(reposition_prologue_and_epilogue_notes): Allow

for zero length prologue and epilogue list.

From-SVN: r3465

gcc/function.c

@@ -4750,7 +4750,8 @@ reposition_prologue_and_epilogue_notes (f)
 	     reorg has run.  */
 	  for (len = 0; prologue[len]; len++)
 	    ;
-	  for (insn = f; insn; insn = NEXT_INSN (insn))
+	  for (insn = f; len && insn; insn = NEXT_INSN (insn))
+	    {
 	      if (GET_CODE (insn) == NOTE)
 		{
 		  if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PROLOGUE_END)
@@ -4761,10 +4762,12 @@ reposition_prologue_and_epilogue_notes (f)
 		  /* Find the prologue-end note if we haven't already, and
 		     move it to just after the last prologue insn.  */
 		  if (note == 0)
+		    {
 		      for (note = insn; note = NEXT_INSN (note);)
 			if (GET_CODE (note) == NOTE
 			    && NOTE_LINE_NUMBER (note) == NOTE_INSN_PROLOGUE_END)
 			  break;
+		    }
 		  next = NEXT_INSN (note);
 		  prev = PREV_INSN (note);
 		  if (prev)
@@ -4772,7 +4775,7 @@ reposition_prologue_and_epilogue_notes (f)
 		  if (next)
 		    PREV_INSN (next) = prev;
 		  add_insn_after (note, insn);
-		break;
+		}
 	    }
 	}
 
@@ -4785,7 +4788,8 @@ reposition_prologue_and_epilogue_notes (f)
 	     reorg has run.  */
 	  for (len = 0; epilogue[len]; len++)
 	    ;
-	  for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
+	  for (insn = get_last_insn (); len && insn; insn = PREV_INSN (insn))
+	    {
 	      if (GET_CODE (insn) == NOTE)
 		{
 		  if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EPILOGUE_BEG)
@@ -4796,10 +4800,12 @@ reposition_prologue_and_epilogue_notes (f)
 		  /* Find the epilogue-begin note if we haven't already, and
 		     move it to just before the first epilogue insn.  */
 		  if (note == 0)
+		    {
 		      for (note = insn; note = PREV_INSN (note);)
 			if (GET_CODE (note) == NOTE
 			    && NOTE_LINE_NUMBER (note) == NOTE_INSN_EPILOGUE_BEG)
 			  break;
+		    }
 		  next = NEXT_INSN (note);
 		  prev = PREV_INSN (note);
 		  if (prev)
@@ -4807,7 +4813,7 @@ reposition_prologue_and_epilogue_notes (f)
 		  if (next)
 		    PREV_INSN (next) = prev;
 		  add_insn_after (note, PREV_INSN (insn));
-		break;
+		}
 	    }
 	}
     }