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22 * @brief peephole optimisation framework
23 * @author Matthias Braun
31 extern ir_node **register_values;
33 static inline ir_node *be_peephole_get_value(unsigned register_idx)
35 return register_values[register_idx];
38 static inline ir_node *be_peephole_get_reg_value(const arch_register_t *reg)
40 unsigned register_idx = reg->global_index;
41 return be_peephole_get_value(register_idx);
45 * Datatype of the generic op handler for optimisation.
47 typedef void (*peephole_opt_func) (ir_node *node);
50 * Notify the peephole phase about a newly added node, so it can update its
51 * internal state. This is not needed for the new node, when
52 * be_peephole_exchange() is used.
53 * Note: Contrary to normal exchange you mustn't remove the node from the
54 * schedule either before exchange. Exchange will do that for you.
56 void be_peephole_new_node(ir_node *nw);
59 * When doing peephole optimisation use this function instead of plain
60 * exchange(), so it can update its internal state. */
61 void be_peephole_exchange(ir_node *old, ir_node *nw);
64 * Tries to optimize a beIncSp node with its previous IncSP node.
65 * Must be run from a be_peephole_opt() context.
67 * @param node a be_IncSP node
69 * @return the new IncSP node or node itself
71 ir_node *be_peephole_IncSP_IncSP(ir_node *node);
73 bool be_has_only_one_user(ir_node *node);
76 * In a scheduled program with registers assigned,
77 * checks wether @p node can be moved before @p before without changing program
80 * Note: It is allowed to use this function without being in a peephole
83 bool be_can_move_down(ir_heights_t *heights, const ir_node *node,
84 const ir_node *before);
86 bool be_can_move_up(ir_heights_t *heights, const ir_node *node,
87 const ir_node *after);
90 * Do peephole optimisations. It traverses the schedule of all blocks in
91 * backward direction. The register_values variable indicates which (live)
92 * values are stored in which register.
93 * The generic op handler is called for each node if it exists. That's where
94 * backend specific optimisations should be performed based on the
95 * register-liveness information.
97 void be_peephole_opt(ir_graph *irg);