Introduce rtx_sequence subclass of rtx_def

gcc/
2014-08-27  David Malcolm  <dmalcolm@redhat.com>

	* coretypes.h (class rtx_sequence): Add forward declaration.
	* rtl.h (class rtx_sequence): New subclass of rtx_def, adding
	invariant: GET_CODE (X) == SEQUENCE.
	(is_a_helper <rtx_sequence *>::test): New.
	(is_a_helper <const rtx_sequence *>::test): New.
	(rtx_sequence::len): New.
	(rtx_sequence::element): New.
	(rtx_sequence::insn): New.

From-SVN: r214591

gcc/ChangeLog

 2014-08-27  David Malcolm  <dmalcolm@redhat.com>
 
+	* coretypes.h (class rtx_sequence): Add forward declaration.
+	* rtl.h (class rtx_sequence): New subclass of rtx_def, adding
+	invariant: GET_CODE (X) == SEQUENCE.
+	(is_a_helper <rtx_sequence *>::test): New.
+	(is_a_helper <const rtx_sequence *>::test): New.
+	(rtx_sequence::len): New.
+	(rtx_sequence::element): New.
+	(rtx_sequence::insn): New.
+
+2014-08-27  David Malcolm  <dmalcolm@redhat.com>
+
 	* rtl.h (free_INSN_LIST_list): Strengthen param from rtx * to
 	rtx_insn_list **.
 	(alloc_INSN_LIST): Strengthen return type from rtx to

gcc/coretypes.h

@@ -61,6 +61,7 @@ typedef const struct rtx_def *const_rtx;
    Where possible, keep this list in the same order as in rtl.def.  */
 class rtx_def;
   class rtx_insn_list;           /* GET_CODE (X) == INSN_LIST */
+  class rtx_sequence;            /* GET_CODE (X) == SEQUENCE */
   class rtx_insn;
     class rtx_debug_insn;      /* DEBUG_INSN_P (X) */
     class rtx_nonjump_insn;    /* NONJUMP_INSN_P (X) */

gcc/rtl.h

@@ -431,6 +431,41 @@ is_a_helper <rtx_insn_list *>::test (rtx rt)
   return rt->code == INSN_LIST;
 }
 
+/* A node with invariant GET_CODE (X) == SEQUENCE i.e. a vector of rtx,
+   typically (but not always) of rtx_insn *, used in the late passes.  */
+
+class GTY(()) rtx_sequence : public rtx_def
+{
+  /* No extra fields, but adds invariant: (GET_CODE (X) == SEQUENCE).  */
+
+public:
+  /* Get number of elements in sequence.  */
+  int len () const;
+
+  /* Get i-th element of the sequence.  */
+  rtx element (int index) const;
+
+  /* Get i-th element of the sequence, with a checked cast to
+     rtx_insn *.  */
+  rtx_insn *insn (int index) const;
+};
+
+template <>
+template <>
+inline bool
+is_a_helper <rtx_sequence *>::test (rtx rt)
+{
+  return rt->code == SEQUENCE;
+}
+
+template <>
+template <>
+inline bool
+is_a_helper <const rtx_sequence *>::test (const_rtx rt)
+{
+  return rt->code == SEQUENCE;
+}
+
 class GTY(()) rtx_insn : public rtx_def
 {
   /* No extra fields, but adds the invariant:
@@ -1212,6 +1247,23 @@ inline rtx_insn *rtx_insn_list::insn () const
   return safe_as_a <rtx_insn *> (tmp);
 }
 
+/* Methods of rtx_sequence.  */
+
+inline int rtx_sequence::len () const
+{
+  return XVECLEN (this, 0);
+}
+
+inline rtx rtx_sequence::element (int index) const
+{
+  return XVECEXP (this, 0, index);
+}
+
+inline rtx_insn *rtx_sequence::insn (int index) const
+{
+  return as_a <rtx_insn *> (XVECEXP (this, 0, index));
+}
+
 /* ACCESS MACROS for particular fields of insns.  */
 
 /* Holds a unique number for each insn.