_phi_arg_p (op0, smaller))
bound = op1;
else if (operand_equal_for_phi_arg_p (op1, smaller))
bound = op0;
else
return false;
/* We need BOUND <= LARGER. */
if (!integer_nonzerop (fold_build2 (LE_EXPR, boolean_type_node,
bound, larger)))
return false;
}
else if (operand_equal_for_phi_arg_p (arg_false, smaller))
{
/* Case
if (smaller < larger)
{
r' = MIN_EXPR (larger, bound)
}
r = PHI <r', smaller> --> to be turned to MAX_EXPR. */
if (ass_code != MIN_EXPR)
return false;
minmax = MAX_EXPR;
if (operand_equal_for_phi_arg_p (op0, larger))
bound = op1;
else if (operand_equal_for_phi_arg_p (op1, larger))
bound = op0;
else
return false;
/* We need BOUND >= SMALLER. */
if (!integer_nonzerop (fold_build2 (GE_EXPR, boolean_type_node,
bound, smaller)))
return false;
}
else
return false;
}
else
{
/* We got here if the condition is false, i.e., SMALLER > LARGER. */
if (!operand_equal_for_phi_arg_p (lhs, arg_false))
return false;
if (operand_equal_for_phi_arg_p (arg_true, larger))
{
/* Case
if (smaller > larger)
{
r' = MIN_EXPR (smaller, bound)
}
r = PHI <r', larger> --> to be turned to MAX_EXPR. */
if (ass_code != MIN_EXPR)
return false;
minmax = MAX_EXPR;
if (operand_equal_for_phi_arg_p (op0, smaller))
bound = op1;
else if (operand_equal_for_phi_arg_p (op1, smaller))
bound = op0;
else
return false;
/* We need BOUND >= LARGER. */
if (!integer_nonzerop (fold_build2 (GE_EXPR, boolean_type_node,
bound, larger)))
return false;
}
else if (operand_equal_for_phi_arg_p (arg_true, smaller))
{
/* Case
if (smaller > larger)
{
r' = MAX_EXPR (larger, bound)
}
r = PHI <r', smaller> --> to be turned to MIN_EXPR. */
if (ass_code != MAX_EXPR)
return false;
minmax = MIN_EXPR;
if (operand_equal_for_phi_arg_p (op0, larger))
bound = op1;
else if (operand_equal_for_phi_arg_p (op1, larger))
bound = op0;
else
return false;
/* We need BOUND <= SMALLER. */
if (!integer_nonzerop (fold_build2 (LE_EXPR, boolean_type_node,
bound, smaller)))
return false;
}
else
return false;
}
/* Move the statement from the middle block. */
gsi = gsi_last_bb (cond_bb);
gsi_from = gsi_last_bb (middle_bb);
gsi_move_before (&gsi_from, &gsi);
}
/* Emit the statement to compute min/max. */
result = duplicate_ssa_name (PHI_RESULT (phi), NULL);
new_stmt = gimple_build_assign_with_ops (minmax, result, arg0, arg1);
gsi = gsi_last_bb (cond_bb);
gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT);
replace_phi_edge_with_variable (cond_bb, e1, phi, result);
return true;
}
static bool
value_replacement (basic_block cond_bb, basic_block middle_bb,
edge e0, edge e1, gimple phi,
tree arg0, tree arg1)
{
gimple cond;
edge true_edge, false_edge;
enum tree_code code;
/* If the type says honor signed zeros we cannot do this
optimization. */
if (HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
return false;
if (!empty_block_p (middle_bb))
return false;
cond = last_stmt (cond_bb);
code = gimple_cond_code (cond);
/* This transformation is only valid for equality comparisons. */
if (code != NE_EXPR && code != EQ_EXPR)
return false;
/* We need to know which is the true edge and which is the false
edge so that we know if have abs or negative abs. */
extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge);
/* At this point we know we have a COND_EXPR with two successors.
One successor is BB, the other successor is an empty block which
falls through into BB.
The condition for the COND_EXPR is known to be NE_EXPR or EQ_EXPR.
There is a single PHI node at the join point (BB) with two arguments.
We now need to verify that the two arguments in the PHI node match
the two arguments to the equality comparison. */
if ((operand_equal_for_phi_arg_p (arg0, gimple_cond_lhs (cond))
&& operand_equal_for_phi_arg_p (arg1, gimple_cond_rhs (cond)))
|| (operand_equal_for_phi_arg_p (arg1, gimple_cond_lhs (cond))
&& operand_equal_for_phi_arg_p (arg0, gimple_cond_rhs (cond))))
{
edge e;
tree arg;
/* For NE_EXPR, we want to build an assignment result = arg where
arg is the PHI argument associated with the true edge. For
EQ_EXPR we want the PHI argument associated with the false edge. */
e = (code == NE_EXPR ? true_edge : false_edge);
/* Unfortunately, E may not reach BB (it may instead have gone to
OTHER_BLOCK). If that is the case, then we want the single outgoing
edge from OTHER_BLOCK which reaches BB and represents the desired
path from COND_BLOCK. */
if (e->dest == middle_bb)
e = single_succ_edge (e->dest);
/* Now we know the incoming edge to BB that has the argument for the
RHS of our new assignment statement. */
if (e0 == e)
arg = arg0;
else
arg = arg1;
replace_phi_edge_with_variable (cond_bb, e1, phi, arg);
/* Note that we optimized this PHI. */
return true;
}
return false;
}
static bool
conditional_replacement (basic_block cond_bb, basic_block middle_bb,
edge e0, edge e1, gimple phi,
tree arg0, tree arg1)
{
tree result;
gimple stmt, new_stmt;
tree cond;
gimple_stmt_iterator gsi;
edge true_edge, false_edge;
tree new_var, new_var2;
/* FIXME: Gimplification of complex type is too hard for now. */
if (TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
|| TREE_CODE (TREE_TYPE (arg1)) == COMPLEX_TYPE)
return false;
/* The PHI arguments have the constants 0 and 1, then convert
it to the conditional. */
if ((integer_zerop (arg0) && integer_onep (arg1))
|| (integer_zerop (arg1) && integer_onep (arg0)))
;
else
return false;
if (!empty_block_p (middle_bb))
return false;
/* At this point we know we have a GIMPLE_COND with two successors.
One successor is BB, the other successor is an empty block which
falls through into BB.
There is a single PHI node at the join point (BB) and its arguments
are constants (0, 1).
So, given the condition COND, and the two PHI arguments, we can
rewrite this PHI into non-branching code:
dest = (COND) or dest = COND'
We use the condition as-is if the argument associated with the
true edge has the value one or the argument associated with the
false edge as the value zero. Note that those conditions are not
the same since only one of the outgoing edges from the GIMPLE_COND
will directly reach BB and thus be associated with an argument. */
stmt = last_stmt (cond_bb);
result = PHI_RESULT (phi);
/* To handle special cases like floating point comparison, it is easier and
less error-prone to build a tree and gimplify it on the fly though it is
less efficient. */
cond = fold_build2 (gimple_cond_code (stmt), boolean_type_node,
gimple_cond_lhs (stmt), gimple_cond_rhs (stmt));
/* We need to know which is the true edge and which is the false
edge so that we know when to invert the condition below. */
extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge);
if ((e0 == true_edge && integer_zerop (arg0))
|| (e0 == false_edge && integer_onep (arg0))
|| (e1 == true_edge && integer_zerop (arg1))
|| (e1 == false_edge && integer_onep (arg1)))
cond = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (cond), cond);
/* Insert our new statements at the end of conditional block before the
COND_STMT. */
gsi = gsi_for_stmt (stmt);
new_var = force_gimple_operand_gsi (&gsi, cond, true, NULL, true,
GSI_SAME_STMT);
if (!useless_type_conversion_p (TREE_TYPE (result), TREE_TYPE (new_var)))
{
new_var2 = create_tmp_var (TREE_TYPE (result), NULL);
add_referenced_var (new_var2);
new_stmt = gimple_build_assign_with_ops (CONVERT_EXPR, new_var2,
new_var, NULL);
new_var2 = make_ssa_name (new_var2, new_stmt);
gimple_assign_set_lhs (new_stmt, new_var2);
gsi_insert_before (&gsi, new_stmt, GSI_SAME_STMT);
new_var = new_var2;
}
replace_phi_edge_with_variable (cond_bb, e1, phi, new_var);
/* Note that we optimized this PHI. */
return true;
}
static bool
check_process_case (tree cs, struct switch_conv_info *info)
{
tree ldecl;
basic_block label_bb, following_bb;
edge e;
ldecl = CASE_LABEL (cs);
label_bb = label_to_block (ldecl);
e = find_edge (info->switch_bb, label_bb);
gcc_assert (e);
if (CASE_LOW (cs) == NULL_TREE)
{
/* Default branch. */
info->default_prob = e->probability;
info->default_count = e->count;
}
else
{
int i;
info->other_count += e->count;
for (i = 0; i < 2; i++)
if (info->bit_test_bb[i] == label_bb)
break;
else if (info->bit_test_bb[i] == NULL)
{
info->bit_test_bb[i] = label_bb;
info->bit_test_uniq++;
break;
}
if (i == 2)
info->bit_test_uniq = 3;
if (CASE_HIGH (cs) != NULL_TREE
&& ! tree_int_cst_equal (CASE_LOW (cs), CASE_HIGH (cs)))
info->bit_test_count += 2;
else
info->bit_test_count++;
}
if (!label_bb)
{
info->reason = "bad case - cs BB label is NULL";
return false;
}
if (!single_pred_p (label_bb))
{
if (info->final_bb && info->final_bb != label_bb)
{
info->reason = "bad case - a non-final BB has two predecessors";
return false; /* sth complex going on in this branch */
}
following_bb = label_bb;
}
else
{
if (!empty_block_p (label_bb))
{
info->reason = "bad case - a non-final BB not empty";
return false;
}
e = single_succ_edge (label_bb);
following_bb = single_succ (label_bb);
}
if (!info->final_bb)
info->final_bb = following_bb;
else if (info->final_bb != following_bb)
{
info->reason = "bad case - different final BB";
return false; /* the only successor is not common for all the branches */
}
return true;
}