re PR rtl-optimization/56131 (gcc.dg/pr56035.c ICEs gcc on sparc-linux)

2013-02-25  Tom de Vries  <tom@codesourcery.com>

	PR rtl-optimization/56131
	* insn-notes.def (INSN_NOTE_BASIC_BLOCK): Update comment.
	* cfgrtl.c (delete_insn): Don't reorder NOTE_INSN_DELETED_LABEL and
	NOTE_INSN_BASIC_BLOCK if BLOCK_FOR_INSN == NULL.

From-SVN: r196255

gcc/ChangeLog

+2013-02-25  Tom de Vries  <tom@codesourcery.com>
+
+	PR rtl-optimization/56131
+	* insn-notes.def (INSN_NOTE_BASIC_BLOCK): Update comment.
+	* cfgrtl.c (delete_insn): Don't reorder NOTE_INSN_DELETED_LABEL and
+	NOTE_INSN_BASIC_BLOCK if BLOCK_FOR_INSN == NULL.
+
 2013-02-25  Tobias Burnus  <burnus@net-b.de>
 
 	* doc/invoke.texi (-fsanitize=): Move from optimization

gcc/cfgrtl.c

@@ -135,7 +135,7 @@ delete_insn (rtx insn)
       if (! can_delete_label_p (insn))
 	{
 	  const char *name = LABEL_NAME (insn);
-	  basic_block bb, label_bb = BLOCK_FOR_INSN (insn);
+	  basic_block bb = BLOCK_FOR_INSN (insn);
 	  rtx bb_note = NEXT_INSN (insn);
 
 	  really_delete = false;
@@ -144,15 +144,13 @@ delete_insn (rtx insn)
 	  NOTE_DELETED_LABEL_NAME (insn) = name;
 
 	  /* If the note following the label starts a basic block, and the
-	     label is a member of the same basic block, interchange the two.
-	     If the label is not marked with a bb, assume it's the same bb.  */
+	     label is a member of the same basic block, interchange the two.  */
 	  if (bb_note != NULL_RTX
 	      && NOTE_INSN_BASIC_BLOCK_P (bb_note)
-	      && (label_bb == NOTE_BASIC_BLOCK (bb_note)
-		  || label_bb == NULL))
+	      && bb != NULL
+	      && bb == BLOCK_FOR_INSN (bb_note))
 	    {
 	      reorder_insns_nobb (insn, insn, bb_note);
-	      bb = NOTE_BASIC_BLOCK (bb_note);
 	      BB_HEAD (bb) = bb_note;
 	      if (BB_END (bb) == bb_note)
 		BB_END (bb) = insn;

gcc/insn-notes.def

@@ -70,7 +70,9 @@ INSN_NOTE (CALL_ARG_LOCATION)
 
 /* Record the struct for the following basic block.  Uses
    NOTE_BASIC_BLOCK.  FIXME: Redundant with the basic block pointer
-   now included in every insn.  */
+   now included in every insn.  NOTE: If there's no CFG anymore, in other words,
+   if BLOCK_FOR_INSN () == NULL, NOTE_BASIC_BLOCK cannot be considered reliable
+   anymore.  */
 INSN_NOTE (BASIC_BLOCK)
 
 /* Mark the inflection point in the instruction stream where we switch