contrib/gcc/jump.c

47 #include "insn-config.h"
48 #include "insn-attr.h"
84   rtx insn;
94   for (insn = forced_labels; insn; insn = XEXP (insn, 1))
95     if (LABEL_P (XEXP (insn, 0)))
96       LABEL_NUSES (XEXP (insn, 0))++;
102    non-fallthru insn.  This is not generally true, as multiple barriers
104    real insn by one or more NOTEs.
112   rtx insn, next, prev;
113   for (insn = get_insns (); insn; insn = next)
115       next = NEXT_INSN (insn);
116       if (BARRIER_P (insn))
118 	  prev = prev_nonnote_insn (insn);
120 	    delete_insn (insn);
121 	  else if (prev != PREV_INSN (insn))
122 	    reorder_insns (insn, insn, prev);
149   rtx insn;
155   for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
156     if (NOTE_P (insn))
158 	if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG)
162 	else if (NOTE_LINE_NUMBER (insn) >= 0)
167 		&& NOTE_SOURCE_LOCATION (insn) == NOTE_SOURCE_LOCATION (last_note)
169 		&& NOTE_SOURCE_FILE (insn) == NOTE_SOURCE_FILE (last_note)
170 		&& NOTE_LINE_NUMBER (insn) == NOTE_LINE_NUMBER (last_note)
174 		delete_related_insns (insn);
178 	    last_note = insn;
204    notes whose labels don't occur in the insn any more.  Returns the
209   rtx insn;
211   for (insn = f; insn; insn = NEXT_INSN (insn))
212     if (LABEL_P (insn))
213       LABEL_NUSES (insn) = (LABEL_PRESERVE_P (insn) != 0);
214     else if (JUMP_P (insn))
215       JUMP_LABEL (insn) = 0;
216     else if (NONJUMP_INSN_P (insn) || CALL_P (insn))
220 	for (note = REG_NOTES (insn); note; note = next)
224 		&& ! reg_mentioned_p (XEXP (note, 0), PATTERN (insn)))
225 	      remove_note (insn, note);
236   rtx insn;
238   for (insn = f; insn; insn = NEXT_INSN (insn))
239     if (INSN_P (insn))
241 	mark_jump_label (PATTERN (insn), insn, 0);
242 	if (! INSN_DELETED_P (insn) && JUMP_P (insn))
247 	    if (JUMP_LABEL (insn) == 0)
249 		rtx label_note = find_reg_note (insn, REG_LABEL, NULL_RTX);
257 		    mark_jump_label (label_ref, insn, 0);
259 		    JUMP_LABEL (insn) = XEXP (label_note, 0);
279   rtx insn;
284   for (insn = start; insn != past_end; insn = next)
286       next = NEXT_INSN (insn);
287       if (NOTE_P (insn)
288 	  && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END
289 	      || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG))
292 	  gcc_assert (NOTE_LINE_NUMBER (insn) != NOTE_INSN_BLOCK_BEG
293 		      && NOTE_LINE_NUMBER (insn) != NOTE_INSN_BLOCK_END);
295 	  if (insn == start)
299 	      rtx prev = PREV_INSN (insn);
300 	      PREV_INSN (insn) = PREV_INSN (start);
301 	      NEXT_INSN (insn) = start;
302 	      NEXT_INSN (PREV_INSN (insn)) = insn;
303 	      PREV_INSN (NEXT_INSN (insn)) = insn;
309 	last = insn;
327 get_label_before (rtx insn)
333   label = prev_nonnote_insn (insn);
337       rtx prev = PREV_INSN (insn);
349 get_label_after (rtx insn)
355   label = next_nonnote_insn (insn);
360       emit_label_after (label, insn);
367 /* Given a comparison (CODE ARG0 ARG1), inside an insn, INSN, return a code
374 reversed_comparison_code_parts (enum rtx_code code, rtx arg0, rtx arg1, rtx insn)
436       if (! insn)
439       for (prev = prev_nonnote_insn (insn);
487 reversed_comparison_code (rtx comparison, rtx insn)
493 					 XEXP (comparison, 1), insn);
798 simplejump_p (rtx insn)
800   return (JUMP_P (insn)
801 	  && GET_CODE (PATTERN (insn)) == SET
802 	  && GET_CODE (SET_DEST (PATTERN (insn))) == PC
803 	  && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF);
813 condjump_p (rtx insn)
815   rtx x = PATTERN (insn);
841 condjump_in_parallel_p (rtx insn)
843   rtx x = PATTERN (insn);
872 pc_set (rtx insn)
875   if (!JUMP_P (insn))
877   pat = PATTERN (insn);
879   /* The set is allowed to appear either as the insn pattern or
889 /* Return true when insn is an unconditional direct jump,
893 any_uncondjump_p (rtx insn)
895   rtx x = pc_set (insn);
900   if (find_reg_note (insn, REG_NON_LOCAL_GOTO, NULL_RTX))
905 /* Return true when insn is a conditional jump.  This function works for
913 any_condjump_p (rtx insn)
915   rtx x = pc_set (insn);
933 condjump_label (rtx insn)
935   rtx x = pc_set (insn);
951 /* Return true if INSN is a (possibly conditional) return insn.  */
963 returnjump_p (rtx insn)
965   if (!JUMP_P (insn))
967   return for_each_rtx (&PATTERN (insn), returnjump_p_1, NULL);
974 onlyjump_p (rtx insn)
978   if (!JUMP_P (insn))
981   set = single_set (insn);
1050    since that tells caller to avoid changing the insn.
1057   rtx insn;
1064 	&& (insn = next_active_insn (value)) != 0
1065 	&& JUMP_P (insn)
1066 	&& ((JUMP_LABEL (insn) != 0 && any_uncondjump_p (insn)
1067 	     && onlyjump_p (insn))
1068 	    || GET_CODE (PATTERN (insn)) == RETURN)
1069 	&& (next = NEXT_INSN (insn))
1078 	  for (tem = value; tem != insn; tem = NEXT_INSN (tem))
1083       /* If we have found a cycle, make the insn jump to itself.  */
1084       if (JUMP_LABEL (insn) == label)
1087       tem = next_active_insn (JUMP_LABEL (insn));
1092       value = JUMP_LABEL (insn);
1115 mark_jump_label (rtx x, rtx insn, int in_mem)
1142 	mark_jump_label (get_pool_constant (x), insn, in_mem);
1162 	if (! insn || ! INSN_DELETED_P (insn))
1165 	if (insn)
1167 	    if (JUMP_P (insn))
1168 	      JUMP_LABEL (insn) = label;
1175 		if (! find_reg_note (insn, REG_LABEL, label))
1176 		  REG_NOTES (insn) = gen_rtx_INSN_LIST (REG_LABEL, label,
1177 							REG_NOTES (insn));
1187       if (! INSN_DELETED_P (insn))
1204 	mark_jump_label (XEXP (x, i), insn, in_mem);
1209 	    mark_jump_label (XVECEXP (x, i, j), insn, in_mem);
1215    and delete the insn that set the condition codes for it
1219 delete_jump (rtx insn)
1221   rtx set = single_set (insn);
1224     delete_computation (insn);
1232 delete_prior_computation (rtx note, rtx insn)
1237   for (our_prev = prev_nonnote_insn (insn);
1272 		 delete the insn.  */
1334 	 insn becomes the new place for the REG_DEAD note.  */
1350    Otherwise, look at all our REG_DEAD notes.  If a previous insn does
1351    nothing other than set a register that dies in this insn, we can delete
1352    that insn as well.
1354    On machines with CC0, if CC0 is used in this insn, we may be able to
1355    delete the insn that set it.  */
1358 delete_computation (rtx insn)
1363   if (reg_referenced_p (cc0_rtx, PATTERN (insn)))
1365       rtx prev = prev_nonnote_insn (insn);
1369 	 will use them.  So if the previous insn
1386   for (note = REG_NOTES (insn); note; note = next)
1395       delete_prior_computation (note, insn);
1398   delete_related_insns (insn);
1402 /* Delete insn INSN from the chain of insns and update label ref counts
1405    Returns the first insn after INSN that was not deleted.
1411 delete_related_insns (rtx insn)
1413   int was_code_label = (LABEL_P (insn));
1415   rtx next = NEXT_INSN (insn), prev = PREV_INSN (insn);
1420   /* This insn is already deleted => return first following nondeleted.  */
1421   if (INSN_DELETED_P (insn))
1424   delete_insn (insn);
1435   if (JUMP_P (insn) && JUMP_LABEL (insn))
1437       rtx lab = JUMP_LABEL (insn), lab_next;
1448 	     to find the first insn after INSN that is not now deleted.
1454       else if (tablejump_p (insn, NULL, &lab_next))
1466   if (JUMP_P (insn)
1467       && (GET_CODE (PATTERN (insn)) == ADDR_VEC
1468 	  || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC))
1470       rtx pat = PATTERN (insn);
1483   if (NONJUMP_INSN_P (insn) || CALL_P (insn))
1484     for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
1499       && NEXT_INSN (insn) != 0
1500       && JUMP_P (NEXT_INSN (insn))
1501       && (GET_CODE (PATTERN (NEXT_INSN (insn))) == ADDR_VEC
1502 	  || GET_CODE (PATTERN (NEXT_INSN (insn))) == ADDR_DIFF_VEC))
1503     next = delete_related_insns (NEXT_INSN (insn));
1537    peephole insn that will replace them.  */
1542   rtx insn = from;
1546       rtx next = NEXT_INSN (insn);
1547       rtx prev = PREV_INSN (insn);
1549       if (!NOTE_P (insn))
1551 	  INSN_DELETED_P (insn) = 1;
1553 	  /* Patch this insn out of the chain.  */
1563       if (insn == to)
1565       insn = next;
1579 redirect_exp_1 (rtx *loc, rtx olabel, rtx nlabel, rtx insn)
1596 	  validate_change (insn, loc, n, 1);
1606       if (loc == &PATTERN (insn))
1608       validate_change (insn, loc, x, 1);
1616       validate_change (insn, loc, gen_rtx_RETURN (VOIDmode), 1);
1624 	redirect_exp_1 (&XEXP (x, i), olabel, nlabel, insn);
1629 	    redirect_exp_1 (&XVECEXP (x, i, j), olabel, nlabel, insn);
1658    RETURN insn.
1681    If DELETE_UNUSED is positive, delete related insn to OLABEL if its ref
1715       /* Undefined labels will remain outside the insn stream.  */
1722 /* Invert the jump condition X contained in jump insn INSN.  Accrue the
1725 invert_exp_1 (rtx x, rtx insn)
1740       reversed_code = reversed_comparison_code (comp, insn);
1744 	  validate_change (insn, &XEXP (x, 0),
1753       validate_change (insn, &XEXP (x, 1), XEXP (x, 2), 1);
1754       validate_change (insn, &XEXP (x, 2), tem, 1);