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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
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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
28 #ifndef FIRM_BE_BESPILL_H
29 #define FIRM_BE_BESPILL_H
31 #include "firm_types.h"
37 typedef struct spill_env_t spill_env_t;
40 * Creates a new spill environment.
42 spill_env_t *be_new_spill_env(be_irg_t *birg);
45 * Deletes a spill environment.
47 void be_delete_spill_env(spill_env_t *senv);
49 ir_node *be_get_end_of_block_insertion_point(const ir_node *block);
52 * Inserts a new entry into the list of reloads to place (the real nodes will
53 * be created when be_insert_spills_reloads is run). You don't have to
54 * explicitly create spill nodes, they will be created automatically after
55 * the definition of a value as soon as a reload is created. (we should add a
56 * possibility for explicit spill placement in the future)
58 * @param senv The spill environment
59 * @param to_spill The node which is about to be spilled
60 * @param before The node before the reload should be added
61 * @param reload_cls The register class the reloaded value will be put into
62 * @param allow_remat Set to 1 if the node may be rematerialized instead of
65 void be_add_reload(spill_env_t *senv, ir_node *to_spill, ir_node *before,
66 const arch_register_class_t *reload_cls, int allow_remat);
69 * Add a reload at the end of a block.
70 * Similar to be_add_reload_on_edge().
72 void be_add_reload_at_end(spill_env_t *env, ir_node *to_spill, const ir_node *block,
73 const arch_register_class_t *reload_cls,
77 * Analog to be_add_reload, but places the reload "on an edge" between 2 blocks
80 void be_add_reload_on_edge(spill_env_t *senv, ir_node *to_spill, ir_node *bl,
81 int pos, const arch_register_class_t *reload_cls,
85 * Analog to be_add_reload but adds an already created rematerialized node.
87 void be_add_remat(spill_env_t *env, ir_node *to_spill, ir_node *before,
88 ir_node *rematted_node);
91 * The main function that places real spills/reloads (or rematerializes values)
92 * for all values where be_add_reload was called. It then rebuilds the
93 * SSA-form and updates liveness information
95 void be_insert_spills_reloads(spill_env_t *senv);
98 * There are 2 possibilities to spill a phi node: Only it's value, or replacing
99 * the whole phi-node with a memory phi. Normally only the value of a phi will
100 * be spilled unless you mark the phi with be_spill_phi.
101 * (Remember that each phi needs a register, so you have to spill phis when
102 * there are more phis than registers in a block)
104 void be_spill_phi(spill_env_t *env, ir_node *node);
107 * Returns the estimated costs if a node would ge spilled. This does only return
108 * the costs for the spill instructions, not the costs for needed reload
109 * instructions. The value is weighted by the estimated execution frequency of
112 double be_get_spill_costs(spill_env_t *env, ir_node *to_spill, ir_node *after);
115 * Returns the estimated costs if a node would get reloaded at a specific place
116 * This returns the costs for a reload instructions, or when possible the costs
117 * for a rematerialisation. The value is weighted by the estimated execution
118 * frequency of the reload/rematerialisation.
120 double be_get_reload_costs(spill_env_t *env, ir_node *to_spill,
124 * Analog to be_get_reload_costs but returns the cost if the reload would be
125 * placed "on an edge" between 2 blocks
127 double be_get_reload_costs_on_edge(spill_env_t *env, ir_node *to_spill,
128 ir_node *block, int pos);
135 } be_total_spill_costs_t;
138 * Collect spill/reload cost statistics for a graph.
139 * @param birg The backend graph.
140 * @param costs A struct which will be filled with the costs.
142 void be_get_total_spill_costs(be_irg_t *birg, be_total_spill_costs_t *costs);
145 * Check, if a node is rematerializable.
146 * @param env The spill env.
149 int be_is_rematerializable(spill_env_t *env, const ir_node *to_remat, const ir_node *before);