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Diffstat (limited to 'contrib/gcc/tree-ssa-propagate.h')
-rw-r--r-- | contrib/gcc/tree-ssa-propagate.h | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/contrib/gcc/tree-ssa-propagate.h b/contrib/gcc/tree-ssa-propagate.h new file mode 100644 index 0000000..dac9a5e --- /dev/null +++ b/contrib/gcc/tree-ssa-propagate.h @@ -0,0 +1,125 @@ +/* Data structures and function declarations for the SSA value propagation + engine. + Copyright (C) 2004, 2005 Free Software Foundation, Inc. + Contributed by Diego Novillo <dnovillo@redhat.com> + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GCC is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING. If not, write to +the Free Software Foundation, 51 Franklin Street, Fifth Floor, +Boston, MA 02110-1301, USA. */ + +#ifndef _TREE_SSA_PROPAGATE_H +#define _TREE_SSA_PROPAGATE_H 1 + +/* Use the TREE_VISITED bitflag to mark statements and PHI nodes that + have been deemed varying and should not be simulated again. */ +#define DONT_SIMULATE_AGAIN(T) TREE_VISITED (T) + +/* Lattice values used for propagation purposes. Specific instances + of a propagation engine must return these values from the statement + and PHI visit functions to direct the engine. */ +enum ssa_prop_result { + /* The statement produces nothing of interest. No edges will be + added to the work lists. */ + SSA_PROP_NOT_INTERESTING, + + /* The statement produces an interesting value. The set SSA_NAMEs + returned by SSA_PROP_VISIT_STMT should be added to + INTERESTING_SSA_EDGES. If the statement being visited is a + conditional jump, SSA_PROP_VISIT_STMT should indicate which edge + out of the basic block should be marked executable. */ + SSA_PROP_INTERESTING, + + /* The statement produces a varying (i.e., useless) value and + should not be simulated again. If the statement being visited + is a conditional jump, all the edges coming out of the block + will be considered executable. */ + SSA_PROP_VARYING +}; + + +struct prop_value_d { + /* Lattice value. Each propagator is free to define its own + lattice and this field is only meaningful while propagating. + It will not be used by substitute_and_fold. */ + unsigned lattice_val; + + /* Propagated value. */ + tree value; + + /* If this value is held in an SSA name for a non-register + variable, this field holds the actual memory reference + associated with this value. This field is taken from + the LHS of the assignment that generated the associated SSA + name. However, in the case of PHI nodes, this field is copied + from the PHI arguments (assuming that all the arguments have + the same memory reference). See replace_vuses_in for a more + detailed description. */ + tree mem_ref; +}; + +typedef struct prop_value_d prop_value_t; + + +/* Type of value ranges. See value_range_d for a description of these + types. */ +enum value_range_type { VR_UNDEFINED, VR_RANGE, VR_ANTI_RANGE, VR_VARYING }; + +/* Range of values that can be associated with an SSA_NAME after VRP + has executed. */ +struct value_range_d +{ + /* Lattice value represented by this range. */ + enum value_range_type type; + + /* Minimum and maximum values represented by this range. These + values should be interpreted as follows: + + - If TYPE is VR_UNDEFINED or VR_VARYING then MIN and MAX must + be NULL. + + - If TYPE == VR_RANGE then MIN holds the minimum value and + MAX holds the maximum value of the range [MIN, MAX]. + + - If TYPE == ANTI_RANGE the variable is known to NOT + take any values in the range [MIN, MAX]. */ + tree min; + tree max; + + /* Set of SSA names whose value ranges are equivalent to this one. + This set is only valid when TYPE is VR_RANGE or VR_ANTI_RANGE. */ + bitmap equiv; +}; + +typedef struct value_range_d value_range_t; + + +/* Call-back functions used by the value propagation engine. */ +typedef enum ssa_prop_result (*ssa_prop_visit_stmt_fn) (tree, edge *, tree *); +typedef enum ssa_prop_result (*ssa_prop_visit_phi_fn) (tree); + + +/* In tree-ssa-propagate.c */ +void ssa_propagate (ssa_prop_visit_stmt_fn, ssa_prop_visit_phi_fn); +tree get_rhs (tree); +bool set_rhs (tree *, tree); +tree first_vdef (tree); +bool stmt_makes_single_load (tree); +bool stmt_makes_single_store (tree); +prop_value_t *get_value_loaded_by (tree, prop_value_t *); +bool replace_uses_in (tree, bool *, prop_value_t *); +void substitute_and_fold (prop_value_t *, bool); + +#endif /* _TREE_SSA_PROPAGATE_H */ |