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jump.c (get_label_after): Delete.

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2007-02-15  Paolo Bonzini  <bonzini@gnu.org>

	* jump.c (get_label_after): Delete.
	(get_label_before, delete_computation, delete_jump,
	delete_prior_computation, follow_jumps): Move...
	* reorg.c (delete_computation, delete_prior_computation): ... here...
	(get_label_before, delete_jump): ... making these static ...
	(follow_jumps): ... and simplifying this since it only runs after
	reload.
	* rtl.h (get_label_after, get_label_before, delete_jump,
	follow_jumps): Delete prototypes.

From-SVN: r122003
This commit is contained in:
Paolo Bonzini 2007-02-15 16:40:16 +00:00 • committed by Paolo Bonzini
parent fe60528edc
commit c47277a619
4 changed files with 268 additions and 287 deletions
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12
gcc/ChangeLog
View file

@ -1,3 +1,15 @@
2007-02-15 Paolo Bonzini <bonzini@gnu.org>
* jump.c (get_label_after): Delete.
(get_label_before, delete_computation, delete_jump,
delete_prior_computation, follow_jumps): Move...
* reorg.c (delete_computation, delete_prior_computation): ... here...
(get_label_before, delete_jump): ... making these static ...
(follow_jumps): ... and simplifying this since it only runs after
reload.
* rtl.h (get_label_after, get_label_before, delete_jump,
follow_jumps): Delete prototypes.
2007-02-15 Paolo Bonzini <bonzini@gnu.org>
* caller-save.c (save_call_clobbered_regs): Do not process sibcalls.

283
gcc/jump.c
View file

@ -285,48 +285,6 @@ squeeze_notes (rtx* startp, rtx* endp)
return false;
}
/* Return the label before INSN, or put a new label there. */
rtx
get_label_before (rtx insn)
{
rtx label;
/* Find an existing label at this point
or make a new one if there is none. */
label = prev_nonnote_insn (insn);
if (label == 0 || !LABEL_P (label))
{
rtx prev = PREV_INSN (insn);
label = gen_label_rtx ();
emit_label_after (label, prev);
LABEL_NUSES (label) = 0;
}
return label;
}
/* Return the label after INSN, or put a new label there. */
rtx
get_label_after (rtx insn)
{
rtx label;
/* Find an existing label at this point
or make a new one if there is none. */
label = next_nonnote_insn (insn);
if (label == 0 || !LABEL_P (label))
{
label = gen_label_rtx ();
emit_label_after (label, insn);
LABEL_NUSES (label) = 0;
}
return label;
}
/* Given a comparison (CODE ARG0 ARG1), inside an insn, INSN, return a code
of reversed comparison if it is possible to do so. Otherwise return UNKNOWN.
UNKNOWN may be returned in case we are having CC_MODE compare and we don't
@ -1000,61 +958,6 @@ sets_cc0_p (rtx x)
return 0;
}
#endif
/* Follow any unconditional jump at LABEL;
return the ultimate label reached by any such chain of jumps.
Return null 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.
If RELOAD_COMPLETED is 0, we do not chain across a USE or CLOBBER. */
rtx
follow_jumps (rtx label)
{
rtx insn;
rtx next;
rtx value = label;
int depth;
for (depth = 0;
(depth < 10
&& (insn = next_active_insn (value)) != 0
&& JUMP_P (insn)
&& ((JUMP_LABEL (insn) != 0 && any_uncondjump_p (insn)
&& onlyjump_p (insn))
|| GET_CODE (PATTERN (insn)) == RETURN)
&& (next = NEXT_INSN (insn))
&& BARRIER_P (next));
depth++)
{
rtx tem;
if (!reload_completed && flag_test_coverage)
{
/* ??? Optional. Disables some optimizations, but makes
gcov output more accurate with -O. */
for (tem = value; tem != insn; tem = NEXT_INSN (tem))
if (NOTE_P (tem) && NOTE_LINE_NUMBER (tem) > 0)
return value;
}
/* If we have found a cycle, make the insn jump to itself. */
if (JUMP_LABEL (insn) == label)
return label;
tem = next_active_insn (JUMP_LABEL (insn));
if (tem && (GET_CODE (PATTERN (tem)) == ADDR_VEC
|| GET_CODE (PATTERN (tem)) == ADDR_DIFF_VEC))
break;
value = JUMP_LABEL (insn);
}
if (depth == 10)
return label;
return value;
}
/* Find all CODE_LABELs referred to in X, and increment their use counts.
If INSN is a JUMP_INSN and there is at least one CODE_LABEL referenced
@ -1169,192 +1072,6 @@ mark_jump_label (rtx x, rtx insn, int in_mem)
}
}
/* If all INSN does is set the pc, delete it,
and delete the insn that set the condition codes for it
if that's what the previous thing was. */
void
delete_jump (rtx insn)
{
rtx set = single_set (insn);
if (set && GET_CODE (SET_DEST (set)) == PC)
delete_computation (insn);
}
/* Recursively delete prior insns that compute the value (used only by INSN
which the caller is deleting) stored in the register mentioned by NOTE
which is a REG_DEAD note associated with INSN. */
static void
delete_prior_computation (rtx note, rtx insn)
{
rtx our_prev;
rtx reg = XEXP (note, 0);
for (our_prev = prev_nonnote_insn (insn);
our_prev && (NONJUMP_INSN_P (our_prev)
|| CALL_P (our_prev));
our_prev = prev_nonnote_insn (our_prev))
{
rtx pat = PATTERN (our_prev);
/* If we reach a CALL which is not calling a const function
or the callee pops the arguments, then give up. */
if (CALL_P (our_prev)
&& (! CONST_OR_PURE_CALL_P (our_prev)
|| GET_CODE (pat) != SET || GET_CODE (SET_SRC (pat)) != CALL))
break;
/* If we reach a SEQUENCE, it is too complex to try to
do anything with it, so give up. We can be run during
and after reorg, so SEQUENCE rtl can legitimately show
up here. */
if (GET_CODE (pat) == SEQUENCE)
break;
if (GET_CODE (pat) == USE
&& NONJUMP_INSN_P (XEXP (pat, 0)))
/* reorg creates USEs that look like this. We leave them
alone because reorg needs them for its own purposes. */
break;
if (reg_set_p (reg, pat))
{
if (side_effects_p (pat) && !CALL_P (our_prev))
break;
if (GET_CODE (pat) == PARALLEL)
{
/* If we find a SET of something else, we can't
delete the insn. */
int i;
for (i = 0; i < XVECLEN (pat, 0); i++)
{
rtx part = XVECEXP (pat, 0, i);
if (GET_CODE (part) == SET
&& SET_DEST (part) != reg)
break;
}
if (i == XVECLEN (pat, 0))
delete_computation (our_prev);
}
else if (GET_CODE (pat) == SET
&& REG_P (SET_DEST (pat)))
{
int dest_regno = REGNO (SET_DEST (pat));
int dest_endregno
= (dest_regno
+ (dest_regno < FIRST_PSEUDO_REGISTER
? hard_regno_nregs[dest_regno]
[GET_MODE (SET_DEST (pat))] : 1));
int regno = REGNO (reg);
int endregno
= (regno
+ (regno < FIRST_PSEUDO_REGISTER
? hard_regno_nregs[regno][GET_MODE (reg)] : 1));
if (dest_regno >= regno
&& dest_endregno <= endregno)
delete_computation (our_prev);
/* We may have a multi-word hard register and some, but not
all, of the words of the register are needed in subsequent
insns. Write REG_UNUSED notes for those parts that were not
needed. */
else if (dest_regno <= regno
&& dest_endregno >= endregno)
{
int i;
REG_NOTES (our_prev)
= gen_rtx_EXPR_LIST (REG_UNUSED, reg,
REG_NOTES (our_prev));
for (i = dest_regno; i < dest_endregno; i++)
if (! find_regno_note (our_prev, REG_UNUSED, i))
break;
if (i == dest_endregno)
delete_computation (our_prev);
}
}
break;
}
/* If PAT references the register that dies here, it is an
additional use. Hence any prior SET isn't dead. However, this
insn becomes the new place for the REG_DEAD note. */
if (reg_overlap_mentioned_p (reg, pat))
{
XEXP (note, 1) = REG_NOTES (our_prev);
REG_NOTES (our_prev) = note;
break;
}
}
}
/* Delete INSN and recursively delete insns that compute values used only
by INSN. This uses the REG_DEAD notes computed during flow analysis.
If we are running before flow.c, we need do nothing since flow.c will
delete dead code. We also can't know if the registers being used are
dead or not at this point.
Otherwise, look at all our REG_DEAD notes. If a previous insn does
nothing other than set a register that dies in this insn, we can delete
that insn as well.
On machines with CC0, if CC0 is used in this insn, we may be able to
delete the insn that set it. */
static void
delete_computation (rtx insn)
{
rtx note, next;
#ifdef HAVE_cc0
if (reg_referenced_p (cc0_rtx, PATTERN (insn)))
{
rtx prev = prev_nonnote_insn (insn);
/* We assume that at this stage
CC's are always set explicitly
and always immediately before the jump that
will use them. So if the previous insn
exists to set the CC's, delete it
(unless it performs auto-increments, etc.). */
if (prev && NONJUMP_INSN_P (prev)
&& sets_cc0_p (PATTERN (prev)))
{
if (sets_cc0_p (PATTERN (prev)) > 0
&& ! side_effects_p (PATTERN (prev)))
delete_computation (prev);
else
/* Otherwise, show that cc0 won't be used. */
REG_NOTES (prev) = gen_rtx_EXPR_LIST (REG_UNUSED,
cc0_rtx, REG_NOTES (prev));
}
}
#endif
for (note = REG_NOTES (insn); note; note = next)
{
next = XEXP (note, 1);
if (REG_NOTE_KIND (note) != REG_DEAD
/* Verify that the REG_NOTE is legitimate. */
|| !REG_P (XEXP (note, 0)))
continue;
delete_prior_computation (note, insn);
}
delete_related_insns (insn);
}
/* Delete insn INSN from the chain of insns and update label ref counts
and delete insns now unreachable.

256
gcc/reorg.c
View file

@ -1972,6 +1972,28 @@ update_reg_unused_notes (rtx insn, rtx redundant_insn)
}
}
/* Return the label before INSN, or put a new label there. */
static rtx
get_label_before (rtx insn)
{
rtx label;
/* Find an existing label at this point
or make a new one if there is none. */
label = prev_nonnote_insn (insn);
if (label == 0 || !LABEL_P (label))
{
rtx prev = PREV_INSN (insn);
label = gen_label_rtx ();
emit_label_after (label, prev);
LABEL_NUSES (label) = 0;
}
return label;
}
/* Scan a function looking for insns that need a delay slot and find insns to
put into the delay slot.
@ -2468,6 +2490,50 @@ fill_simple_delay_slots (int non_jumps_p)
#endif
}
/* Follow any unconditional jump at LABEL;
return the ultimate label reached by any such chain of jumps.
Return null 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. */
static rtx
follow_jumps (rtx label)
{
rtx insn;
rtx next;
rtx value = label;
int depth;
for (depth = 0;
(depth < 10
&& (insn = next_active_insn (value)) != 0
&& JUMP_P (insn)
&& ((JUMP_LABEL (insn) != 0 && any_uncondjump_p (insn)
&& onlyjump_p (insn))
|| GET_CODE (PATTERN (insn)) == RETURN)
&& (next = NEXT_INSN (insn))
&& BARRIER_P (next));
depth++)
{
rtx tem;
/* If we have found a cycle, make the insn jump to itself. */
if (JUMP_LABEL (insn) == label)
return label;
tem = next_active_insn (JUMP_LABEL (insn));
if (tem && (GET_CODE (PATTERN (tem)) == ADDR_VEC
|| GET_CODE (PATTERN (tem)) == ADDR_DIFF_VEC))
break;
value = JUMP_LABEL (insn);
}
if (depth == 10)
return label;
return value;
}
/* Try to find insns to place in delay slots.
INSN is the jump needing SLOTS_TO_FILL delay slots. It tests CONDITION
@ -3036,6 +3102,196 @@ fill_eager_delay_slots (void)
note_delay_statistics (slots_filled, 1);
}
}
static void delete_computation (rtx insn);
/* Recursively delete prior insns that compute the value (used only by INSN
which the caller is deleting) stored in the register mentioned by NOTE
which is a REG_DEAD note associated with INSN. */
static void
delete_prior_computation (rtx note, rtx insn)
{
rtx our_prev;
rtx reg = XEXP (note, 0);
for (our_prev = prev_nonnote_insn (insn);
our_prev && (NONJUMP_INSN_P (our_prev)
|| CALL_P (our_prev));
our_prev = prev_nonnote_insn (our_prev))
{
rtx pat = PATTERN (our_prev);
/* If we reach a CALL which is not calling a const function
or the callee pops the arguments, then give up. */
if (CALL_P (our_prev)
&& (! CONST_OR_PURE_CALL_P (our_prev)
|| GET_CODE (pat) != SET || GET_CODE (SET_SRC (pat)) != CALL))
break;
/* If we reach a SEQUENCE, it is too complex to try to
do anything with it, so give up. We can be run during
and after reorg, so SEQUENCE rtl can legitimately show
up here. */
if (GET_CODE (pat) == SEQUENCE)
break;
if (GET_CODE (pat) == USE
&& NONJUMP_INSN_P (XEXP (pat, 0)))
/* reorg creates USEs that look like this. We leave them
alone because reorg needs them for its own purposes. */
break;
if (reg_set_p (reg, pat))
{
if (side_effects_p (pat) && !CALL_P (our_prev))
break;
if (GET_CODE (pat) == PARALLEL)
{
/* If we find a SET of something else, we can't
delete the insn. */
int i;
for (i = 0; i < XVECLEN (pat, 0); i++)
{
rtx part = XVECEXP (pat, 0, i);
if (GET_CODE (part) == SET
&& SET_DEST (part) != reg)
break;
}
if (i == XVECLEN (pat, 0))
delete_computation (our_prev);
}
else if (GET_CODE (pat) == SET
&& REG_P (SET_DEST (pat)))
{
int dest_regno = REGNO (SET_DEST (pat));
int dest_endregno
= (dest_regno
+ (dest_regno < FIRST_PSEUDO_REGISTER
? hard_regno_nregs[dest_regno]
[GET_MODE (SET_DEST (pat))] : 1));
int regno = REGNO (reg);
int endregno
= (regno
+ (regno < FIRST_PSEUDO_REGISTER
? hard_regno_nregs[regno][GET_MODE (reg)] : 1));
if (dest_regno >= regno
&& dest_endregno <= endregno)
delete_computation (our_prev);
/* We may have a multi-word hard register and some, but not
all, of the words of the register are needed in subsequent
insns. Write REG_UNUSED notes for those parts that were not
needed. */
else if (dest_regno <= regno
&& dest_endregno >= endregno)
{
int i;
REG_NOTES (our_prev)
= gen_rtx_EXPR_LIST (REG_UNUSED, reg,
REG_NOTES (our_prev));
for (i = dest_regno; i < dest_endregno; i++)
if (! find_regno_note (our_prev, REG_UNUSED, i))
break;
if (i == dest_endregno)
delete_computation (our_prev);
}
}
break;
}
/* If PAT references the register that dies here, it is an
additional use. Hence any prior SET isn't dead. However, this
insn becomes the new place for the REG_DEAD note. */
if (reg_overlap_mentioned_p (reg, pat))
{
XEXP (note, 1) = REG_NOTES (our_prev);
REG_NOTES (our_prev) = note;
break;
}
}
}
/* Delete INSN and recursively delete insns that compute values used only
by INSN. This uses the REG_DEAD notes computed during flow analysis.
If we are running before flow.c, we need do nothing since flow.c will
delete dead code. We also can't know if the registers being used are
dead or not at this point.
Otherwise, look at all our REG_DEAD notes. If a previous insn does
nothing other than set a register that dies in this insn, we can delete
that insn as well.
On machines with CC0, if CC0 is used in this insn, we may be able to
delete the insn that set it. */
static void
delete_computation (rtx insn)
{
rtx note, next;
#ifdef HAVE_cc0
if (reg_referenced_p (cc0_rtx, PATTERN (insn)))
{
rtx prev = prev_nonnote_insn (insn);
/* We assume that at this stage
CC's are always set explicitly
and always immediately before the jump that
will use them. So if the previous insn
exists to set the CC's, delete it
(unless it performs auto-increments, etc.). */
if (prev && NONJUMP_INSN_P (prev)
&& sets_cc0_p (PATTERN (prev)))
{
if (sets_cc0_p (PATTERN (prev)) > 0
&& ! side_effects_p (PATTERN (prev)))
delete_computation (prev);
else
/* Otherwise, show that cc0 won't be used. */
REG_NOTES (prev) = gen_rtx_EXPR_LIST (REG_UNUSED,
cc0_rtx, REG_NOTES (prev));
}
}
#endif
for (note = REG_NOTES (insn); note; note = next)
{
next = XEXP (note, 1);
if (REG_NOTE_KIND (note) != REG_DEAD
/* Verify that the REG_NOTE is legitimate. */
|| !REG_P (XEXP (note, 0)))
continue;
delete_prior_computation (note, insn);
}
delete_related_insns (insn);
}
/* If all INSN does is set the pc, delete it,
and delete the insn that set the condition codes for it
if that's what the previous thing was. */
static void
delete_jump (rtx insn)
{
rtx set = single_set (insn);
if (set && GET_CODE (SET_DEST (set)) == PC)
delete_computation (insn);
}
/* Once we have tried two ways to fill a delay slot, make a pass over the
code to try to improve the results and to do such things as more jump

4
gcc/rtl.h
View file

@ -1598,10 +1598,6 @@ extern unsigned int cleanup_barriers (void);
/* In jump.c */
extern bool squeeze_notes (rtx *, rtx *);
extern rtx delete_related_insns (rtx);
extern void delete_jump (rtx);
extern rtx get_label_before (rtx);
extern rtx get_label_after (rtx);
extern rtx follow_jumps (rtx);
/* In recog.c */
extern rtx *find_constant_term_loc (rtx *);