From: Herman A.J. ten Brugge <Haj.Ten.Brugge@net.HCC.nl>
Date: Thu, 7 Sep 2000 15:18:46 +0000 (+0200)
Subject: reorg.c (find_end_label): If the basic block reorder pass moves the return insn to... 
X-Git-Tag: prereleases/libstdc++-2.92~4186
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=bf6302f0e771555388849d8f525a63231cec79f5;p=thirdparty%2Fgcc.git

reorg.c (find_end_label): If the basic block reorder pass moves the return insn to some other place try...


	* reorg.c (find_end_label): If the basic block reorder pass moves the
	return insn to some other place try to locate it again and put our
	end_of_function_label there.
	* reorg.c (relax_delay_slots): Check if find_end_label created a
	new label that invalidates the current optimazation.

From-SVN: r36237
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 186abc4e9cd9..0cbe30760bdc 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2000-09-07 Herman A.J. ten Brugge <Haj.Ten.Brugge@net.HCC.nl>
+
+	* reorg.c (find_end_label): If the basic block reorder pass moves the
+	return insn to some other place try to locate it again and put our
+	end_of_function_label there.
+	* reorg.c (relax_delay_slots): Check if find_end_label created a
+	new label that invalidates the current optimazation.
+
 2000-09-07  Catherine Moore  <clm@redhat.com>
 
         * unroll.c (unroll_loop): Check for unconditional jumps
diff --git a/gcc/reorg.c b/gcc/reorg.c
index 99f24c8bca4d..00cafffe8647 100644
--- a/gcc/reorg.c
+++ b/gcc/reorg.c
@@ -375,22 +375,42 @@ find_end_label ()
     end_of_function_label = insn;
   else
     {
-      /* Otherwise, make a new label and emit a RETURN and BARRIER,
-	 if needed.  */
       end_of_function_label = gen_label_rtx ();
       LABEL_NUSES (end_of_function_label) = 0;
-      emit_label (end_of_function_label);
-#ifdef HAVE_return
-      if (HAVE_return)
+      /* If the basic block reorder pass moves the return insn to
+	 some other place try to locate it again and put our
+	 end_of_function_label there.  */
+      while (insn && ! (GET_CODE (insn) == JUMP_INSN
+		        && (GET_CODE (PATTERN (insn)) == RETURN)))
+	insn = PREV_INSN (insn);
+      if (insn)
 	{
-	  /* The return we make may have delay slots too.  */
-	  rtx insn = gen_return ();
-	  insn = emit_jump_insn (insn);
-	  emit_barrier ();
-          if (num_delay_slots (insn) > 0)
-	    obstack_ptr_grow (&unfilled_slots_obstack, insn);
+	  insn = PREV_INSN (insn);
+
+      	  /* Put the label before an USE insns that may proceed the
+	     RETURN insn.  */
+      	  while (GET_CODE (insn) == USE)
+	    insn = PREV_INSN (insn);
+
+      	  emit_label_after (end_of_function_label, insn);
 	}
+      else
+	{
+          /* Otherwise, make a new label and emit a RETURN and BARRIER,
+	     if needed.  */
+          emit_label (end_of_function_label);
+#ifdef HAVE_return
+          if (HAVE_return)
+	    {
+	      /* The return we make may have delay slots too.  */
+	      rtx insn = gen_return ();
+	      insn = emit_jump_insn (insn);
+	      emit_barrier ();
+              if (num_delay_slots (insn) > 0)
+	        obstack_ptr_grow (&unfilled_slots_obstack, insn);
+	    }
 #endif
+	}
     }
 
   /* Show one additional use for this label so it won't go away until
@@ -3322,7 +3342,9 @@ relax_delay_slots (first)
 	  if (label == 0)
 	    label = find_end_label ();
 
-	  if (redirect_with_delay_slots_safe_p (delay_insn, label, insn))
+	  /* find_end_label can generate a new label. Check this first.  */
+	  if (no_labels_between_p (insn, next)
+	      && redirect_with_delay_slots_safe_p (delay_insn, label, insn))
 	    {
 	      /* Be careful how we do this to avoid deleting code or labels
 		 that are momentarily dead.  See similar optimization in