#define unfilled_slots_next \
((rtx *) obstack_next_free (&unfilled_slots_obstack))
-/* Points to the label before the end of the function. */
-static rtx end_of_function_label;
+/* Points to the label before the end of the function, or before a
+ return insn. */
+static rtx function_return_label;
+/* Likewise for a simple_return. */
+static rtx function_simple_return_label;
/* Mapping between INSN_UID's and position in the code since INSN_UID's do
not always monotonically increase. */
static int resource_conflicts_p (struct resources *, struct resources *);
static int insn_references_resource_p (rtx, struct resources *, bool);
static int insn_sets_resource_p (rtx, struct resources *, bool);
-static rtx find_end_label (void);
+static rtx find_end_label (rtx);
static rtx emit_delay_sequence (rtx, rtx, int);
static rtx add_to_delay_list (rtx, rtx);
static rtx delete_from_delay_slot (rtx);
return next_active_insn (insn);
}
\f
+/* Return true iff INSN is a simplejump, or any kind of return insn. */
+
+static bool
+simplejump_or_return_p (rtx insn)
+{
+ return (JUMP_P (insn)
+ && (simplejump_p (insn) || ANY_RETURN_P (PATTERN (insn))));
+}
+\f
/* Return TRUE if this insn should stop the search for insn to fill delay
slots. LABELS_P indicates that labels should terminate the search.
In all cases, jumps terminate the search. */
??? There may be a problem with the current implementation. Suppose
we start with a bare RETURN insn and call find_end_label. It may set
- end_of_function_label just before the RETURN. Suppose the machinery
+ function_return_label just before the RETURN. Suppose the machinery
is able to fill the delay slot of the RETURN insn afterwards. Then
- end_of_function_label is no longer valid according to the property
+ function_return_label is no longer valid according to the property
described above and find_end_label will still return it unmodified.
Note that this is probably mitigated by the following observation:
- once end_of_function_label is made, it is very likely the target of
+ once function_return_label is made, it is very likely the target of
a jump, so filling the delay slot of the RETURN will be much more
- difficult. */
+ difficult.
+ KIND is either simple_return_rtx or ret_rtx, indicating which type of
+ return we're looking for. */
static rtx
-find_end_label (void)
+find_end_label (rtx kind)
{
rtx insn;
+ rtx *plabel;
+
+ if (kind == ret_rtx)
+ plabel = &function_return_label;
+ else
+ {
+ gcc_assert (kind == simple_return_rtx);
+ plabel = &function_simple_return_label;
+ }
/* If we found one previously, return it. */
- if (end_of_function_label)
- return end_of_function_label;
+ if (*plabel)
+ return *plabel;
/* Otherwise, see if there is a label at the end of the function. If there
is, it must be that RETURN insns aren't needed, so that is our return
/* When a target threads its epilogue we might already have a
suitable return insn. If so put a label before it for the
- end_of_function_label. */
+ function_return_label. */
if (BARRIER_P (insn)
&& JUMP_P (PREV_INSN (insn))
- && GET_CODE (PATTERN (PREV_INSN (insn))) == RETURN)
+ && PATTERN (PREV_INSN (insn)) == kind)
{
rtx temp = PREV_INSN (PREV_INSN (insn));
- end_of_function_label = gen_label_rtx ();
- LABEL_NUSES (end_of_function_label) = 0;
+ rtx label = gen_label_rtx ();
+ LABEL_NUSES (label) = 0;
- /* Put the label before an USE insns that may precede the RETURN insn. */
+ /* Put the label before any USE insns that may precede the RETURN
+ insn. */
while (GET_CODE (temp) == USE)
temp = PREV_INSN (temp);
- emit_label_after (end_of_function_label, temp);
+ emit_label_after (label, temp);
+ *plabel = label;
}
else if (LABEL_P (insn))
- end_of_function_label = insn;
+ *plabel = insn;
else
{
- end_of_function_label = gen_label_rtx ();
- LABEL_NUSES (end_of_function_label) = 0;
+ rtx label = gen_label_rtx ();
+ LABEL_NUSES (label) = 0;
/* If the basic block reorder pass moves the return insn to
some other place try to locate it again and put our
- end_of_function_label there. */
- while (insn && ! (JUMP_P (insn)
- && (GET_CODE (PATTERN (insn)) == RETURN)))
+ function_return_label there. */
+ while (insn && ! (JUMP_P (insn) && (PATTERN (insn) == kind)))
insn = PREV_INSN (insn);
if (insn)
{
insn = PREV_INSN (insn);
- /* Put the label before an USE insns that may proceed the
+ /* Put the label before any USE insns that may precede the
RETURN insn. */
while (GET_CODE (insn) == USE)
insn = PREV_INSN (insn);
- emit_label_after (end_of_function_label, insn);
+ emit_label_after (label, insn);
}
else
{
&& ! HAVE_return
#endif
)
- {
- /* The RETURN insn has its delay slot filled so we cannot
- emit the label just before it. Since we already have
- an epilogue and cannot emit a new RETURN, we cannot
- emit the label at all. */
- end_of_function_label = NULL_RTX;
- return end_of_function_label;
- }
+ /* The RETURN insn has its delay slot filled so we cannot
+ emit the label just before it. Since we already have
+ an epilogue and cannot emit a new RETURN, we cannot
+ emit the label at all. */
+ return NULL_RTX;
#endif /* HAVE_epilogue */
/* Otherwise, make a new label and emit a RETURN and BARRIER,
if needed. */
- emit_label (end_of_function_label);
+ emit_label (label);
#ifdef HAVE_return
/* We don't bother trying to create a return insn if the
epilogue has filled delay-slots; we would have to try and
}
#endif
}
+ *plabel = label;
}
/* Show one additional use for this label so it won't go away until
we are done. */
- ++LABEL_NUSES (end_of_function_label);
+ ++LABEL_NUSES (*plabel);
- return end_of_function_label;
+ return *plabel;
}
\f
/* Put INSN and LIST together in a SEQUENCE rtx of LENGTH, and replace
if ((next_trial == next_active_insn (JUMP_LABEL (insn))
&& ! (next_trial == 0 && crtl->epilogue_delay_list != 0))
|| (next_trial != 0
- && JUMP_P (next_trial)
- && JUMP_LABEL (insn) == JUMP_LABEL (next_trial)
- && (simplejump_p (next_trial)
- || GET_CODE (PATTERN (next_trial)) == RETURN)))
+ && simplejump_or_return_p (next_trial)
+ && JUMP_LABEL (insn) == JUMP_LABEL (next_trial)))
{
if (eligible_for_annul_false (insn, 0, trial, flags))
{
branch, thread our jump to the target of that branch. Don't
change this into a RETURN here, because it may not accept what
we have in the delay slot. We'll fix this up later. */
- if (next_trial && JUMP_P (next_trial)
- && (simplejump_p (next_trial)
- || GET_CODE (PATTERN (next_trial)) == RETURN))
+ if (next_trial && simplejump_or_return_p (next_trial))
{
rtx target_label = JUMP_LABEL (next_trial);
if (ANY_RETURN_P (target_label))
- target_label = find_end_label ();
+ target_label = find_end_label (target_label);
if (target_label)
{
return. */
return 2;
case JUMP_INSN:
- if (GET_CODE (PATTERN (insn)) == RETURN)
+ if (ANY_RETURN_P (PATTERN (insn)))
return 1;
else if (simplejump_p (insn)
&& jump_count++ < 10)
/* We can't do anything if SEQ's delay insn isn't an
unconditional branch. */
- if (! simplejump_p (XVECEXP (seq, 0, 0))
- && GET_CODE (PATTERN (XVECEXP (seq, 0, 0))) != RETURN)
+ if (! simplejump_or_return_p (XVECEXP (seq, 0, 0)))
return delay_list;
for (i = 1; i < XVECLEN (seq, 0); i++)
if (new_label != 0)
new_label = get_label_before (new_label);
else
- new_label = find_end_label ();
+ new_label = find_end_label (simple_return_rtx);
if (new_label)
{
\f
/* Follow any unconditional jump at LABEL;
return the ultimate label reached by any such chain of jumps.
- Return ret_rtx if the chain ultimately leads to a return instruction.
+ Return a suitable return rtx if the chain ultimately leads to a
+ return instruction.
If LABEL is not followed by a jump, return LABEL.
If the chain loops or we can't find end, return LABEL,
since that tells caller to avoid changing the insn. */
&& JUMP_P (insn)
&& JUMP_LABEL (insn) != NULL_RTX
&& ((any_uncondjump_p (insn) && onlyjump_p (insn))
- || GET_CODE (PATTERN (insn)) == RETURN)
+ || ANY_RETURN_P (PATTERN (insn)))
&& (next = NEXT_INSN (insn))
&& BARRIER_P (next));
depth++)
gcc_assert (thread_if_true);
- if (new_thread && JUMP_P (new_thread)
- && (simplejump_p (new_thread)
- || GET_CODE (PATTERN (new_thread)) == RETURN)
+ if (new_thread && simplejump_or_return_p (new_thread)
&& redirect_with_delay_list_safe_p (insn,
JUMP_LABEL (new_thread),
delay_list))
new_thread = follow_jumps (JUMP_LABEL (new_thread));
if (ANY_RETURN_P (new_thread))
- label = find_end_label ();
+ label = find_end_label (new_thread);
else if (LABEL_P (new_thread))
label = new_thread;
else
{
target_label = skip_consecutive_labels (follow_jumps (target_label));
if (ANY_RETURN_P (target_label))
- target_label = find_end_label ();
+ target_label = find_end_label (target_label);
if (target_label && next_active_insn (target_label) == next
&& ! condjump_in_parallel_p (insn))
/* See if this jump conditionally branches around an unconditional
jump. If so, invert this jump and point it to the target of the
second jump. */
- if (next && JUMP_P (next)
+ if (next && simplejump_or_return_p (next)
&& any_condjump_p (insn)
- && (simplejump_p (next) || GET_CODE (PATTERN (next)) == RETURN)
&& target_label
&& next_active_insn (target_label) == next_active_insn (next)
&& no_labels_between_p (insn, next))
Don't do this if we expect the conditional branch to be true, because
we would then be making the more common case longer. */
- if (JUMP_P (insn)
- && (simplejump_p (insn) || GET_CODE (PATTERN (insn)) == RETURN)
+ if (simplejump_or_return_p (insn)
&& (other = prev_active_insn (insn)) != 0
&& any_condjump_p (other)
&& no_labels_between_p (other, insn)
Only do so if optimizing for size since this results in slower, but
smaller code. */
if (optimize_function_for_size_p (cfun)
- && GET_CODE (PATTERN (delay_insn)) == RETURN
+ && ANY_RETURN_P (PATTERN (delay_insn))
&& next
&& JUMP_P (next)
- && GET_CODE (PATTERN (next)) == RETURN)
+ && PATTERN (next) == PATTERN (delay_insn))
{
rtx after;
int i;
continue;
target_label = JUMP_LABEL (delay_insn);
+ if (target_label && ANY_RETURN_P (target_label))
+ continue;
- if (!ANY_RETURN_P (target_label))
- {
- /* If this jump goes to another unconditional jump, thread it, but
- don't convert a jump into a RETURN here. */
- trial = skip_consecutive_labels (follow_jumps (target_label));
- if (ANY_RETURN_P (trial))
- trial = find_end_label ();
-
- if (trial && trial != target_label
- && redirect_with_delay_slots_safe_p (delay_insn, trial, insn))
- {
- reorg_redirect_jump (delay_insn, trial);
- target_label = trial;
- }
+ /* If this jump goes to another unconditional jump, thread it, but
+ don't convert a jump into a RETURN here. */
+ trial = skip_consecutive_labels (follow_jumps (target_label));
+ if (ANY_RETURN_P (trial))
+ trial = find_end_label (trial);
- /* If the first insn at TARGET_LABEL is redundant with a previous
- insn, redirect the jump to the following insn and process again.
- We use next_real_insn instead of next_active_insn so we
- don't skip USE-markers, or we'll end up with incorrect
- liveness info. */
- trial = next_real_insn (target_label);
- if (trial && GET_CODE (PATTERN (trial)) != SEQUENCE
- && redundant_insn (trial, insn, 0)
- && ! can_throw_internal (trial))
- {
- /* Figure out where to emit the special USE insn so we don't
- later incorrectly compute register live/death info. */
- rtx tmp = next_active_insn (trial);
- if (tmp == 0)
- tmp = find_end_label ();
+ if (trial && trial != target_label
+ && redirect_with_delay_slots_safe_p (delay_insn, trial, insn))
+ {
+ reorg_redirect_jump (delay_insn, trial);
+ target_label = trial;
+ }
- if (tmp)
- {
- /* Insert the special USE insn and update dataflow info. */
- update_block (trial, tmp);
+ /* If the first insn at TARGET_LABEL is redundant with a previous
+ insn, redirect the jump to the following insn and process again.
+ We use next_real_insn instead of next_active_insn so we
+ don't skip USE-markers, or we'll end up with incorrect
+ liveness info. */
+ trial = next_real_insn (target_label);
+ if (trial && GET_CODE (PATTERN (trial)) != SEQUENCE
+ && redundant_insn (trial, insn, 0)
+ && ! can_throw_internal (trial))
+ {
+ /* Figure out where to emit the special USE insn so we don't
+ later incorrectly compute register live/death info. */
+ rtx tmp = next_active_insn (trial);
+ if (tmp == 0)
+ tmp = find_end_label (simple_return_rtx);
- /* Now emit a label before the special USE insn, and
- redirect our jump to the new label. */
- target_label = get_label_before (PREV_INSN (tmp));
- reorg_redirect_jump (delay_insn, target_label);
- next = insn;
- continue;
- }
+ if (tmp)
+ {
+ /* Insert the special USE insn and update dataflow info. */
+ update_block (trial, tmp);
+
+ /* Now emit a label before the special USE insn, and
+ redirect our jump to the new label. */
+ target_label = get_label_before (PREV_INSN (tmp));
+ reorg_redirect_jump (delay_insn, target_label);
+ next = insn;
+ continue;
}
+ }
- /* Similarly, if it is an unconditional jump with one insn in its
- delay list and that insn is redundant, thread the jump. */
- if (trial && GET_CODE (PATTERN (trial)) == SEQUENCE
- && XVECLEN (PATTERN (trial), 0) == 2
- && JUMP_P (XVECEXP (PATTERN (trial), 0, 0))
- && (simplejump_p (XVECEXP (PATTERN (trial), 0, 0))
- || GET_CODE (PATTERN (XVECEXP (PATTERN (trial), 0, 0))) == RETURN)
- && redundant_insn (XVECEXP (PATTERN (trial), 0, 1), insn, 0))
+ /* Similarly, if it is an unconditional jump with one insn in its
+ delay list and that insn is redundant, thread the jump. */
+ if (trial && GET_CODE (PATTERN (trial)) == SEQUENCE
+ && XVECLEN (PATTERN (trial), 0) == 2
+ && JUMP_P (XVECEXP (PATTERN (trial), 0, 0))
+ && simplejump_or_return_p (XVECEXP (PATTERN (trial), 0, 0))
+ && redundant_insn (XVECEXP (PATTERN (trial), 0, 1), insn, 0))
+ {
+ target_label = JUMP_LABEL (XVECEXP (PATTERN (trial), 0, 0));
+ if (ANY_RETURN_P (target_label))
+ target_label = find_end_label (target_label);
+
+ if (target_label
+ && redirect_with_delay_slots_safe_p (delay_insn, target_label,
+ insn))
{
- target_label = JUMP_LABEL (XVECEXP (PATTERN (trial), 0, 0));
- if (ANY_RETURN_P (target_label))
- target_label = find_end_label ();
-
- if (target_label
- && redirect_with_delay_slots_safe_p (delay_insn, target_label,
- insn))
- {
- reorg_redirect_jump (delay_insn, target_label);
- next = insn;
- continue;
- }
+ reorg_redirect_jump (delay_insn, target_label);
+ next = insn;
+ continue;
}
}
a RETURN here. */
if (! INSN_ANNULLED_BRANCH_P (delay_insn)
&& any_condjump_p (delay_insn)
- && next && JUMP_P (next)
- && (simplejump_p (next) || GET_CODE (PATTERN (next)) == RETURN)
+ && next && simplejump_or_return_p (next)
&& next_active_insn (target_label) == next_active_insn (next)
&& no_labels_between_p (insn, next))
{
rtx old_label = JUMP_LABEL (delay_insn);
if (ANY_RETURN_P (label))
- label = find_end_label ();
+ label = find_end_label (label);
/* find_end_label can generate a new label. Check this first. */
if (label
make_return_insns (rtx first)
{
rtx insn, jump_insn, pat;
- rtx real_return_label = end_of_function_label;
+ rtx real_return_label = function_return_label;
+ rtx real_simple_return_label = function_simple_return_label;
int slots, i;
#ifdef DELAY_SLOTS_FOR_EPILOGUE
made for END_OF_FUNCTION_LABEL. If so, set up anything we can't change
into a RETURN to jump to it. */
for (insn = first; insn; insn = NEXT_INSN (insn))
- if (JUMP_P (insn) && GET_CODE (PATTERN (insn)) == RETURN)
+ if (JUMP_P (insn) && ANY_RETURN_P (PATTERN (insn)))
{
- real_return_label = get_label_before (insn);
+ rtx t = get_label_before (insn);
+ if (PATTERN (insn) == ret_rtx)
+ real_return_label = t;
+ else
+ real_simple_return_label = t;
break;
}
/* Show an extra usage of REAL_RETURN_LABEL so it won't go away if it
was equal to END_OF_FUNCTION_LABEL. */
- LABEL_NUSES (real_return_label)++;
+ if (real_return_label)
+ LABEL_NUSES (real_return_label)++;
+ if (real_simple_return_label)
+ LABEL_NUSES (real_simple_return_label)++;
/* Clear the list of insns to fill so we can use it. */
obstack_free (&unfilled_slots_obstack, unfilled_firstobj);
for (insn = first; insn; insn = NEXT_INSN (insn))
{
int flags;
+ rtx kind, real_label;
/* Only look at filled JUMP_INSNs that go to the end of function
label. */
if (!NONJUMP_INSN_P (insn)
|| GET_CODE (PATTERN (insn)) != SEQUENCE
- || !JUMP_P (XVECEXP (PATTERN (insn), 0, 0))
- || JUMP_LABEL (XVECEXP (PATTERN (insn), 0, 0)) != end_of_function_label)
+ || !jump_to_label_p (XVECEXP (PATTERN (insn), 0, 0)))
+ continue;
+
+ if (JUMP_LABEL (XVECEXP (PATTERN (insn), 0, 0)) == function_return_label)
+ {
+ kind = ret_rtx;
+ real_label = real_return_label;
+ }
+ else if (JUMP_LABEL (XVECEXP (PATTERN (insn), 0, 0))
+ == function_simple_return_label)
+ {
+ kind = simple_return_rtx;
+ real_label = real_simple_return_label;
+ }
+ else
continue;
pat = PATTERN (insn);
/* If we can't make the jump into a RETURN, try to redirect it to the best
RETURN and go on to the next insn. */
- if (! reorg_redirect_jump (jump_insn, ret_rtx))
+ if (!reorg_redirect_jump (jump_insn, kind))
{
/* Make sure redirecting the jump will not invalidate the delay
slot insns. */
- if (redirect_with_delay_slots_safe_p (jump_insn,
- real_return_label,
- insn))
- reorg_redirect_jump (jump_insn, real_return_label);
+ if (redirect_with_delay_slots_safe_p (jump_insn, real_label, insn))
+ reorg_redirect_jump (jump_insn, real_label);
continue;
}
RETURN, delete the SEQUENCE and output the individual insns,
followed by the RETURN. Then set things up so we try to find
insns for its delay slots, if it needs some. */
- if (GET_CODE (PATTERN (jump_insn)) == RETURN)
+ if (ANY_RETURN_P (PATTERN (jump_insn)))
{
rtx prev = PREV_INSN (insn);
else
/* It is probably more efficient to keep this with its current
delay slot as a branch to a RETURN. */
- reorg_redirect_jump (jump_insn, real_return_label);
+ reorg_redirect_jump (jump_insn, real_label);
}
/* Now delete REAL_RETURN_LABEL if we never used it. Then try to fill any
new delay slots we have created. */
- if (--LABEL_NUSES (real_return_label) == 0)
+ if (real_return_label != NULL_RTX && --LABEL_NUSES (real_return_label) == 0)
delete_related_insns (real_return_label);
+ if (real_simple_return_label != NULL_RTX
+ && --LABEL_NUSES (real_simple_return_label) == 0)
+ delete_related_insns (real_simple_return_label);
fill_simple_delay_slots (1);
fill_simple_delay_slots (0);
{
rtx insn, next, epilogue_insn = 0;
int i;
+ bool need_return_insns;
/* If the current function has no insns other than the prologue and
epilogue, then do not try to fill any delay slots. */
init_resource_info (epilogue_insn);
/* Show we haven't computed an end-of-function label yet. */
- end_of_function_label = 0;
+ function_return_label = function_simple_return_label = NULL_RTX;
/* Initialize the statistics for this function. */
memset (num_insns_needing_delays, 0, sizeof num_insns_needing_delays);
/* If we made an end of function label, indicate that it is now
safe to delete it by undoing our prior adjustment to LABEL_NUSES.
If it is now unused, delete it. */
- if (end_of_function_label && --LABEL_NUSES (end_of_function_label) == 0)
- delete_related_insns (end_of_function_label);
+ if (function_return_label && --LABEL_NUSES (function_return_label) == 0)
+ delete_related_insns (function_return_label);
+ if (function_simple_return_label
+ && --LABEL_NUSES (function_simple_return_label) == 0)
+ delete_related_insns (function_simple_return_label);
+ need_return_insns = false;
#ifdef HAVE_return
- if (HAVE_return && end_of_function_label != 0)
- make_return_insns (first);
+ need_return_insns |= HAVE_return && function_return_label != 0;
+#endif
+#ifdef HAVE_simple_return
+ need_return_insns |= HAVE_simple_return && function_simple_return_label != 0;
#endif
+ if (need_return_insns)
+ make_return_insns (first);
/* Delete any USE insns made by update_block; subsequent passes don't need
them or know how to deal with them. */
projects / thirdparty / gcc.git / commitdiff
