146 lines
5.8 KiB
C++
146 lines
5.8 KiB
C++
/* Support routines for Value Range Propagation (VRP).
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Copyright (C) 2016-2019 Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3, or (at your option)
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any later version.
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GCC is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING3. If not see
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<http://www.gnu.org/licenses/>. */
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#ifndef GCC_VR_VALUES_H
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#define GCC_VR_VALUES_H
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/* The VR_VALUES class holds the current view of range information
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for all the SSA_NAMEs in the IL.
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It can be used to hold context sensitive range information during
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a dominator walk or it may be used to hold range information in the
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standard VRP pass as ranges are propagated through the lattice to a
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steady state.
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This information is independent of the range information that gets
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attached to SSA_NAMEs. A pass such as VRP may choose to transfer
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the global information it produces into global range information that
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gets attached to an SSA_NAME. It's unclear how useful that global
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information will be in a world where we can compute context sensitive
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range information fast or perform on-demand queries. */
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class vr_values
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{
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public:
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vr_values (void);
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~vr_values (void);
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value_range *get_value_range (const_tree);
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void set_vr_value (tree, value_range *);
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void set_defs_to_varying (gimple *);
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bool update_value_range (const_tree, value_range *);
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tree op_with_constant_singleton_value_range (tree);
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void adjust_range_with_scev (value_range *, struct loop *, gimple *, tree);
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tree vrp_evaluate_conditional (tree_code, tree, tree, gimple *);
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void dump_all_value_ranges (FILE *);
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void extract_range_for_var_from_comparison_expr (tree, enum tree_code,
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tree, tree, value_range *);
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void extract_range_from_phi_node (gphi *, value_range *);
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void extract_range_basic (value_range *, gimple *);
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void extract_range_from_stmt (gimple *, edge *, tree *, value_range *);
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void vrp_visit_cond_stmt (gcond *, edge *);
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void simplify_cond_using_ranges_2 (gcond *);
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bool simplify_stmt_using_ranges (gimple_stmt_iterator *);
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/* Indicate that propagation through the lattice is complete. */
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void set_lattice_propagation_complete (void) { values_propagated = true; }
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/* Allocate a new value_range object. */
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value_range *allocate_value_range (void)
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{ return vrp_value_range_pool.allocate (); }
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/* */
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void cleanup_edges_and_switches (void);
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private:
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bool vrp_stmt_computes_nonzero (gimple *);
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bool op_with_boolean_value_range_p (tree);
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bool check_for_binary_op_overflow (enum tree_code, tree, tree, tree, bool *);
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value_range *get_vr_for_comparison (int, value_range *);
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tree compare_name_with_value (enum tree_code, tree, tree, bool *, bool);
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tree compare_names (enum tree_code, tree, tree, bool *);
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bool two_valued_val_range_p (tree, tree *, tree *);
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tree vrp_evaluate_conditional_warnv_with_ops_using_ranges (enum tree_code,
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tree, tree,
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bool *);
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tree vrp_evaluate_conditional_warnv_with_ops (enum tree_code,
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tree, tree, bool,
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bool *, bool *);
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void extract_range_from_assignment (value_range *, gassign *);
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void extract_range_from_assert (value_range *, tree);
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void extract_range_from_ssa_name (value_range *, tree);
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void extract_range_from_binary_expr (value_range *, enum tree_code,
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tree, tree, tree);
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void extract_range_from_unary_expr (value_range *, enum tree_code,
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tree, tree);
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void extract_range_from_cond_expr (value_range *, gassign *);
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void extract_range_from_comparison (value_range *, enum tree_code,
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tree, tree, tree);
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void vrp_visit_assignment_or_call (gimple*, tree *, value_range *);
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void vrp_visit_switch_stmt (gswitch *, edge *);
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bool simplify_truth_ops_using_ranges (gimple_stmt_iterator *, gimple *);
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bool simplify_div_or_mod_using_ranges (gimple_stmt_iterator *, gimple *);
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bool simplify_abs_using_ranges (gimple_stmt_iterator *, gimple *);
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bool simplify_bit_ops_using_ranges (gimple_stmt_iterator *, gimple *);
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bool simplify_min_or_max_using_ranges (gimple_stmt_iterator *, gimple *);
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bool simplify_cond_using_ranges_1 (gcond *);
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bool simplify_switch_using_ranges (gswitch *);
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bool simplify_float_conversion_using_ranges (gimple_stmt_iterator *,
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gimple *);
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bool simplify_internal_call_using_ranges (gimple_stmt_iterator *, gimple *);
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/* Allocation pools for value_range objects. */
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object_allocator<value_range> vrp_value_range_pool;
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/* This probably belongs in the lattice rather than in here. */
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bool values_propagated;
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/* Allocations for equivalences all come from this obstack. */
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bitmap_obstack vrp_equiv_obstack;
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/* Value range array. After propagation, VR_VALUE[I] holds the range
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of values that SSA name N_I may take. */
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unsigned int num_vr_values;
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value_range **vr_value;
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/* For a PHI node which sets SSA name N_I, VR_COUNTS[I] holds the
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number of executable edges we saw the last time we visited the
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node. */
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int *vr_phi_edge_counts;
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/* Vectors of edges that need removing and switch statements that
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need updating. It is expected that a pass using the simplification
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routines will, at the end of the pass, clean up the edges and
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switch statements. The class dtor will try to detect cases
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that do not follow that expectation. */
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struct switch_update {
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gswitch *stmt;
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tree vec;
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};
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vec<edge> to_remove_edges;
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vec<switch_update> to_update_switch_stmts;
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};
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extern tree get_output_for_vrp (gimple *);
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#endif /* GCC_VR_VALUES_H */
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