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4 * This file is part of libFirm.
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15 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * @brief higher level abstraction for the creation of spill and reload
23 * instructions and rematerialisation of values.
24 * @author Daniel Grund, Sebastian Hack, Matthias Braun
27 #ifndef FIRM_BE_BESPILLUTIL_H
28 #define FIRM_BE_BESPILLUTIL_H
30 #include "firm_types.h"
35 typedef struct spill_env_t spill_env_t;
38 * Creates a new spill environment.
40 spill_env_t *be_new_spill_env(ir_graph *irg);
43 * Deletes a spill environment.
45 void be_delete_spill_env(spill_env_t *senv);
48 * Return the last control flow node of a block.
50 ir_node *be_get_end_of_block_insertion_point(const ir_node *block);
53 * Marks a point until which a node must be spilled.
55 void be_add_spill(spill_env_t *senv, ir_node *to_spill, ir_node *after);
58 * Inserts a new entry into the list of reloads to place (the real nodes will
59 * be created when be_insert_spills_reloads is run). You don't have to
60 * explicitly create spill nodes, they will be created automatically after
61 * the definition of a value as soon as a reload is created. (we should add a
62 * possibility for explicit spill placement in the future)
64 * @param senv The spill environment
65 * @param to_spill The node which is about to be spilled
66 * @param before The node before the reload should be added
67 * @param reload_cls The register class the reloaded value will be put into
68 * @param allow_remat Set to 1 if the node may be rematerialized instead of
71 void be_add_reload(spill_env_t *senv, ir_node *to_spill, ir_node *before,
72 const arch_register_class_t *reload_cls, int allow_remat);
75 * Analog to be_add_reload, but places the reload "on an edge" between 2 blocks
78 void be_add_reload_on_edge(spill_env_t *senv, ir_node *to_spill, ir_node *bl,
79 int pos, const arch_register_class_t *reload_cls,
83 * The main function that places real spills/reloads (or rematerializes values)
84 * for all values where be_add_reload was called. It then rebuilds the
85 * SSA-form and updates liveness information
87 void be_insert_spills_reloads(spill_env_t *senv);
90 * There are 2 possibilities to spill a phi node: Only its value, or replacing
91 * the whole phi-node with a memory phi. Normally only the value of a phi will
92 * be spilled unless you mark the phi with be_spill_phi.
93 * (Remember that each phi needs a register, so you have to spill phis when
94 * there are more phis than registers in a block)
96 void be_spill_phi(spill_env_t *env, ir_node *node);
99 * Returns the estimated costs if a node would ge spilled. This does only return
100 * the costs for the spill instructions, not the costs for needed reload
101 * instructions. The value is weighted by the estimated execution frequency of
104 double be_get_spill_costs(spill_env_t *env, ir_node *to_spill, ir_node *before);
107 * Returns the estimated costs if a node would get reloaded at a specific place
108 * This returns the costs for a reload instructions, or when possible the costs
109 * for a rematerialisation. The value is weighted by the estimated execution
110 * frequency of the reload/rematerialisation.
112 double be_get_reload_costs(spill_env_t *env, ir_node *to_spill,
115 unsigned be_get_reload_costs_no_weight(spill_env_t *env, const ir_node *to_spill,
116 const ir_node *before);
120 * Analog to be_get_reload_costs but returns the cost if the reload would be
121 * placed "on an edge" between 2 blocks
123 double be_get_reload_costs_on_edge(spill_env_t *env, ir_node *to_spill,
124 ir_node *block, int pos);
131 } be_total_spill_costs_t;
134 * Insert a spill after the definition of the given node if there is a reload that is not dominated by some spill.
135 * This function checks whether there is a reload that is not dominated by some spill for that node.
136 * If so, it inserts a spill right after the definition of the node.
137 * @param env The spill environment.
138 * @param irn The node to check for.
140 void make_spill_locations_dominate_irn(spill_env_t *env, ir_node *irn);
143 * Collect spill/reload cost statistics for a graph.
144 * @param irg The graph.
145 * @param costs A struct which will be filled with the costs.
147 void be_get_total_spill_costs(ir_graph *irg, be_total_spill_costs_t *costs);
150 * Check, if a node is rematerializable.
151 * @param env The spill env.
154 int be_is_rematerializable(spill_env_t *env, const ir_node *to_remat, const ir_node *before);
157 * Create a be_Spill node. This function is compatible to the
158 * arch_env->new_spill callback.
160 ir_node *be_new_spill(ir_node *value, ir_node *after);
163 * Create a be_Reload node. This function is compatible to the
164 * arch_env->new_reload interface.
166 ir_node *be_new_reload(ir_node *value, ir_node *spilled, ir_node *before);