* rtl.h (rebuild_jump_labels): Declare.

        * jump.c (jump_optimize_1): Renamed from jump_optimize.  Make static.
        Add new argument MARK_LABELS_ONLY.  Quit after mark_all_labels if
        requested.
        (jump_optimize, rebuild_jump_labels): New wrapper functions for
        jump_optimize_1.
        * toplev.c (rest_of_compilation): Use rebuild_jump_labels instead of
        running the entire jump optimizer.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@26327 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 53 insertions, 14 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6acde6141fa..fd8f5d7a3e0 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -14,6 +14,15 @@
 
 Sat Apr 10 03:50:12 1999  Jeffrey A Law  (law@cygnus.com)
 
+	* rtl.h (rebuild_jump_labels): Declare.
+	* jump.c (jump_optimize_1): Renamed from jump_optimize.  Make static.
+	Add new argument MARK_LABELS_ONLY.  Quit after mark_all_labels if
+	requested.
+	(jump_optimize, rebuild_jump_labels): New wrapper functions for
+	jump_optimize_1.
+	* toplev.c (rest_of_compilation): Use rebuild_jump_labels instead of
+	running the entire jump optimizer.
+
 	* rtl.h (local_alloc): Returns an integer now.
 	* local-alloc.c (recorded_label_ref): New file scoped variable.
 	(local_alloc): Initialize recorded_label_ref to zero.  Return its
diff --git a/gcc/jump.c b/gcc/jump.c
index 4ffeeff3f21..9a031937dd2 100644
--- a/gcc/jump.c
+++ b/gcc/jump.c
@@ -126,9 +126,33 @@ static void delete_from_jump_chain	PROTO((rtx));
 static int delete_labelref_insn		PROTO((rtx, rtx, int));
 static void mark_modified_reg		PROTO((rtx, rtx));
 static void redirect_tablejump		PROTO((rtx, rtx));
+static void jump_optimize_1		PROTO ((rtx, int, int, int, int));
 #ifndef HAVE_cc0
 static rtx find_insert_position         PROTO((rtx, rtx));
 #endif
+
+/* Main external entry point into the jump optimizer.  See comments before
+   jump_optimize_1 for descriptions of the arguments.  */
+void
+jump_optimize (f, cross_jump, noop_moves, after_regscan)
+     rtx f;
+     int cross_jump;
+     int noop_moves;
+     int after_regscan;
+{
+  jump_optimize_1 (f, cross_jump, noop_moves, after_regscan, 0);
+}
+
+/* Alternate entry into the jump optimizer.  This entry point only rebuilds
+   the JUMP_LABEL field in jumping insns and REG_LABEL notes in non-jumping
+   instructions.  */
+void
+rebuild_jump_labels (f)
+     rtx f;
+{
+  jump_optimize_1 (f, 0, 0, 0, 1);
+}
+
 
 /* Delete no-op jumps and optimize jumps to jumps
    and jumps around jumps.
@@ -143,6 +167,9 @@ static rtx find_insert_position         PROTO((rtx, rtx));
    If AFTER_REGSCAN is nonzero, then this jump pass is being run immediately
    after regscan, and it is safe to use regno_first_uid and regno_last_uid.
 
+   If MARK_LABELS_ONLY is nonzero, then we only rebuild the jump chain
+   and JUMP_LABEL field for jumping insns.
+
    If `optimize' is zero, don't change any code,
    just determine whether control drops off the end of the function.
    This case occurs when we have -W and not -O.
@@ -150,11 +177,12 @@ static rtx find_insert_position         PROTO((rtx, rtx));
    and refrains from actually deleting when that is 0.  */
 
 void
-jump_optimize (f, cross_jump, noop_moves, after_regscan)
+jump_optimize_1 (f, cross_jump, noop_moves, after_regscan, mark_labels_only)
      rtx f;
      int cross_jump;
      int noop_moves;
      int after_regscan;
+     int mark_labels_only;
 {
   register rtx insn, next;
   int changed;
@@ -182,6 +210,11 @@ jump_optimize (f, cross_jump, noop_moves, after_regscan)
 
   mark_all_labels (f, cross_jump);
 
+  /* Quit now if we just wanted to rebuild the JUMP_LABEL and REG_LABEL
+     notes.  */
+  if (mark_labels_only)
+    return;
+
   /* Keep track of labels used from static data;
      they cannot ever be deleted.  */
 
diff --git a/gcc/rtl.h b/gcc/rtl.h
index eee7473cd33..9fb8c4ac30a 100644
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -1354,6 +1354,7 @@ extern int rtx_renumbered_equal_p	PROTO ((rtx, rtx));
 extern int true_regnum			PROTO ((rtx));
 extern int redirect_jump		PROTO ((rtx, rtx));
 extern void jump_optimize		PROTO ((rtx, int, int, int));
+extern void rebuild_jump_labels		PROTO ((rtx));
 extern void thread_jumps		PROTO ((rtx, int, int));
 extern int redirect_exp			PROTO ((rtx *, rtx, rtx, rtx));
 extern int rtx_equal_for_thread_p	PROTO ((rtx, rtx, rtx));
diff --git a/gcc/toplev.c b/gcc/toplev.c
index 3847c5dcd7b..28292843508 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -3526,7 +3526,7 @@ rest_of_compilation (decl)
   /* Likewise, for DECL_ARGUMENTS.  */
   tree saved_arguments = 0;
   int failure = 0;
-  int run_jump_after_reload;
+  int rebuild_label_notes_after_reload;
 
   /* If we are reconsidering an inline function
      at the end of compilation, skip the stuff for making it inline.  */
@@ -4074,10 +4074,10 @@ rest_of_compilation (decl)
 	     {
 	       recompute_reg_usage (insns, ! optimize_size);
 	       regclass (insns, max_reg_num ());
-	       run_jump_after_reload = local_alloc ();
+	       rebuild_label_notes_after_reload = local_alloc ();
 	     });
   else
-    run_jump_after_reload = 0;
+    rebuild_label_notes_after_reload = 0;
 
   /* Dump rtl code after allocating regs within basic blocks.  */
 
@@ -4112,20 +4112,16 @@ rest_of_compilation (decl)
   if (failure)
     goto exit_rest_of_compilation;
 
-  /* Register allocation and reloading may have turned an indirect jump into
-     a direct jump.  If so, we must rerun the jump optimizer to ensure that
-     the JUMP_LABEL of any jump changed by that transformation is valid.
-
-     We do this before reload_cse_regs since it may allow reload_cse to do
-     a better job.  */
-  if (run_jump_after_reload)
-    TIMEVAR (jump_time, jump_optimize (insns, !JUMP_CROSS_JUMP,
-				       !JUMP_NOOP_MOVES, !JUMP_AFTER_REGSCAN));
-
   /* Do a very simple CSE pass over just the hard registers.  */
   if (optimize > 0)
     reload_cse_regs (insns);
 
+  /* Register allocation and reloading may have turned an indirect jump into
+     a direct jump.  If so, we must rebuild the JUMP_LABEL fields of
+     jumping instructions.  */
+  if (rebuild_label_notes_after_reload)
+    TIMEVAR (jump_time, rebuild_jump_labels (insns));
+
   /* If optimizing and we are performing instruction scheduling after
      reload, then go ahead and split insns now since we are about to
      recompute flow information anyway.