Put phi nodes after NOTE_INSN_BASIC_BLOCK.

	* rtl.h (NOTE_INSN_BASIC_BLOCK_P): New macro.
	* bb-reorder.c (get_next_bb_note): Use NOTE_INSN_BASIC_BLOCK_P.
	(get_prev_bb_note): Likewise.
	(remove_scope_notes): Likewise.
	* flow.c (commit_one_edge_insertion): Likewise.
	(merge_blocks_nomove): Likewise.
	(verify_flow_info): Likewise.
	* gcse.c (insert_insn_end_bb): Likewise.
	* reg-stack.c (emit_swap_insn): Likewise.
	* ssa.c (first_insn_after_basic_block_note): New function.
	(insert_phi_node): Use it.
	(rename_block): Likewise.
	(eliminate_phi): Likewise.
	(make_regs_equivalent_over_bad_edges): Likewise.
	(make_equivalent_phi_alternatives_equivalent): Likewise.
	(for_each_successor_phi): Likewise.
	(convert_from_ssa): Modify phi-node deletion algorithm.

From-SVN: r35296

gcc/bb-reorder.c

@@ -777,8 +777,7 @@ get_next_bb_note (x)
 {
   while (x)
     {
-      if (GET_CODE (x) == NOTE
-	  && NOTE_LINE_NUMBER (x) == NOTE_INSN_BASIC_BLOCK)
+      if (NOTE_INSN_BASIC_BLOCK_P (x))
 	return x;
       x = NEXT_INSN (x);
     }
@@ -792,8 +791,7 @@ get_prev_bb_note (x)
 {
   while (x)
     {
-      if (GET_CODE (x) == NOTE
-	  && NOTE_LINE_NUMBER (x) == NOTE_INSN_BASIC_BLOCK)
+      if (NOTE_INSN_BASIC_BLOCK_P (x))
 	return x;
       x = PREV_INSN (x);
     }
@@ -1050,8 +1048,7 @@ remove_scope_notes ()
   for (x = get_insns (); x; x = next)
     {
       next = NEXT_INSN (x);
-      if (GET_CODE (x) == NOTE
-	  && NOTE_LINE_NUMBER (x) == NOTE_INSN_BASIC_BLOCK)
+      if (NOTE_INSN_BASIC_BLOCK_P (x))
 	currbb = NOTE_BASIC_BLOCK (x);
 
       if (GET_CODE (x) == NOTE

gcc/flow.c

@@ -1673,8 +1673,7 @@ commit_one_edge_insertion (e)
       tmp = bb->head;
       if (GET_CODE (tmp) == CODE_LABEL)
 	tmp = NEXT_INSN (tmp);
-      if (GET_CODE (tmp) == NOTE
-	  && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_BASIC_BLOCK)
+      if (NOTE_INSN_BASIC_BLOCK_P (tmp))
 	tmp = NEXT_INSN (tmp);
       if (tmp == bb->head)
 	before = tmp;
@@ -2164,8 +2163,7 @@ merge_blocks_nomove (a, b)
     }
 
   /* Delete the basic block note.  */
-  if (GET_CODE (b_head) == NOTE 
-      && NOTE_LINE_NUMBER (b_head) == NOTE_INSN_BASIC_BLOCK)
+  if (NOTE_INSN_BASIC_BLOCK_P (b_head))
     {
       if (b_head == b_end)
 	b_empty = 1;
@@ -6471,9 +6469,7 @@ verify_flow_info ()
 	    }
 	  x = NEXT_INSN (x);
 	}
-      if (GET_CODE (x) != NOTE
-	  || NOTE_LINE_NUMBER (x) != NOTE_INSN_BASIC_BLOCK
-	  || NOTE_BASIC_BLOCK (x) != bb)
+      if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb)
 	{
 	  error ("NOTE_INSN_BASIC_BLOCK is missing for block %d\n",
 		 bb->index);
@@ -6489,8 +6485,7 @@ verify_flow_info ()
 	  x = NEXT_INSN (x);
 	  while (x)
 	    {
-	      if (GET_CODE (x) == NOTE
-		  && NOTE_LINE_NUMBER (x) == NOTE_INSN_BASIC_BLOCK)
+	      if (NOTE_INSN_BASIC_BLOCK_P (x))
 		{
 		  error ("NOTE_INSN_BASIC_BLOCK %d in the middle of basic block %d",
 			 INSN_UID (x), bb->index);
@@ -6518,8 +6513,7 @@ verify_flow_info ()
   x = rtx_first;
   while (x)
     {
-      if (GET_CODE (x) == NOTE
-	  && NOTE_LINE_NUMBER (x) == NOTE_INSN_BASIC_BLOCK)
+      if (NOTE_INSN_BASIC_BLOCK_P (x))
 	{
 	  basic_block bb = NOTE_BASIC_BLOCK (x);
 	  num_bb_notes++;

gcc/gcse.c

@@ -4331,8 +4331,7 @@ insert_insn_end_bb (expr, bb, pre)
 	 the insn in the wrong basic block.  In that case, put the insn
 	 after the CODE_LABEL.  Also, respect NOTE_INSN_BASIC_BLOCK.  */
       while (GET_CODE (insn) == CODE_LABEL
-	     || (GET_CODE (insn) == NOTE
-		 && NOTE_LINE_NUMBER (insn) == NOTE_INSN_BASIC_BLOCK))
+	     || NOTE_INSN_BASIC_BLOCK_P (insn))
 	insn = NEXT_INSN (insn);
 
       new_insn = emit_block_insn_before (pat, insn, BASIC_BLOCK (bb));

gcc/reg-stack.c

@@ -978,8 +978,7 @@ emit_swap_insn (insn, regstack, reg)
       while (tmp != limit)
 	{
 	  if (GET_CODE (tmp) == CODE_LABEL
-	      || (GET_CODE (tmp) == NOTE
-		  && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_BASIC_BLOCK)
+	      || NOTE_INSN_BASIC_BLOCK_P (tmp)
 	      || (GET_CODE (tmp) == INSN
 		  && stack_regs_mentioned (tmp)))
 	    {

gcc/rtl.h

@@ -565,6 +565,11 @@ extern const char * const reg_note_name[];
    Other kinds of NOTEs are identified by negative numbers here.  */
 #define NOTE_LINE_NUMBER(INSN) XCINT(INSN, 4, NOTE)
 
+/* Nonzero if INSN is a note marking the beginning of a basic block.  */
+#define NOTE_INSN_BASIC_BLOCK_P(INSN) 			\
+  (GET_CODE (INSN) == NOTE				\
+   && NOTE_LINE_NUMBER (INSN) == NOTE_INSN_BASIC_BLOCK)
+
 /* Codes that appear in the NOTE_LINE_NUMBER field
    for kinds of notes that are not line numbers.
 

gcc/ssa.c

@@ -98,6 +98,8 @@ struct rename_context;
 static inline rtx * phi_alternative
   PARAMS ((rtx, int));
 
+static rtx first_insn_after_basic_block_note PARAMS ((basic_block));
+
 static int remove_phi_alternative
   PARAMS ((rtx, int));
 static void simplify_to_immediate_dominators 
@@ -449,6 +451,28 @@ compute_iterated_dominance_frontiers (idfs, frontiers, evals, nregs)
     }
 }
 
+/* Return the INSN immediately following the NOTE_INSN_BASIC_BLOCK
+   note associated with the BLOCK.  */
+
+static rtx
+first_insn_after_basic_block_note (block)
+     basic_block block;
+{
+  rtx insn;
+
+  /* Get the first instruction in the block.  */
+  insn = block->head;
+
+  if (insn == NULL_RTX)
+    return NULL_RTX;
+  if (GET_CODE (insn) == CODE_LABEL)
+    insn = NEXT_INSN (insn);
+  if (!NOTE_INSN_BASIC_BLOCK_P (insn))
+    abort ();
+
+  return NEXT_INSN (insn);
+}
+
 
 /* Insert the phi nodes.  */
 
@@ -461,6 +485,8 @@ insert_phi_node (regno, bb)
   int npred, i;
   rtvec vec;
   rtx phi, reg;
+  rtx insn;
+  int end_p;
 
   /* Find out how many predecessors there are.  */
   for (e = b->pred, npred = 0; e; e = e->pred_next)
@@ -488,10 +514,11 @@ insert_phi_node (regno, bb)
   phi = gen_rtx_PHI (VOIDmode, vec);
   phi = gen_rtx_SET (VOIDmode, reg, phi);
 
-  if (GET_CODE (b->head) == CODE_LABEL)
-    emit_insn_after (phi, b->head);
-  else
-    b->head = emit_insn_before (phi, b->head);
+  insn = first_insn_after_basic_block_note (b);
+  end_p = PREV_INSN (insn) == b->end;
+  emit_insn_before (phi, insn);
+  if (end_p)
+    b->end = PREV_INSN (insn);
 }
 
 
@@ -811,9 +838,7 @@ rename_block (bb, idom)
       if (e->dest == EXIT_BLOCK_PTR)
 	continue;
 
-      insn = e->dest->head;
-      if (GET_CODE (insn) == CODE_LABEL)
-	insn = NEXT_INSN (insn);
+      insn = first_insn_after_basic_block_note (e->dest);
 
       while (PHI_NODE_P (insn))
 	{
@@ -1145,9 +1170,7 @@ eliminate_phi (e, reg_partition)
 
   /* Collect an upper bound on the number of registers needing processing.  */
 
-  insn = e->dest->head;
-  if (GET_CODE (insn) == CODE_LABEL)
-    insn = next_nonnote_insn (insn);
+  insn = first_insn_after_basic_block_note (e->dest);
 
   n_nodes = 0;
   while (PHI_NODE_P (insn))
@@ -1171,9 +1194,7 @@ eliminate_phi (e, reg_partition)
   sbitmap_vector_zero (pred, n_nodes);
   sbitmap_vector_zero (succ, n_nodes);
 
-  insn = e->dest->head;
-  if (GET_CODE (insn) == CODE_LABEL)
-    insn = next_nonnote_insn (insn);
+  insn = first_insn_after_basic_block_note (e->dest);
 
   n_nodes = 0;
   for (; PHI_NODE_P (insn); insn = next_nonnote_insn (insn))
@@ -1271,11 +1292,10 @@ make_regs_equivalent_over_bad_edges (bb, reg_partition)
 {
   int changed = 0;
   basic_block b = BASIC_BLOCK (bb);
-  rtx phi = b->head;
+  rtx phi;
 
   /* Advance to the first phi node.  */
-  if (GET_CODE (phi) == CODE_LABEL)
-    phi = next_nonnote_insn (phi);
+  phi = first_insn_after_basic_block_note (b);
 
   /* Scan all the phi nodes.  */
   for (; 
@@ -1341,12 +1361,11 @@ make_equivalent_phi_alternatives_equivalent (bb, reg_partition)
      partition reg_partition;
 {
   int changed = 0;
-  rtx phi = BLOCK_HEAD (bb);
   basic_block b = BASIC_BLOCK (bb);
+  rtx phi;
 
   /* Advance to the first phi node.  */
-  if (GET_CODE (phi) == CODE_LABEL)
-    phi = next_nonnote_insn (phi);
+  phi = first_insn_after_basic_block_note (b);
 
   /* Scan all the phi nodes.  */
   for (; 
@@ -1889,23 +1908,27 @@ convert_from_ssa()
   for (bb = n_basic_blocks; --bb >= 0; )
     {
       rtx insn = BLOCK_HEAD (bb);
-      int start = (GET_CODE (insn) != CODE_LABEL);
 
-      if (! start)
-	insn = next_nonnote_insn (insn);
-      while (PHI_NODE_P (insn))
+      while (1)
 	{
-	  /* If a phi node is the last insn in the block, there must
-	     have been nothing else.  Set the block end to the block
-	     head.  */
-	  if (insn == BLOCK_END (bb))
-	    BLOCK_END (bb) = BLOCK_HEAD (bb);
-	  insn = delete_insn (insn);
-	  if (GET_CODE (insn) == NOTE)
-	    insn = next_nonnote_insn (insn);
+	  /* If this is a PHI node delete it.  */
+	  if (PHI_NODE_P (insn))
+	    {
+	      if (insn == BLOCK_END (bb))
+		BLOCK_END (bb) = PREV_INSN (insn);
+	      insn = delete_insn (insn);
+	    }
+	  /* Since all the phi nodes come at the beginning of the
+	     block, if we find an ordinary insn, we can stop looking
+	     for more phi nodes.  */
+	  else if (INSN_P (insn))
+	    break;
+	  /* If we've reached the end of the block, stop.  */
+	  else if (insn == BLOCK_END (bb))
+	    break;
+	  else 
+	    insn = NEXT_INSN (insn);
 	}
-      if (start)
-	BLOCK_HEAD (bb) = insn;
     }
 
   /* Commit all the copy nodes needed to convert out of SSA form.  */
@@ -1947,11 +1970,7 @@ for_each_successor_phi (bb, fn, data)
 	continue;
 
       /* Advance to the first non-label insn of the successor block.  */
-      insn = successor->head;
-      while (insn != NULL 
-	     && (GET_CODE (insn) == CODE_LABEL
-		 || GET_CODE (insn) == NOTE))
-	insn = NEXT_INSN (insn);
+      insn = first_insn_after_basic_block_note (successor);
 
       if (insn == NULL)
 	continue;