/* Header file for the value range relational processing. Copyright (C) 2020-2021 Free Software Foundation, Inc. Contributed by Andrew MacLeod 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 "backend.h" #include "tree.h" #include "gimple.h" #include "ssa.h" #include "gimple-range.h" #include "tree-pretty-print.h" #include "gimple-pretty-print.h" #include "alloc-pool.h" #include "dominance.h" // These VREL codes are arranged such that VREL_NONE is the first // code, and all the rest are contiguous up to and including VREL_LAST. #define VREL_FIRST VREL_NONE #define VREL_LAST NE_EXPR #define VREL_COUNT (VREL_LAST - VREL_FIRST + 1) // vrel_range_assert will either assert that the tree code passed is valid, // or mark invalid codes as unreachable to help with table optimation. #if CHECKING_P #define vrel_range_assert(c) \ gcc_checking_assert ((c) >= VREL_FIRST && (c) <= VREL_LAST) #else #define vrel_range_assert(c) \ if ((c) < VREL_FIRST || (c) > VREL_LAST) \ gcc_unreachable (); #endif static const char *kind_string[VREL_COUNT] = { "none", "<", "<=", ">", ">=", "empty", "==", "!=" }; // Print a relation_kind REL to file F. void print_relation (FILE *f, relation_kind rel) { vrel_range_assert (rel); fprintf (f, " %s ", kind_string[rel - VREL_FIRST]); } // This table is used to negate the operands. op1 REL op2 -> !(op1 REL op2). relation_kind rr_negate_table[VREL_COUNT] = { // NONE, LT_EXPR, LE_EXPR, GT_EXPR, GE_EXPR, EMPTY, EQ_EXPR, NE_EXPR VREL_NONE, GE_EXPR, GT_EXPR, LE_EXPR, LT_EXPR, VREL_EMPTY, NE_EXPR, EQ_EXPR }; // Negate the relation, as in logical negation. relation_kind relation_negate (relation_kind r) { vrel_range_assert (r); return rr_negate_table [r - VREL_FIRST]; } // This table is used to swap the operands. op1 REL op2 -> op2 REL op1. relation_kind rr_swap_table[VREL_COUNT] = { // NONE, LT_EXPR, LE_EXPR, GT_EXPR, GE_EXPR, EMPTY, EQ_EXPR, NE_EXPR VREL_NONE, GT_EXPR, GE_EXPR, LT_EXPR, LE_EXPR, VREL_EMPTY, EQ_EXPR, NE_EXPR }; // Return the relation as if the operands were swapped. relation_kind relation_swap (relation_kind r) { vrel_range_assert (r); return rr_swap_table [r - VREL_FIRST]; } // This table is used to perform an intersection between 2 relations. relation_kind rr_intersect_table[VREL_COUNT][VREL_COUNT] = { // NONE, LT_EXPR, LE_EXPR, GT_EXPR, GE_EXPR, EMPTY, EQ_EXPR, NE_EXPR // VREL_NONE { VREL_NONE, LT_EXPR, LE_EXPR, GT_EXPR, GE_EXPR, VREL_EMPTY, EQ_EXPR, NE_EXPR }, // LT_EXPR { LT_EXPR, LT_EXPR, LT_EXPR, VREL_EMPTY, VREL_EMPTY, VREL_EMPTY, VREL_EMPTY, LT_EXPR }, // LE_EXPR { LE_EXPR, LT_EXPR, LE_EXPR, VREL_EMPTY, EQ_EXPR, VREL_EMPTY, EQ_EXPR, LT_EXPR }, // GT_EXPR { GT_EXPR, VREL_EMPTY, VREL_EMPTY, GT_EXPR, GT_EXPR, VREL_EMPTY, VREL_EMPTY, GT_EXPR }, // GE_EXPR { GE_EXPR, VREL_EMPTY, EQ_EXPR, GT_EXPR, GE_EXPR, VREL_EMPTY, EQ_EXPR, GT_EXPR }, // VREL_EMPTY { VREL_EMPTY, VREL_EMPTY, VREL_EMPTY, VREL_EMPTY, VREL_EMPTY, VREL_EMPTY, VREL_EMPTY, VREL_EMPTY }, // EQ_EXPR { EQ_EXPR, VREL_EMPTY, EQ_EXPR, VREL_EMPTY, EQ_EXPR, VREL_EMPTY, EQ_EXPR, VREL_EMPTY }, // NE_EXPR { NE_EXPR, LT_EXPR, LT_EXPR, GT_EXPR, GT_EXPR, VREL_EMPTY, VREL_EMPTY, NE_EXPR } }; // Intersect relation R1 with relation R2 and return the resulting relation. relation_kind relation_intersect (relation_kind r1, relation_kind r2) { vrel_range_assert (r1); vrel_range_assert (r2); return rr_intersect_table[r1 - VREL_FIRST][r2 - VREL_FIRST]; } // This table is used to perform a union between 2 relations. relation_kind rr_union_table[VREL_COUNT][VREL_COUNT] = { // NONE, LT_EXPR, LE_EXPR, GT_EXPR, GE_EXPR, EMPTY, EQ_EXPR, NE_EXPR // VREL_NONE { VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE }, // LT_EXPR { VREL_NONE, LT_EXPR, LE_EXPR, NE_EXPR, VREL_NONE, LT_EXPR, LE_EXPR, NE_EXPR }, // LE_EXPR { VREL_NONE, LE_EXPR, LE_EXPR, VREL_NONE, VREL_NONE, LE_EXPR, LE_EXPR, VREL_NONE }, // GT_EXPR { VREL_NONE, NE_EXPR, VREL_NONE, GT_EXPR, GE_EXPR, GT_EXPR, GE_EXPR, NE_EXPR }, // GE_EXPR { VREL_NONE, VREL_NONE, VREL_NONE, GE_EXPR, GE_EXPR, GE_EXPR, GE_EXPR, VREL_NONE }, // VREL_EMPTY { VREL_NONE, LT_EXPR, LE_EXPR, GT_EXPR, GE_EXPR, VREL_EMPTY, EQ_EXPR, NE_EXPR }, // EQ_EXPR { VREL_NONE, LE_EXPR, LE_EXPR, GE_EXPR, GE_EXPR, EQ_EXPR, EQ_EXPR, VREL_NONE }, // NE_EXPR { VREL_NONE, NE_EXPR, VREL_NONE, NE_EXPR, VREL_NONE, NE_EXPR, VREL_NONE, NE_EXPR } }; // Union relation R1 with relation R2 and return the result. relation_kind relation_union (relation_kind r1, relation_kind r2) { vrel_range_assert (r1); vrel_range_assert (r2); return rr_union_table[r1 - VREL_FIRST][r2 - VREL_FIRST]; } // This table is used to determine transitivity between 2 relations. // (A relation0 B) and (B relation1 C) implies (A result C) relation_kind rr_transitive_table[VREL_COUNT][VREL_COUNT] = { // NONE, LT_EXPR, LE_EXPR, GT_EXPR, GE_EXPR, EMPTY, EQ_EXPR, NE_EXPR // VREL_NONE { VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE }, // LT_EXPR { VREL_NONE, LT_EXPR, LT_EXPR, VREL_NONE, VREL_NONE, VREL_NONE, LT_EXPR, VREL_NONE }, // LE_EXPR { VREL_NONE, LT_EXPR, LE_EXPR, VREL_NONE, VREL_NONE, VREL_NONE, LE_EXPR, VREL_NONE }, // GT_EXPR { VREL_NONE, VREL_NONE, VREL_NONE, GT_EXPR, GT_EXPR, VREL_NONE, GT_EXPR, VREL_NONE }, // GE_EXPR { VREL_NONE, VREL_NONE, VREL_NONE, GT_EXPR, GE_EXPR, VREL_NONE, GE_EXPR, VREL_NONE }, // VREL_EMPTY { VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE }, // EQ_EXPR { VREL_NONE, LT_EXPR, LE_EXPR, GT_EXPR, GE_EXPR, VREL_NONE, EQ_EXPR, VREL_NONE }, // NE_EXPR { VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE, VREL_NONE } }; // Apply transitive operation between relation R1 and relation R2, and // return the resulting relation, if any. relation_kind relation_transitive (relation_kind r1, relation_kind r2) { vrel_range_assert (r1); vrel_range_assert (r2); return rr_transitive_table[r1 - VREL_FIRST][r2 - VREL_FIRST]; } // ------------------------------------------------------------------------- // The very first element in the m_equiv chain is actually just a summary // element in which the m_names bitmap is used to indicate that an ssa_name // has an equivalence set in this block. // This allows for much faster traversal of the DOM chain, as a search for // SSA_NAME simply requires walking the DOM chain until a block is found // which has the bit for SSA_NAME set. Then scan for the equivalency set in // that block. No previous lists need be searched. // If SSA has an equivalence in this list, find and return it. // Otherwise return NULL. equiv_chain * equiv_chain::find (unsigned ssa) { equiv_chain *ptr = NULL; // If there are equiv sets and SSA is in one in this list, find it. // Otherwise return NULL. if (bitmap_bit_p (m_names, ssa)) { for (ptr = m_next; ptr; ptr = ptr->m_next) if (bitmap_bit_p (ptr->m_names, ssa)) break; } return ptr; } // Dump the names in this equivalence set. void equiv_chain::dump (FILE *f) const { bitmap_iterator bi; unsigned i; if (!m_names) return; fprintf (f, "Equivalence set : ["); unsigned c = 0; EXECUTE_IF_SET_IN_BITMAP (m_names, 0, i, bi) { if (ssa_name (i)) { if (c++) fprintf (f, ", "); print_generic_expr (f, ssa_name (i), TDF_SLIM); } } fprintf (f, "]\n"); } // Instantiate an equivalency oracle. equiv_oracle::equiv_oracle () { bitmap_obstack_initialize (&m_bitmaps); m_equiv.create (0); m_equiv.safe_grow_cleared (last_basic_block_for_fn (cfun) + 1); m_equiv_set = BITMAP_ALLOC (&m_bitmaps); obstack_init (&m_chain_obstack); m_self_equiv.create (0); m_self_equiv.safe_grow_cleared (num_ssa_names + 1); } // Destruct an equivalency oracle. equiv_oracle::~equiv_oracle () { m_self_equiv.release (); obstack_free (&m_chain_obstack, NULL); m_equiv.release (); bitmap_obstack_release (&m_bitmaps); } // Find and return the equivalency set for SSA along the dominators of BB. // This is the external API. const_bitmap equiv_oracle::equiv_set (tree ssa, basic_block bb) { // Search the dominator tree for an equivalency. equiv_chain *equiv = find_equiv_dom (ssa, bb); if (equiv) return equiv->m_names; // Otherwise return a cached equiv set containing just this SSA. unsigned v = SSA_NAME_VERSION (ssa); if (v >= m_self_equiv.length ()) m_self_equiv.safe_grow_cleared (num_ssa_names + 1); if (!m_self_equiv[v]) { m_self_equiv[v] = BITMAP_ALLOC (&m_bitmaps); bitmap_set_bit (m_self_equiv[v], v); } return m_self_equiv[v]; } // Query if thre is a relation (equivalence) between 2 SSA_NAMEs. relation_kind equiv_oracle::query_relation (basic_block bb, tree ssa1, tree ssa2) { // If the 2 ssa names share the same equiv set, they are equal. if (equiv_set (ssa1, bb) == equiv_set (ssa2, bb)) return EQ_EXPR; return VREL_NONE; } // Query if thre is a relation (equivalence) between 2 SSA_NAMEs. relation_kind equiv_oracle::query_relation (basic_block bb ATTRIBUTE_UNUSED, const_bitmap e1, const_bitmap e2) { // If the 2 ssa names share the same equiv set, they are equal. if (bitmap_equal_p (e1, e2)) return EQ_EXPR; return VREL_NONE; } // If SSA has an equivalence in block BB, find and return it. // Otherwise return NULL. equiv_chain * equiv_oracle::find_equiv_block (unsigned ssa, int bb) const { if (bb >= (int)m_equiv.length () || !m_equiv[bb]) return NULL; return m_equiv[bb]->find (ssa); } // Starting at block BB, walk the dominator chain looking for the nearest // equivalence set containing NAME. equiv_chain * equiv_oracle::find_equiv_dom (tree name, basic_block bb) const { unsigned v = SSA_NAME_VERSION (name); // Short circuit looking for names which have no equivalences. // Saves time looking for something which does not exist. if (!bitmap_bit_p (m_equiv_set, v)) return NULL; // NAME has at least once equivalence set, check to see if it has one along // the dominator tree. for ( ; bb; bb = get_immediate_dominator (CDI_DOMINATORS, bb)) { equiv_chain *ptr = find_equiv_block (v, bb->index); if (ptr) return ptr; } return NULL; } // Register equivalance between ssa_name V and set EQUIV in block BB, bitmap equiv_oracle::register_equiv (basic_block bb, unsigned v, equiv_chain *equiv) { // V will have an equivalency now. bitmap_set_bit (m_equiv_set, v); // If that equiv chain is in this block, simply use it. if (equiv->m_bb == bb) { bitmap_set_bit (equiv->m_names, v); bitmap_set_bit (m_equiv[bb->index]->m_names, v); return NULL; } // Otherwise create an equivalence for this block which is a copy // of equiv, the add V to the set. bitmap b = BITMAP_ALLOC (&m_bitmaps); bitmap_copy (b, equiv->m_names); bitmap_set_bit (b, v); return b; } // Register equivalence between set equiv_1 and equiv_2 in block BB. // Return NULL if either name can be merged with the other. Otherwise // return a pointer to the combined bitmap of names. This allows the // caller to do any setup required for a new element. bitmap equiv_oracle::register_equiv (basic_block bb, equiv_chain *equiv_1, equiv_chain *equiv_2) { // If equiv_1 is alreayd in BB, use it as the combined set. if (equiv_1->m_bb == bb) { bitmap_ior_into (equiv_1->m_names, equiv_2->m_names); // Its hard to delete from a single linked list, so // just clear the second one. if (equiv_2->m_bb == bb) bitmap_clear (equiv_2->m_names); else // Ensure equiv_2s names are in the summary for BB. bitmap_ior_into (m_equiv[bb->index]->m_names, equiv_2->m_names); return NULL; } // If equiv_2 is in BB, use it for the combined set. if (equiv_2->m_bb == bb) { bitmap_ior_into (equiv_2->m_names, equiv_1->m_names); // Add equiv_1 names into the summary. bitmap_ior_into (m_equiv[bb->index]->m_names, equiv_1->m_names); return NULL; } // At this point, neither equivalence is from this block. bitmap b = BITMAP_ALLOC (&m_bitmaps); bitmap_copy (b, equiv_1->m_names); bitmap_ior_into (b, equiv_2->m_names); return b; } // Register an equivalence between SSA1 and SSA2 in block BB. // The equivalence oracle maintains a vector of equivalencies indexed by basic // block. When an equivalence bteween SSA1 and SSA2 is registered in block BB, // a query is made as to what equivalences both names have already, and // any preexisting equivalences are merged to create a single equivalence // containing all the ssa_names in this basic block. void equiv_oracle::register_relation (basic_block bb, relation_kind k, tree ssa1, tree ssa2) { // Only handle equality relations. if (k != EQ_EXPR) return; unsigned v1 = SSA_NAME_VERSION (ssa1); unsigned v2 = SSA_NAME_VERSION (ssa2); equiv_chain *equiv_1 = find_equiv_dom (ssa1, bb); equiv_chain *equiv_2 = find_equiv_dom (ssa2, bb); // Check if they are the same set if (equiv_1 && equiv_1 == equiv_2) return; bitmap equiv_set; // Case where we have 2 SSA_NAMEs that are not in any set. if (!equiv_1 && !equiv_2) { bitmap_set_bit (m_equiv_set, v1); bitmap_set_bit (m_equiv_set, v2); equiv_set = BITMAP_ALLOC (&m_bitmaps); bitmap_set_bit (equiv_set, v1); bitmap_set_bit (equiv_set, v2); } else if (!equiv_1 && equiv_2) equiv_set = register_equiv (bb, v1, equiv_2); else if (equiv_1 && !equiv_2) equiv_set = register_equiv (bb, v2, equiv_1); else equiv_set = register_equiv (bb, equiv_1, equiv_2); // A non-null return is a bitmap that is to be added to the current // block as a new equivalence. if (!equiv_set) return; equiv_chain *ptr; // Check if this is the first time a block has an equivalence added. // and create a header block. And set the summary for this block. if (!m_equiv[bb->index]) { ptr = (equiv_chain *) obstack_alloc (&m_chain_obstack, sizeof (equiv_chain)); ptr->m_names = BITMAP_ALLOC (&m_bitmaps); bitmap_copy (ptr->m_names, equiv_set); ptr->m_bb = bb; ptr->m_next = NULL; m_equiv[bb->index] = ptr; } // Now create the element for this equiv set and initialize it. ptr = (equiv_chain *) obstack_alloc (&m_chain_obstack, sizeof (equiv_chain)); ptr->m_names = equiv_set; ptr->m_bb = bb; gcc_checking_assert (bb->index < (int)m_equiv.length ()); ptr->m_next = m_equiv[bb->index]->m_next; m_equiv[bb->index]->m_next = ptr; bitmap_ior_into (m_equiv[bb->index]->m_names, equiv_set); } // Make sure the BB vector is big enough and grow it if needed. void equiv_oracle::limit_check (basic_block bb) { int i = (bb) ? bb->index : last_basic_block_for_fn (cfun); if (i >= (int)m_equiv.length ()) m_equiv.safe_grow_cleared (last_basic_block_for_fn (cfun) + 1); } // Dump the equivalence sets in BB to file F. void equiv_oracle::dump (FILE *f, basic_block bb) const { if (bb->index >= (int)m_equiv.length ()) return; if (!m_equiv[bb->index]) return; equiv_chain *ptr = m_equiv[bb->index]->m_next; for (; ptr; ptr = ptr->m_next) ptr->dump (f); } // Dump all equivalence sets known to the oracle. void equiv_oracle::dump (FILE *f) const { fprintf (f, "Equivalency dump\n"); for (unsigned i = 0; i < m_equiv.length (); i++) if (m_equiv[i] && BASIC_BLOCK_FOR_FN (cfun, i)) { fprintf (f, "BB%d\n", i); dump (f, BASIC_BLOCK_FOR_FN (cfun, i)); } } // -------------------------------------------------------------------------- // The value-relation class is used to encapsulate the represention of an // individual relation between 2 ssa-names, and to facilitate operating on // the relation. class value_relation { public: value_relation (); value_relation (relation_kind kind, tree n1, tree n2); void set_relation (relation_kind kind, tree n1, tree n2); inline relation_kind kind () const { return related; } inline tree op1 () const { return name1; } inline tree op2 () const { return name2; } bool union_ (value_relation &p); bool intersect (value_relation &p); void negate (); bool apply_transitive (const value_relation &rel); void dump (FILE *f) const; private: relation_kind related; tree name1, name2; }; // Set relation R between ssa_name N1 and N2. inline void value_relation::set_relation (relation_kind r, tree n1, tree n2) { gcc_checking_assert (SSA_NAME_VERSION (n1) != SSA_NAME_VERSION (n2)); related = r; name1 = n1; name2 = n2; } // Default constructor. inline value_relation::value_relation () { related = VREL_NONE; name1 = NULL_TREE; name2 = NULL_TREE; } // Constructor for relation R between SSA version N1 nd N2. inline value_relation::value_relation (relation_kind kind, tree n1, tree n2) { set_relation (kind, n1, n2); } // Negate the current relation. void value_relation::negate () { related = relation_negate (related); } // Perform an intersection between 2 relations. *this &&= p. bool value_relation::intersect (value_relation &p) { // Save previous value relation_kind old = related; if (p.op1 () == op1 () && p.op2 () == op2 ()) related = relation_intersect (kind (), p.kind ()); else if (p.op2 () == op1 () && p.op1 () == op2 ()) related = relation_intersect (kind (), relation_swap (p.kind ())); else return false; return old != related; } // Perform a union between 2 relations. *this ||= p. bool value_relation::union_ (value_relation &p) { // Save previous value relation_kind old = related; if (p.op1 () == op1 () && p.op2 () == op2 ()) related = relation_union (kind(), p.kind()); else if (p.op2 () == op1 () && p.op1 () == op2 ()) related = relation_union (kind(), relation_swap (p.kind ())); else return false; return old != related; } // Identify and apply any transitive relations between REL // and THIS. Return true if there was a transformation. bool value_relation::apply_transitive (const value_relation &rel) { relation_kind k = VREL_NONE; // Idenity any common operand, and notrmalize the relations to // the form : A < B B < C produces A < C if (rel.op1 () == name2) { // A < B B < C if (rel.op2 () == name1) return false; k = relation_transitive (kind (), rel.kind ()); if (k != VREL_NONE) { related = k; name2 = rel.op2 (); return true; } } else if (rel.op1 () == name1) { // B > A B < C if (rel.op2 () == name2) return false; k = relation_transitive (relation_swap (kind ()), rel.kind ()); if (k != VREL_NONE) { related = k; name1 = name2; name2 = rel.op2 (); return true; } } else if (rel.op2 () == name2) { // A < B C > B if (rel.op1 () == name1) return false; k = relation_transitive (kind (), relation_swap (rel.kind ())); if (k != VREL_NONE) { related = k; name2 = rel.op1 (); return true; } } else if (rel.op2 () == name1) { // B > A C > B if (rel.op1 () == name2) return false; k = relation_transitive (relation_swap (kind ()), relation_swap (rel.kind ())); if (k != VREL_NONE) { related = k; name1 = name2; name2 = rel.op1 (); return true; } } return false; } // Dump the relation to file F. void value_relation::dump (FILE *f) const { if (!name1 || !name2) { fprintf (f, "uninitialized"); return; } fputc ('(', f); print_generic_expr (f, op1 (), TDF_SLIM); print_relation (f, kind ()); print_generic_expr (f, op2 (), TDF_SLIM); fputc(')', f); } // This container is used to link relations in a chain. class relation_chain : public value_relation { public: relation_chain *m_next; }; // ------------------------------------------------------------------------ // Find the relation between any ssa_name in B1 and any name in B2 in LIST. // This will allow equivalencies to be applied to any SSA_NAME in a relation. relation_kind relation_chain_head::find_relation (const_bitmap b1, const_bitmap b2) const { if (!m_names) return VREL_NONE; // If both b1 and b2 aren't referenced in thie block, cant be a relation if (!bitmap_intersect_p (m_names, b1) || !bitmap_intersect_p (m_names, b2)) return VREL_NONE; // Search for the fiorst relation that contains BOTH an element from B1 // and B2, and return that relation. for (relation_chain *ptr = m_head; ptr ; ptr = ptr->m_next) { unsigned op1 = SSA_NAME_VERSION (ptr->op1 ()); unsigned op2 = SSA_NAME_VERSION (ptr->op2 ()); if (bitmap_bit_p (b1, op1) && bitmap_bit_p (b2, op2)) return ptr->kind (); if (bitmap_bit_p (b1, op2) && bitmap_bit_p (b2, op1)) return relation_swap (ptr->kind ()); } return VREL_NONE; } // Instantiate a relation oracle. dom_oracle::dom_oracle () { m_relations.create (0); m_relations.safe_grow_cleared (last_basic_block_for_fn (cfun) + 1); m_relation_set = BITMAP_ALLOC (&m_bitmaps); m_tmp = BITMAP_ALLOC (&m_bitmaps); m_tmp2 = BITMAP_ALLOC (&m_bitmaps); } // Destruct a relation oracle. dom_oracle::~dom_oracle () { m_relations.release (); } // Register relation K between ssa_name OP1 and OP2 on STMT. void relation_oracle::register_stmt (gimple *stmt, relation_kind k, tree op1, tree op2) { gcc_checking_assert (TREE_CODE (op1) == SSA_NAME); gcc_checking_assert (TREE_CODE (op2) == SSA_NAME); gcc_checking_assert (stmt && gimple_bb (stmt)); // Don't register lack of a relation. if (k == VREL_NONE) return; if (dump_file && (dump_flags & TDF_DETAILS)) { value_relation vr (k, op1, op2); fprintf (dump_file, " Registering value_relation "); vr.dump (dump_file); fprintf (dump_file, " (bb%d) at ", gimple_bb (stmt)->index); print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); } register_relation (gimple_bb (stmt), k, op1, op2); } // Register relation K between ssa_name OP1 and OP2 on edge E. void relation_oracle::register_edge (edge e, relation_kind k, tree op1, tree op2) { gcc_checking_assert (TREE_CODE (op1) == SSA_NAME); gcc_checking_assert (TREE_CODE (op2) == SSA_NAME); // Do not register lack of relation, or blocks which have more than // edge E for a predecessor. if (k == VREL_NONE || !single_pred_p (e->dest)) return; if (dump_file && (dump_flags & TDF_DETAILS)) { value_relation vr (k, op1, op2); fprintf (dump_file, " Registering value_relation "); vr.dump (dump_file); fprintf (dump_file, " on (%d->%d)\n", e->src->index, e->dest->index); } register_relation (e->dest, k, op1, op2); } // Register relation K between OP! and OP2 in block BB. // This creates the record and searches for existing records in the dominator // tree to merge with. void dom_oracle::register_relation (basic_block bb, relation_kind k, tree op1, tree op2) { // Equivalencies are handled by the equivalence oracle. if (k == EQ_EXPR) equiv_oracle::register_relation (bb, k, op1, op2); else { relation_chain *ptr = set_one_relation (bb, k, op1, op2); register_transitives (bb, *ptr); } } // Register relation K between OP! and OP2 in block BB. // This creates the record and searches for existing records in the dominator // tree to merge with. relation_chain * dom_oracle::set_one_relation (basic_block bb, relation_kind k, tree op1, tree op2) { gcc_checking_assert (k != VREL_NONE && k != EQ_EXPR); value_relation vr(k, op1, op2); int bbi = bb->index; if (bbi >= (int)m_relations.length()) m_relations.safe_grow_cleared (last_basic_block_for_fn (cfun) + 1); // Summary bitmap indicating what ssa_names have relations in this BB. bitmap bm = m_relations[bbi].m_names; if (!bm) bm = m_relations[bbi].m_names = BITMAP_ALLOC (&m_bitmaps); unsigned v1 = SSA_NAME_VERSION (op1); unsigned v2 = SSA_NAME_VERSION (op2); relation_kind curr; relation_chain *ptr; curr = find_relation_block (bbi, v1, v2, &ptr); // There is an existing relation in this block, just intersect with it. if (curr != VREL_NONE) { if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, " Intersecting with existing "); ptr->dump (dump_file); } // Check into whether we can simply replace the relation rather than // intersecting it. THis may help with some optimistic iterative // updating algorithms. ptr->intersect (vr); if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, " to produce "); ptr->dump (dump_file); fprintf (dump_file, "\n"); } } else { // Check for an existing relation further up the DOM chain. // By including dominating relations, The first one found in any search // will be the aggregate of all the previous ones. curr = find_relation_dom (bb, v1, v2); if (curr != VREL_NONE) k = relation_intersect (curr, k); bitmap_set_bit (bm, v1); bitmap_set_bit (bm, v2); bitmap_set_bit (m_relation_set, v1); bitmap_set_bit (m_relation_set, v2); ptr = (relation_chain *) obstack_alloc (&m_chain_obstack, sizeof (relation_chain)); ptr->set_relation (k, op1, op2); ptr->m_next = m_relations[bbi].m_head; m_relations[bbi].m_head = ptr; } return ptr; } // Starting at ROOT_BB search the DOM tree looking for relations which // may produce transitive relations to RELATION. EQUIV1 and EQUIV2 are // bitmaps for op1/op2 and any of their equivalences that should also be // considered. void dom_oracle::register_transitives (basic_block root_bb, const value_relation &relation) { basic_block bb; // Only apply transitives to certain kinds of operations. switch (relation.kind ()) { case LE_EXPR: case LT_EXPR: case GT_EXPR: case GE_EXPR: break; default: return; } const_bitmap equiv1 = equiv_set (relation.op1 (), root_bb); const_bitmap equiv2 = equiv_set (relation.op2 (), root_bb); for (bb = root_bb; bb; bb = get_immediate_dominator (CDI_DOMINATORS, bb)) { int bbi = bb->index; if (bbi >= (int)m_relations.length()) continue; const_bitmap bm = m_relations[bbi].m_names; if (!bm) continue; if (!bitmap_intersect_p (bm, equiv1) && !bitmap_intersect_p (bm, equiv2)) continue; // At least one of the 2 ops has a relation in this block. relation_chain *ptr; for (ptr = m_relations[bbi].m_head; ptr ; ptr = ptr->m_next) { // In the presence of an equivalence, 2 operands may do not // naturally match. ie with equivalence a_2 == b_3 // given c_1 < a_2 && b_3 < d_4 // convert the second relation (b_3 < d_4) to match any // equivalences to found in the first relation. // ie convert b_3 < d_4 to a_2 < d_4, which then exposes the // transitive operation: c_1 < a_2 && a_2 < d_4 -> c_1 < d_4 tree r1, r2; tree p1 = ptr->op1 (); tree p2 = ptr->op2 (); // Find which equivalence is in the first operand. if (bitmap_bit_p (equiv1, SSA_NAME_VERSION (p1))) r1 = p1; else if (bitmap_bit_p (equiv1, SSA_NAME_VERSION (p2))) r1 = p2; else r1 = NULL_TREE; // Find which equivalence is in the second operand. if (bitmap_bit_p (equiv2, SSA_NAME_VERSION (p1))) r2 = p1; else if (bitmap_bit_p (equiv2, SSA_NAME_VERSION (p2))) r2 = p2; else r2 = NULL_TREE; // Ignore if both NULL (not relevant relation) or the same, if (r1 == r2) continue; // Any operand not an equivalence, just take the real operand. if (!r1) r1 = relation.op1 (); if (!r2) r2 = relation.op2 (); value_relation nr (relation.kind (), r1, r2); if (nr.apply_transitive (*ptr)) { set_one_relation (root_bb, nr.kind (), nr.op1 (), nr.op2 ()); if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, " Registering transitive relation "); nr.dump (dump_file); fputc ('\n', dump_file); } } } } } // Find the relation between any ssa_name in B1 and any name in B2 in block BB. // This will allow equivalencies to be applied to any SSA_NAME in a relation. relation_kind dom_oracle::find_relation_block (unsigned bb, const_bitmap b1, const_bitmap b2) const { if (bb >= m_relations.length()) return VREL_NONE; return m_relations[bb].find_relation (b1, b2); } // Search the DOM tree for a relation between an element of equivalency set B1 // and B2, starting with block BB. relation_kind dom_oracle::query_relation (basic_block bb, const_bitmap b1, const_bitmap b2) { relation_kind r; if (bitmap_equal_p (b1, b2)) return EQ_EXPR; // If either name does not occur in a relation anywhere, there isnt one. if (!bitmap_intersect_p (m_relation_set, b1) || !bitmap_intersect_p (m_relation_set, b2)) return VREL_NONE; // Search each block in the DOM tree checking. for ( ; bb; bb = get_immediate_dominator (CDI_DOMINATORS, bb)) { r = find_relation_block (bb->index, b1, b2); if (r != VREL_NONE) return r; } return VREL_NONE; } // Find a relation in block BB between ssa version V1 and V2. If a relation // is found, return a pointer to the chain object in OBJ. relation_kind dom_oracle::find_relation_block (int bb, unsigned v1, unsigned v2, relation_chain **obj) const { if (bb >= (int)m_relations.length()) return VREL_NONE; const_bitmap bm = m_relations[bb].m_names; if (!bm) return VREL_NONE; // If both b1 and b2 aren't referenced in thie block, cant be a relation if (!bitmap_bit_p (bm, v1) || !bitmap_bit_p (bm, v2)) return VREL_NONE; relation_chain *ptr; for (ptr = m_relations[bb].m_head; ptr ; ptr = ptr->m_next) { unsigned op1 = SSA_NAME_VERSION (ptr->op1 ()); unsigned op2 = SSA_NAME_VERSION (ptr->op2 ()); if (v1 == op1 && v2 == op2) { if (obj) *obj = ptr; return ptr->kind (); } if (v1 == op2 && v2 == op1) { if (obj) *obj = ptr; return relation_swap (ptr->kind ()); } } return VREL_NONE; } // Find a relation between SSA version V1 and V2 in the dominator tree // starting with block BB relation_kind dom_oracle::find_relation_dom (basic_block bb, unsigned v1, unsigned v2) const { relation_kind r; // IF either name does not occur in a relation anywhere, there isnt one. if (!bitmap_bit_p (m_relation_set, v1) || !bitmap_bit_p (m_relation_set, v2)) return VREL_NONE; for ( ; bb; bb = get_immediate_dominator (CDI_DOMINATORS, bb)) { r = find_relation_block (bb->index, v1, v2); if (r != VREL_NONE) return r; } return VREL_NONE; } // Query if there is a relation between SSA1 and SS2 in block BB or a // dominator of BB relation_kind dom_oracle::query_relation (basic_block bb, tree ssa1, tree ssa2) { relation_kind kind; unsigned v1 = SSA_NAME_VERSION (ssa1); unsigned v2 = SSA_NAME_VERSION (ssa2); if (v1 == v2) return EQ_EXPR; // Check for equivalence first. They must be in each equivalency set. const_bitmap equiv1 = equiv_set (ssa1, bb); const_bitmap equiv2 = equiv_set (ssa2, bb); if (bitmap_bit_p (equiv1, v2) && bitmap_bit_p (equiv2, v1)) return EQ_EXPR; // Initially look for a direct relationship and just return that. kind = find_relation_dom (bb, v1, v2); if (kind != VREL_NONE) return kind; // Query using the equiovalence sets. kind = query_relation (bb, equiv1, equiv2); return kind; } // Dump all the relations in block BB to file F. void dom_oracle::dump (FILE *f, basic_block bb) const { equiv_oracle::dump (f,bb); if (bb->index >= (int)m_relations.length ()) return; if (!m_relations[bb->index].m_names) return; relation_chain *ptr = m_relations[bb->index].m_head; for (; ptr; ptr = ptr->m_next) { fprintf (f, "Relational : "); ptr->dump (f); fprintf (f, "\n"); } } // Dump all the relations known to file F. void dom_oracle::dump (FILE *f) const { fprintf (f, "Relation dump\n"); for (unsigned i = 0; i < m_relations.length (); i++) if (BASIC_BLOCK_FOR_FN (cfun, i)) { fprintf (f, "BB%d\n", i); dump (f, BASIC_BLOCK_FOR_FN (cfun, i)); } } void relation_oracle::debug () const { dump (stderr); } path_oracle::path_oracle (relation_oracle *oracle) { m_root = oracle; bitmap_obstack_initialize (&m_bitmaps); obstack_init (&m_chain_obstack); // Initialize header records. m_equiv.m_names = BITMAP_ALLOC (&m_bitmaps); m_equiv.m_bb = NULL; m_equiv.m_next = NULL; m_relations.m_names = BITMAP_ALLOC (&m_bitmaps); m_relations.m_head = NULL; } path_oracle::~path_oracle () { obstack_free (&m_chain_obstack, NULL); bitmap_obstack_release (&m_bitmaps); } // Return the equiv set for SSA, and if there isn't one, check for equivs // starting in block BB. const_bitmap path_oracle::equiv_set (tree ssa, basic_block bb) { // Check the list first. equiv_chain *ptr = m_equiv.find (SSA_NAME_VERSION (ssa)); if (ptr) return ptr->m_names; // Otherwise defer to the root oracle. if (m_root) return m_root->equiv_set (ssa, bb); // Allocate a throw away bitmap if there isn't a root oracle. bitmap tmp = BITMAP_ALLOC (&m_bitmaps); bitmap_set_bit (tmp, SSA_NAME_VERSION (ssa)); return tmp; } // Register an equivalence between SSA1 and SSA2 resolving unkowns from // block BB. void path_oracle::register_equiv (basic_block bb, tree ssa1, tree ssa2) { const_bitmap equiv_1 = equiv_set (ssa1, bb); const_bitmap equiv_2 = equiv_set (ssa2, bb); // Check if they are the same set, if so, we're done. if (bitmap_equal_p (equiv_1, equiv_2)) return; // Don't mess around, simply create a new record and insert it first. bitmap b = BITMAP_ALLOC (&m_bitmaps); bitmap_copy (b, equiv_1); bitmap_ior_into (b, equiv_2); equiv_chain *ptr = (equiv_chain *) obstack_alloc (&m_chain_obstack, sizeof (equiv_chain)); ptr->m_names = b; ptr->m_bb = NULL; ptr->m_next = m_equiv.m_next; m_equiv.m_next = ptr; bitmap_ior_into (m_equiv.m_names, b); } // Register relation K between SSA1 and SSA2, resolving unknowns by // querying from BB. void path_oracle::register_relation (basic_block bb, relation_kind k, tree ssa1, tree ssa2) { if (dump_file && (dump_flags & TDF_DETAILS)) { value_relation vr (k, ssa1, ssa2); fprintf (dump_file, " Registering value_relation (path_oracle) "); vr.dump (dump_file); fprintf (dump_file, " (bb%d)\n", bb->index); } if (k == EQ_EXPR) { register_equiv (bb, ssa1, ssa2); return; } relation_kind curr = query_relation (bb, ssa1, ssa2); if (curr != VREL_NONE) k = relation_intersect (curr, k); bitmap_set_bit (m_relations.m_names, SSA_NAME_VERSION (ssa1)); bitmap_set_bit (m_relations.m_names, SSA_NAME_VERSION (ssa2)); relation_chain *ptr = (relation_chain *) obstack_alloc (&m_chain_obstack, sizeof (relation_chain)); ptr->set_relation (k, ssa1, ssa2); ptr->m_next = m_relations.m_head; m_relations.m_head = ptr; } // Query for a relationship between equiv set B1 and B2, resolving unknowns // starting at block BB. relation_kind path_oracle::query_relation (basic_block bb, const_bitmap b1, const_bitmap b2) { if (bitmap_equal_p (b1, b2)) return EQ_EXPR; relation_kind k = m_relations.find_relation (b1, b2); if (k == VREL_NONE && m_root) k = m_root->query_relation (bb, b1, b2); return k; } // Query for a relationship between SSA1 and SSA2, resolving unknowns // starting at block BB. relation_kind path_oracle::query_relation (basic_block bb, tree ssa1, tree ssa2) { unsigned v1 = SSA_NAME_VERSION (ssa1); unsigned v2 = SSA_NAME_VERSION (ssa2); if (v1 == v2) return EQ_EXPR; const_bitmap equiv_1 = equiv_set (ssa1, bb); const_bitmap equiv_2 = equiv_set (ssa2, bb); if (bitmap_bit_p (equiv_1, v2) && bitmap_bit_p (equiv_2, v1)) return EQ_EXPR; return query_relation (bb, equiv_1, equiv_2); } // Reset any relations registered on this path. void path_oracle::reset_path () { m_equiv.m_next = NULL; bitmap_clear (m_equiv.m_names); m_relations.m_head = NULL; bitmap_clear (m_relations.m_names); } // Dump relation in basic block... Do nothing here. void path_oracle::dump (FILE *, basic_block) const { } // Dump the relations and equivalencies found in the path. void path_oracle::dump (FILE *f) const { equiv_chain *ptr = m_equiv.m_next; for (; ptr; ptr = ptr->m_next) ptr->dump (f); relation_chain *ptr2 = m_relations.m_head; for (; ptr2; ptr2 = ptr2->m_next) { fprintf (f, "Relational : "); ptr2->dump (f); fprintf (f, "\n"); } }