+struct arch_register_class_t {
+ unsigned index; /**< index of this register class */
+ const char *name; /**< The name of the register class.*/
+ unsigned n_regs; /**< Number of registers in this
+ class. */
+ ir_mode *mode; /**< The mode of the register class.*/
+ const arch_register_t *regs; /**< The array of registers. */
+ arch_register_class_flags_t flags; /**< register class flags. */
+ const arch_register_req_t *class_req;
+};
+
+/** return the number of registers in this register class */
+#define arch_register_class_n_regs(cls) ((cls)->n_regs)
+
+/** return the largest mode of this register class */
+#define arch_register_class_mode(cls) ((cls)->mode)
+
+/** return the name of this register class */
+#define arch_register_class_name(cls) ((cls)->name)
+
+/** return the index of this register class */
+#define arch_register_class_index(cls) ((cls)->index)
+
+/** return the register class flags */
+#define arch_register_class_flags(cls) ((cls)->flags)
+
+static inline const arch_register_t *arch_register_for_index(
+ const arch_register_class_t *cls, unsigned idx)
+{
+ assert(idx < cls->n_regs);
+ return &cls->regs[idx];
+}
+
+/**
+ * Convenience macro to check for set constraints.
+ * @param req A pointer to register requirements.
+ * @param kind The kind of constraint to check for
+ * (see arch_register_req_type_t).
+ * @return 1, If the kind of constraint is present, 0 if not.
+ */
+#define arch_register_req_is(req, kind) \
+ (((req)->type & (arch_register_req_type_ ## kind)) != 0)
+
+/**
+ * Expresses requirements to register allocation for an operand.
+ */
+struct arch_register_req_t {
+ arch_register_req_type_t type; /**< The type of the constraint. */
+ const arch_register_class_t *cls; /**< The register class this constraint
+ belongs to. */
+ const unsigned *limited; /**< allowed register bitset */
+ unsigned other_same; /**< Bitmask of ins which should use the
+ same register (should_be_same). */
+ unsigned other_different; /**< Bitmask of ins which shall use a
+ different register
+ (must_be_different) */
+ unsigned char width; /**< specifies how many sequential
+ registers are required */
+};
+
+static inline int reg_reqs_equal(const arch_register_req_t *req1,
+ const arch_register_req_t *req2)
+{
+ if (req1 == req2)
+ return 1;
+
+ if (req1->type != req2->type
+ || req1->cls != req2->cls
+ || req1->other_same != req2->other_same
+ || req1->other_different != req2->other_different)
+ return 0;
+
+ if (req1->limited != NULL) {
+ size_t n_regs;
+
+ if (req2->limited == NULL)
+ return 0;
+
+ n_regs = arch_register_class_n_regs(req1->cls);
+ if (!rbitsets_equal(req1->limited, req2->limited, n_regs))
+ return 0;
+ }
+
+ return 1;
+}
+
+/**
+ * An inverse operation returned by the backend
+ */
+struct arch_inverse_t {
+ int n; /**< count of nodes returned in nodes array */
+ int costs; /**< costs of this remat */
+
+ /** nodes for this inverse operation. shall be in schedule order.
+ * last element is the target value */
+ ir_node **nodes;
+};
+
+struct arch_irn_ops_t {
+
+ /**
+ * Classify the node.
+ * @param irn The node.
+ * @return A classification.
+ */
+ arch_irn_class_t (*classify)(const ir_node *irn);
+
+ /**
+ * Get the entity on the stack frame this node depends on.
+ * @param irn The node in question.
+ * @return The entity on the stack frame or NULL, if the node does not have
+ * a stack frame entity.
+ */
+ ir_entity *(*get_frame_entity)(const ir_node *irn);
+
+ /**
+ * Set the offset of a node carrying an entity on the stack frame.
+ * @param irn The node.
+ * @param offset The offset of the node's stack frame entity.
+ */
+ void (*set_frame_offset)(ir_node *irn, int offset);
+
+ /**
+ * Returns the delta of the stackpointer for nodes that increment or
+ * decrement the stackpointer with a constant value. (push, pop
+ * nodes on most architectures).
+ * A positive value stands for an expanding stack area, a negative value for
+ * a shrinking one.
+ *
+ * @param irn The node
+ * @return 0 if the stackpointer is not modified with a constant
+ * value, otherwise the increment/decrement value
+ */
+ int (*get_sp_bias)(const ir_node *irn);
+
+ /**
+ * Returns an inverse operation which yields the i-th argument
+ * of the given node as result.
+ *
+ * @param irn The original operation
+ * @param i Index of the argument we want the inverse operation to
+ * yield
+ * @param inverse struct to be filled with the resulting inverse op
+ * @param obstack The obstack to use for allocation of the returned nodes
+ * array
+ * @return The inverse operation or NULL if operation invertible
+ */
+ arch_inverse_t *(*get_inverse)(const ir_node *irn, int i,
+ arch_inverse_t *inverse,
+ struct obstack *obstack);
+
+ /**
+ * Get the estimated cycle count for @p irn.
+ *
+ * @param irn The node.
+ * @return The estimated cycle count for this operation
+ */
+ int (*get_op_estimated_cost)(const ir_node *irn);
+
+ /**
+ * Asks the backend whether operand @p i of @p irn can be loaded form memory
+ * internally
+ *
+ * @param irn The node.
+ * @param i Index of the argument we would like to know whether @p irn
+ * can load it form memory internally
+ * @return nonzero if argument can be loaded or zero otherwise
+ */
+ int (*possible_memory_operand)(const ir_node *irn, unsigned int i);
+
+ /**
+ * Ask the backend to assimilate @p reload of operand @p i into @p irn.
+ *
+ * @param irn The node.
+ * @param spill The spill.
+ * @param i The position of the reload.
+ */
+ void (*perform_memory_operand)(ir_node *irn, ir_node *spill,
+ unsigned int i);
+};
+
+/**
+ * Architecture interface.
+ */
+struct arch_isa_if_t {
+ /**
+ * Initialize the isa interface.
+ * @param file_handle the file handle to write the output to
+ * @return a new isa instance
+ */
+ arch_env_t *(*init)(FILE *file_handle);
+
+ /**
+ * lowers current program for target. See the documentation for
+ * be_lower_for_target() for details.
+ */
+ void (*lower_for_target)(void);
+
+ /**
+ * Free the isa instance.
+ */
+ void (*done)(void *self);
+
+ /**
+ * Called directly after initialization. Backend should handle all
+ * intrinsics here.
+ */
+ void (*handle_intrinsics)(void);
+
+ /**
+ * Get the register class which shall be used to store a value of a given
+ * mode.
+ * @param self The this pointer.
+ * @param mode The mode in question.
+ * @return A register class which can hold values of the given mode.
+ */
+ const arch_register_class_t *(*get_reg_class_for_mode)(const ir_mode *mode);
+
+ /**
+ * Get the ABI restrictions for procedure calls.
+ * @param self The this pointer.
+ * @param call_type The call type of the method (procedure) in question.
+ * @param p The array of parameter locations to be filled.
+ */
+ void (*get_call_abi)(const void *self, ir_type *call_type,
+ be_abi_call_t *abi);
+
+ /**
+ * Get the necessary alignment for storing a register of given class.
+ * @param self The isa object.
+ * @param cls The register class.
+ * @return The alignment in bytes.
+ */
+ int (*get_reg_class_alignment)(const arch_register_class_t *cls);
+
+ /**
+ * A "static" function, returns the frontend settings
+ * needed for this backend.
+ */
+ const backend_params *(*get_params)(void);
+
+ /**
+ * Return an ordered list of irgs where code should be generated for.
+ * If NULL is returned, all irg will be taken into account and they will be
+ * generated in an arbitrary order.
+ * @param self The isa object.
+ * @param irgs A flexible array ARR_F of length 0 where the backend can
+ * append the desired irgs.
+ * @return A flexible array ARR_F containing all desired irgs in the
+ * desired order.
+ */
+ ir_graph **(*get_backend_irg_list)(const void *self, ir_graph ***irgs);
+
+ /**
+ * mark node as rematerialized
+ */
+ void (*mark_remat)(ir_node *node);
+
+ /**
+ * parse an assembler constraint part and set flags according to its nature
+ * advances the *c pointer to point to the last parsed character (so if you
+ * parse a single character don't advance c)
+ */
+ asm_constraint_flags_t (*parse_asm_constraint)(const char **c);
+
+ /**
+ * returns true if the string is a valid clobbered (register) in this
+ * backend
+ */
+ int (*is_valid_clobber)(const char *clobber);
+
+ /**
+ * Initialize the code generator.
+ * @param irg A graph
+ * @return A newly created code generator.
+ */
+ void (*init_graph)(ir_graph *irg);
+
+ /**
+ * return node used as base in pic code addresses
+ */
+ ir_node* (*get_pic_base)(ir_graph *irg);
+
+ /**
+ * Called before abi introduce.
+ */
+ void (*before_abi)(ir_graph *irg);
+
+ /**
+ * Called, when the graph is being normalized.
+ */
+ void (*prepare_graph)(ir_graph *irg);
+
+ /**
+ * Called before register allocation.
+ */
+ void (*before_ra)(ir_graph *irg);
+
+ /**
+ * Called after register allocation.
+ */
+ void (*after_ra)(ir_graph *irg);
+
+ /**
+ * Called directly before done is called. This should be the last place
+ * where the irg is modified.
+ */
+ void (*finish)(ir_graph *irg);
+
+ /**
+ * Called after everything happened. This call should emit the final
+ * assembly code but avoid changing the irg.
+ * The code generator must also be de-allocated here.
+ */
+ void (*emit)(ir_graph *irg);
+};
+
+#define arch_env_done(env) ((env)->impl->done(env))
+#define arch_env_handle_intrinsics(env) \
+ do { if((env)->impl->handle_intrinsics != NULL) (env)->impl->handle_intrinsics(); } while(0)
+#define arch_env_get_reg_class_for_mode(env,mode) ((env)->impl->get_reg_class_for_mode((mode)))
+#define arch_env_get_call_abi(env,tp,abi) ((env)->impl->get_call_abi((env), (tp), (abi)))
+#define arch_env_get_reg_class_alignment(env,cls) ((env)->impl->get_reg_class_alignment((cls)))
+#define arch_env_get_params(env) ((env)->impl->get_params())
+#define arch_env_get_allowed_execution_units(env,irn) ((env)->impl->get_allowed_execution_units((irn)))
+#define arch_env_get_machine(env) ((env)->impl->get_machine(env))
+#define arch_env_get_backend_irg_list(env,irgs) ((env)->impl->get_backend_irg_list((env), (irgs)))
+#define arch_env_parse_asm_constraint(env,c) ((env)->impl->parse_asm_constraint((c))
+#define arch_env_is_valid_clobber(env,clobber) ((env)->impl->is_valid_clobber((clobber))
+#define arch_env_mark_remat(env,node) \
+ do { if ((env)->impl->mark_remat != NULL) (env)->impl->mark_remat((node)); } while(0)