jump.c (redirect_exp_1): Rework from old redirect_exp.

        * jump.c (redirect_exp_1): Rework from old redirect_exp.  Never
        commit change group changes.
        (invert_exp_1): Similarly.
        (redirect_exp, invert_exp): Use them.
        (redirect_jump_1): New.
        (invert_jump_1): New.
        (jump_optimize_1): Remove code subsumed by condexec.c.
        * rtl.h (invert_jump_1, redirect_jump_1): Declare.

From-SVN: r33474

3 files changed, 217 insertions, 149 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 9e4c0d5..abc9490 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,16 @@
 2000-04-26  Richard Henderson  <rth@cygnus.com>
 
+	* jump.c (redirect_exp_1): Rework from old redirect_exp.  Never
+	commit change group changes.
+	(invert_exp_1): Similarly.
+	(redirect_exp, invert_exp): Use them.
+	(redirect_jump_1): New.
+	(invert_jump_1): New.
+	(jump_optimize_1): Remove code subsumed by condexec.c.
+	* rtl.h (invert_jump_1, redirect_jump_1): Declare.
+
+2000-04-26  Richard Henderson  <rth@cygnus.com>
+
 	* rtlanal.c (dead_or_set_regno_p): Use find_regno_note.
 
 	* genconfig.c (main): Set all HAVE_foo to 1.
@@ -125,8 +136,8 @@
 
 2000-04-26  Andreas Jaeger  <aj@suse.de>
 
-        * extend.texi (Function Attributes): Fix description of pure
-        attribute.
+	* extend.texi (Function Attributes): Fix description of pure
+	attribute.
 
 2000-04-26  Jason Merrill  <jason@casey.cygnus.com>
 
@@ -140,7 +151,7 @@
 
 2000-04-25  Richard Henderson  <rth@cygnus.com>
 
-        * cse.c (cse_insn): Emit barrier after unconditional jump.
+	* cse.c (cse_insn): Emit barrier after unconditional jump.
 
 	* calls.c (expand_call): Disable tail call generation once
 	rtx_equal_function_value_matters is false.
@@ -192,11 +203,11 @@
 
 2000-04-25  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
 
-        * acconfig.h (ENABLE_STD_NAMESPACE, ENABLE_CHECKING,
+	* acconfig.h (ENABLE_STD_NAMESPACE, ENABLE_CHECKING,
 	ENABLE_TREE_CHECKING, ENABLE_RTL_CHECKING, ENABLE_GC_CHECKING,
 	ENABLE_GC_ALWAYS_COLLECT): Delete entries.
 	        
-        * configure.in (ENABLE_STD_NAMESPACE, ENABLE_CHECKING,
+	* configure.in (ENABLE_STD_NAMESPACE, ENABLE_CHECKING,
 	ENABLE_TREE_CHECKING, ENABLE_RTL_CHECKING, ENABLE_GC_CHECKING,
 	ENABLE_GC_ALWAYS_COLLECT): Use three argument form of AC_DEFINE
 	for these macros.  Clean up spacing and linewraps.
diff --git a/gcc/jump.c b/gcc/jump.c
index 06b5bd5..3e98386 100644
--- a/gcc/jump.c
+++ b/gcc/jump.c
@@ -121,6 +121,8 @@ static int jump_back_p			PARAMS ((rtx, rtx));
 static int tension_vector_labels	PARAMS ((rtx, int));
 static void mark_jump_label		PARAMS ((rtx, rtx, int, int));
 static void delete_computation		PARAMS ((rtx));
+static void redirect_exp_1		PARAMS ((rtx *, rtx, rtx, rtx));
+static void invert_exp_1		PARAMS ((rtx, rtx));
 static void delete_from_jump_chain	PARAMS ((rtx));
 static int delete_labelref_insn		PARAMS ((rtx, rtx, int));
 static void mark_modified_reg		PARAMS ((rtx, rtx, void *));
@@ -4414,109 +4416,102 @@ never_reached_warning (avoided_insn)
 				"will never be executed");
 }
 
-/* Invert the condition of the jump JUMP, and make it jump
-   to label NLABEL instead of where it jumps now.  */
+/* Throughout LOC, redirect OLABEL to NLABEL.  Treat null OLABEL or
+   NLABEL as a return.  Accrue modifications into the change group.  */
 
-int
-invert_jump (jump, nlabel)
-     rtx jump, nlabel;
-{
-  /* We have to either invert the condition and change the label or
-     do neither.  Either operation could fail.  We first try to invert
-     the jump. If that succeeds, we try changing the label.  If that fails,
-     we invert the jump back to what it was.  */
-
-  if (! invert_exp (PATTERN (jump), jump))
-    return 0;
-
-  if (redirect_jump (jump, nlabel))
-    {
-      /* An inverted jump means that a probability taken becomes a
-	 probability not taken.  Subtract the branch probability from the
-	 probability base to convert it back to a taken probability.  */
-
-      rtx note = find_reg_note (jump, REG_BR_PROB, 0);
-      if (note)
-	XEXP (note, 0) = GEN_INT (REG_BR_PROB_BASE - INTVAL (XEXP (note, 0)));
-
-      return 1;
-    }
-
-  if (! invert_exp (PATTERN (jump), jump))
-    /* This should just be putting it back the way it was.  */
-    abort ();
-
-  return  0;
-}
-
-/* Invert the jump condition of rtx X contained in jump insn, INSN. 
-
-   Return 1 if we can do so, 0 if we cannot find a way to do so that
-   matches a pattern.  */
-
-int
-invert_exp (x, insn)
-     rtx x;
+static void
+redirect_exp_1 (loc, olabel, nlabel, insn)
+     rtx *loc;
+     rtx olabel, nlabel;
      rtx insn;
 {
-  register RTX_CODE code;
+  register rtx x = *loc;
+  register RTX_CODE code = GET_CODE (x);
   register int i;
   register const char *fmt;
 
-  code = GET_CODE (x);
-
-  if (code == IF_THEN_ELSE)
+  if (code == LABEL_REF)
     {
-      register rtx comp = XEXP (x, 0);
-      register rtx tem;
+      if (XEXP (x, 0) == olabel)
+	{
+	  rtx n;
+	  if (nlabel)
+	    n = gen_rtx_LABEL_REF (VOIDmode, nlabel);
+	  else
+	    n = gen_rtx_RETURN (VOIDmode); 
 
-      /* We can do this in two ways:  The preferable way, which can only
-	 be done if this is not an integer comparison, is to reverse
-	 the comparison code.  Otherwise, swap the THEN-part and ELSE-part
-	 of the IF_THEN_ELSE.  If we can't do either, fail.  */
+	  validate_change (insn, loc, n, 1);
+	  return;
+	}
+    }
+  else if (code == RETURN && olabel == 0)
+    {
+      x = gen_rtx_LABEL_REF (VOIDmode, nlabel);
+      if (loc == &PATTERN (insn))
+	x = gen_rtx_SET (VOIDmode, pc_rtx, x);
+      validate_change (insn, loc, x, 1);
+      return;
+    }
 
-      if (can_reverse_comparison_p (comp, insn)
-	  && validate_change (insn, &XEXP (x, 0),
-			      gen_rtx_fmt_ee (reverse_condition (GET_CODE (comp)),
-					      GET_MODE (comp), XEXP (comp, 0),
-					      XEXP (comp, 1)), 0))
-	return 1;
-				       
-      tem = XEXP (x, 1);
-      validate_change (insn, &XEXP (x, 1), XEXP (x, 2), 1);
-      validate_change (insn, &XEXP (x, 2), tem, 1);
-      return apply_change_group ();
+  if (code == SET && nlabel == 0 && SET_DEST (x) == pc_rtx
+      && GET_CODE (SET_SRC (x)) == LABEL_REF
+      && XEXP (SET_SRC (x), 0) == olabel)
+    {
+      validate_change (insn, loc, gen_rtx_RETURN (VOIDmode), 1);
+      return;
     }
 
   fmt = GET_RTX_FORMAT (code);
   for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
     {
       if (fmt[i] == 'e')
-	{
-	  if (! invert_exp (XEXP (x, i), insn))
-	    return 0;
-	}
+	redirect_exp_1 (&XEXP (x, i), olabel, nlabel, insn);
       else if (fmt[i] == 'E')
 	{
 	  register int j;
 	  for (j = 0; j < XVECLEN (x, i); j++)
-	    if (!invert_exp (XVECEXP (x, i, j), insn))
-	      return 0;
+	    redirect_exp_1 (&XVECEXP (x, i, j), olabel, nlabel, insn);
 	}
     }
+}
 
-  return 1;
+/* Similar, but apply the change group and report success or failure.  */
+
+int
+redirect_exp (loc, olabel, nlabel, insn)
+     rtx *loc;
+     rtx olabel, nlabel;
+     rtx insn;
+{
+  redirect_exp_1 (loc, olabel, nlabel, insn);
+  if (num_validated_changes () == 0)
+    return 0;
+
+  return apply_change_group ();
 }
-
-/* Make jump JUMP jump to label NLABEL instead of where it jumps now.
-   If the old jump target label is unused as a result,
-   it and the code following it may be deleted.
+
+/* Make JUMP go to NLABEL instead of where it jumps now.  Accrue
+   the modifications into the change group.  Return false if we did
+   not see how to do that.  */
+
+int
+redirect_jump_1 (jump, nlabel)
+     rtx jump, nlabel;
+{
+  int ochanges = num_validated_changes ();
+  redirect_exp_1 (&PATTERN (jump), JUMP_LABEL (jump), nlabel, jump);
+  return num_validated_changes () > ochanges;
+}
+
+/* Make JUMP go to NLABEL instead of where it jumps now.  If the old
+   jump target label is unused as a result, it and the code following
+   it may be deleted.
 
    If NLABEL is zero, we are to turn the jump into a (possibly conditional)
    RETURN insn.
 
-   The return value will be 1 if the change was made, 0 if it wasn't (this
-   can only occur for NLABEL == 0).  */
+   The return value will be 1 if the change was made, 0 if it wasn't
+   (this can only occur for NLABEL == 0).  */
 
 int
 redirect_jump (jump, nlabel)
@@ -4564,6 +4559,131 @@ redirect_jump (jump, nlabel)
   return 1;
 }
 
+/* Invert the jump condition of rtx X contained in jump insn, INSN.  
+   Accrue the modifications into the change group.  */
+
+static void
+invert_exp_1 (x, insn)
+     rtx x;
+     rtx insn;
+{
+  register RTX_CODE code;
+  register int i;
+  register const char *fmt;
+
+  code = GET_CODE (x);
+
+  if (code == IF_THEN_ELSE)
+    {
+      register rtx comp = XEXP (x, 0);
+      register rtx tem;
+
+      /* We can do this in two ways:  The preferable way, which can only
+	 be done if this is not an integer comparison, is to reverse
+	 the comparison code.  Otherwise, swap the THEN-part and ELSE-part
+	 of the IF_THEN_ELSE.  If we can't do either, fail.  */
+
+      if (can_reverse_comparison_p (comp, insn))
+	{
+	  validate_change (insn, &XEXP (x, 0),
+			   gen_rtx_fmt_ee (reverse_condition (GET_CODE (comp)),
+					   GET_MODE (comp), XEXP (comp, 0),
+					   XEXP (comp, 1)),
+			   1);
+	  return;
+	}
+				       
+      tem = XEXP (x, 1);
+      validate_change (insn, &XEXP (x, 1), XEXP (x, 2), 1);
+      validate_change (insn, &XEXP (x, 2), tem, 1);
+      return;
+    }
+
+  fmt = GET_RTX_FORMAT (code);
+  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+    {
+      if (fmt[i] == 'e')
+	invert_exp_1 (XEXP (x, i), insn);
+      else if (fmt[i] == 'E')
+	{
+	  register int j;
+	  for (j = 0; j < XVECLEN (x, i); j++)
+	    invert_exp_1 (XVECEXP (x, i, j), insn);
+	}
+    }
+}
+
+/* Invert the jump condition of rtx X contained in jump insn, INSN. 
+
+   Return 1 if we can do so, 0 if we cannot find a way to do so that
+   matches a pattern.  */
+
+int
+invert_exp (x, insn)
+     rtx x;
+     rtx insn;
+{
+  invert_exp_1 (x, insn);
+  if (num_validated_changes () == 0)
+    return 0;
+
+  return apply_change_group ();
+}
+
+/* Invert the condition of the jump JUMP, and make it jump to label
+   NLABEL instead of where it jumps now.  Accrue changes into the
+   change group.  Return false if we didn't see how to perform the
+   inversion and redirection.  */
+
+int
+invert_jump_1 (jump, nlabel)
+     rtx jump, nlabel;
+{
+  int ochanges;
+
+  ochanges = num_validated_changes ();
+  invert_exp_1 (PATTERN (jump), jump);
+  if (num_validated_changes () == ochanges)
+    return 0;
+
+  return redirect_jump_1 (jump, nlabel);
+}
+
+/* Invert the condition of the jump JUMP, and make it jump to label
+   NLABEL instead of where it jumps now.  Return true if successful.  */
+
+int
+invert_jump (jump, nlabel)
+     rtx jump, nlabel;
+{
+  /* We have to either invert the condition and change the label or
+     do neither.  Either operation could fail.  We first try to invert
+     the jump. If that succeeds, we try changing the label.  If that fails,
+     we invert the jump back to what it was.  */
+
+  if (! invert_exp (PATTERN (jump), jump))
+    return 0;
+
+  if (redirect_jump (jump, nlabel))
+    {
+      /* An inverted jump means that a probability taken becomes a
+	 probability not taken.  Subtract the branch probability from the
+	 probability base to convert it back to a taken probability.  */
+
+      rtx note = find_reg_note (jump, REG_BR_PROB, NULL_RTX);
+      if (note)
+	XEXP (note, 0) = GEN_INT (REG_BR_PROB_BASE - INTVAL (XEXP (note, 0)));
+
+      return 1;
+    }
+
+  if (! invert_exp (PATTERN (jump), jump))
+    /* This should just be putting it back the way it was.  */
+    abort ();
+
+  return 0;
+}
+
 /* Delete the instruction JUMP from any jump chain it might be on.  */
 
 static void
@@ -4599,72 +4719,6 @@ delete_from_jump_chain (jump)
 	  }
     }
 }
-
-/* If NLABEL is nonzero, throughout the rtx at LOC,
-   alter (LABEL_REF OLABEL) to (LABEL_REF NLABEL).  If OLABEL is
-   zero, alter (RETURN) to (LABEL_REF NLABEL).
-
-   If NLABEL is zero, alter (LABEL_REF OLABEL) to (RETURN) and check
-   validity with validate_change.  Convert (set (pc) (label_ref olabel))
-   to (return).
-
-   Return 0 if we found a change we would like to make but it is invalid.
-   Otherwise, return 1.  */
-
-int
-redirect_exp (loc, olabel, nlabel, insn)
-     rtx *loc;
-     rtx olabel, nlabel;
-     rtx insn;
-{
-  register rtx x = *loc;
-  register RTX_CODE code = GET_CODE (x);
-  register int i;
-  register const char *fmt;
-
-  if (code == LABEL_REF)
-    {
-      if (XEXP (x, 0) == olabel)
-	{
-	  if (nlabel)
-	    XEXP (x, 0) = nlabel;
-	  else
-	    return validate_change (insn, loc, gen_rtx_RETURN (VOIDmode), 0);
-	  return 1;
-	}
-    }
-  else if (code == RETURN && olabel == 0)
-    {
-      x = gen_rtx_LABEL_REF (VOIDmode, nlabel);
-      if (loc == &PATTERN (insn))
-	x = gen_rtx_SET (VOIDmode, pc_rtx, x);
-      return validate_change (insn, loc, x, 0);
-    }
-
-  if (code == SET && nlabel == 0 && SET_DEST (x) == pc_rtx
-      && GET_CODE (SET_SRC (x)) == LABEL_REF
-      && XEXP (SET_SRC (x), 0) == olabel)
-    return validate_change (insn, loc, gen_rtx_RETURN (VOIDmode), 0);
-
-  fmt = GET_RTX_FORMAT (code);
-  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
-    {
-      if (fmt[i] == 'e')
-	{
-	  if (! redirect_exp (&XEXP (x, i), olabel, nlabel, insn))
-	    return 0;
-	}
-      else if (fmt[i] == 'E')
-	{
-	  register int j;
-	  for (j = 0; j < XVECLEN (x, i); j++)
-	    if (! redirect_exp (&XVECEXP (x, i, j), olabel, nlabel, insn))
-	      return 0;
-	}
-    }
-
-  return 1;
-}
 
 /* Make jump JUMP jump to label NLABEL, assuming it used to be a tablejump.
 
diff --git a/gcc/rtl.h b/gcc/rtl.h
index 2997238..172691e 100644
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -1502,9 +1502,11 @@ extern int simplejump_p			PARAMS ((rtx));
 extern int returnjump_p			PARAMS ((rtx));
 extern int onlyjump_p			PARAMS ((rtx));
 extern int sets_cc0_p			PARAMS ((rtx));
+extern int invert_jump_1		PARAMS ((rtx, rtx));
 extern int invert_jump			PARAMS ((rtx, rtx));
 extern int rtx_renumbered_equal_p	PARAMS ((rtx, rtx));
 extern int true_regnum			PARAMS ((rtx));
+extern int redirect_jump_1		PARAMS ((rtx, rtx));
 extern int redirect_jump		PARAMS ((rtx, rtx));
 extern void jump_optimize		PARAMS ((rtx, int, int, int));
 extern void jump_optimize_minimal	PARAMS ((rtx));
@@ -1823,11 +1825,12 @@ extern int stack_regs_mentioned		PARAMS ((rtx insn));
 #endif
 
 /* In toplev.c */
-
 extern rtx stack_limit_rtx;
 
 /* In regrename.c */
-
 extern void regrename_optimize		PARAMS ((void));
 
+/* In condexec.c */
+extern void if_convert			PARAMS ((int));
+
 #endif /* _RTL_H */