+extern enum reg_note ds_to_dk (ds_t);
+extern ds_t dk_to_ds (enum reg_note);
+
+/* Information about the dependency. */
+struct _dep
+{
+ /* Producer. */
+ rtx pro;
+
+ /* Consumer. */
+ rtx con;
+
+ /* Dependency major type. This field is superseded by STATUS below.
+ Though, it is still in place because some targets use it. */
+ enum reg_note type;
+
+ /* Dependency status. This field holds all dependency types and additional
+ information for speculative dependencies. */
+ ds_t status;
+
+ /* Cached cost of the dependency. */
+ int cost;
+};
+
+typedef struct _dep dep_def;
+typedef dep_def *dep_t;
+
+#define DEP_PRO(D) ((D)->pro)
+#define DEP_CON(D) ((D)->con)
+#define DEP_TYPE(D) ((D)->type)
+#define DEP_STATUS(D) ((D)->status)
+#define DEP_COST(D) ((D)->cost)
+
+#define UNKNOWN_DEP_COST INT_MIN
+
+/* Functions to work with dep. */
+
+extern void init_dep_1 (dep_t, rtx, rtx, enum reg_note, ds_t);
+extern void init_dep (dep_t, rtx, rtx, enum reg_note);
+
+extern void sd_debug_dep (dep_t);
+
+/* Definition of this struct resides below. */
+struct _dep_node;
+typedef struct _dep_node *dep_node_t;
+
+/* A link in the dependency list. This is essentially an equivalent of a
+ single {INSN, DEPS}_LIST rtx. */
+struct _dep_link
+{
+ /* Dep node with all the data. */
+ dep_node_t node;
+
+ /* Next link in the list. For the last one it is NULL. */
+ struct _dep_link *next;
+
+ /* Pointer to the next field of the previous link in the list.
+ For the first link this points to the deps_list->first.
+
+ With help of this field it is easy to remove and insert links to the
+ list. */
+ struct _dep_link **prev_nextp;
+};
+typedef struct _dep_link *dep_link_t;
+
+#define DEP_LINK_NODE(N) ((N)->node)
+#define DEP_LINK_NEXT(N) ((N)->next)
+#define DEP_LINK_PREV_NEXTP(N) ((N)->prev_nextp)
+
+/* Macros to work dep_link. For most usecases only part of the dependency
+ information is need. These macros conveniently provide that piece of
+ information. */
+
+#define DEP_LINK_DEP(N) (DEP_NODE_DEP (DEP_LINK_NODE (N)))
+#define DEP_LINK_PRO(N) (DEP_PRO (DEP_LINK_DEP (N)))
+#define DEP_LINK_CON(N) (DEP_CON (DEP_LINK_DEP (N)))
+#define DEP_LINK_TYPE(N) (DEP_TYPE (DEP_LINK_DEP (N)))
+#define DEP_LINK_STATUS(N) (DEP_STATUS (DEP_LINK_DEP (N)))
+
+/* A list of dep_links. */
+struct _deps_list
+{
+ /* First element. */
+ dep_link_t first;
+
+ /* Total number of elements in the list. */
+ int n_links;
+};
+typedef struct _deps_list *deps_list_t;
+
+#define DEPS_LIST_FIRST(L) ((L)->first)
+#define DEPS_LIST_N_LINKS(L) ((L)->n_links)
+
+/* Suppose we have a dependence Y between insn pro1 and con1, where pro1 has
+ additional dependents con0 and con2, and con1 is dependent on additional
+ insns pro0 and pro1:
+
+ .con0 pro0
+ . ^ |
+ . | |
+ . | |
+ . X A
+ . | |
+ . | |
+ . | V
+ .pro1--Y-->con1
+ . | ^
+ . | |
+ . | |
+ . Z B
+ . | |
+ . | |
+ . V |
+ .con2 pro2
+
+ This is represented using a "dep_node" for each dependence arc, which are
+ connected as follows (diagram is centered around Y which is fully shown;
+ other dep_nodes shown partially):
+
+ . +------------+ +--------------+ +------------+
+ . : dep_node X : | dep_node Y | : dep_node Z :
+ . : : | | : :
+ . : : | | : :
+ . : forw : | forw | : forw :
+ . : +--------+ : | +--------+ | : +--------+ :
+ forw_deps : |dep_link| : | |dep_link| | : |dep_link| :
+ +-----+ : | +----+ | : | | +----+ | | : | +----+ | :
+ |first|----->| |next|-+------+->| |next|-+--+----->| |next|-+--->NULL
+ +-----+ : | +----+ | : | | +----+ | | : | +----+ | :
+ . ^ ^ : | ^ | : | | ^ | | : | | :
+ . | | : | | | : | | | | | : | | :
+ . | +--<----+--+ +--+---<--+--+--+ +--+--+--<---+--+ | :
+ . | : | | | : | | | | | : | | | :
+ . | : | +----+ | : | | +----+ | | : | +----+ | :
+ . | : | |prev| | : | | |prev| | | : | |prev| | :
+ . | : | |next| | : | | |next| | | : | |next| | :
+ . | : | +----+ | : | | +----+ | | : | +----+ | :
+ . | : | | :<-+ | | | |<-+ : | | :<-+
+ . | : | +----+ | : | | | +----+ | | | : | +----+ | : |
+ . | : | |node|-+----+ | | |node|-+--+--+ : | |node|-+----+
+ . | : | +----+ | : | | +----+ | | : | +----+ | :
+ . | : | | : | | | | : | | :
+ . | : +--------+ : | +--------+ | : +--------+ :
+ . | : : | | : :
+ . | : SAME pro1 : | +--------+ | : SAME pro1 :
+ . | : DIFF con0 : | |dep | | : DIFF con2 :
+ . | : : | | | | : :
+ . | | | +----+ | |
+ .RTX<------------------------+--+-|pro1| | |
+ .pro1 | | +----+ | |
+ . | | | |
+ . | | +----+ | |
+ .RTX<------------------------+--+-|con1| | |
+ .con1 | | +----+ | |
+ . | | | | |
+ . | | | +----+ | |
+ . | | | |kind| | |
+ . | | | +----+ | |
+ . | : : | | |stat| | | : :
+ . | : DIFF pro0 : | | +----+ | | : DIFF pro2 :
+ . | : SAME con1 : | | | | : SAME con1 :
+ . | : : | +--------+ | : :
+ . | : : | | : :
+ . | : back : | back | : back :
+ . v : +--------+ : | +--------+ | : +--------+ :
+ back_deps : |dep_link| : | |dep_link| | : |dep_link| :
+ +-----+ : | +----+ | : | | +----+ | | : | +----+ | :
+ |first|----->| |next|-+------+->| |next|-+--+----->| |next|-+--->NULL
+ +-----+ : | +----+ | : | | +----+ | | : | +----+ | :
+ . ^ : | ^ | : | | ^ | | : | | :
+ . | : | | | : | | | | | : | | :
+ . +--<----+--+ +--+---<--+--+--+ +--+--+--<---+--+ | :
+ . : | | | : | | | | | : | | | :
+ . : | +----+ | : | | +----+ | | : | +----+ | :
+ . : | |prev| | : | | |prev| | | : | |prev| | :
+ . : | |next| | : | | |next| | | : | |next| | :
+ . : | +----+ | : | | +----+ | | : | +----+ | :
+ . : | | :<-+ | | | |<-+ : | | :<-+
+ . : | +----+ | : | | | +----+ | | | : | +----+ | : |
+ . : | |node|-+----+ | | |node|-+--+--+ : | |node|-+----+
+ . : | +----+ | : | | +----+ | | : | +----+ | :
+ . : | | : | | | | : | | :
+ . : +--------+ : | +--------+ | : +--------+ :
+ . : : | | : :
+ . : dep_node A : | dep_node Y | : dep_node B :
+ . +------------+ +--------------+ +------------+
+*/
+
+struct _dep_node
+{
+ /* Backward link. */
+ struct _dep_link back;
+
+ /* The dep. */
+ struct _dep dep;
+
+ /* Forward link. */
+ struct _dep_link forw;
+};
+
+#define DEP_NODE_BACK(N) (&(N)->back)
+#define DEP_NODE_DEP(N) (&(N)->dep)
+#define DEP_NODE_FORW(N) (&(N)->forw)
+
+/* The following enumeration values tell us what dependencies we
+ should use to implement the barrier. We use true-dependencies for
+ TRUE_BARRIER and anti-dependencies for MOVE_BARRIER. */
+enum reg_pending_barrier_mode
+{
+ NOT_A_BARRIER = 0,
+ MOVE_BARRIER,
+ TRUE_BARRIER
+};
+
+/* Whether a register movement is associated with a call. */
+enum post_call_group
+{
+ not_post_call,
+ post_call,
+ post_call_initial
+};
+
+/* Insns which affect pseudo-registers. */
+struct deps_reg
+{
+ rtx uses;
+ rtx sets;
+ rtx implicit_sets;
+ rtx clobbers;
+ int uses_length;
+ int clobbers_length;
+};
+