toplev.c (rest_of_compilation): Rebuild jump labels if combine_instructions has created a new direct jump.

	* toplev.c (rest_of_compilation): Rebuild jump labels if
	combine_instructions has created a new direct jump.
	* combine.c (try_combine): Add new_direct_jump_p argument.  Set it
	when appropriate.
	(combine_instructions): Call try_combine with new argument.
	Return non-null value when new direct jump instruction is created.
	* rtl.h: combine_instructions returns an int.

From-SVN: r32162

4 files changed, 69 insertions, 20 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e3f100c..0823934 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2000-02-25  Anthony Green  <green@cygnus.com>
+
+	* toplev.c (rest_of_compilation): Rebuild jump labels if
+	combine_instructions has created a new direct jump.
+	* combine.c (try_combine): Add new_direct_jump_p argument.  Set it
+	when appropriate.
+	(combine_instructions): Call try_combine with new argument.
+	Return non-null value when new direct jump instruction is created.
+	* rtl.h: combine_instructions returns an int.
+
 Fri Feb 25 19:49:08 2000  Jeffrey A Law  (law@cygnus.com)
 
 	* cse.c (cse_insn): Replace the PATTERN of the insn with an new
diff --git a/gcc/combine.c b/gcc/combine.c
index fd07574..d24ef18 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -359,7 +359,7 @@ static int can_combine_p	PARAMS ((rtx, rtx, rtx, rtx, rtx *, rtx *));
 static int sets_function_arg_p	PARAMS ((rtx));
 static int combinable_i3pat	PARAMS ((rtx, rtx *, rtx, rtx, int, rtx *));
 static int contains_muldiv	PARAMS ((rtx));
-static rtx try_combine		PARAMS ((rtx, rtx, rtx));
+static rtx try_combine		PARAMS ((rtx, rtx, rtx, int *));
 static void undo_all		PARAMS ((void));
 static void undo_commit		PARAMS ((void));
 static rtx *find_split_point	PARAMS ((rtx *, rtx));
@@ -480,9 +480,11 @@ do_SUBST_INT(into, newval)
 #define SUBST_INT(INTO, NEWVAL)  do_SUBST_INT(&(INTO), (NEWVAL))
 
 /* Main entry point for combiner.  F is the first insn of the function.
-   NREGS is the first unused pseudo-reg number.  */
+   NREGS is the first unused pseudo-reg number. 
 
-void
+   Return non-zero if the combiner has turned an indirect jump
+   instruction into a direct jump.  */
+int
 combine_instructions (f, nregs)
      rtx f;
      int nregs;
@@ -494,6 +496,8 @@ combine_instructions (f, nregs)
   register int i;
   register rtx links, nextlinks;
 
+  int new_direct_jump_p = 0;
+
   combine_attempts = 0;
   combine_merges = 0;
   combine_extras = 0;
@@ -617,7 +621,8 @@ combine_instructions (f, nregs)
 	  /* Try this insn with each insn it links back to.  */
 
 	  for (links = LOG_LINKS (insn); links; links = XEXP (links, 1))
-	    if ((next = try_combine (insn, XEXP (links, 0), NULL_RTX)) != 0)
+	    if ((next = try_combine (insn, XEXP (links, 0), 
+				     NULL_RTX, &new_direct_jump_p)) != 0)
 	      goto retry;
 
 	  /* Try each sequence of three linked insns ending with this one.  */
@@ -626,7 +631,8 @@ combine_instructions (f, nregs)
 	    for (nextlinks = LOG_LINKS (XEXP (links, 0)); nextlinks;
 		 nextlinks = XEXP (nextlinks, 1))
 	      if ((next = try_combine (insn, XEXP (links, 0),
-				       XEXP (nextlinks, 0))) != 0)
+				       XEXP (nextlinks, 0),
+				       &new_direct_jump_p)) != 0)
 		goto retry;
 
 #ifdef HAVE_cc0
@@ -642,13 +648,15 @@ combine_instructions (f, nregs)
 	      && GET_CODE (prev) == INSN
 	      && sets_cc0_p (PATTERN (prev)))
 	    {
-	      if ((next = try_combine (insn, prev, NULL_RTX)) != 0)
+	      if ((next = try_combine (insn, prev, 
+				       NULL_RTX, &new_direct_jump_p)) != 0)
 		goto retry;
 
 	      for (nextlinks = LOG_LINKS (prev); nextlinks;
 		   nextlinks = XEXP (nextlinks, 1))
 		if ((next = try_combine (insn, prev,
-					 XEXP (nextlinks, 0))) != 0)
+					 XEXP (nextlinks, 0),
+					 &new_direct_jump_p)) != 0)
 		  goto retry;
 	    }
 
@@ -660,13 +668,15 @@ combine_instructions (f, nregs)
 	      && GET_CODE (PATTERN (insn)) == SET
 	      && reg_mentioned_p (cc0_rtx, SET_SRC (PATTERN (insn))))
 	    {
-	      if ((next = try_combine (insn, prev, NULL_RTX)) != 0)
+	      if ((next = try_combine (insn, prev, 
+				       NULL_RTX, &new_direct_jump_p)) != 0)
 		goto retry;
 
 	      for (nextlinks = LOG_LINKS (prev); nextlinks;
 		   nextlinks = XEXP (nextlinks, 1))
 		if ((next = try_combine (insn, prev,
-					 XEXP (nextlinks, 0))) != 0)
+					 XEXP (nextlinks, 0),
+					 &new_direct_jump_p)) != 0)
 		  goto retry;
 	    }
 
@@ -680,7 +690,8 @@ combine_instructions (f, nregs)
 		&& (prev = prev_nonnote_insn (XEXP (links, 0))) != 0
 		&& GET_CODE (prev) == INSN
 		&& sets_cc0_p (PATTERN (prev))
-		&& (next = try_combine (insn, XEXP (links, 0), prev)) != 0)
+		&& (next = try_combine (insn, XEXP (links, 0), 
+					prev, &new_direct_jump_p)) != 0)
 	      goto retry;
 #endif
 
@@ -690,7 +701,8 @@ combine_instructions (f, nregs)
 	    for (nextlinks = XEXP (links, 1); nextlinks;
 		 nextlinks = XEXP (nextlinks, 1))
 	      if ((next = try_combine (insn, XEXP (links, 0),
-				       XEXP (nextlinks, 0))) != 0)
+				       XEXP (nextlinks, 0),
+				       &new_direct_jump_p)) != 0)
 		goto retry;
 
 	  if (GET_CODE (insn) != NOTE)
@@ -742,6 +754,8 @@ combine_instructions (f, nregs)
 
   /* Make recognizer allow volatile MEMs again.  */
   init_recog ();
+
+  return new_direct_jump_p;
 }
 
 /* Wipe the reg_last_xxx arrays in preparation for another pass.  */
@@ -1426,11 +1440,15 @@ contains_muldiv (x)
 
    Return 0 if the combination does not work.  Then nothing is changed. 
    If we did the combination, return the insn at which combine should
-   resume scanning.  */
+   resume scanning.  
+   
+   Set NEW_DIRECT_JUMP_P to a non-zero value if try_combine creates a
+   new direct jump instruction.  */
 
 static rtx
-try_combine (i3, i2, i1)
+try_combine (i3, i2, i1, new_direct_jump_p)
      register rtx i3, i2, i1;
+     register int *new_direct_jump_p;
 {
   /* New patterns for I3 and I3, respectively.  */
   rtx newpat, newi2pat = 0;
@@ -2684,14 +2702,21 @@ try_combine (i3, i2, i1)
     if (newi2pat)
       note_stores (newi2pat, set_nonzero_bits_and_sign_copies, NULL);
 
-    /* If I3 is now an unconditional jump, ensure that it has a 
+    /* Set new_direct_jump_p if a new return or simple jump instruction
+       has been created.
+
+       If I3 is now an unconditional jump, ensure that it has a 
        BARRIER following it since it may have initially been a
        conditional jump.  It may also be the last nonnote insn.  */
+    
+    if (GET_CODE (newpat) == RETURN || simplejump_p (i3))
+      {
+	*new_direct_jump_p = 1;
 
-    if ((GET_CODE (newpat) == RETURN || simplejump_p (i3))
-	&& ((temp = next_nonnote_insn (i3)) == NULL_RTX
-	    || GET_CODE (temp) != BARRIER))
-      emit_barrier_after (i3);
+	if ((temp = next_nonnote_insn (i3)) == NULL_RTX
+	    || GET_CODE (temp) != BARRIER)
+	  emit_barrier_after (i3);
+      }
   }
 
   combine_successes++;
diff --git a/gcc/rtl.h b/gcc/rtl.h
index d3ca9b0..af67efb 100644
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -1470,7 +1470,7 @@ extern void remove_unncessary_notes             PARAMS ((void));
 extern void add_clobbers		PARAMS ((rtx, int));
 
 /* In combine.c */
-extern void combine_instructions	PARAMS ((rtx, int));
+extern int combine_instructions	PARAMS ((rtx, int));
 extern int extended_count		PARAMS ((rtx, enum machine_mode, int));
 extern rtx remove_death			PARAMS ((int, rtx));
 #ifdef BUFSIZ
diff --git a/gcc/toplev.c b/gcc/toplev.c
index ada79f9..058ccfa 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -3311,7 +3311,21 @@ rest_of_compilation (decl)
 
   if (optimize > 0)
     {
-      TIMEVAR (combine_time, combine_instructions (insns, max_reg_num ()));
+      int rebuild_jump_labels_after_combine = 0;
+
+      TIMEVAR (combine_time, 
+	       {
+		 rebuild_jump_labels_after_combine = 
+		   combine_instructions (insns, max_reg_num ());
+	       });
+      
+      /* Combining insns may have turned an indirect jump into a
+	 direct jump.  Rebuid the JUMP_LABEL fields of jumping
+	 instructions.  */
+      if (rebuild_jump_labels_after_combine)
+	{
+	  TIMEVAR (jump_time, rebuild_jump_labels (insns));
+	}
 
       /* Dump rtl code after insn combination.  */