flow.c (commit_one_edge_insertion): Be prepared for a return insn to be inserted on the edge with a normal jump.

        * flow.c (commit_one_edge_insertion): Be prepared for a return
        insn to be inserted on the edge with a normal jump.
        * jump.c (jump_optimize_1): Don't look to create return isns.

        * flow.c (flow_delete_insn): Don't adjust reference count of notes.
        * jump.c (jump_optimize_1): Likewise.
        (returnjump_p): Verify the argument is a JUMP_INSN.
        * rtl.def (NOTE): Add 5th element for NOTE_INSN_DELETED_LABEL.

From-SVN: r33950

4 files changed, 91 insertions, 78 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5efee53..30504a9 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,14 @@
+2000-05-16  Richard Henderson  <rth@cygnus.com>
+
+	* flow.c (commit_one_edge_insertion): Be prepared for a return
+	insn to be inserted on the edge with a normal jump.
+	* jump.c (jump_optimize_1): Don't look to create return isns.
+
+	* flow.c (flow_delete_insn): Don't adjust reference count of notes.
+	* jump.c (jump_optimize_1): Likewise.
+	(returnjump_p): Verify the argument is a JUMP_INSN.
+	* rtl.def (NOTE): Add 5th element for NOTE_INSN_DELETED_LABEL.
+
 2000-05-16  Nick Clifton  <nickc@cygnus.com>
 
 	* config/m32r/m32r.c (small_insn_p): Use INSN_P() to replace
@@ -307,23 +318,23 @@ Fri May 12 19:03:58 2000  Philippe De Muyter  <phdm@macqel.be>
 
 2000-05-12  Zack Weinberg <zack@wolery.cumb.org>
 
-        * fixinc/fixfixes.c (IO_use_fix, IO_defn_fix, CTRL_use_fix,
-        CTRL_defn_fix): Delete.
-        (fix_char_macro_defines, fix_char_macro_uses): Rename to
-        char_macro_def_fix and char_macro_use_fix, respectively.  Put
-        them into the FIXUP_TABLE.  Get the string to search for from
-        a c_fix_arg.
+	* fixinc/fixfixes.c (IO_use_fix, IO_defn_fix, CTRL_use_fix,
+	CTRL_defn_fix): Delete.
+	(fix_char_macro_defines, fix_char_macro_uses): Rename to
+	char_macro_def_fix and char_macro_use_fix, respectively.  Put
+	them into the FIXUP_TABLE.  Get the string to search for from
+	a c_fix_arg.
 
-        (format_write): New function.
-        (format_fix): Use it.
+	(format_write): New function.
+	(format_fix): Use it.
 
-        (FIX_PROC_HEAD): Constify text parameter.
-        (machine_name_fix): Constify all char *s.
-        * fixtests.c (skip_quote): Remove double static.
+	(FIX_PROC_HEAD): Constify text parameter.
+	(machine_name_fix): Constify all char *s.
+	* fixtests.c (skip_quote): Remove double static.
 
-        * inclhack.def (io_def_quotes, io_use_quotes, ctrl_def_quotes,
-        ctrl_use_quotes): Update for new scheme.
-        * fixincl.x: Regenerate.
+	* inclhack.def (io_def_quotes, io_use_quotes, ctrl_def_quotes,
+	ctrl_use_quotes): Update for new scheme.
+	* fixincl.x: Regenerate.
 
 2000-05-12  Alexandre Oliva  <aoliva@cygnus.com>
 
@@ -492,9 +503,9 @@ Wed 10 May 09:36:47 2000  Neil Booth  <NeilB@earthling.net>
 
 Wed 10 May 09:08:30 2000  Neil Booth  <NeilB@earthling.net>
 
-        * cpplex.c (_cpp_lex_line): Maintain PREV_WHITESPACE flag
-        when removing escaped newlines.  Reverse sense of test for
-        escaped newline.
+	* cpplex.c (_cpp_lex_line): Maintain PREV_WHITESPACE flag
+	when removing escaped newlines.  Reverse sense of test for
+	escaped newline.
 
 2000-05-09  Richard Henderson  <rth@cygnus.com>
 
@@ -1206,17 +1217,17 @@ Thu May  4 09:45:12 2000  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
 	MEM_COPY_ATTRIBUTES.
 
 2000-05-03  Robert Lipe <robertlipe@usa.net>
-        
-        * configure.in (i[34567]86-*-isc*) [tmake_file]: Add t-i386bare
-        to suppress libgcc1.
-        (i[34567]86-*-sco3.2v5*) Likewise.
-        (i[34567]86-*-sco3.2v4*) Likewise.
-        (i[34567]86-*-sco) Likewise.
-        (i[34567]86-*-solaris2) Likewise.
-        (i[34567]86-*-sysv5*) Likewise.
-        (i[34567]86-*-sysv4*) Likewise.
-        (i[34567]86-*-udk*) Likewise.
-        (i[34567]86-*-sysv*) Likewise.
+	
+	* configure.in (i[34567]86-*-isc*) [tmake_file]: Add t-i386bare
+	to suppress libgcc1.
+	(i[34567]86-*-sco3.2v5*) Likewise.
+	(i[34567]86-*-sco3.2v4*) Likewise.
+	(i[34567]86-*-sco) Likewise.
+	(i[34567]86-*-solaris2) Likewise.
+	(i[34567]86-*-sysv5*) Likewise.
+	(i[34567]86-*-sysv4*) Likewise.
+	(i[34567]86-*-udk*) Likewise.
+	(i[34567]86-*-sysv*) Likewise.
 
 2000-05-03  Zack Weinberg  <zack@wolery.cumb.org>
 
@@ -1242,14 +1253,14 @@ Thu May  4 09:45:12 2000  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
 
 Wed May  3 21:01:46 2000  Jason Eckhardt  <jle@cygnus.com>
 
-        * bb-reorder.c (struct reorder_block_def): Member succ removed.
-        (REORDER_BLOCK_SUCC): Removed.
-        (enum reorder_skip_type): Removed.
-        (skip_insns_between_block): Renamed to skip_insns_after_block.
-        Removed second argument. Removed dead code and cleaned up.
-        (make_reorder_chain): Removed use of REORDER_BLOCK_SUCC.
-        (reorder_basic_blocks): Remove use of REORDER_SKIP_AFTER. Removed
-        second parameter to skip_insns_after_block.
+	* bb-reorder.c (struct reorder_block_def): Member succ removed.
+	(REORDER_BLOCK_SUCC): Removed.
+	(enum reorder_skip_type): Removed.
+	(skip_insns_between_block): Renamed to skip_insns_after_block.
+	Removed second argument. Removed dead code and cleaned up.
+	(make_reorder_chain): Removed use of REORDER_BLOCK_SUCC.
+	(reorder_basic_blocks): Remove use of REORDER_SKIP_AFTER. Removed
+	second parameter to skip_insns_after_block.
 
 Wed May  3 13:29:54 2000  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
 
diff --git a/gcc/flow.c b/gcc/flow.c
index a8573e1..e24822e 100644
--- a/gcc/flow.c
+++ b/gcc/flow.c
@@ -1598,7 +1598,7 @@ static void
 commit_one_edge_insertion (e)
      edge e;
 {
-  rtx before = NULL_RTX, after = NULL_RTX, insns, tmp;
+  rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last;
   basic_block bb;
 
   /* Pull the insns off the edge now since the edge might go away.  */
@@ -1675,37 +1675,38 @@ commit_one_edge_insertion (e)
       emit_insns_before (insns, before);
       if (before == bb->head)
 	bb->head = insns;
+
+      last = prev_nonnote_insn (before);
     }
   else
     {
-      rtx last = emit_insns_after (insns, after);
+      last = emit_insns_after (insns, after);
       if (after == bb->end)
-	{
-	  bb->end = last;
+	bb->end = last;
+    }
 
-	  if (GET_CODE (last) == JUMP_INSN)
-	    {
-	      if (returnjump_p (last))
-		{
-		  /* ??? Remove all outgoing edges from BB and add one
-		     for EXIT.  This is not currently a problem because
-		     this only happens for the (single) epilogue, which
-		     already has a fallthru edge to EXIT.  */
-
-		  e = bb->succ;
-		  if (e->dest != EXIT_BLOCK_PTR
-		      || e->succ_next != NULL
-		      || (e->flags & EDGE_FALLTHRU) == 0)
-		    abort ();
-		  e->flags &= ~EDGE_FALLTHRU;
-
-		  emit_barrier_after (last);
-		}
-	      else
-		abort ();
-	    }
-	}
+  if (returnjump_p (last))
+    {
+      /* ??? Remove all outgoing edges from BB and add one for EXIT. 
+         This is not currently a problem because this only happens
+	 for the (single) epilogue, which already has a fallthru edge
+	 to EXIT.  */
+
+      e = bb->succ;
+      if (e->dest != EXIT_BLOCK_PTR
+	  || e->succ_next != NULL
+	  || (e->flags & EDGE_FALLTHRU) == 0)
+	abort ();
+      e->flags &= ~EDGE_FALLTHRU;
+
+      emit_barrier_after (last);
+      bb->end = last;
+
+      if (before)
+	flow_delete_insn (before);
     }
+  else if (GET_CODE (last) == JUMP_INSN)
+    abort ();
 }
 
 /* Update the CFG for all queued instructions.  */
@@ -2027,11 +2028,14 @@ flow_delete_insn (insn)
 
   /* If deleting a jump, decrement the use count of the label.  Deleting
      the label itself should happen in the normal course of block merging.  */
-  if (GET_CODE (insn) == JUMP_INSN && JUMP_LABEL (insn))
+  if (GET_CODE (insn) == JUMP_INSN
+      && JUMP_LABEL (insn)
+      && GET_CODE (JUMP_LABEL (insn)) == CODE_LABEL)
     LABEL_NUSES (JUMP_LABEL (insn))--;
 
   /* Also if deleting an insn that references a label.  */
-  else if ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX)
+  else if ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX
+	   && GET_CODE (XEXP (note, 0)) == CODE_LABEL)
     LABEL_NUSES (XEXP (note, 0))--;
 
   return next;
diff --git a/gcc/jump.c b/gcc/jump.c
index dad373f..7f42235 100644
--- a/gcc/jump.c
+++ b/gcc/jump.c
@@ -231,11 +231,13 @@ jump_optimize_1 (f, cross_jump, noop_moves, after_regscan,
 
   mark_all_labels (f, cross_jump);
 
-  /* Keep track of labels used from static data;
-     they cannot ever be deleted.  */
+  /* Keep track of labels used from static data; we don't track them
+     closely enough to delete them here, so make sure their reference
+     count doesn't drop to zero.  */
 
   for (insn = forced_labels; insn; insn = XEXP (insn, 1))
-    LABEL_NUSES (XEXP (insn, 0))++;
+    if (GET_CODE (XEXP (insn, 0)) == CODE_LABEL)
+      LABEL_NUSES (XEXP (insn, 0))++;
 
   check_exception_handler_labels ();
 
@@ -381,14 +383,6 @@ jump_optimize_1 (f, cross_jump, noop_moves, after_regscan,
 		}
 	    }
 
-	  /* If a jump references the end of the function, try to turn
-	     it into a RETURN insn, possibly a conditional one.  */
-	  if (JUMP_LABEL (insn) != 0
-	      && (next_active_insn (JUMP_LABEL (insn)) == 0
-		  || GET_CODE (PATTERN (next_active_insn (JUMP_LABEL (insn))))
-		      == RETURN))
-	    changed |= redirect_jump (insn, NULL_RTX);
-
 	  reallabelprev = prev_active_insn (JUMP_LABEL (insn));
 
 	  /* Detect jump to following insn.  */
@@ -2261,6 +2255,8 @@ int
 returnjump_p (insn)
      rtx insn;
 {
+  if (GET_CODE (insn) != JUMP_INSN)
+    return 0;
   return for_each_rtx (&PATTERN (insn), returnjump_p_1, NULL);
 }
 
diff --git a/gcc/rtl.def b/gcc/rtl.def
index 97df537..1f628aa 100644
--- a/gcc/rtl.def
+++ b/gcc/rtl.def
@@ -421,9 +421,11 @@ DEF_RTL_EXPR(BARRIER, "barrier", "iuu", 'x')
 DEF_RTL_EXPR(CODE_LABEL, "code_label", "iuu00iss", 'x')
      
 /* Say where in the code a source line starts, for symbol table's sake.
-   Contains a filename and a line number.  Line numbers <= 0 are special;
-   See enum note_insn in rtl.h.  */
-DEF_RTL_EXPR(NOTE, "note", "iuu0n", 'x')
+   Operand:
+   3: filename, if line number > 0, note-specific data otherwise.
+   4: line number if > 0, enum note_insn otherwise.
+   5: unique number if line number == note_insn_deleted_label.  */
+DEF_RTL_EXPR(NOTE, "note", "iuu0ni", 'x')
 
 /* ----------------------------------------------------------------------
    Top level constituents of INSN, JUMP_INSN and CALL_INSN.