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/*
* This file is part of libFirm.
* Copyright (C) 2012 University of Karlsruhe.
*/
/**
* @file
* @brief SSA construction for a set of nodes
* @author Sebastian Hack, Daniel Grund, Matthias Braun, Christian Wuerdig
* @date 30.03.2007
*
* The problem: Given a value and a set of "copies" that are known to
* represent the same abstract value, rewire all usages of the original value
* to their closest copy while introducing phis as necessary.
*
* Algorithm: Mark all blocks in the iterated dominance frontiers of the value
* and its copies. Link the copies ordered by dominance to the blocks. Then
* we search for each use all definitions in the current block, if none is
* found, then we search one in the immediate dominator. If we are in a block
* of the dominance frontier, create a phi and do the same search for all
* phi arguments.
*
* A copy in this context means, that you want to introduce several new
* abstract values (in Firm: nodes) for which you know, that they
* represent the same concrete value. This is the case if you
* - copy
* - spill and reload
* - re-materialize
* a value.
*
* This function reroutes all uses of the original value to the copies in the
* corresponding dominance subtrees and creates Phi functions where necessary.
*/
#ifndef FIRM_BE_BESSACONSTR_H
#define FIRM_BE_BESSACONSTR_H
#include <stdbool.h>
#include "firm_types.h"
#include "belive.h"
#include "pdeq.h"
#include "irnodemap.h"
#include "obst.h"
typedef struct be_ssa_construction_env_t {
ir_graph *irg;
const arch_register_req_t *phi_req;
deq_t worklist;
ir_node **new_phis;
bool iterated_domfront_calculated;
ir_nodemap infos;
struct obstack obst;
} be_ssa_construction_env_t;
/**
* Initializes an SSA construction environment.
*
* @param env an empty SSA construction environment
* @param irg the graph
*/
void be_ssa_construction_init(be_ssa_construction_env_t *env, ir_graph *irg);
void be_ssa_construction_add_copy(be_ssa_construction_env_t *env,
ir_node *value);
void be_ssa_construction_add_copies(be_ssa_construction_env_t *env,
ir_node **copies, size_t copies_len);
/**
* Reconstructs the SSA form for all users of node @p node
*/
void be_ssa_construction_fix_users(be_ssa_construction_env_t *env,
ir_node *node);
void be_ssa_construction_fix_users_array(be_ssa_construction_env_t *env,
ir_node **nodes, size_t nodes_len);
/**
* Recompute the liveness of the inserted phis.
* @note Remember that you have to call update_liveness on the copies yourself
*/
void be_ssa_construction_update_liveness_phis(be_ssa_construction_env_t *env,
be_lv_t *lv);
ir_node **be_ssa_construction_get_new_phis(be_ssa_construction_env_t *env);
/**
* Destroys an SSA construction environment.
*/
void be_ssa_construction_destroy(be_ssa_construction_env_t *env);
#endif
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