/* Tracking equivalence classes and constraints at a point on an execution path. Copyright (C) 2019-2020 Free Software Foundation, Inc. Contributed by David Malcolm . 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 3, 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 COPYING3. If not see . */ #include "config.h" #include "system.h" #include "coretypes.h" #include "tree.h" #include "function.h" #include "basic-block.h" #include "gimple.h" #include "gimple-iterator.h" #include "fold-const.h" #include "selftest.h" #include "diagnostic-core.h" #include "graphviz.h" #include "function.h" #include "analyzer/analyzer.h" #include "ordered-hash-map.h" #include "options.h" #include "cgraph.h" #include "cfg.h" #include "digraph.h" #include "analyzer/supergraph.h" #include "sbitmap.h" #include "bitmap.h" #include "tristate.h" #include "analyzer/region-model.h" #include "analyzer/constraint-manager.h" #include "analyzer/analyzer-selftests.h" #if ENABLE_ANALYZER namespace ana { /* One of the end-points of a range. */ struct bound { bound () : m_constant (NULL_TREE), m_closed (false) {} bound (tree constant, bool closed) : m_constant (constant), m_closed (closed) {} void ensure_closed (bool is_upper); const char * get_relation_as_str () const; tree m_constant; bool m_closed; }; /* A range of values, used for determining if a value has been constrained to just one possible constant value. */ struct range { range () : m_lower_bound (), m_upper_bound () {} range (const bound &lower, const bound &upper) : m_lower_bound (lower), m_upper_bound (upper) {} void dump (pretty_printer *pp) const; bool constrained_to_single_element (tree *out); bound m_lower_bound; bound m_upper_bound; }; /* struct bound. */ /* Ensure that this bound is closed by converting an open bound to a closed one. */ void bound::ensure_closed (bool is_upper) { if (!m_closed) { /* Offset by 1 in the appropriate direction. For example, convert 3 < x into 4 <= x, and convert x < 5 into x <= 4. */ gcc_assert (CONSTANT_CLASS_P (m_constant)); m_constant = fold_build2 (is_upper ? MINUS_EXPR : PLUS_EXPR, TREE_TYPE (m_constant), m_constant, integer_one_node); gcc_assert (CONSTANT_CLASS_P (m_constant)); m_closed = true; } } /* Get "<=" vs "<" for this bound. */ const char * bound::get_relation_as_str () const { if (m_closed) return "<="; else return "<"; } /* struct range. */ /* Dump this range to PP, which must support %E for tree. */ void range::dump (pretty_printer *pp) const { pp_printf (pp, "%qE %s x %s %qE", m_lower_bound.m_constant, m_lower_bound.get_relation_as_str (), m_upper_bound.get_relation_as_str (), m_upper_bound.m_constant); } /* Determine if there is only one possible value for this range. If so, return true and write the constant to *OUT. Otherwise, return false. */ bool range::constrained_to_single_element (tree *out) { if (!INTEGRAL_TYPE_P (TREE_TYPE (m_lower_bound.m_constant))) return false; if (!INTEGRAL_TYPE_P (TREE_TYPE (m_upper_bound.m_constant))) return false; /* Convert any open bounds to closed bounds. */ m_lower_bound.ensure_closed (false); m_upper_bound.ensure_closed (true); // Are they equal? tree comparison = fold_binary (EQ_EXPR, boolean_type_node, m_lower_bound.m_constant, m_upper_bound.m_constant); if (comparison == boolean_true_node) { *out = m_lower_bound.m_constant; return true; } else return false; } /* class equiv_class. */ /* equiv_class's default ctor. */ equiv_class::equiv_class () : m_constant (NULL_TREE), m_cst_sid (svalue_id::null ()), m_vars () { } /* equiv_class's copy ctor. */ equiv_class::equiv_class (const equiv_class &other) : m_constant (other.m_constant), m_cst_sid (other.m_cst_sid), m_vars (other.m_vars.length ()) { int i; svalue_id *sid; FOR_EACH_VEC_ELT (other.m_vars, i, sid) m_vars.quick_push (*sid); } /* Print an all-on-one-line representation of this equiv_class to PP, which must support %E for trees. */ void equiv_class::print (pretty_printer *pp) const { pp_character (pp, '{'); int i; svalue_id *sid; FOR_EACH_VEC_ELT (m_vars, i, sid) { if (i > 0) pp_string (pp, " == "); sid->print (pp); } if (m_constant) { if (i > 0) pp_string (pp, " == "); pp_printf (pp, "%qE", m_constant); } pp_character (pp, '}'); } /* Generate a hash value for this equiv_class. */ hashval_t equiv_class::hash () const { inchash::hash hstate; int i; svalue_id *sid; inchash::add_expr (m_constant, hstate); FOR_EACH_VEC_ELT (m_vars, i, sid) inchash::add (*sid, hstate); return hstate.end (); } /* Equality operator for equiv_class. */ bool equiv_class::operator== (const equiv_class &other) { if (m_constant != other.m_constant) return false; // TODO: use tree equality here? /* FIXME: should we compare m_cst_sid? */ if (m_vars.length () != other.m_vars.length ()) return false; int i; svalue_id *sid; FOR_EACH_VEC_ELT (m_vars, i, sid) if (! (*sid == other.m_vars[i])) return false; return true; } /* Add SID to this equiv_class, using CM to check if it's a constant. */ void equiv_class::add (svalue_id sid, const constraint_manager &cm) { gcc_assert (!sid.null_p ()); if (tree cst = cm.maybe_get_constant (sid)) { gcc_assert (CONSTANT_CLASS_P (cst)); /* FIXME: should we canonicalize which svalue is the constant when there are multiple equal constants? */ m_constant = cst; m_cst_sid = sid; } m_vars.safe_push (sid); } /* Remove SID from this equivalence class. Return true if SID was the last var in the equivalence class (suggesting a possible leak). */ bool equiv_class::del (svalue_id sid) { gcc_assert (!sid.null_p ()); gcc_assert (sid != m_cst_sid); int i; svalue_id *iv; FOR_EACH_VEC_ELT (m_vars, i, iv) { if (*iv == sid) { m_vars[i] = m_vars[m_vars.length () - 1]; m_vars.pop (); return m_vars.length () == 0; } } /* SID must be in the class. */ gcc_unreachable (); return false; } /* Get a representative member of this class, for handling cases where the IDs can change mid-traversal. */ svalue_id equiv_class::get_representative () const { if (!m_cst_sid.null_p ()) return m_cst_sid; else { gcc_assert (m_vars.length () > 0); return m_vars[0]; } } /* Remap all svalue_ids within this equiv_class using MAP. */ void equiv_class::remap_svalue_ids (const svalue_id_map &map) { int i; svalue_id *iv; FOR_EACH_VEC_ELT (m_vars, i, iv) map.update (iv); map.update (&m_cst_sid); } /* Comparator for use by equiv_class::canonicalize. */ static int svalue_id_cmp_by_id (const void *p1, const void *p2) { const svalue_id *sid1 = (const svalue_id *)p1; const svalue_id *sid2 = (const svalue_id *)p2; return sid1->as_int () - sid2->as_int (); } /* Sort the svalues_ids within this equiv_class. */ void equiv_class::canonicalize () { m_vars.qsort (svalue_id_cmp_by_id); } /* Get a debug string for C_OP. */ const char * constraint_op_code (enum constraint_op c_op) { switch (c_op) { default: gcc_unreachable (); case CONSTRAINT_NE: return "!="; case CONSTRAINT_LT: return "<"; case CONSTRAINT_LE: return "<="; } } /* Convert C_OP to an enum tree_code. */ enum tree_code constraint_tree_code (enum constraint_op c_op) { switch (c_op) { default: gcc_unreachable (); case CONSTRAINT_NE: return NE_EXPR; case CONSTRAINT_LT: return LT_EXPR; case CONSTRAINT_LE: return LE_EXPR; } } /* Given "lhs C_OP rhs", determine "lhs T_OP rhs". For example, given "x < y", then "x > y" is false. */ static tristate eval_constraint_op_for_op (enum constraint_op c_op, enum tree_code t_op) { switch (c_op) { default: gcc_unreachable (); case CONSTRAINT_NE: if (t_op == EQ_EXPR) return tristate (tristate::TS_FALSE); if (t_op == NE_EXPR) return tristate (tristate::TS_TRUE); break; case CONSTRAINT_LT: if (t_op == LT_EXPR || t_op == LE_EXPR || t_op == NE_EXPR) return tristate (tristate::TS_TRUE); if (t_op == EQ_EXPR || t_op == GT_EXPR || t_op == GE_EXPR) return tristate (tristate::TS_FALSE); break; case CONSTRAINT_LE: if (t_op == LE_EXPR) return tristate (tristate::TS_TRUE); if (t_op == GT_EXPR) return tristate (tristate::TS_FALSE); break; } return tristate (tristate::TS_UNKNOWN); } /* class constraint. */ /* Print this constraint to PP (which must support %E for trees), using CM to look up equiv_class instances from ids. */ void constraint::print (pretty_printer *pp, const constraint_manager &cm) const { m_lhs.print (pp); pp_string (pp, ": "); m_lhs.get_obj (cm).print (pp); pp_string (pp, " "); pp_string (pp, constraint_op_code (m_op)); pp_string (pp, " "); m_rhs.print (pp); pp_string (pp, ": "); m_rhs.get_obj (cm).print (pp); } /* Generate a hash value for this constraint. */ hashval_t constraint::hash () const { inchash::hash hstate; hstate.add_int (m_lhs.m_idx); hstate.add_int (m_op); hstate.add_int (m_rhs.m_idx); return hstate.end (); } /* Equality operator for constraints. */ bool constraint::operator== (const constraint &other) const { if (m_lhs != other.m_lhs) return false; if (m_op != other.m_op) return false; if (m_rhs != other.m_rhs) return false; return true; } /* class equiv_class_id. */ /* Get the underlying equiv_class for this ID from CM. */ const equiv_class & equiv_class_id::get_obj (const constraint_manager &cm) const { return cm.get_equiv_class_by_index (m_idx); } /* Access the underlying equiv_class for this ID from CM. */ equiv_class & equiv_class_id::get_obj (constraint_manager &cm) const { return cm.get_equiv_class_by_index (m_idx); } /* Print this equiv_class_id to PP. */ void equiv_class_id::print (pretty_printer *pp) const { if (null_p ()) pp_printf (pp, "null"); else pp_printf (pp, "ec%i", m_idx); } /* class constraint_manager. */ /* constraint_manager's copy ctor. */ constraint_manager::constraint_manager (const constraint_manager &other) : m_equiv_classes (other.m_equiv_classes.length ()), m_constraints (other.m_constraints.length ()) { int i; equiv_class *ec; FOR_EACH_VEC_ELT (other.m_equiv_classes, i, ec) m_equiv_classes.quick_push (new equiv_class (*ec)); constraint *c; FOR_EACH_VEC_ELT (other.m_constraints, i, c) m_constraints.quick_push (*c); } /* constraint_manager's assignment operator. */ constraint_manager& constraint_manager::operator= (const constraint_manager &other) { gcc_assert (m_equiv_classes.length () == 0); gcc_assert (m_constraints.length () == 0); int i; equiv_class *ec; m_equiv_classes.reserve (other.m_equiv_classes.length ()); FOR_EACH_VEC_ELT (other.m_equiv_classes, i, ec) m_equiv_classes.quick_push (new equiv_class (*ec)); constraint *c; m_constraints.reserve (other.m_constraints.length ()); FOR_EACH_VEC_ELT (other.m_constraints, i, c) m_constraints.quick_push (*c); return *this; } /* Generate a hash value for this constraint_manager. */ hashval_t constraint_manager::hash () const { inchash::hash hstate; int i; equiv_class *ec; constraint *c; FOR_EACH_VEC_ELT (m_equiv_classes, i, ec) hstate.merge_hash (ec->hash ()); FOR_EACH_VEC_ELT (m_constraints, i, c) hstate.merge_hash (c->hash ()); return hstate.end (); } /* Equality operator for constraint_manager. */ bool constraint_manager::operator== (const constraint_manager &other) const { if (m_equiv_classes.length () != other.m_equiv_classes.length ()) return false; if (m_constraints.length () != other.m_constraints.length ()) return false; int i; equiv_class *ec; FOR_EACH_VEC_ELT (m_equiv_classes, i, ec) if (!(*ec == *other.m_equiv_classes[i])) return false; constraint *c; FOR_EACH_VEC_ELT (m_constraints, i, c) if (!(*c == other.m_constraints[i])) return false; return true; } /* Print this constraint_manager to PP (which must support %E for trees). */ void constraint_manager::print (pretty_printer *pp) const { pp_string (pp, "{"); int i; equiv_class *ec; FOR_EACH_VEC_ELT (m_equiv_classes, i, ec) { if (i > 0) pp_string (pp, ", "); equiv_class_id (i).print (pp); pp_string (pp, ": "); ec->print (pp); } pp_string (pp, " | "); constraint *c; FOR_EACH_VEC_ELT (m_constraints, i, c) { if (i > 0) pp_string (pp, " && "); c->print (pp, *this); } pp_printf (pp, "}"); } /* Dump a multiline representation of this constraint_manager to PP (which must support %E for trees). */ void constraint_manager::dump_to_pp (pretty_printer *pp) const { // TODO pp_string (pp, " equiv classes:"); pp_newline (pp); int i; equiv_class *ec; FOR_EACH_VEC_ELT (m_equiv_classes, i, ec) { pp_string (pp, " "); equiv_class_id (i).print (pp); pp_string (pp, ": "); ec->print (pp); pp_newline (pp); } pp_string (pp, " constraints:"); pp_newline (pp); constraint *c; FOR_EACH_VEC_ELT (m_constraints, i, c) { pp_printf (pp, " %i: ", i); c->print (pp, *this); pp_newline (pp); } } /* Dump a multiline representation of this constraint_manager to FP. */ void constraint_manager::dump (FILE *fp) const { pretty_printer pp; pp_format_decoder (&pp) = default_tree_printer; pp_show_color (&pp) = pp_show_color (global_dc->printer); pp.buffer->stream = fp; dump_to_pp (&pp); pp_flush (&pp); } /* Dump a multiline representation of this constraint_manager to stderr. */ DEBUG_FUNCTION void constraint_manager::dump () const { dump (stderr); } /* Dump a multiline representation of CM to stderr. */ DEBUG_FUNCTION void debug (const constraint_manager &cm) { cm.dump (); } /* Attempt to add the constraint LHS OP RHS to this constraint_manager. Return true if the constraint could be added (or is already true). Return false if the constraint contradicts existing knowledge. */ bool constraint_manager::add_constraint (svalue_id lhs, enum tree_code op, svalue_id rhs) { equiv_class_id lhs_ec_id = get_or_add_equiv_class (lhs); equiv_class_id rhs_ec_id = get_or_add_equiv_class (rhs); return add_constraint (lhs_ec_id, op,rhs_ec_id); } /* Attempt to add the constraint LHS_EC_ID OP RHS_EC_ID to this constraint_manager. Return true if the constraint could be added (or is already true). Return false if the constraint contradicts existing knowledge. */ bool constraint_manager::add_constraint (equiv_class_id lhs_ec_id, enum tree_code op, equiv_class_id rhs_ec_id) { tristate t = eval_condition (lhs_ec_id, op, rhs_ec_id); /* Discard constraints that are already known. */ if (t.is_true ()) return true; /* Reject unsatisfiable constraints. */ if (t.is_false ()) return false; gcc_assert (lhs_ec_id != rhs_ec_id); /* For now, simply accumulate constraints, without attempting any further optimization. */ switch (op) { case EQ_EXPR: { /* Merge rhs_ec into lhs_ec. */ equiv_class &lhs_ec_obj = lhs_ec_id.get_obj (*this); const equiv_class &rhs_ec_obj = rhs_ec_id.get_obj (*this); int i; svalue_id *sid; FOR_EACH_VEC_ELT (rhs_ec_obj.m_vars, i, sid) lhs_ec_obj.add (*sid, *this); if (rhs_ec_obj.m_constant) { lhs_ec_obj.m_constant = rhs_ec_obj.m_constant; lhs_ec_obj.m_cst_sid = rhs_ec_obj.m_cst_sid; } /* Drop rhs equivalence class, overwriting it with the final ec (which might be the same one). */ equiv_class_id final_ec_id = m_equiv_classes.length () - 1; equiv_class *old_ec = m_equiv_classes[rhs_ec_id.m_idx]; equiv_class *final_ec = m_equiv_classes.pop (); if (final_ec != old_ec) m_equiv_classes[rhs_ec_id.m_idx] = final_ec; delete old_ec; /* Update the constraints. */ constraint *c; FOR_EACH_VEC_ELT (m_constraints, i, c) { /* Update references to the rhs_ec so that they refer to the lhs_ec. */ if (c->m_lhs == rhs_ec_id) c->m_lhs = lhs_ec_id; if (c->m_rhs == rhs_ec_id) c->m_rhs = lhs_ec_id; /* Renumber all constraints that refer to the final rhs_ec to the old rhs_ec, where the old final_ec now lives. */ if (c->m_lhs == final_ec_id) c->m_lhs = rhs_ec_id; if (c->m_rhs == final_ec_id) c->m_rhs = rhs_ec_id; } } break; case GE_EXPR: add_constraint_internal (rhs_ec_id, CONSTRAINT_LE, lhs_ec_id); break; case LE_EXPR: add_constraint_internal (lhs_ec_id, CONSTRAINT_LE, rhs_ec_id); break; case NE_EXPR: add_constraint_internal (lhs_ec_id, CONSTRAINT_NE, rhs_ec_id); break; case GT_EXPR: add_constraint_internal (rhs_ec_id, CONSTRAINT_LT, lhs_ec_id); break; case LT_EXPR: add_constraint_internal (lhs_ec_id, CONSTRAINT_LT, rhs_ec_id); break; default: /* do nothing. */ break; } validate (); return true; } /* Subroutine of constraint_manager::add_constraint, for handling all operations other than equality (for which equiv classes are merged). */ void constraint_manager::add_constraint_internal (equiv_class_id lhs_id, enum constraint_op c_op, equiv_class_id rhs_id) { /* Add the constraint. */ m_constraints.safe_push (constraint (lhs_id, c_op, rhs_id)); if (!flag_analyzer_transitivity) return; if (c_op != CONSTRAINT_NE) { /* The following can potentially add EQ_EXPR facts, which could lead to ECs being merged, which would change the meaning of the EC IDs. Hence we need to do this via representatives. */ svalue_id lhs = lhs_id.get_obj (*this).get_representative (); svalue_id rhs = rhs_id.get_obj (*this).get_representative (); /* We have LHS is_ordering_p ()) { /* Refresh the EC IDs, in case any mergers have happened. */ lhs_id = get_or_add_equiv_class (lhs); rhs_id = get_or_add_equiv_class (rhs); tree lhs_const = lhs_id.get_obj (*this).m_constant; tree rhs_const = rhs_id.get_obj (*this).m_constant; tree other_lhs_const = other->m_lhs.get_obj (*this).m_constant; tree other_rhs_const = other->m_rhs.get_obj (*this).m_constant; /* We have "LHS m_lhs && other->m_rhs == lhs_id) { /* We must have equality for this to be possible. */ gcc_assert (c_op == CONSTRAINT_LE && other->m_op == CONSTRAINT_LE); add_constraint (lhs_id, EQ_EXPR, rhs_id); /* Adding an equality will merge the two ECs and potentially reorganize the constraints. Stop iterating. */ return; } /* Otherwise, check for transitivity. */ if (rhs_id == other->m_lhs) { /* With RHS == other.lhs, we have: "LHS m_op == CONSTRAINT_LE)); tree constant; if (r.constrained_to_single_element (&constant)) { svalue_id cst_sid = get_sid_for_constant (constant); add_constraint (rhs_id, EQ_EXPR, get_or_add_equiv_class (cst_sid)); return; } } /* Otherwise, add the constraint implied by transitivity. */ enum tree_code new_op = ((c_op == CONSTRAINT_LE && other->m_op == CONSTRAINT_LE) ? LE_EXPR : LT_EXPR); add_constraint (lhs_id, new_op, other->m_rhs); } else if (other->m_rhs == lhs_id) { /* With other.rhs == LHS, we have: "other.lhs m_op == CONSTRAINT_LE), bound (rhs_const, c_op == CONSTRAINT_LE)); tree constant; if (r.constrained_to_single_element (&constant)) { svalue_id cst_sid = get_sid_for_constant (constant); add_constraint (lhs_id, EQ_EXPR, get_or_add_equiv_class (cst_sid)); return; } } /* Otherwise, add the constraint implied by transitivity. */ enum tree_code new_op = ((c_op == CONSTRAINT_LE && other->m_op == CONSTRAINT_LE) ? LE_EXPR : LT_EXPR); add_constraint (other->m_lhs, new_op, rhs_id); } } } } } /* Look for SID within the equivalence classes of this constraint_manager; if found, write the id to *OUT and return true, otherwise return false. */ bool constraint_manager::get_equiv_class_by_sid (svalue_id sid, equiv_class_id *out) const { /* TODO: should we have a map, rather than these searches? */ int i; equiv_class *ec; FOR_EACH_VEC_ELT (m_equiv_classes, i, ec) { int j; svalue_id *iv; FOR_EACH_VEC_ELT (ec->m_vars, j, iv) if (*iv == sid) { *out = equiv_class_id (i); return true; } } return false; } /* Ensure that SID has an equivalence class within this constraint_manager; return the ID of the class. */ equiv_class_id constraint_manager::get_or_add_equiv_class (svalue_id sid) { equiv_class_id result (-1); /* Try svalue_id match. */ if (get_equiv_class_by_sid (sid, &result)) return result; /* Try equality of constants. */ if (tree cst = maybe_get_constant (sid)) { int i; equiv_class *ec; FOR_EACH_VEC_ELT (m_equiv_classes, i, ec) if (ec->m_constant && types_compatible_p (TREE_TYPE (cst), TREE_TYPE (ec->m_constant))) { tree eq = fold_binary (EQ_EXPR, boolean_type_node, cst, ec->m_constant); if (eq == boolean_true_node) { ec->add (sid, *this); return equiv_class_id (i); } } } /* Not found. */ equiv_class *new_ec = new equiv_class (); new_ec->add (sid, *this); m_equiv_classes.safe_push (new_ec); equiv_class_id new_id (m_equiv_classes.length () - 1); if (maybe_get_constant (sid)) { /* If we have a new EC for a constant, add constraints comparing this to other constants we may have (so that we accumulate the transitive closure of all constraints on constants as the constants are added). */ for (equiv_class_id other_id (0); other_id.m_idx < new_id.m_idx; other_id.m_idx++) { const equiv_class &other_ec = other_id.get_obj (*this); if (other_ec.m_constant && types_compatible_p (TREE_TYPE (new_ec->m_constant), TREE_TYPE (other_ec.m_constant))) { /* If we have two ECs, both with constants, the constants must be non-equal (or they would be in the same EC). Determine the direction of the inequality, and record that fact. */ tree lt = fold_binary (LT_EXPR, boolean_type_node, new_ec->m_constant, other_ec.m_constant); if (lt == boolean_true_node) add_constraint_internal (new_id, CONSTRAINT_LT, other_id); else if (lt == boolean_false_node) add_constraint_internal (other_id, CONSTRAINT_LT, new_id); /* Refresh new_id, in case ECs were merged. SID should always be present by now, so this should never lead to a recursion. */ new_id = get_or_add_equiv_class (sid); } } } return new_id; } /* Evaluate the condition LHS_EC OP RHS_EC. */ tristate constraint_manager::eval_condition (equiv_class_id lhs_ec, enum tree_code op, equiv_class_id rhs_ec) { if (lhs_ec == rhs_ec) { switch (op) { case EQ_EXPR: case GE_EXPR: case LE_EXPR: return tristate (tristate::TS_TRUE); case NE_EXPR: case GT_EXPR: case LT_EXPR: return tristate (tristate::TS_FALSE); default: break; } } tree lhs_const = lhs_ec.get_obj (*this).get_any_constant (); tree rhs_const = rhs_ec.get_obj (*this).get_any_constant (); if (lhs_const && rhs_const) { tree comparison = fold_binary (op, boolean_type_node, lhs_const, rhs_const); if (comparison == boolean_true_node) return tristate (tristate::TS_TRUE); if (comparison == boolean_false_node) return tristate (tristate::TS_FALSE); } enum tree_code swapped_op = swap_tree_comparison (op); int i; constraint *c; FOR_EACH_VEC_ELT (m_constraints, i, c) { if (c->m_lhs == lhs_ec && c->m_rhs == rhs_ec) { tristate result_for_constraint = eval_constraint_op_for_op (c->m_op, op); if (result_for_constraint.is_known ()) return result_for_constraint; } /* Swapped operands. */ if (c->m_lhs == rhs_ec && c->m_rhs == lhs_ec) { tristate result_for_constraint = eval_constraint_op_for_op (c->m_op, swapped_op); if (result_for_constraint.is_known ()) return result_for_constraint; } } return tristate (tristate::TS_UNKNOWN); } /* Evaluate the condition LHS OP RHS, creating equiv_class instances for LHS and RHS if they aren't already in equiv_classes. */ tristate constraint_manager::eval_condition (svalue_id lhs, enum tree_code op, svalue_id rhs) { return eval_condition (get_or_add_equiv_class (lhs), op, get_or_add_equiv_class (rhs)); } /* Delete any information about svalue_id instances identified by P. Such instances are removed from equivalence classes, and any redundant ECs and constraints are also removed. Accumulate stats into STATS. */ void constraint_manager::purge (const purge_criteria &p, purge_stats *stats) { /* Delete any svalue_ids identified by P within the various equivalence classes. */ for (unsigned ec_idx = 0; ec_idx < m_equiv_classes.length (); ) { equiv_class *ec = m_equiv_classes[ec_idx]; int i; svalue_id *pv; bool delete_ec = false; FOR_EACH_VEC_ELT (ec->m_vars, i, pv) { if (*pv == ec->m_cst_sid) continue; if (p.should_purge_p (*pv)) { if (ec->del (*pv)) if (!ec->m_constant) delete_ec = true; } } if (delete_ec) { delete ec; m_equiv_classes.ordered_remove (ec_idx); if (stats) stats->m_num_equiv_classes++; /* Update the constraints, potentially removing some. */ for (unsigned con_idx = 0; con_idx < m_constraints.length (); ) { constraint *c = &m_constraints[con_idx]; /* Remove constraints that refer to the deleted EC. */ if (c->m_lhs == ec_idx || c->m_rhs == ec_idx) { m_constraints.ordered_remove (con_idx); if (stats) stats->m_num_constraints++; } else { /* Renumber constraints that refer to ECs that have had their idx changed. */ c->m_lhs.update_for_removal (ec_idx); c->m_rhs.update_for_removal (ec_idx); con_idx++; } } } else ec_idx++; } /* Now delete any constraints that are purely between constants. */ for (unsigned con_idx = 0; con_idx < m_constraints.length (); ) { constraint *c = &m_constraints[con_idx]; if (m_equiv_classes[c->m_lhs.m_idx]->m_vars.length () == 0 && m_equiv_classes[c->m_rhs.m_idx]->m_vars.length () == 0) { m_constraints.ordered_remove (con_idx); if (stats) stats->m_num_constraints++; } else { con_idx++; } } /* Finally, delete any ECs that purely contain constants and aren't referenced by any constraints. */ for (unsigned ec_idx = 0; ec_idx < m_equiv_classes.length (); ) { equiv_class *ec = m_equiv_classes[ec_idx]; if (ec->m_vars.length () == 0) { equiv_class_id ec_id (ec_idx); bool has_constraint = false; for (unsigned con_idx = 0; con_idx < m_constraints.length (); con_idx++) { constraint *c = &m_constraints[con_idx]; if (c->m_lhs == ec_id || c->m_rhs == ec_id) { has_constraint = true; break; } } if (!has_constraint) { delete ec; m_equiv_classes.ordered_remove (ec_idx); if (stats) stats->m_num_equiv_classes++; /* Renumber constraints that refer to ECs that have had their idx changed. */ for (unsigned con_idx = 0; con_idx < m_constraints.length (); con_idx++) { constraint *c = &m_constraints[con_idx]; c->m_lhs.update_for_removal (ec_idx); c->m_rhs.update_for_removal (ec_idx); } continue; } } ec_idx++; } validate (); } /* Remap all svalue_ids within this constraint_manager using MAP. */ void constraint_manager::remap_svalue_ids (const svalue_id_map &map) { int i; equiv_class *ec; FOR_EACH_VEC_ELT (m_equiv_classes, i, ec) ec->remap_svalue_ids (map); } /* Comparator for use by constraint_manager::canonicalize. Sort a pair of equiv_class instances, using the representative svalue_id as a sort key. */ static int equiv_class_cmp (const void *p1, const void *p2) { const equiv_class *ec1 = *(const equiv_class * const *)p1; const equiv_class *ec2 = *(const equiv_class * const *)p2; svalue_id rep1 = ec1->get_representative (); svalue_id rep2 = ec2->get_representative (); return rep1.as_int () - rep2.as_int (); } /* Comparator for use by constraint_manager::canonicalize. Sort a pair of constraint instances. */ static int constraint_cmp (const void *p1, const void *p2) { const constraint *c1 = (const constraint *)p1; const constraint *c2 = (const constraint *)p2; int lhs_cmp = c1->m_lhs.as_int () - c2->m_lhs.as_int (); if (lhs_cmp) return lhs_cmp; int rhs_cmp = c1->m_rhs.as_int () - c2->m_rhs.as_int (); if (rhs_cmp) return rhs_cmp; return c1->m_op - c2->m_op; } /* Reorder the equivalence classes and constraints within this constraint_manager into a canonical order, to increase the chances of finding equality with another instance. */ void constraint_manager::canonicalize (unsigned num_svalue_ids) { /* First, sort svalue_ids within the ECs. */ unsigned i; equiv_class *ec; FOR_EACH_VEC_ELT (m_equiv_classes, i, ec) ec->canonicalize (); /* Next, sort the ECs into a canonical order. */ /* We will need to remap the equiv_class_ids in the constraints, so we need to store the original index of each EC. Build a lookup table, mapping from representative svalue_id to the original equiv_class_id of that svalue_id. */ auto_vec original_ec_id (num_svalue_ids); for (i = 0; i < num_svalue_ids; i++) original_ec_id.quick_push (equiv_class_id::null ()); FOR_EACH_VEC_ELT (m_equiv_classes, i, ec) { svalue_id rep = ec->get_representative (); gcc_assert (!rep.null_p ()); original_ec_id[rep.as_int ()] = i; } /* Sort the equivalence classes. */ m_equiv_classes.qsort (equiv_class_cmp); /* Populate ec_id_map based on the old vs new EC ids. */ one_way_id_map ec_id_map (m_equiv_classes.length ()); FOR_EACH_VEC_ELT (m_equiv_classes, i, ec) { svalue_id rep = ec->get_representative (); ec_id_map.put (original_ec_id[rep.as_int ()], i); } /* Update the EC ids within the constraints. */ constraint *c; FOR_EACH_VEC_ELT (m_constraints, i, c) { ec_id_map.update (&c->m_lhs); ec_id_map.update (&c->m_rhs); } /* Finally, sort the constraints. */ m_constraints.qsort (constraint_cmp); } /* A concrete subclass of constraint_manager for use when merging two constraint_manager into a third constraint_manager, each of which has its own region_model. Calls are delegated to the constraint_manager for the merged model, and thus affect its region_model. */ class cleaned_constraint_manager : public constraint_manager { public: cleaned_constraint_manager (constraint_manager *merged) : m_merged (merged) {} constraint_manager *clone (region_model *) const FINAL OVERRIDE { gcc_unreachable (); } tree maybe_get_constant (svalue_id sid) const FINAL OVERRIDE { return m_merged->maybe_get_constant (sid); } svalue_id get_sid_for_constant (tree cst) const FINAL OVERRIDE { return m_merged->get_sid_for_constant (cst); } virtual int get_num_svalues () const FINAL OVERRIDE { return m_merged->get_num_svalues (); } private: constraint_manager *m_merged; }; /* Concrete subclass of fact_visitor for use by constraint_manager::merge. For every fact in CM_A, see if it is also true in *CM_B. Add such facts to *OUT. */ class merger_fact_visitor : public fact_visitor { public: merger_fact_visitor (constraint_manager *cm_b, constraint_manager *out) : m_cm_b (cm_b), m_out (out) {} void on_fact (svalue_id lhs, enum tree_code code, svalue_id rhs) FINAL OVERRIDE { if (m_cm_b->eval_condition (lhs, code, rhs).is_true ()) { bool sat = m_out->add_constraint (lhs, code, rhs); gcc_assert (sat); } } private: constraint_manager *m_cm_b; constraint_manager *m_out; }; /* Use MERGER to merge CM_A and CM_B into *OUT. If one thinks of a constraint_manager as a subset of N-dimensional space, this takes the union of the points of CM_A and CM_B, and expresses that into *OUT. Alternatively, it can be thought of as the intersection of the constraints. */ void constraint_manager::merge (const constraint_manager &cm_a, const constraint_manager &cm_b, constraint_manager *out, const model_merger &merger) { gcc_assert (merger.m_sid_mapping); /* Map svalue_ids in each equiv class from both sources to the merged region_model, dropping ids that don't survive merger, and potentially creating svalues in *OUT for constants. */ cleaned_constraint_manager cleaned_cm_a (out); const one_way_svalue_id_map &map_a_to_m = merger.m_sid_mapping->m_map_from_a_to_m; clean_merger_input (cm_a, map_a_to_m, &cleaned_cm_a); cleaned_constraint_manager cleaned_cm_b (out); const one_way_svalue_id_map &map_b_to_m = merger.m_sid_mapping->m_map_from_b_to_m; clean_merger_input (cm_b, map_b_to_m, &cleaned_cm_b); /* At this point, the two cleaned CMs have ECs and constraints referring to svalues in the merged region model, but both of them have separate ECs. */ /* Merge the equivalence classes and constraints. The easiest way to do this seems to be to enumerate all of the facts in cleaned_cm_a, see which are also true in cleaned_cm_b, and add those to *OUT. */ merger_fact_visitor v (&cleaned_cm_b, out); cleaned_cm_a.for_each_fact (&v); } /* A subroutine of constraint_manager::merge. Use MAP_SID_TO_M to map equivalence classes and constraints from SM_IN to *OUT. Purge any non-constant svalue_id that don't appear in the result of MAP_SID_TO_M, purging any ECs and their constraints that become empty as a result. Potentially create svalues in the merged region_model for constants that weren't already in use there. */ void constraint_manager:: clean_merger_input (const constraint_manager &cm_in, const one_way_svalue_id_map &map_sid_to_m, constraint_manager *out) { one_way_id_map map_ec_to_m (cm_in.m_equiv_classes.length ()); unsigned ec_idx; equiv_class *ec; FOR_EACH_VEC_ELT (cm_in.m_equiv_classes, ec_idx, ec) { equiv_class cleaned_ec; if (tree cst = ec->get_any_constant ()) { cleaned_ec.m_constant = cst; /* Lazily create the constant in the out region_model. */ cleaned_ec.m_cst_sid = out->get_sid_for_constant (cst); } unsigned var_idx; svalue_id *var_in_sid; FOR_EACH_VEC_ELT (ec->m_vars, var_idx, var_in_sid) { svalue_id var_m_sid = map_sid_to_m.get_dst_for_src (*var_in_sid); if (!var_m_sid.null_p ()) cleaned_ec.m_vars.safe_push (var_m_sid); } if (cleaned_ec.get_any_constant () || !cleaned_ec.m_vars.is_empty ()) { map_ec_to_m.put (ec_idx, out->m_equiv_classes.length ()); out->m_equiv_classes.safe_push (new equiv_class (cleaned_ec)); } } /* Write out to *OUT any constraints for which both sides survived cleaning, using the new EC IDs. */ unsigned con_idx; constraint *c; FOR_EACH_VEC_ELT (cm_in.m_constraints, con_idx, c) { equiv_class_id new_lhs = map_ec_to_m.get_dst_for_src (c->m_lhs); if (new_lhs.null_p ()) continue; equiv_class_id new_rhs = map_ec_to_m.get_dst_for_src (c->m_rhs); if (new_rhs.null_p ()) continue; out->m_constraints.safe_push (constraint (new_lhs, c->m_op, new_rhs)); } } /* Call VISITOR's on_fact vfunc repeatedly to express the various equivalence classes and constraints. This is used by constraint_manager::merge to find the common facts between two input constraint_managers. */ void constraint_manager::for_each_fact (fact_visitor *visitor) const { /* First, call EQ_EXPR within the various equivalence classes. */ unsigned ec_idx; equiv_class *ec; FOR_EACH_VEC_ELT (m_equiv_classes, ec_idx, ec) { if (!ec->m_cst_sid.null_p ()) { unsigned i; svalue_id *sid; FOR_EACH_VEC_ELT (ec->m_vars, i, sid) visitor->on_fact (ec->m_cst_sid, EQ_EXPR, *sid); } for (unsigned i = 0; i < ec->m_vars.length (); i++) for (unsigned j = i + 1; j < ec->m_vars.length (); j++) visitor->on_fact (ec->m_vars[i], EQ_EXPR, ec->m_vars[j]); } /* Now, express the various constraints. */ unsigned con_idx; constraint *c; FOR_EACH_VEC_ELT (m_constraints, con_idx, c) { const equiv_class &ec_lhs = c->m_lhs.get_obj (*this); const equiv_class &ec_rhs = c->m_rhs.get_obj (*this); enum tree_code code = constraint_tree_code (c->m_op); if (!ec_lhs.m_cst_sid.null_p ()) { for (unsigned j = 0; j < ec_rhs.m_vars.length (); j++) { visitor->on_fact (ec_lhs.m_cst_sid, code, ec_rhs.m_vars[j]); } } for (unsigned i = 0; i < ec_lhs.m_vars.length (); i++) { if (!ec_rhs.m_cst_sid.null_p ()) visitor->on_fact (ec_lhs.m_vars[i], code, ec_rhs.m_cst_sid); for (unsigned j = 0; j < ec_rhs.m_vars.length (); j++) visitor->on_fact (ec_lhs.m_vars[i], code, ec_rhs.m_vars[j]); } } } /* Assert that this object is valid. */ void constraint_manager::validate () const { /* Skip this in a release build. */ #if !CHECKING_P return; #endif int i; equiv_class *ec; FOR_EACH_VEC_ELT (m_equiv_classes, i, ec) { gcc_assert (ec); int j; svalue_id *sid; FOR_EACH_VEC_ELT (ec->m_vars, j, sid) { gcc_assert (!sid->null_p ()); gcc_assert (sid->as_int () < get_num_svalues ()); } if (ec->m_constant) { gcc_assert (CONSTANT_CLASS_P (ec->m_constant)); gcc_assert (!ec->m_cst_sid.null_p ()); gcc_assert (ec->m_cst_sid.as_int () < get_num_svalues ()); } #if 0 else gcc_assert (ec->m_vars.length () > 0); #endif } constraint *c; FOR_EACH_VEC_ELT (m_constraints, i, c) { gcc_assert (!c->m_lhs.null_p ()); gcc_assert (c->m_lhs.as_int () <= (int)m_equiv_classes.length ()); gcc_assert (!c->m_rhs.null_p ()); gcc_assert (c->m_rhs.as_int () <= (int)m_equiv_classes.length ()); } } #if CHECKING_P namespace selftest { /* Various constraint_manager selftests. These have to be written in terms of a region_model, since the latter is responsible for managing svalue and svalue_id instances. */ /* Verify that setting and getting simple conditions within a region_model work (thus exercising the underlying constraint_manager). */ static void test_constraint_conditions () { tree int_42 = build_int_cst (integer_type_node, 42); tree int_0 = build_int_cst (integer_type_node, 0); tree x = build_global_decl ("x", integer_type_node); tree y = build_global_decl ("y", integer_type_node); tree z = build_global_decl ("z", integer_type_node); /* Self-comparisons. */ { region_model model; ASSERT_CONDITION_TRUE (model, x, EQ_EXPR, x); ASSERT_CONDITION_TRUE (model, x, LE_EXPR, x); ASSERT_CONDITION_TRUE (model, x, GE_EXPR, x); ASSERT_CONDITION_FALSE (model, x, NE_EXPR, x); ASSERT_CONDITION_FALSE (model, x, LT_EXPR, x); ASSERT_CONDITION_FALSE (model, x, GT_EXPR, x); } /* x == y. */ { region_model model; ASSERT_CONDITION_UNKNOWN (model, x, EQ_EXPR, y); ADD_SAT_CONSTRAINT (model, x, EQ_EXPR, y); ASSERT_CONDITION_TRUE (model, x, EQ_EXPR, y); ASSERT_CONDITION_TRUE (model, x, LE_EXPR, y); ASSERT_CONDITION_TRUE (model, x, GE_EXPR, y); ASSERT_CONDITION_FALSE (model, x, NE_EXPR, y); ASSERT_CONDITION_FALSE (model, x, LT_EXPR, y); ASSERT_CONDITION_FALSE (model, x, GT_EXPR, y); /* Swapped operands. */ ASSERT_CONDITION_TRUE (model, y, EQ_EXPR, x); ASSERT_CONDITION_TRUE (model, y, LE_EXPR, x); ASSERT_CONDITION_TRUE (model, y, GE_EXPR, x); ASSERT_CONDITION_FALSE (model, y, NE_EXPR, x); ASSERT_CONDITION_FALSE (model, y, LT_EXPR, x); ASSERT_CONDITION_FALSE (model, y, GT_EXPR, x); /* Comparison with other var. */ ASSERT_CONDITION_UNKNOWN (model, x, EQ_EXPR, z); ASSERT_CONDITION_UNKNOWN (model, x, LE_EXPR, z); ASSERT_CONDITION_UNKNOWN (model, x, GE_EXPR, z); ASSERT_CONDITION_UNKNOWN (model, x, NE_EXPR, z); ASSERT_CONDITION_UNKNOWN (model, x, LT_EXPR, z); ASSERT_CONDITION_UNKNOWN (model, x, GT_EXPR, z); } /* x == y, then y == z */ { region_model model; ASSERT_CONDITION_UNKNOWN (model, x, EQ_EXPR, y); ADD_SAT_CONSTRAINT (model, x, EQ_EXPR, y); ADD_SAT_CONSTRAINT (model, y, EQ_EXPR, z); ASSERT_CONDITION_TRUE (model, x, EQ_EXPR, z); ASSERT_CONDITION_TRUE (model, x, LE_EXPR, z); ASSERT_CONDITION_TRUE (model, x, GE_EXPR, z); ASSERT_CONDITION_FALSE (model, x, NE_EXPR, z); ASSERT_CONDITION_FALSE (model, x, LT_EXPR, z); ASSERT_CONDITION_FALSE (model, x, GT_EXPR, z); } /* x != y. */ { region_model model; ADD_SAT_CONSTRAINT (model, x, NE_EXPR, y); ASSERT_CONDITION_TRUE (model, x, NE_EXPR, y); ASSERT_CONDITION_FALSE (model, x, EQ_EXPR, y); ASSERT_CONDITION_UNKNOWN (model, x, LE_EXPR, y); ASSERT_CONDITION_UNKNOWN (model, x, GE_EXPR, y); ASSERT_CONDITION_UNKNOWN (model, x, LT_EXPR, y); ASSERT_CONDITION_UNKNOWN (model, x, GT_EXPR, y); /* Swapped operands. */ ASSERT_CONDITION_TRUE (model, y, NE_EXPR, x); ASSERT_CONDITION_FALSE (model, y, EQ_EXPR, x); ASSERT_CONDITION_UNKNOWN (model, y, LE_EXPR, x); ASSERT_CONDITION_UNKNOWN (model, y, GE_EXPR, x); ASSERT_CONDITION_UNKNOWN (model, y, LT_EXPR, x); ASSERT_CONDITION_UNKNOWN (model, y, GT_EXPR, x); /* Comparison with other var. */ ASSERT_CONDITION_UNKNOWN (model, x, EQ_EXPR, z); ASSERT_CONDITION_UNKNOWN (model, x, LE_EXPR, z); ASSERT_CONDITION_UNKNOWN (model, x, GE_EXPR, z); ASSERT_CONDITION_UNKNOWN (model, x, NE_EXPR, z); ASSERT_CONDITION_UNKNOWN (model, x, LT_EXPR, z); ASSERT_CONDITION_UNKNOWN (model, x, GT_EXPR, z); } /* x < y. */ { region_model model; ADD_SAT_CONSTRAINT (model, x, LT_EXPR, y); ASSERT_CONDITION_TRUE (model, x, LT_EXPR, y); ASSERT_CONDITION_TRUE (model, x, LE_EXPR, y); ASSERT_CONDITION_TRUE (model, x, NE_EXPR, y); ASSERT_CONDITION_FALSE (model, x, EQ_EXPR, y); ASSERT_CONDITION_FALSE (model, x, GT_EXPR, y); ASSERT_CONDITION_FALSE (model, x, GE_EXPR, y); /* Swapped operands. */ ASSERT_CONDITION_FALSE (model, y, LT_EXPR, x); ASSERT_CONDITION_FALSE (model, y, LE_EXPR, x); ASSERT_CONDITION_TRUE (model, y, NE_EXPR, x); ASSERT_CONDITION_FALSE (model, y, EQ_EXPR, x); ASSERT_CONDITION_TRUE (model, y, GT_EXPR, x); ASSERT_CONDITION_TRUE (model, y, GE_EXPR, x); } /* x <= y. */ { region_model model; ADD_SAT_CONSTRAINT (model, x, LE_EXPR, y); ASSERT_CONDITION_UNKNOWN (model, x, LT_EXPR, y); ASSERT_CONDITION_TRUE (model, x, LE_EXPR, y); ASSERT_CONDITION_UNKNOWN (model, x, NE_EXPR, y); ASSERT_CONDITION_UNKNOWN (model, x, EQ_EXPR, y); ASSERT_CONDITION_FALSE (model, x, GT_EXPR, y); ASSERT_CONDITION_UNKNOWN (model, x, GE_EXPR, y); /* Swapped operands. */ ASSERT_CONDITION_FALSE (model, y, LT_EXPR, x); ASSERT_CONDITION_UNKNOWN (model, y, LE_EXPR, x); ASSERT_CONDITION_UNKNOWN (model, y, NE_EXPR, x); ASSERT_CONDITION_UNKNOWN (model, y, EQ_EXPR, x); ASSERT_CONDITION_UNKNOWN (model, y, GT_EXPR, x); ASSERT_CONDITION_TRUE (model, y, GE_EXPR, x); } /* x > y. */ { region_model model; ADD_SAT_CONSTRAINT (model, x, GT_EXPR, y); ASSERT_CONDITION_TRUE (model, x, GT_EXPR, y); ASSERT_CONDITION_TRUE (model, x, GE_EXPR, y); ASSERT_CONDITION_TRUE (model, x, NE_EXPR, y); ASSERT_CONDITION_FALSE (model, x, EQ_EXPR, y); ASSERT_CONDITION_FALSE (model, x, LT_EXPR, y); ASSERT_CONDITION_FALSE (model, x, LE_EXPR, y); /* Swapped operands. */ ASSERT_CONDITION_FALSE (model, y, GT_EXPR, x); ASSERT_CONDITION_FALSE (model, y, GE_EXPR, x); ASSERT_CONDITION_TRUE (model, y, NE_EXPR, x); ASSERT_CONDITION_FALSE (model, y, EQ_EXPR, x); ASSERT_CONDITION_TRUE (model, y, LT_EXPR, x); ASSERT_CONDITION_TRUE (model, y, LE_EXPR, x); } /* x >= y. */ { region_model model; ADD_SAT_CONSTRAINT (model, x, GE_EXPR, y); ASSERT_CONDITION_UNKNOWN (model, x, GT_EXPR, y); ASSERT_CONDITION_TRUE (model, x, GE_EXPR, y); ASSERT_CONDITION_UNKNOWN (model, x, NE_EXPR, y); ASSERT_CONDITION_UNKNOWN (model, x, EQ_EXPR, y); ASSERT_CONDITION_FALSE (model, x, LT_EXPR, y); ASSERT_CONDITION_UNKNOWN (model, x, LE_EXPR, y); /* Swapped operands. */ ASSERT_CONDITION_FALSE (model, y, GT_EXPR, x); ASSERT_CONDITION_UNKNOWN (model, y, GE_EXPR, x); ASSERT_CONDITION_UNKNOWN (model, y, NE_EXPR, x); ASSERT_CONDITION_UNKNOWN (model, y, EQ_EXPR, x); ASSERT_CONDITION_UNKNOWN (model, y, LT_EXPR, x); ASSERT_CONDITION_TRUE (model, y, LE_EXPR, x); } // TODO: implied orderings /* Constants. */ { region_model model; ASSERT_CONDITION_FALSE (model, int_0, EQ_EXPR, int_42); ASSERT_CONDITION_TRUE (model, int_0, NE_EXPR, int_42); ASSERT_CONDITION_TRUE (model, int_0, LT_EXPR, int_42); ASSERT_CONDITION_TRUE (model, int_0, LE_EXPR, int_42); ASSERT_CONDITION_FALSE (model, int_0, GT_EXPR, int_42); ASSERT_CONDITION_FALSE (model, int_0, GE_EXPR, int_42); } /* x == 0, y == 42. */ { region_model model; ADD_SAT_CONSTRAINT (model, x, EQ_EXPR, int_0); ADD_SAT_CONSTRAINT (model, y, EQ_EXPR, int_42); ASSERT_CONDITION_TRUE (model, x, NE_EXPR, y); ASSERT_CONDITION_FALSE (model, x, EQ_EXPR, y); ASSERT_CONDITION_TRUE (model, x, LE_EXPR, y); ASSERT_CONDITION_FALSE (model, x, GE_EXPR, y); ASSERT_CONDITION_TRUE (model, x, LT_EXPR, y); ASSERT_CONDITION_FALSE (model, x, GT_EXPR, y); } /* Unsatisfiable combinations. */ /* x == y && x != y. */ { region_model model; ADD_SAT_CONSTRAINT (model, x, EQ_EXPR, y); ADD_UNSAT_CONSTRAINT (model, x, NE_EXPR, y); } /* x == 0 then x == 42. */ { region_model model; ADD_SAT_CONSTRAINT (model, x, EQ_EXPR, int_0); ADD_UNSAT_CONSTRAINT (model, x, EQ_EXPR, int_42); } /* x == 0 then x != 0. */ { region_model model; ADD_SAT_CONSTRAINT (model, x, EQ_EXPR, int_0); ADD_UNSAT_CONSTRAINT (model, x, NE_EXPR, int_0); } /* x == 0 then x > 0. */ { region_model model; ADD_SAT_CONSTRAINT (model, x, EQ_EXPR, int_0); ADD_UNSAT_CONSTRAINT (model, x, GT_EXPR, int_0); } /* x != y && x == y. */ { region_model model; ADD_SAT_CONSTRAINT (model, x, NE_EXPR, y); ADD_UNSAT_CONSTRAINT (model, x, EQ_EXPR, y); } /* x <= y && x > y. */ { region_model model; ADD_SAT_CONSTRAINT (model, x, LE_EXPR, y); ADD_UNSAT_CONSTRAINT (model, x, GT_EXPR, y); } // etc } /* Test transitivity of conditions. */ static void test_transitivity () { tree a = build_global_decl ("a", integer_type_node); tree b = build_global_decl ("b", integer_type_node); tree c = build_global_decl ("c", integer_type_node); tree d = build_global_decl ("d", integer_type_node); /* a == b, then c == d, then c == b. */ { region_model model; ASSERT_CONDITION_UNKNOWN (model, a, EQ_EXPR, b); ASSERT_CONDITION_UNKNOWN (model, b, EQ_EXPR, c); ASSERT_CONDITION_UNKNOWN (model, c, EQ_EXPR, d); ASSERT_CONDITION_UNKNOWN (model, a, EQ_EXPR, d); ADD_SAT_CONSTRAINT (model, a, EQ_EXPR, b); ASSERT_CONDITION_TRUE (model, a, EQ_EXPR, b); ADD_SAT_CONSTRAINT (model, c, EQ_EXPR, d); ASSERT_CONDITION_TRUE (model, c, EQ_EXPR, d); ASSERT_CONDITION_UNKNOWN (model, a, EQ_EXPR, d); ADD_SAT_CONSTRAINT (model, c, EQ_EXPR, b); ASSERT_CONDITION_TRUE (model, c, EQ_EXPR, b); ASSERT_CONDITION_TRUE (model, a, EQ_EXPR, d); } /* Transitivity: "a < b", "b < c" should imply "a < c". */ { region_model model; ADD_SAT_CONSTRAINT (model, a, LT_EXPR, b); ADD_SAT_CONSTRAINT (model, b, LT_EXPR, c); ASSERT_CONDITION_TRUE (model, a, LT_EXPR, c); ASSERT_CONDITION_FALSE (model, a, EQ_EXPR, c); } /* Transitivity: "a <= b", "b < c" should imply "a < c". */ { region_model model; ADD_SAT_CONSTRAINT (model, a, LE_EXPR, b); ADD_SAT_CONSTRAINT (model, b, LT_EXPR, c); ASSERT_CONDITION_TRUE (model, a, LT_EXPR, c); ASSERT_CONDITION_FALSE (model, a, EQ_EXPR, c); } /* Transitivity: "a <= b", "b <= c" should imply "a <= c". */ { region_model model; ADD_SAT_CONSTRAINT (model, a, LE_EXPR, b); ADD_SAT_CONSTRAINT (model, b, LE_EXPR, c); ASSERT_CONDITION_TRUE (model, a, LE_EXPR, c); ASSERT_CONDITION_UNKNOWN (model, a, EQ_EXPR, c); } /* Transitivity: "a > b", "b > c" should imply "a > c". */ { region_model model; ADD_SAT_CONSTRAINT (model, a, GT_EXPR, b); ADD_SAT_CONSTRAINT (model, b, GT_EXPR, c); ASSERT_CONDITION_TRUE (model, a, GT_EXPR, c); ASSERT_CONDITION_FALSE (model, a, EQ_EXPR, c); } /* Transitivity: "a >= b", "b > c" should imply " a > c". */ { region_model model; ADD_SAT_CONSTRAINT (model, a, GE_EXPR, b); ADD_SAT_CONSTRAINT (model, b, GT_EXPR, c); ASSERT_CONDITION_TRUE (model, a, GT_EXPR, c); ASSERT_CONDITION_FALSE (model, a, EQ_EXPR, c); } /* Transitivity: "a >= b", "b >= c" should imply "a >= c". */ { region_model model; ADD_SAT_CONSTRAINT (model, a, GE_EXPR, b); ADD_SAT_CONSTRAINT (model, b, GE_EXPR, c); ASSERT_CONDITION_TRUE (model, a, GE_EXPR, c); ASSERT_CONDITION_UNKNOWN (model, a, EQ_EXPR, c); } /* Transitivity: "(a < b)", "(c < d)", "(b < c)" should imply the easy cases: (a < c) (b < d) but also that: (a < d). */ { region_model model; ADD_SAT_CONSTRAINT (model, a, LT_EXPR, b); ADD_SAT_CONSTRAINT (model, c, LT_EXPR, d); ADD_SAT_CONSTRAINT (model, b, LT_EXPR, c); ASSERT_CONDITION_TRUE (model, a, LT_EXPR, c); ASSERT_CONDITION_TRUE (model, b, LT_EXPR, d); ASSERT_CONDITION_TRUE (model, a, LT_EXPR, d); } /* Transitivity: "a >= b", "b >= a" should imply that a == b. */ { region_model model; ADD_SAT_CONSTRAINT (model, a, GE_EXPR, b); ADD_SAT_CONSTRAINT (model, b, GE_EXPR, a); // TODO: ASSERT_CONDITION_TRUE (model, a, EQ_EXPR, b); } /* Transitivity: "a >= b", "b > a" should be impossible. */ { region_model model; ADD_SAT_CONSTRAINT (model, a, GE_EXPR, b); ADD_UNSAT_CONSTRAINT (model, b, GT_EXPR, a); } /* Transitivity: "a >= b", "b >= c", "c >= a" should imply that a == b == c. */ { region_model model; ADD_SAT_CONSTRAINT (model, a, GE_EXPR, b); ADD_SAT_CONSTRAINT (model, b, GE_EXPR, c); ADD_SAT_CONSTRAINT (model, c, GE_EXPR, a); ASSERT_CONDITION_TRUE (model, a, EQ_EXPR, c); } /* Transitivity: "a > b", "b > c", "c > a" should be impossible. */ { region_model model; ADD_SAT_CONSTRAINT (model, a, GT_EXPR, b); ADD_SAT_CONSTRAINT (model, b, GT_EXPR, c); ADD_UNSAT_CONSTRAINT (model, c, GT_EXPR, a); } } /* Test various conditionals involving constants where the results ought to be implied based on the values of the constants. */ static void test_constant_comparisons () { tree int_3 = build_int_cst (integer_type_node, 3); tree int_4 = build_int_cst (integer_type_node, 4); tree int_5 = build_int_cst (integer_type_node, 5); tree int_1023 = build_int_cst (integer_type_node, 1023); tree int_1024 = build_int_cst (integer_type_node, 1024); tree a = build_global_decl ("a", integer_type_node); tree b = build_global_decl ("b", integer_type_node); /* Given a >= 1024, then a <= 1023 should be impossible. */ { region_model model; ADD_SAT_CONSTRAINT (model, a, GE_EXPR, int_1024); ADD_UNSAT_CONSTRAINT (model, a, LE_EXPR, int_1023); } /* a > 4. */ { region_model model; ADD_SAT_CONSTRAINT (model, a, GT_EXPR, int_4); ASSERT_CONDITION_TRUE (model, a, GT_EXPR, int_4); ASSERT_CONDITION_TRUE (model, a, NE_EXPR, int_3); ASSERT_CONDITION_UNKNOWN (model, a, NE_EXPR, int_5); } /* a <= 4. */ { region_model model; ADD_SAT_CONSTRAINT (model, a, LE_EXPR, int_4); ASSERT_CONDITION_FALSE (model, a, GT_EXPR, int_4); ASSERT_CONDITION_FALSE (model, a, GT_EXPR, int_5); ASSERT_CONDITION_UNKNOWN (model, a, NE_EXPR, int_3); } /* If "a > b" and "a == 3", then "b == 4" ought to be unsatisfiable. */ { region_model model; ADD_SAT_CONSTRAINT (model, a, GT_EXPR, b); ADD_SAT_CONSTRAINT (model, a, EQ_EXPR, int_3); ADD_UNSAT_CONSTRAINT (model, b, EQ_EXPR, int_4); } /* Various tests of int ranges where there is only one possible candidate. */ { /* If "a <= 4" && "a > 3", then "a == 4", assuming a is of integral type. */ { region_model model; ADD_SAT_CONSTRAINT (model, a, LE_EXPR, int_4); ADD_SAT_CONSTRAINT (model, a, GT_EXPR, int_3); ASSERT_CONDITION_TRUE (model, a, EQ_EXPR, int_4); } /* If "a > 3" && "a <= 4", then "a == 4", assuming a is of integral type. */ { region_model model; ADD_SAT_CONSTRAINT (model, a, GT_EXPR, int_3); ADD_SAT_CONSTRAINT (model, a, LE_EXPR, int_4); ASSERT_CONDITION_TRUE (model, a, EQ_EXPR, int_4); } /* If "a > 3" && "a < 5", then "a == 4", assuming a is of integral type. */ { region_model model; ADD_SAT_CONSTRAINT (model, a, GT_EXPR, int_3); ADD_SAT_CONSTRAINT (model, a, LT_EXPR, int_5); ASSERT_CONDITION_TRUE (model, a, EQ_EXPR, int_4); } /* If "a >= 4" && "a < 5", then "a == 4", assuming a is of integral type. */ { region_model model; ADD_SAT_CONSTRAINT (model, a, GE_EXPR, int_4); ADD_SAT_CONSTRAINT (model, a, LT_EXPR, int_5); ASSERT_CONDITION_TRUE (model, a, EQ_EXPR, int_4); } /* If "a >= 4" && "a <= 4", then "a == 4". */ { region_model model; ADD_SAT_CONSTRAINT (model, a, GE_EXPR, int_4); ADD_SAT_CONSTRAINT (model, a, LE_EXPR, int_4); ASSERT_CONDITION_TRUE (model, a, EQ_EXPR, int_4); } } /* As above, but for floating-point: if "f > 3" && "f <= 4" we don't know that f == 4. */ { tree f = build_global_decl ("f", double_type_node); tree float_3 = build_real_from_int_cst (double_type_node, int_3); tree float_4 = build_real_from_int_cst (double_type_node, int_4); region_model model; ADD_SAT_CONSTRAINT (model, f, GT_EXPR, float_3); ADD_SAT_CONSTRAINT (model, f, LE_EXPR, float_4); ASSERT_CONDITION_UNKNOWN (model, f, EQ_EXPR, float_4); ASSERT_CONDITION_UNKNOWN (model, f, EQ_EXPR, int_4); } } /* Verify various lower-level implementation details about constraint_manager. */ static void test_constraint_impl () { tree int_42 = build_int_cst (integer_type_node, 42); tree int_0 = build_int_cst (integer_type_node, 0); tree x = build_global_decl ("x", integer_type_node); tree y = build_global_decl ("y", integer_type_node); tree z = build_global_decl ("z", integer_type_node); /* x == y. */ { region_model model; ADD_SAT_CONSTRAINT (model, x, EQ_EXPR, y); /* Assert various things about the insides of model. */ constraint_manager *cm = model.get_constraints (); ASSERT_EQ (cm->m_constraints.length (), 0); ASSERT_EQ (cm->m_equiv_classes.length (), 1); } /* y <= z; x == y. */ { region_model model; ASSERT_CONDITION_UNKNOWN (model, x, EQ_EXPR, y); ASSERT_CONDITION_UNKNOWN (model, x, GE_EXPR, z); ADD_SAT_CONSTRAINT (model, y, GE_EXPR, z); ASSERT_CONDITION_TRUE (model, y, GE_EXPR, z); ASSERT_CONDITION_UNKNOWN (model, x, GE_EXPR, z); ADD_SAT_CONSTRAINT (model, x, EQ_EXPR, y); /* Assert various things about the insides of model. */ constraint_manager *cm = model.get_constraints (); ASSERT_EQ (cm->m_constraints.length (), 1); ASSERT_EQ (cm->m_equiv_classes.length (), 2); /* Ensure that we merged the constraints. */ ASSERT_CONDITION_TRUE (model, x, GE_EXPR, z); } /* y <= z; y == x. */ { region_model model; ASSERT_CONDITION_UNKNOWN (model, x, EQ_EXPR, y); ASSERT_CONDITION_UNKNOWN (model, x, GE_EXPR, z); ADD_SAT_CONSTRAINT (model, y, GE_EXPR, z); ASSERT_CONDITION_TRUE (model, y, GE_EXPR, z); ASSERT_CONDITION_UNKNOWN (model, x, GE_EXPR, z); ADD_SAT_CONSTRAINT (model, y, EQ_EXPR, x); /* Assert various things about the insides of model. */ constraint_manager *cm = model.get_constraints (); ASSERT_EQ (cm->m_constraints.length (), 1); ASSERT_EQ (cm->m_equiv_classes.length (), 2); /* Ensure that we merged the constraints. */ ASSERT_CONDITION_TRUE (model, x, GE_EXPR, z); } /* x == 0, then x != 42. */ { region_model model; ADD_SAT_CONSTRAINT (model, x, EQ_EXPR, int_0); ADD_SAT_CONSTRAINT (model, x, NE_EXPR, int_42); /* Assert various things about the insides of model. */ constraint_manager *cm = model.get_constraints (); ASSERT_EQ (cm->m_constraints.length (), 1); ASSERT_EQ (cm->m_equiv_classes.length (), 2); ASSERT_EQ (cm->m_constraints[0].m_lhs, cm->get_or_add_equiv_class (model.get_rvalue (int_0, NULL))); ASSERT_EQ (cm->m_constraints[0].m_rhs, cm->get_or_add_equiv_class (model.get_rvalue (int_42, NULL))); ASSERT_EQ (cm->m_constraints[0].m_op, CONSTRAINT_LT); } // TODO: selftest for merging ecs "in the middle" // where a non-final one gets overwritten // TODO: selftest where there are pre-existing constraints } /* Check that operator== and hashing works as expected for the various types. */ static void test_equality () { tree x = build_global_decl ("x", integer_type_node); tree y = build_global_decl ("y", integer_type_node); { region_model model0; region_model model1; constraint_manager *cm0 = model0.get_constraints (); constraint_manager *cm1 = model1.get_constraints (); ASSERT_EQ (cm0->hash (), cm1->hash ()); ASSERT_EQ (*cm0, *cm1); ASSERT_EQ (model0.hash (), model1.hash ()); ASSERT_EQ (model0, model1); ADD_SAT_CONSTRAINT (model1, x, EQ_EXPR, y); ASSERT_NE (cm0->hash (), cm1->hash ()); ASSERT_NE (*cm0, *cm1); ASSERT_NE (model0.hash (), model1.hash ()); ASSERT_NE (model0, model1); region_model model2; constraint_manager *cm2 = model2.get_constraints (); /* Make the same change to cm2. */ ADD_SAT_CONSTRAINT (model2, x, EQ_EXPR, y); ASSERT_EQ (cm1->hash (), cm2->hash ()); ASSERT_EQ (*cm1, *cm2); ASSERT_EQ (model1.hash (), model2.hash ()); ASSERT_EQ (model1, model2); } } /* Verify tracking inequality of a variable against many constants. */ static void test_many_constants () { tree a = build_global_decl ("a", integer_type_node); region_model model; auto_vec constants; for (int i = 0; i < 20; i++) { tree constant = build_int_cst (integer_type_node, i); constants.safe_push (constant); ADD_SAT_CONSTRAINT (model, a, NE_EXPR, constant); /* Merge, and check the result. */ region_model other (model); region_model merged; ASSERT_TRUE (model.can_merge_with_p (other, &merged)); model.canonicalize (NULL); merged.canonicalize (NULL); ASSERT_EQ (model, merged); for (int j = 0; j <= i; j++) ASSERT_CONDITION_TRUE (model, a, NE_EXPR, constants[j]); } } /* Run the selftests in this file, temporarily overriding flag_analyzer_transitivity with TRANSITIVITY. */ static void run_constraint_manager_tests (bool transitivity) { int saved_flag_analyzer_transitivity = flag_analyzer_transitivity; flag_analyzer_transitivity = transitivity; test_constraint_conditions (); if (flag_analyzer_transitivity) { /* These selftests assume transitivity. */ test_transitivity (); test_constant_comparisons (); } test_constraint_impl (); test_equality (); test_many_constants (); flag_analyzer_transitivity = saved_flag_analyzer_transitivity; } /* Run all of the selftests within this file. */ void analyzer_constraint_manager_cc_tests () { /* Run the tests twice: with and without transitivity. */ run_constraint_manager_tests (true); run_constraint_manager_tests (false); } } // namespace selftest #endif /* CHECKING_P */ } // namespace ana #endif /* #if ENABLE_ANALYZER */