flow.c (propagate_block_delete_insn): Handle deletion of ADDR_VEC and ADDR_DIFF_VEC insns when...

        * flow.c (propagate_block_delete_insn): Handle deletion of ADDR_VEC
        and ADDR_DIFF_VEC insns when the proceeding CODE_LABEL was put
        into the constant pool.
        * jump.c (jump_optimize_1): Remove barrier successors after all
        the LABEL_NUSES counds have been computed.
        (delete_barrier_successors): When deleting a tablejump insn, also
        delete the jump table it uses.
        * varasm.c (force_const_mem): Set LABEL_PRESERVE_P when forcing a
        label into memory.

From-SVN: r41662

gcc/ChangeLog

+Sat Apr 28 10:36:23 2001  Jeffrey A Law  (law@cygnus.com)
+
+	* flow.c (propagate_block_delete_insn): Handle deletion of ADDR_VEC
+	and ADDR_DIFF_VEC insns when the proceeding CODE_LABEL was put
+	into the constant pool.
+	* jump.c (jump_optimize_1): Remove barrier successors after all
+	the LABEL_NUSES counds have been computed.
+	(delete_barrier_successors): When deleting a tablejump insn, also
+	delete the jump table it uses.
+	* varasm.c (force_const_mem): Set LABEL_PRESERVE_P when forcing a
+	label into memory.
+
 2001-04-28  Martin Kalen  <martin.kalen@todaysystems.com.au>
 
         * pa.c (FRP): Remove erroneous white space in macro definition.

gcc/flow.c

@@ -3638,7 +3638,10 @@ propagate_block_delete_insn (bb, insn)
       rtx label = XEXP (inote, 0);
       rtx next;
 
-      if (LABEL_NUSES (label) == 1
+      /* The label may be forced if it has been put in the constant
+	 pool.  If that is the only use we must discard the table
+	 jump following it, but not the label itself.  */
+      if (LABEL_NUSES (label) == 1 + LABEL_PRESERVE_P (label)
 	  && (next = next_nonnote_insn (label)) != NULL
 	  && GET_CODE (next) == JUMP_INSN
 	  && (GET_CODE (PATTERN (next)) == ADDR_VEC

gcc/jump.c

@@ -214,9 +214,6 @@ jump_optimize_1 (f, cross_jump, noop_moves, after_regscan,
   cross_jump_death_matters = (cross_jump == 2);
   max_uid = init_label_info (f) + 1;
 
-  if (! mark_labels_only)
-    delete_barrier_successors (f);
-
   /* Leave some extra room for labels and duplicate exit test insns
      we make.  */
   max_jump_chain = max_uid * 14 / 10;
@@ -239,6 +236,9 @@ jump_optimize_1 (f, cross_jump, noop_moves, after_regscan,
     if (GET_CODE (XEXP (insn, 0)) == CODE_LABEL)
       LABEL_NUSES (XEXP (insn, 0))++;
 
+  if (! mark_labels_only)
+    delete_barrier_successors (f);
+
   /* Quit now if we just wanted to rebuild the JUMP_LABEL and REG_LABEL
      notes and recompute LABEL_NUSES.  */
   if (mark_labels_only)
@@ -792,7 +792,24 @@ delete_barrier_successors (f)
 
 	  while (insn != 0 && GET_CODE (insn) != CODE_LABEL)
 	    {
-	      if (GET_CODE (insn) == NOTE
+	      if (GET_CODE (insn) == JUMP_INSN)
+		{
+		  /* Detect when we're deleting a tablejump; get rid of
+		     the jump table as well.  */
+		  rtx next1 = next_nonnote_insn (insn);
+		  rtx next2 = next1 ? next_nonnote_insn (next1) : 0;
+		  if (next2 && GET_CODE (next1) == CODE_LABEL
+		      && GET_CODE (next2) == JUMP_INSN
+		      && (GET_CODE (PATTERN (next2)) == ADDR_VEC
+			  || GET_CODE (PATTERN (next2)) == ADDR_DIFF_VEC))
+		    {
+		      delete_insn (insn);
+		      insn = next2;
+		    }
+		  else
+		    insn = delete_insn (insn);
+		}
+	      else if (GET_CODE (insn) == NOTE
 		  && NOTE_LINE_NUMBER (insn) != NOTE_INSN_FUNCTION_END)
 		insn = NEXT_INSN (insn);
 	      else

gcc/varasm.c

@@ -3589,6 +3589,9 @@ force_const_mem (mode, x)
       pool_offset += align - 1;
       pool_offset &= ~ (align - 1);
 
+      if (GET_CODE (x) == LABEL_REF)
+	LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
+
       /* Allocate a pool constant descriptor, fill it in, and chain it in.  */
 
       pool = (struct pool_constant *) ggc_alloc (sizeof (struct pool_constant));