static bool
ifcombine_ifandif (basic_block inner_cond_bb, bool inner_inv,
basic_block outer_cond_bb, bool outer_inv, bool result_inv)
{
gimple_stmt_iterator gsi;
gimple inner_stmt, outer_stmt;
gcond *inner_cond, *outer_cond;
tree name1, name2, bit1, bit2, bits1, bits2;
inner_stmt = last_stmt (inner_cond_bb);
if (!inner_stmt
|| gimple_code (inner_stmt) != GIMPLE_COND)
return false;
inner_cond = as_a <gcond *> (inner_stmt);
outer_stmt = last_stmt (outer_cond_bb);
if (!outer_stmt
|| gimple_code (outer_stmt) != GIMPLE_COND)
return false;
outer_cond = as_a <gcond *> (outer_stmt);
/* See if we test a single bit of the same name in both tests. In
that case remove the outer test, merging both else edges,
and change the inner one to test for
name & (bit1 | bit2) == (bit1 | bit2). */
if (recognize_single_bit_test (inner_cond, &name1, &bit1, inner_inv)
&& recognize_single_bit_test (outer_cond, &name2, &bit2, outer_inv)
&& name1 == name2)
{
tree t, t2;
/* Do it. */
gsi = gsi_for_stmt (inner_cond);
t = fold_build2 (LSHIFT_EXPR, TREE_TYPE (name1),
build_int_cst (TREE_TYPE (name1), 1), bit1);
t2 = fold_build2 (LSHIFT_EXPR, TREE_TYPE (name1),
build_int_cst (TREE_TYPE (name1), 1), bit2);
t = fold_build2 (BIT_IOR_EXPR, TREE_TYPE (name1), t, t2);
t = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
true, GSI_SAME_STMT);
t2 = fold_build2 (BIT_AND_EXPR, TREE_TYPE (name1), name1, t);
t2 = force_gimple_operand_gsi (&gsi, t2, true, NULL_TREE,
true, GSI_SAME_STMT);
t = fold_build2 (result_inv ? NE_EXPR : EQ_EXPR,
boolean_type_node, t2, t);
t = canonicalize_cond_expr_cond (t);
if (!t)
return false;
gimple_cond_set_condition_from_tree (inner_cond, t);
update_stmt (inner_cond);
/* Leave CFG optimization to cfg_cleanup. */
gimple_cond_set_condition_from_tree (outer_cond,
outer_inv ? boolean_false_node : boolean_true_node);
update_stmt (outer_cond);
if (dump_file)
{
fprintf (dump_file, "optimizing double bit test to ");
print_generic_expr (dump_file, name1, 0);
fprintf (dump_file, " & T == T\nwith temporary T = (1 << ");
print_generic_expr (dump_file, bit1, 0);
fprintf (dump_file, ") | (1 << ");
print_generic_expr (dump_file, bit2, 0);
fprintf (dump_file, ")\n");
}
return true;
}
/* See if we have two bit tests of the same name in both tests.
In that case remove the outer test and change the inner one to
test for name & (bits1 | bits2) != 0. */
else if (recognize_bits_test (inner_cond, &name1, &bits1, !inner_inv)
&& recognize_bits_test (outer_cond, &name2, &bits2, !outer_inv))
{
gimple_stmt_iterator gsi;
tree t;
/* Find the common name which is bit-tested. */
if (name1 == name2)
;
else if (bits1 == bits2)
{
t = name2;
name2 = bits2;
bits2 = t;
t = name1;
name1 = bits1;
bits1 = t;
}
else if (name1 == bits2)
{
t = name2;
name2 = bits2;
bits2 = t;
}
else if (bits1 == name2)
{
t = name1;
name1 = bits1;
bits1 = t;
}
else
return false;
/* As we strip non-widening conversions in finding a common
name that is tested make sure to end up with an integral
type for building the bit operations. */
if (TYPE_PRECISION (TREE_TYPE (bits1))
>= TYPE_PRECISION (TREE_TYPE (bits2)))
{
bits1 = fold_convert (unsigned_type_for (TREE_TYPE (bits1)), bits1);
name1 = fold_convert (TREE_TYPE (bits1), name1);
bits2 = fold_convert (unsigned_type_for (TREE_TYPE (bits2)), bits2);
bits2 = fold_convert (TREE_TYPE (bits1), bits2);
}
else
{
bits2 = fold_convert (unsigned_type_for (TREE_TYPE (bits2)), bits2);
name1 = fold_convert (TREE_TYPE (bits2), name1);
bits1 = fold_convert (unsigned_type_for (TREE_TYPE (bits1)), bits1);
bits1 = fold_convert (TREE_TYPE (bits2), bits1);
}
/* Do it. */
gsi = gsi_for_stmt (inner_cond);
t = fold_build2 (BIT_IOR_EXPR, TREE_TYPE (name1), bits1, bits2);
t = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
true, GSI_SAME_STMT);
t = fold_build2 (BIT_AND_EXPR, TREE_TYPE (name1), name1, t);
t = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
true, GSI_SAME_STMT);
t = fold_build2 (result_inv ? NE_EXPR : EQ_EXPR, boolean_type_node, t,
build_int_cst (TREE_TYPE (t), 0));
t = canonicalize_cond_expr_cond (t);
if (!t)
return false;
gimple_cond_set_condition_from_tree (inner_cond, t);
update_stmt (inner_cond);
/* Leave CFG optimization to cfg_cleanup. */
gimple_cond_set_condition_from_tree (outer_cond,
outer_inv ? boolean_false_node : boolean_true_node);
update_stmt (outer_cond);
if (dump_file)
{
fprintf (dump_file, "optimizing bits or bits test to ");
print_generic_expr (dump_file, name1, 0);
fprintf (dump_file, " & T != 0\nwith temporary T = ");
print_generic_expr (dump_file, bits1, 0);
fprintf (dump_file, " | ");
print_generic_expr (dump_file, bits2, 0);
fprintf (dump_file, "\n");
}
return true;
}
/* See if we have two comparisons that we can merge into one. */
else if (TREE_CODE_CLASS (gimple_cond_code (inner_cond)) == tcc_comparison
&& TREE_CODE_CLASS (gimple_cond_code (outer_cond)) == tcc_comparison)
{
tree t;
enum tree_code inner_cond_code = gimple_cond_code (inner_cond);
enum tree_code outer_cond_code = gimple_cond_code (outer_cond);
/* Invert comparisons if necessary (and possible). */
if (inner_inv)
inner_cond_code = invert_tree_comparison (inner_cond_code,
HONOR_NANS (gimple_cond_lhs (inner_cond)));
if (inner_cond_code == ERROR_MARK)
return false;
if (outer_inv)
outer_cond_code = invert_tree_comparison (outer_cond_code,
HONOR_NANS (gimple_cond_lhs (outer_cond)));
if (outer_cond_code == ERROR_MARK)
return false;
/* Don't return false so fast, try maybe_fold_or_comparisons? */
if (!(t = maybe_fold_and_comparisons (inner_cond_code,
gimple_cond_lhs (inner_cond),
gimple_cond_rhs (inner_cond),
outer_cond_code,
gimple_cond_lhs (outer_cond),
gimple_cond_rhs (outer_cond))))
{
tree t1, t2;
gimple_stmt_iterator gsi;
if (!LOGICAL_OP_NON_SHORT_CIRCUIT)
return false;
/* Only do this optimization if the inner bb contains only the conditional. */
if (!gsi_one_before_end_p (gsi_start_nondebug_after_labels_bb (inner_cond_bb)))
return false;
t1 = fold_build2_loc (gimple_location (inner_cond),
inner_cond_code,
boolean_type_node,
gimple_cond_lhs (inner_cond),
gimple_cond_rhs (inner_cond));
t2 = fold_build2_loc (gimple_location (outer_cond),
outer_cond_code,
boolean_type_node,
gimple_cond_lhs (outer_cond),
gimple_cond_rhs (outer_cond));
t = fold_build2_loc (gimple_location (inner_cond),
TRUTH_AND_EXPR, boolean_type_node, t1, t2);
if (result_inv)
{
t = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (t), t);
result_inv = false;
}
gsi = gsi_for_stmt (inner_cond);
t = force_gimple_operand_gsi_1 (&gsi, t, is_gimple_condexpr, NULL, true,
GSI_SAME_STMT);
}
if (result_inv)
t = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (t), t);
t = canonicalize_cond_expr_cond (t);
if (!t)
return false;
gimple_cond_set_condition_from_tree (inner_cond, t);
update_stmt (inner_cond);
/* Leave CFG optimization to cfg_cleanup. */
gimple_cond_set_condition_from_tree (outer_cond,
outer_inv ? boolean_false_node : boolean_true_node);
update_stmt (outer_cond);
if (dump_file)
{
fprintf (dump_file, "optimizing two comparisons to ");
print_generic_expr (dump_file, t, 0);
fprintf (dump_file, "\n");
}
return true;
}
return false;
}
basic_block
isolate_path (basic_block bb, basic_block duplicate,
edge e, gimple stmt, tree op)
{
gimple_stmt_iterator si, si2;
edge_iterator ei;
edge e2;
/* First duplicate BB if we have not done so already and remove all
the duplicate's outgoing edges as duplicate is going to unconditionally
trap. Removing the outgoing edges is both an optimization and ensures
we don't need to do any PHI node updates. */
if (!duplicate)
{
duplicate = duplicate_block (bb, NULL, NULL);
for (ei = ei_start (duplicate->succs); (e2 = ei_safe_edge (ei)); )
remove_edge (e2);
}
/* Complete the isolation step by redirecting E to reach DUPLICATE. */
e2 = redirect_edge_and_branch (e, duplicate);
if (e2)
flush_pending_stmts (e2);
/* There may be more than one statement in DUPLICATE which exhibits
undefined behaviour. Ultimately we want the first such statement in
DUPLCIATE so that we're able to delete as much code as possible.
So each time we discover undefined behaviour in DUPLICATE, search for
the statement which triggers undefined behaviour. If found, then
transform the statement into a trap and delete everything after the
statement. If not found, then this particular instance was subsumed by
an earlier instance of undefined behaviour and there's nothing to do.
This is made more complicated by the fact that we have STMT, which is in
BB rather than in DUPLICATE. So we set up two iterators, one for each
block and walk forward looking for STMT in BB, advancing each iterator at
each step.
When we find STMT the second iterator should point to STMT's equivalent in
duplicate. If DUPLICATE ends before STMT is found in BB, then there's
nothing to do.
Ignore labels and debug statements. */
si = gsi_start_nondebug_after_labels_bb (bb);
si2 = gsi_start_nondebug_after_labels_bb (duplicate);
while (!gsi_end_p (si) && !gsi_end_p (si2) && gsi_stmt (si) != stmt)
{
gsi_next_nondebug (&si);
gsi_next_nondebug (&si2);
}
/* This would be an indicator that we never found STMT in BB, which should
never happen. */
gcc_assert (!gsi_end_p (si));
/* If we did not run to the end of DUPLICATE, then SI points to STMT and
SI2 points to the duplicate of STMT in DUPLICATE. Insert a trap
before SI2 and remove SI2 and all trailing statements. */
if (!gsi_end_p (si2))
insert_trap_and_remove_trailing_statements (&si2, op);
return duplicate;
}
