static void init_label_info (rtx);
static void mark_all_labels (rtx);
-static void delete_computation (rtx);
static void redirect_exp_1 (rtx *, rtx, rtx, rtx);
static int invert_exp_1 (rtx, rtx);
static int returnjump_p_1 (rtx *, void *);
-static void delete_prior_computation (rtx, rtx);
\f
/* Alternate entry into the jump optimizer. This entry point only rebuilds
the JUMP_LABEL field in jumping insns and REG_LABEL notes in non-jumping
return false;
}
\f
-/* 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;
-}
-\f
/* 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
}
#endif
\f
-/* 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;
-}
-
-\f
/* 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
in INSN, then store one of them in JUMP_LABEL (INSN).
in_mem = 1;
break;
+ case SEQUENCE:
+ for (i = 0; i < XVECLEN (x, 0); i++)
+ mark_jump_label (PATTERN (XVECEXP (x, 0, i)),
+ XVECEXP (x, 0, i), 0);
+ return;
+
case SYMBOL_REF:
if (!in_mem)
return;
}
}
-/* 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);
-}
\f
/* Delete insn INSN from the chain of insns and update label ref counts
and delete insns now unreachable.
while (next)
{
code = GET_CODE (next);
- if (code == NOTE
- && NOTE_LINE_NUMBER (next) != NOTE_INSN_FUNCTION_END)
+ if (code == NOTE)
next = NEXT_INSN (next);
/* Keep going past other deleted labels to delete what follows. */
else if (code == CODE_LABEL && INSN_DELETED_P (next))
}
/* Fix up JUMP_LABEL and label ref counts after OLABEL has been replaced with
- NLABEL in JUMP. If DELETE_UNUSED is non-negative, copy a
- NOTE_INSN_FUNCTION_END found after OLABEL to the place after NLABEL.
+ NLABEL in JUMP.
If DELETE_UNUSED is positive, delete related insn to OLABEL if its ref
count has dropped to zero. */
void
{
rtx note;
+ /* Negative DELETE_UNUSED used to be used to signalize behavior on
+ moving FUNCTION_END note. Just sanity check that no user still worry
+ about this. */
+ gcc_assert (delete_unused >= 0);
JUMP_LABEL (jump) = nlabel;
if (nlabel)
++LABEL_NUSES (nlabel);
}
}
- /* If we're eliding the jump over exception cleanups at the end of a
- function, move the function end note so that -Wreturn-type works. */
- if (olabel && nlabel
- && NEXT_INSN (olabel)
- && NOTE_P (NEXT_INSN (olabel))
- && NOTE_LINE_NUMBER (NEXT_INSN (olabel)) == NOTE_INSN_FUNCTION_END
- && delete_unused >= 0)
- emit_note_after (NOTE_INSN_FUNCTION_END, nlabel);
-
if (olabel && --LABEL_NUSES (olabel) == 0 && delete_unused > 0
/* Undefined labels will remain outside the insn stream. */
&& INSN_UID (olabel))
if (GET_CODE (x) == SUBREG)
{
int base = true_regnum (SUBREG_REG (x));
- if (base >= 0 && base < FIRST_PSEUDO_REGISTER)
+ if (base >= 0
+ && base < FIRST_PSEUDO_REGISTER
+ && subreg_offset_representable_p (REGNO (SUBREG_REG (x)),
+ GET_MODE (SUBREG_REG (x)),
+ SUBREG_BYTE (x), GET_MODE (x)))
return base + subreg_regno_offset (REGNO (SUBREG_REG (x)),
GET_MODE (SUBREG_REG (x)),
SUBREG_BYTE (x), GET_MODE (x));
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