/* Misc functions used in this file. */
-/* Compare and hash for any structure which begins with a canonical
- pointer. Assumes all pointers are interchangeable, which is sort
- of already assumed by gcc elsewhere IIRC. */
-
-static int
-struct_ptr_eq (const void *a, const void *b)
-{
- const void * const * x = (const void * const *) a;
- const void * const * y = (const void * const *) b;
- return *x == *y;
-}
-
-static hashval_t
-struct_ptr_hash (const void *a)
-{
- const void * const * x = (const void * const *) a;
- return (size_t)*x >> 4;
-}
-
-
/* Remember and lookup EH landing pad data for arbitrary statements.
Really this means any statement that could_throw_p. We could
stuff this information into the stmt_ann data structure, but:
collect_finally_tree_1 (gimple_eh_filter_failure (stmt), region);
break;
+ case GIMPLE_EH_ELSE:
+ collect_finally_tree_1 (gimple_eh_else_n_body (stmt), region);
+ collect_finally_tree_1 (gimple_eh_else_e_body (stmt), region);
+ break;
+
default:
/* A type, a decl, or some kind of statement that we're not
interested in. Don't walk them. */
case GIMPLE_EH_FILTER:
replace_goto_queue_stmt_list (gimple_eh_filter_failure (stmt), tf);
break;
+ case GIMPLE_EH_ELSE:
+ replace_goto_queue_stmt_list (gimple_eh_else_n_body (stmt), tf);
+ replace_goto_queue_stmt_list (gimple_eh_else_e_body (stmt), tf);
+ break;
default:
/* These won't have gotos in them. */
#define verify_norecord_switch_expr(state, switch_expr)
#endif
-/* Redirect a RETURN_EXPR pointed to by STMT_P to FINLAB. Place in CONT_P
- whatever is needed to finish the return. If MOD is non-null, insert it
- before the new branch. RETURN_VALUE_P is a cache containing a temporary
- variable to be used in manipulating the value returned from the function. */
+/* Redirect a RETURN_EXPR pointed to by Q to FINLAB. If MOD is
+ non-null, insert it before the new branch. */
static void
-do_return_redirection (struct goto_queue_node *q, tree finlab, gimple_seq mod,
- tree *return_value_p)
+do_return_redirection (struct goto_queue_node *q, tree finlab, gimple_seq mod)
{
- tree ret_expr;
gimple x;
- /* In the case of a return, the queue node must be a gimple statement. */
+ /* In the case of a return, the queue node must be a gimple statement. */
gcc_assert (!q->is_label);
- ret_expr = gimple_return_retval (q->stmt.g);
+ /* Note that the return value may have already been computed, e.g.,
- if (ret_expr)
- {
- if (!*return_value_p)
- *return_value_p = ret_expr;
- else
- gcc_assert (*return_value_p == ret_expr);
- q->cont_stmt = q->stmt.g;
- /* The nasty part about redirecting the return value is that the
- return value itself is to be computed before the FINALLY block
- is executed. e.g.
-
- int x;
- int foo (void)
- {
- x = 0;
- try {
- return x;
- } finally {
- x++;
- }
- }
-
- should return 0, not 1. Arrange for this to happen by copying
- computed the return value into a local temporary. This also
- allows us to redirect multiple return statements through the
- same destination block; whether this is a net win or not really
- depends, I guess, but it does make generation of the switch in
- lower_try_finally_switch easier. */
-
- if (TREE_CODE (ret_expr) == RESULT_DECL)
+ int x;
+ int foo (void)
{
- if (!*return_value_p)
- *return_value_p = ret_expr;
- else
- gcc_assert (*return_value_p == ret_expr);
- q->cont_stmt = q->stmt.g;
+ x = 0;
+ try {
+ return x;
+ } finally {
+ x++;
+ }
}
- else
- gcc_unreachable ();
- }
- else
- /* If we don't return a value, all return statements are the same. */
- q->cont_stmt = q->stmt.g;
+
+ should return 0, not 1. We don't have to do anything to make
+ this happens because the return value has been placed in the
+ RESULT_DECL already. */
+
+ q->cont_stmt = q->stmt.g;
if (!q->repl_stmt)
q->repl_stmt = gimple_seq_alloc ();
return label;
}
+/* A subroutine of lower_try_finally. If FINALLY consits of a
+ GIMPLE_EH_ELSE node, return it. */
+
+static inline gimple
+get_eh_else (gimple_seq finally)
+{
+ gimple x = gimple_seq_first_stmt (finally);
+ if (gimple_code (x) == GIMPLE_EH_ELSE)
+ {
+ gcc_assert (gimple_seq_singleton_p (finally));
+ return x;
+ }
+ return NULL;
+}
+
/* A subroutine of lower_try_finally. If the eh_protect_cleanup_actions
langhook returns non-null, then the language requires that the exception
path out of a try_finally be treated specially. To wit: the code within
gimple_stmt_iterator gsi;
bool finally_may_fallthru;
gimple_seq finally;
- gimple x;
+ gimple x, eh_else;
/* First check for nothing to do. */
if (lang_hooks.eh_protect_cleanup_actions == NULL)
return;
finally = gimple_try_cleanup (tf->top_p);
- finally_may_fallthru = gimple_seq_may_fallthru (finally);
+ eh_else = get_eh_else (finally);
/* Duplicate the FINALLY block. Only need to do this for try-finally,
- and not for cleanups. */
- if (this_state)
+ and not for cleanups. If we've got an EH_ELSE, extract it now. */
+ if (eh_else)
+ {
+ finally = gimple_eh_else_e_body (eh_else);
+ gimple_try_set_cleanup (tf->top_p, gimple_eh_else_n_body (eh_else));
+ }
+ else if (this_state)
finally = lower_try_finally_dup_block (finally, outer_state);
+ finally_may_fallthru = gimple_seq_may_fallthru (finally);
/* If this cleanup consists of a TRY_CATCH_EXPR with TRY_CATCH_IS_CLEANUP
set, the handler of the TRY_CATCH_EXPR is another cleanup which ought
lower_try_finally_nofallthru (struct leh_state *state,
struct leh_tf_state *tf)
{
- tree lab, return_val;
- gimple x;
+ tree lab;
+ gimple x, eh_else;
gimple_seq finally;
struct goto_queue_node *q, *qe;
x = gimple_build_label (lab);
gimple_seq_add_stmt (&tf->top_p_seq, x);
- return_val = NULL;
q = tf->goto_queue;
qe = q + tf->goto_queue_active;
for (; q < qe; ++q)
if (q->index < 0)
- do_return_redirection (q, lab, NULL, &return_val);
+ do_return_redirection (q, lab, NULL);
else
do_goto_redirection (q, lab, NULL, tf);
replace_goto_queue (tf);
- lower_eh_constructs_1 (state, finally);
- gimple_seq_add_seq (&tf->top_p_seq, finally);
+ /* Emit the finally block into the stream. Lower EH_ELSE at this time. */
+ eh_else = get_eh_else (finally);
+ if (eh_else)
+ {
+ finally = gimple_eh_else_n_body (eh_else);
+ lower_eh_constructs_1 (state, finally);
+ gimple_seq_add_seq (&tf->top_p_seq, finally);
- if (tf->may_throw)
+ if (tf->may_throw)
+ {
+ finally = gimple_eh_else_e_body (eh_else);
+ lower_eh_constructs_1 (state, finally);
+
+ emit_post_landing_pad (&eh_seq, tf->region);
+ gimple_seq_add_seq (&eh_seq, finally);
+ }
+ }
+ else
{
- emit_post_landing_pad (&eh_seq, tf->region);
+ lower_eh_constructs_1 (state, finally);
+ gimple_seq_add_seq (&tf->top_p_seq, finally);
- x = gimple_build_goto (lab);
- gimple_seq_add_stmt (&eh_seq, x);
+ if (tf->may_throw)
+ {
+ emit_post_landing_pad (&eh_seq, tf->region);
+
+ x = gimple_build_goto (lab);
+ gimple_seq_add_stmt (&eh_seq, x);
+ }
}
}
finally = gimple_try_cleanup (tf->top_p);
tf->top_p_seq = gimple_try_eval (tf->top_p);
+ /* Since there's only one destination, and the destination edge can only
+ either be EH or non-EH, that implies that all of our incoming edges
+ are of the same type. Therefore we can lower EH_ELSE immediately. */
+ x = get_eh_else (finally);
+ if (x)
+ {
+ if (tf->may_throw)
+ finally = gimple_eh_else_e_body (x);
+ else
+ finally = gimple_eh_else_n_body (x);
+ }
+
lower_eh_constructs_1 (state, finally);
if (tf->may_throw)
if (tf->may_return)
{
/* Reachable by return expressions only. Redirect them. */
- tree return_val = NULL;
for (; q < qe; ++q)
- do_return_redirection (q, finally_label, NULL, &return_val);
+ do_return_redirection (q, finally_label, NULL);
replace_goto_queue (tf);
}
else
gimple_seq finally;
gimple_seq new_stmt;
gimple_seq seq;
- gimple x;
+ gimple x, eh_else;
tree tmp;
location_t tf_loc = gimple_location (tf->try_finally_expr);
finally = gimple_try_cleanup (tf->top_p);
+
+ /* Notice EH_ELSE, and simplify some of the remaining code
+ by considering FINALLY to be the normal return path only. */
+ eh_else = get_eh_else (finally);
+ if (eh_else)
+ finally = gimple_eh_else_n_body (eh_else);
+
tf->top_p_seq = gimple_try_eval (tf->top_p);
new_stmt = NULL;
if (tf->may_throw)
{
- seq = lower_try_finally_dup_block (finally, state);
+ /* We don't need to copy the EH path of EH_ELSE,
+ since it is only emitted once. */
+ if (eh_else)
+ seq = gimple_eh_else_e_body (eh_else);
+ else
+ seq = lower_try_finally_dup_block (finally, state);
lower_eh_constructs_1 (state, seq);
emit_post_landing_pad (&eh_seq, tf->region);
if (tf->goto_queue)
{
struct goto_queue_node *q, *qe;
- tree return_val = NULL;
int return_index, index;
struct labels_s
{
= create_artificial_label (tf_loc);
if (index == return_index)
- do_return_redirection (q, lab, NULL, &return_val);
+ do_return_redirection (q, lab, NULL);
else
do_goto_redirection (q, lab, NULL, tf);
lab = labels[index].label;
if (index == return_index)
- do_return_redirection (q, lab, NULL, &return_val);
+ do_return_redirection (q, lab, NULL);
else
do_goto_redirection (q, lab, NULL, tf);
}
lower_try_finally_switch (struct leh_state *state, struct leh_tf_state *tf)
{
struct goto_queue_node *q, *qe;
- tree return_val = NULL;
tree finally_tmp, finally_label;
int return_index, eh_index, fallthru_index;
int nlabels, ndests, j, last_case_index;
tree last_case;
VEC (tree,heap) *case_label_vec;
gimple_seq switch_body;
- gimple x;
+ gimple x, eh_else;
tree tmp;
gimple switch_stmt;
gimple_seq finally;
location_t finally_loc;
switch_body = gimple_seq_alloc ();
+ finally = gimple_try_cleanup (tf->top_p);
+ eh_else = get_eh_else (finally);
/* Mash the TRY block to the head of the chain. */
- finally = gimple_try_cleanup (tf->top_p);
tf->top_p_seq = gimple_try_eval (tf->top_p);
/* The location of the finally is either the last stmt in the finally
nlabels = VEC_length (tree, tf->dest_array);
return_index = nlabels;
eh_index = return_index + tf->may_return;
- fallthru_index = eh_index + tf->may_throw;
+ fallthru_index = eh_index + (tf->may_throw && !eh_else);
ndests = fallthru_index + tf->may_fallthru;
finally_tmp = create_tmp_var (integer_type_node, "finally_tmp");
gimple_seq_add_stmt (&switch_body, x);
}
- if (tf->may_throw)
+ /* For EH_ELSE, emit the exception path (plus resx) now, then
+ subsequently we only need consider the normal path. */
+ if (eh_else)
+ {
+ if (tf->may_throw)
+ {
+ finally = gimple_eh_else_e_body (eh_else);
+ lower_eh_constructs_1 (state, finally);
+
+ emit_post_landing_pad (&eh_seq, tf->region);
+ gimple_seq_add_seq (&eh_seq, finally);
+ emit_resx (&eh_seq, tf->region);
+ }
+
+ finally = gimple_eh_else_n_body (eh_else);
+ }
+ else if (tf->may_throw)
{
emit_post_landing_pad (&eh_seq, tf->region);
build_int_cst (integer_type_node,
return_index));
gimple_seq_add_stmt (&mod, x);
- do_return_redirection (q, finally_label, mod, &return_val);
+ do_return_redirection (q, finally_label, mod);
switch_id = return_index;
}
else
the estimate of the size of the switch machinery we'd have to add. */
static bool
-decide_copy_try_finally (int ndests, gimple_seq finally)
+decide_copy_try_finally (int ndests, bool may_throw, gimple_seq finally)
{
int f_estimate, sw_estimate;
+ gimple eh_else;
+
+ /* If there's an EH_ELSE involved, the exception path is separate
+ and really doesn't come into play for this computation. */
+ eh_else = get_eh_else (finally);
+ if (eh_else)
+ {
+ ndests -= may_throw;
+ finally = gimple_eh_else_n_body (eh_else);
+ }
if (!optimize)
- return false;
+ return ndests == 1;
/* Finally estimate N times, plus N gotos. */
f_estimate = count_insns_seq (finally, &eni_size_weights);
/* We can easily special-case redirection to a single destination. */
else if (ndests == 1)
lower_try_finally_onedest (state, &this_tf);
- else if (decide_copy_try_finally (ndests, gimple_try_cleanup (tp)))
+ else if (decide_copy_try_finally (ndests, this_tf.may_throw,
+ gimple_try_cleanup (tp)))
lower_try_finally_copy (state, &this_tf);
else
lower_try_finally_switch (state, &this_tf);
case GIMPLE_EH_MUST_NOT_THROW:
replace = lower_eh_must_not_throw (state, stmt);
break;
+ case GIMPLE_EH_ELSE:
+ /* This code is only valid with GIMPLE_TRY_FINALLY. */
+ gcc_unreachable ();
default:
replace = lower_cleanup (state, stmt);
break;
/* Return since we don't want gsi_next () */
return;
+ case GIMPLE_EH_ELSE:
+ /* We should be eliminating this in lower_try_finally et al. */
+ gcc_unreachable ();
+
default:
/* A type, a decl, or some kind of statement that we're not
interested in. Don't walk them. */
case GIMPLE_EH_FILTER:
refactor_eh_r (gimple_eh_filter_failure (one));
break;
+ case GIMPLE_EH_ELSE:
+ refactor_eh_r (gimple_eh_else_n_body (one));
+ refactor_eh_r (gimple_eh_else_e_body (one));
+ break;
default:
break;
}
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