Divide REG_LABEL notes into REG_LABEL_OPERAND and REG_LABEL_TARGET.

	* doc/rtl.texi (Insns): Specify when a label_ref makes a jump_insn.
	Similar for what label_refs can go in the JUMP_TARGET field.  Split
	REG_LABEL documentation into REG_LABEL_TARGET and REG_LABEL_OPERAND.
	* reload.c (find_reloads): Generate REG_LABEL_OPERAND, not
	REG_LABEL when replacing an operand with a LABEL_REF for a
	non-jump insn.
	(subst_reloads): When replacing a LABEL_REG with a register,
	instead of generating a REG_LABEL note, assert that there already
	is one or that the label is a known target for the insn.
	* rtlanal.c (computed_jump_p): Instead of looking for a REG_LABEL
	note, check the JUMP_LABEL field.  Remove "else" after return.
	* reorg.c (emit_delay_sequence): Replace case for REG_LABEL with
	cases for REG_LABEL_OPERAND and REG_LABEL_TARGET.
	(fill_slots_from_thread): Handle both REG_LABEL_OPERAND and
	REG_LABEL_TARGET notes, including the JUMP_TARGET field on JUMP_P
	insns.  Iterate over all notes; don't assume there's only one.
	* cse.c (recorded_label_ref): Adjust comment to refer to
	REG_LABEL_OPERAND.
	(cse_extended_basic_block): Do LABEL_REF check for all INSN_P
	insns, not just NONJUMP_INSN_P.
	(check_for_label_ref): For JUMP_P insns, check that the LABEL_REF
	isn't a jump target.
	* jump.c (rebuild_jump_labels): Adjust head comment.
	(init_label_info): Ditto.  Remove REG_LABEL_OPERAND notes only;
	don't reset REG_LABEL_TARGET notes, including the JUMP_LABEL field.
	(mark_all_labels): For JUMP_P insns without a target, check if the
	the target is noted on the previous nonjump insn.
	(mark_jump_label_1): New function, guts from mark_jump_label.
	<case IF_THEN_ELSE>: Handle first operand as a non-target when
	marking jump target labels.
	<case LABEL_REF>: Adjust for whether to generate a
	REG_LABEL_TARGET or a REG_LABEL_OPERAND note.
	For 'E' format rtl, iterate in descending element order.
	(delete_related_insns): Handle both REG_LABEL_TARGET and
	REG_LABEL_OPERAND notes.  For JUMP_P insns with labels with zero
	reference count, delete and fallthrough.  Move finding-next-
	non-deleted insn last in the function.  Look at all INSN_P insns
	for REG_LABEL_OPERAND notes.
	(redirect_jump_2): Assert that OLABEL equals the old JUMP_LABEL of
	JUMP.
	* print-rtl.c (print_rtx): For JUMP_P insns and a non-NULL
	JUMP_LABEL, output the INSN_UID of it.
	* gcse.c: Adjust comments as appropriate to say REG_LABEL_OPERAND
	and/or REG_LABEL_TARGET.
	(add_label_notes): Only add REG_LABEL_OPERAND notes.  Put in line
	with jump.c copy by only adding notes for labels actually
	referenced in the insn.
	* emit-rtl.c (try_split): Don't assume only NONJUMP_INSN_P need
	usage count increment; handle all INSN_P trial insns.
	(emit_copy_of_insn_after): Change to not copy REG_LABEL_OPERAND
	notes.
	* rtl.h (struct rtx_def) <volatil>: Adjust to mention
	REG_LABEL_TARGET and REG_LABEL_OPERAND.
	(LABEL_REF_NONLOCAL_P): Allow REG_LABEL_TARGET and
	REG_LABEL_OPERAND.
	* combine.c (distribute_notes): Adjust for REG_LABEL_TARGET on
	JUMP_P insns and REG_LABEL_OPERAND everywhere.
	* sched-rgn.c (is_cfg_nonregular): Check for REG_LABEL_OPERANDS
	on all INSN_P insns.
	* reg-notes.def (LABEL_TARGET, LABEL_OPERAND): Split from LABEL.
	* cfgrtl.c (delete_insn): Adjust to handle REG_LABEL_TARGET and
	REG_LABEL_OPERAND notes.
	* reload1.c (calculate_needs_all_insns): Adjust comments.
	(set_label_offsets): Adjust to look for REG_LABEL_OPERAND notes.
	* config/alpha/alpha.md (split for load of an address into a
	four-insn sequence on Unicos/Mk): Adjust to use
	REG_LABEL_OPERAND.
	* config/sh/sh.md (sh_reorg, final_prescan_insn): Ditto.

From-SVN: r128287

1 files changed, 18 insertions, 18 deletions

diff --git a/gcc/combine.c b/gcc/combine.c
index 133dfbe..319c532 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -12408,7 +12408,8 @@ distribute_notes (rtx notes, rtx from_insn, rtx i3, rtx i2, rtx elim_i2,
 	    }
 	  break;
 
-	case REG_LABEL:
+	case REG_LABEL_TARGET:
+	case REG_LABEL_OPERAND:
 	  /* This can show up in several ways -- either directly in the
 	     pattern, or hidden off in the constant pool with (or without?)
 	     a REG_EQUAL note.  */
@@ -12431,34 +12432,33 @@ distribute_notes (rtx notes, rtx from_insn, rtx i3, rtx i2, rtx elim_i2,
 		place = i2;
 	    }
 
-	  /* Don't attach REG_LABEL note to a JUMP_INSN.  Add
-	     a JUMP_LABEL instead or decrement LABEL_NUSES.  */
-	  if (place && JUMP_P (place))
+	  /* For REG_LABEL_TARGET on a JUMP_P, we prefer to put the note
+	     as a JUMP_LABEL or decrement LABEL_NUSES if it's already
+	     there.  */
+	  if (place && JUMP_P (place)
+	      && REG_NOTE_KIND (note) == REG_LABEL_TARGET
+	      && (JUMP_LABEL (place) == NULL
+		  || JUMP_LABEL (place) == XEXP (note, 0)))
 	    {
 	      rtx label = JUMP_LABEL (place);
 
 	      if (!label)
 		JUMP_LABEL (place) = XEXP (note, 0);
-	      else
-		{
-		  gcc_assert (label == XEXP (note, 0));
-		  if (LABEL_P (label))
-		    LABEL_NUSES (label)--;
-		}
-	      place = 0;
+	      else if (LABEL_P (label))
+		LABEL_NUSES (label)--;
 	    }
-	  if (place2 && JUMP_P (place2))
+
+	  if (place2 && JUMP_P (place2)
+	      && REG_NOTE_KIND (note) == REG_LABEL_TARGET
+	      && (JUMP_LABEL (place2) == NULL
+		  || JUMP_LABEL (place2) == XEXP (note, 0)))
 	    {
 	      rtx label = JUMP_LABEL (place2);
 
 	      if (!label)
 		JUMP_LABEL (place2) = XEXP (note, 0);
-	      else
-		{
-		  gcc_assert (label == XEXP (note, 0));
-		  if (LABEL_P (label))
-		    LABEL_NUSES (label)--;
-		}
+	      else if (LABEL_P (label))
+		LABEL_NUSES (label)--;
 	      place2 = 0;
 	    }
 	  break;