2 * This file is part of libFirm.
3 * Copyright (C) 2012 University of Karlsruhe.
8 * @brief higher level abstraction for the creation of spill and reload
9 * instructions and rematerialisation of values.
10 * @author Daniel Grund, Sebastian Hack, Matthias Braun
13 #ifndef FIRM_BE_BESPILLUTIL_H
14 #define FIRM_BE_BESPILLUTIL_H
16 #include "firm_types.h"
21 typedef struct spill_env_t spill_env_t;
24 * Creates a new spill environment.
26 spill_env_t *be_new_spill_env(ir_graph *irg);
29 * Deletes a spill environment.
31 void be_delete_spill_env(spill_env_t *senv);
34 * Return the last control flow node of a block.
36 ir_node *be_get_end_of_block_insertion_point(const ir_node *block);
39 * Marks a point until which a node must be spilled.
41 void be_add_spill(spill_env_t *senv, ir_node *to_spill, ir_node *after);
44 * Inserts a new entry into the list of reloads to place (the real nodes will
45 * be created when be_insert_spills_reloads is run). You don't have to
46 * explicitly create spill nodes, they will be created automatically after
47 * the definition of a value as soon as a reload is created. (we should add a
48 * possibility for explicit spill placement in the future)
50 * @param senv The spill environment
51 * @param to_spill The node which is about to be spilled
52 * @param before The node before the reload should be added
53 * @param reload_cls The register class the reloaded value will be put into
54 * @param allow_remat Set to 1 if the node may be rematerialized instead of
57 void be_add_reload(spill_env_t *senv, ir_node *to_spill, ir_node *before,
58 const arch_register_class_t *reload_cls, int allow_remat);
61 * Analog to be_add_reload, but places the reload "on an edge" between 2 blocks
64 void be_add_reload_on_edge(spill_env_t *senv, ir_node *to_spill, ir_node *bl,
65 int pos, const arch_register_class_t *reload_cls,
69 * The main function that places real spills/reloads (or rematerializes values)
70 * for all values where be_add_reload was called. It then rebuilds the
71 * SSA-form and updates liveness information
73 void be_insert_spills_reloads(spill_env_t *senv);
76 * There are 2 possibilities to spill a phi node: Only its value, or replacing
77 * the whole phi-node with a memory phi. Normally only the value of a phi will
78 * be spilled unless you mark the phi with be_spill_phi.
79 * (Remember that each phi needs a register, so you have to spill phis when
80 * there are more phis than registers in a block)
82 void be_spill_phi(spill_env_t *env, ir_node *node);
85 * Returns the estimated costs if a node would ge spilled. This does only return
86 * the costs for the spill instructions, not the costs for needed reload
87 * instructions. The value is weighted by the estimated execution frequency of
90 double be_get_spill_costs(spill_env_t *env, ir_node *to_spill, ir_node *before);
93 * Returns the estimated costs if a node would get reloaded at a specific place
94 * This returns the costs for a reload instructions, or when possible the costs
95 * for a rematerialisation. The value is weighted by the estimated execution
96 * frequency of the reload/rematerialisation.
98 double be_get_reload_costs(spill_env_t *env, ir_node *to_spill,
101 unsigned be_get_reload_costs_no_weight(spill_env_t *env, const ir_node *to_spill,
102 const ir_node *before);
106 * Analog to be_get_reload_costs but returns the cost if the reload would be
107 * placed "on an edge" between 2 blocks
109 double be_get_reload_costs_on_edge(spill_env_t *env, ir_node *to_spill,
110 ir_node *block, int pos);
117 } be_total_spill_costs_t;
120 * Insert a spill after the definition of the given node if there is a reload that is not dominated by some spill.
121 * This function checks whether there is a reload that is not dominated by some spill for that node.
122 * If so, it inserts a spill right after the definition of the node.
123 * @param env The spill environment.
124 * @param irn The node to check for.
126 void make_spill_locations_dominate_irn(spill_env_t *env, ir_node *irn);
129 * Collect spill/reload cost statistics for a graph.
130 * @param irg The graph.
131 * @param costs A struct which will be filled with the costs.
133 void be_get_total_spill_costs(ir_graph *irg, be_total_spill_costs_t *costs);
136 * Check, if a node is rematerializable.
137 * @param env The spill env.
140 int be_is_rematerializable(spill_env_t *env, const ir_node *to_remat, const ir_node *before);
143 * Create a be_Spill node. This function is compatible to the
144 * arch_env->new_spill callback.
146 ir_node *be_new_spill(ir_node *value, ir_node *after);
149 * Create a be_Reload node. This function is compatible to the
150 * arch_env->new_reload interface.
152 ir_node *be_new_reload(ir_node *value, ir_node *spilled, ir_node *before);