+/* Operator, rank pair. */
+typedef struct operand_entry
+{
+ unsigned int rank;
+ tree op;
+} *operand_entry_t;
+
+static alloc_pool operand_entry_pool;
+
+
+/* Starting rank number for a given basic block, so that we can rank
+ operations using unmovable instructions in that BB based on the bb
+ depth. */
+static long *bb_rank;
+
+/* Operand->rank hashtable. */
+static struct pointer_map_t *operand_rank;
+
+
+/* Look up the operand rank structure for expression E. */
+
+static inline long
+find_operand_rank (tree e)
+{
+ void **slot = pointer_map_contains (operand_rank, e);
+ return slot ? (long) (intptr_t) *slot : -1;
+}
+
+/* Insert {E,RANK} into the operand rank hashtable. */
+
+static inline void
+insert_operand_rank (tree e, long rank)
+{
+ void **slot;
+ gcc_assert (rank > 0);
+ slot = pointer_map_insert (operand_rank, e);
+ gcc_assert (!*slot);
+ *slot = (void *) (intptr_t) rank;
+}
+
+/* Given an expression E, return the rank of the expression. */
+
+static long
+get_rank (tree e)
+{
+ /* Constants have rank 0. */
+ if (is_gimple_min_invariant (e))
+ return 0;
+
+ /* SSA_NAME's have the rank of the expression they are the result
+ of.
+ For globals and uninitialized values, the rank is 0.
+ For function arguments, use the pre-setup rank.
+ For PHI nodes, stores, asm statements, etc, we use the rank of
+ the BB.
+ For simple operations, the rank is the maximum rank of any of
+ its operands, or the bb_rank, whichever is less.
+ I make no claims that this is optimal, however, it gives good
+ results. */
+
+ if (TREE_CODE (e) == SSA_NAME)
+ {
+ gimple stmt;
+ long rank, maxrank;
+ int i, n;
+
+ if (TREE_CODE (SSA_NAME_VAR (e)) == PARM_DECL
+ && SSA_NAME_IS_DEFAULT_DEF (e))
+ return find_operand_rank (e);
+
+ stmt = SSA_NAME_DEF_STMT (e);
+ if (gimple_bb (stmt) == NULL)
+ return 0;
+
+ if (!is_gimple_assign (stmt)
+ || gimple_vdef (stmt))
+ return bb_rank[gimple_bb (stmt)->index];
+
+ /* If we already have a rank for this expression, use that. */
+ rank = find_operand_rank (e);
+ if (rank != -1)
+ return rank;
+
+ /* Otherwise, find the maximum rank for the operands, or the bb
+ rank, whichever is less. */
+ rank = 0;
+ maxrank = bb_rank[gimple_bb(stmt)->index];
+ if (gimple_assign_single_p (stmt))
+ {
+ tree rhs = gimple_assign_rhs1 (stmt);
+ n = TREE_OPERAND_LENGTH (rhs);
+ if (n == 0)
+ rank = MAX (rank, get_rank (rhs));
+ else
+ {
+ for (i = 0;
+ i < n && TREE_OPERAND (rhs, i) && rank != maxrank; i++)
+ rank = MAX(rank, get_rank (TREE_OPERAND (rhs, i)));
+ }
+ }
+ else
+ {
+ n = gimple_num_ops (stmt);
+ for (i = 1; i < n && rank != maxrank; i++)
+ {
+ gcc_assert (gimple_op (stmt, i));
+ rank = MAX(rank, get_rank (gimple_op (stmt, i)));
+ }
+ }
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Rank for ");
+ print_generic_expr (dump_file, e, 0);
+ fprintf (dump_file, " is %ld\n", (rank + 1));
+ }
+
+ /* Note the rank in the hashtable so we don't recompute it. */
+ insert_operand_rank (e, (rank + 1));
+ return (rank + 1);
+ }
+
+ /* Globals, etc, are rank 0 */
+ return 0;
+}
+
+DEF_VEC_P(operand_entry_t);
+DEF_VEC_ALLOC_P(operand_entry_t, heap);
+
+/* We want integer ones to end up last no matter what, since they are
+ the ones we can do the most with. */
+#define INTEGER_CONST_TYPE 1 << 3
+#define FLOAT_CONST_TYPE 1 << 2
+#define OTHER_CONST_TYPE 1 << 1
+
+/* Classify an invariant tree into integer, float, or other, so that
+ we can sort them to be near other constants of the same type. */
+static inline int
+constant_type (tree t)
+{
+ if (INTEGRAL_TYPE_P (TREE_TYPE (t)))
+ return INTEGER_CONST_TYPE;
+ else if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (t)))
+ return FLOAT_CONST_TYPE;
+ else
+ return OTHER_CONST_TYPE;
+}
+
+/* qsort comparison function to sort operand entries PA and PB by rank
+ so that the sorted array is ordered by rank in decreasing order. */
+static int
+sort_by_operand_rank (const void *pa, const void *pb)
+{
+ const operand_entry_t oea = *(const operand_entry_t *)pa;
+ const operand_entry_t oeb = *(const operand_entry_t *)pb;
+
+ /* It's nicer for optimize_expression if constants that are likely
+ to fold when added/multiplied//whatever are put next to each
+ other. Since all constants have rank 0, order them by type. */
+ if (oeb->rank == 0 && oea->rank == 0)
+ return constant_type (oeb->op) - constant_type (oea->op);
+
+ /* Lastly, make sure the versions that are the same go next to each
+ other. We use SSA_NAME_VERSION because it's stable. */
+ if ((oeb->rank - oea->rank == 0)
+ && TREE_CODE (oea->op) == SSA_NAME
+ && TREE_CODE (oeb->op) == SSA_NAME)
+ return SSA_NAME_VERSION (oeb->op) - SSA_NAME_VERSION (oea->op);
+
+ return oeb->rank - oea->rank;
+}
+
+/* Add an operand entry to *OPS for the tree operand OP. */
+
+static void
+add_to_ops_vec (VEC(operand_entry_t, heap) **ops, tree op)
+{
+ operand_entry_t oe = (operand_entry_t) pool_alloc (operand_entry_pool);
+
+ oe->op = op;
+ oe->rank = get_rank (op);
+ VEC_safe_push (operand_entry_t, heap, *ops, oe);
+}
+
+/* Return true if STMT is reassociable operation containing a binary
+ operation with tree code CODE, and is inside LOOP. */
+
+static bool
+is_reassociable_op (gimple stmt, enum tree_code code, struct loop *loop)
+{
+ basic_block bb = gimple_bb (stmt);
+
+ if (gimple_bb (stmt) == NULL)
+ return false;
+
+ if (!flow_bb_inside_loop_p (loop, bb))
+ return false;
+
+ if (is_gimple_assign (stmt)
+ && gimple_assign_rhs_code (stmt) == code
+ && has_single_use (gimple_assign_lhs (stmt)))
+ return true;
+
+ return false;
+}
+
+
+/* Given NAME, if NAME is defined by a unary operation OPCODE, return the
+ operand of the negate operation. Otherwise, return NULL. */
+
+static tree
+get_unary_op (tree name, enum tree_code opcode)
+{
+ gimple stmt = SSA_NAME_DEF_STMT (name);
+
+ if (!is_gimple_assign (stmt))
+ return NULL_TREE;
+
+ if (gimple_assign_rhs_code (stmt) == opcode)
+ return gimple_assign_rhs1 (stmt);
+ return NULL_TREE;
+}
+
+/* If CURR and LAST are a pair of ops that OPCODE allows us to
+ eliminate through equivalences, do so, remove them from OPS, and
+ return true. Otherwise, return false. */
+
+static bool
+eliminate_duplicate_pair (enum tree_code opcode,
+ VEC (operand_entry_t, heap) **ops,
+ bool *all_done,
+ unsigned int i,
+ operand_entry_t curr,
+ operand_entry_t last)
+{
+
+ /* If we have two of the same op, and the opcode is & |, min, or max,
+ we can eliminate one of them.
+ If we have two of the same op, and the opcode is ^, we can
+ eliminate both of them. */
+
+ if (last && last->op == curr->op)
+ {
+ switch (opcode)
+ {
+ case MAX_EXPR:
+ case MIN_EXPR:
+ case BIT_IOR_EXPR:
+ case BIT_AND_EXPR:
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Equivalence: ");
+ print_generic_expr (dump_file, curr->op, 0);
+ fprintf (dump_file, " [&|minmax] ");
+ print_generic_expr (dump_file, last->op, 0);
+ fprintf (dump_file, " -> ");
+ print_generic_stmt (dump_file, last->op, 0);
+ }
+
+ VEC_ordered_remove (operand_entry_t, *ops, i);
+ reassociate_stats.ops_eliminated ++;
+
+ return true;
+
+ case BIT_XOR_EXPR:
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Equivalence: ");
+ print_generic_expr (dump_file, curr->op, 0);
+ fprintf (dump_file, " ^ ");
+ print_generic_expr (dump_file, last->op, 0);
+ fprintf (dump_file, " -> nothing\n");
+ }
+
+ reassociate_stats.ops_eliminated += 2;
+
+ if (VEC_length (operand_entry_t, *ops) == 2)
+ {
+ VEC_free (operand_entry_t, heap, *ops);
+ *ops = NULL;
+ add_to_ops_vec (ops, fold_convert (TREE_TYPE (last->op),
+ integer_zero_node));
+ *all_done = true;
+ }
+ else
+ {
+ VEC_ordered_remove (operand_entry_t, *ops, i-1);
+ VEC_ordered_remove (operand_entry_t, *ops, i-1);
+ }
+
+ return true;
+
+ default:
+ break;
+ }
+ }
+ return false;
+}
+
+/* If OPCODE is PLUS_EXPR, CURR->OP is really a negate expression,
+ look in OPS for a corresponding positive operation to cancel it
+ out. If we find one, remove the other from OPS, replace
+ OPS[CURRINDEX] with 0, and return true. Otherwise, return
+ false. */
+
+static bool
+eliminate_plus_minus_pair (enum tree_code opcode,
+ VEC (operand_entry_t, heap) **ops,
+ unsigned int currindex,
+ operand_entry_t curr)
+{
+ tree negateop;
+ unsigned int i;
+ operand_entry_t oe;
+
+ if (opcode != PLUS_EXPR || TREE_CODE (curr->op) != SSA_NAME)
+ return false;
+
+ negateop = get_unary_op (curr->op, NEGATE_EXPR);
+ if (negateop == NULL_TREE)
+ return false;
+
+ /* Any non-negated version will have a rank that is one less than
+ the current rank. So once we hit those ranks, if we don't find
+ one, we can stop. */
+
+ for (i = currindex + 1;
+ VEC_iterate (operand_entry_t, *ops, i, oe)
+ && oe->rank >= curr->rank - 1 ;
+ i++)
+ {
+ if (oe->op == negateop)
+ {
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Equivalence: ");
+ print_generic_expr (dump_file, negateop, 0);
+ fprintf (dump_file, " + -");
+ print_generic_expr (dump_file, oe->op, 0);
+ fprintf (dump_file, " -> 0\n");
+ }
+
+ VEC_ordered_remove (operand_entry_t, *ops, i);
+ add_to_ops_vec (ops, fold_convert(TREE_TYPE (oe->op),
+ integer_zero_node));
+ VEC_ordered_remove (operand_entry_t, *ops, currindex);
+ reassociate_stats.ops_eliminated ++;
+
+ return true;
+ }
+ }
+
+ return false;
+}
+
+/* If OPCODE is BIT_IOR_EXPR, BIT_AND_EXPR, and, CURR->OP is really a
+ bitwise not expression, look in OPS for a corresponding operand to
+ cancel it out. If we find one, remove the other from OPS, replace
+ OPS[CURRINDEX] with 0, and return true. Otherwise, return
+ false. */
+
+static bool
+eliminate_not_pairs (enum tree_code opcode,
+ VEC (operand_entry_t, heap) **ops,
+ unsigned int currindex,
+ operand_entry_t curr)
+{
+ tree notop;
+ unsigned int i;
+ operand_entry_t oe;
+
+ if ((opcode != BIT_IOR_EXPR && opcode != BIT_AND_EXPR)
+ || TREE_CODE (curr->op) != SSA_NAME)
+ return false;
+
+ notop = get_unary_op (curr->op, BIT_NOT_EXPR);
+ if (notop == NULL_TREE)
+ return false;
+
+ /* Any non-not version will have a rank that is one less than
+ the current rank. So once we hit those ranks, if we don't find
+ one, we can stop. */
+
+ for (i = currindex + 1;
+ VEC_iterate (operand_entry_t, *ops, i, oe)
+ && oe->rank >= curr->rank - 1;
+ i++)
+ {
+ if (oe->op == notop)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Equivalence: ");
+ print_generic_expr (dump_file, notop, 0);
+ if (opcode == BIT_AND_EXPR)
+ fprintf (dump_file, " & ~");
+ else if (opcode == BIT_IOR_EXPR)
+ fprintf (dump_file, " | ~");
+ print_generic_expr (dump_file, oe->op, 0);
+ if (opcode == BIT_AND_EXPR)
+ fprintf (dump_file, " -> 0\n");
+ else if (opcode == BIT_IOR_EXPR)
+ fprintf (dump_file, " -> -1\n");
+ }
+
+ if (opcode == BIT_AND_EXPR)
+ oe->op = fold_convert (TREE_TYPE (oe->op), integer_zero_node);
+ else if (opcode == BIT_IOR_EXPR)
+ oe->op = build_low_bits_mask (TREE_TYPE (oe->op),
+ TYPE_PRECISION (TREE_TYPE (oe->op)));
+
+ reassociate_stats.ops_eliminated
+ += VEC_length (operand_entry_t, *ops) - 1;
+ VEC_free (operand_entry_t, heap, *ops);
+ *ops = NULL;
+ VEC_safe_push (operand_entry_t, heap, *ops, oe);
+ return true;
+ }
+ }
+
+ return false;
+}
+
+/* Use constant value that may be present in OPS to try to eliminate
+ operands. Note that this function is only really used when we've
+ eliminated ops for other reasons, or merged constants. Across
+ single statements, fold already does all of this, plus more. There
+ is little point in duplicating logic, so I've only included the
+ identities that I could ever construct testcases to trigger. */
+
+static void
+eliminate_using_constants (enum tree_code opcode,
+ VEC(operand_entry_t, heap) **ops)
+{
+ operand_entry_t oelast = VEC_last (operand_entry_t, *ops);
+ tree type = TREE_TYPE (oelast->op);
+
+ if (oelast->rank == 0
+ && (INTEGRAL_TYPE_P (type) || FLOAT_TYPE_P (type)))
+ {
+ switch (opcode)
+ {
+ case BIT_AND_EXPR:
+ if (integer_zerop (oelast->op))
+ {
+ if (VEC_length (operand_entry_t, *ops) != 1)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Found & 0, removing all other ops\n");
+
+ reassociate_stats.ops_eliminated
+ += VEC_length (operand_entry_t, *ops) - 1;
+
+ VEC_free (operand_entry_t, heap, *ops);
+ *ops = NULL;
+ VEC_safe_push (operand_entry_t, heap, *ops, oelast);
+ return;
+ }
+ }
+ else if (integer_all_onesp (oelast->op))
+ {
+ if (VEC_length (operand_entry_t, *ops) != 1)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Found & -1, removing\n");
+ VEC_pop (operand_entry_t, *ops);
+ reassociate_stats.ops_eliminated++;
+ }
+ }
+ break;
+ case BIT_IOR_EXPR:
+ if (integer_all_onesp (oelast->op))
+ {
+ if (VEC_length (operand_entry_t, *ops) != 1)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Found | -1, removing all other ops\n");
+
+ reassociate_stats.ops_eliminated
+ += VEC_length (operand_entry_t, *ops) - 1;
+
+ VEC_free (operand_entry_t, heap, *ops);
+ *ops = NULL;
+ VEC_safe_push (operand_entry_t, heap, *ops, oelast);
+ return;
+ }
+ }
+ else if (integer_zerop (oelast->op))
+ {
+ if (VEC_length (operand_entry_t, *ops) != 1)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Found | 0, removing\n");
+ VEC_pop (operand_entry_t, *ops);
+ reassociate_stats.ops_eliminated++;
+ }
+ }
+ break;
+ case MULT_EXPR:
+ if (integer_zerop (oelast->op)
+ || (FLOAT_TYPE_P (type)
+ && !HONOR_NANS (TYPE_MODE (type))
+ && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
+ && real_zerop (oelast->op)))
+ {
+ if (VEC_length (operand_entry_t, *ops) != 1)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Found * 0, removing all other ops\n");
+
+ reassociate_stats.ops_eliminated
+ += VEC_length (operand_entry_t, *ops) - 1;
+ VEC_free (operand_entry_t, heap, *ops);
+ *ops = NULL;
+ VEC_safe_push (operand_entry_t, heap, *ops, oelast);
+ return;
+ }
+ }
+ else if (integer_onep (oelast->op)
+ || (FLOAT_TYPE_P (type)
+ && !HONOR_SNANS (TYPE_MODE (type))
+ && real_onep (oelast->op)))
+ {
+ if (VEC_length (operand_entry_t, *ops) != 1)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Found * 1, removing\n");
+ VEC_pop (operand_entry_t, *ops);
+ reassociate_stats.ops_eliminated++;
+ return;
+ }
+ }
+ break;
+ case BIT_XOR_EXPR:
+ case PLUS_EXPR:
+ case MINUS_EXPR:
+ if (integer_zerop (oelast->op)
+ || (FLOAT_TYPE_P (type)
+ && (opcode == PLUS_EXPR || opcode == MINUS_EXPR)
+ && fold_real_zero_addition_p (type, oelast->op,
+ opcode == MINUS_EXPR)))
+ {
+ if (VEC_length (operand_entry_t, *ops) != 1)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Found [|^+] 0, removing\n");
+ VEC_pop (operand_entry_t, *ops);
+ reassociate_stats.ops_eliminated++;
+ return;
+ }
+ }
+ break;
+ default:
+ break;
+ }
+ }
+}
+
+
+static void linearize_expr_tree (VEC(operand_entry_t, heap) **, gimple,
+ bool, bool);
+
+/* Structure for tracking and counting operands. */
+typedef struct oecount_s {
+ int cnt;
+ enum tree_code oecode;
+ tree op;
+} oecount;
+
+DEF_VEC_O(oecount);
+DEF_VEC_ALLOC_O(oecount,heap);
+
+/* The heap for the oecount hashtable and the sorted list of operands. */
+static VEC (oecount, heap) *cvec;
+
+/* Hash function for oecount. */
+
+static hashval_t
+oecount_hash (const void *p)
+{
+ const oecount *c = VEC_index (oecount, cvec, (size_t)p - 42);
+ return htab_hash_pointer (c->op) ^ (hashval_t)c->oecode;
+}
+
+/* Comparison function for oecount. */
+
+static int
+oecount_eq (const void *p1, const void *p2)
+{
+ const oecount *c1 = VEC_index (oecount, cvec, (size_t)p1 - 42);
+ const oecount *c2 = VEC_index (oecount, cvec, (size_t)p2 - 42);
+ return (c1->oecode == c2->oecode
+ && c1->op == c2->op);
+}
+
+/* Comparison function for qsort sorting oecount elements by count. */
+
+static int
+oecount_cmp (const void *p1, const void *p2)
+{
+ const oecount *c1 = (const oecount *)p1;
+ const oecount *c2 = (const oecount *)p2;
+ return c1->cnt - c2->cnt;
+}
+
+/* Walks the linear chain with result *DEF searching for an operation
+ with operand OP and code OPCODE removing that from the chain. *DEF
+ is updated if there is only one operand but no operation left. */
+
+static void
+zero_one_operation (tree *def, enum tree_code opcode, tree op)
+{
+ gimple stmt = SSA_NAME_DEF_STMT (*def);
+
+ do
+ {
+ tree name = gimple_assign_rhs1 (stmt);
+
+ /* If this is the operation we look for and one of the operands
+ is ours simply propagate the other operand into the stmts
+ single use. */
+ if (gimple_assign_rhs_code (stmt) == opcode
+ && (name == op
+ || gimple_assign_rhs2 (stmt) == op))
+ {
+ gimple use_stmt;
+ use_operand_p use;
+ gimple_stmt_iterator gsi;
+ if (name == op)
+ name = gimple_assign_rhs2 (stmt);
+ gcc_assert (has_single_use (gimple_assign_lhs (stmt)));
+ single_imm_use (gimple_assign_lhs (stmt), &use, &use_stmt);
+ if (gimple_assign_lhs (stmt) == *def)
+ *def = name;
+ SET_USE (use, name);
+ if (TREE_CODE (name) != SSA_NAME)
+ update_stmt (use_stmt);
+ gsi = gsi_for_stmt (stmt);
+ gsi_remove (&gsi, true);
+ release_defs (stmt);
+ return;
+ }
+
+ /* Continue walking the chain. */
+ gcc_assert (name != op
+ && TREE_CODE (name) == SSA_NAME);
+ stmt = SSA_NAME_DEF_STMT (name);
+ }
+ while (1);
+}
+
+/* Builds one statement performing OP1 OPCODE OP2 using TMPVAR for
+ the result. Places the statement after the definition of either
+ OP1 or OP2. Returns the new statement. */
+
+static gimple
+build_and_add_sum (tree tmpvar, tree op1, tree op2, enum tree_code opcode)
+{
+ gimple op1def = NULL, op2def = NULL;
+ gimple_stmt_iterator gsi;
+ tree op;
+ gimple sum;
+
+ /* Create the addition statement. */
+ sum = gimple_build_assign_with_ops (opcode, tmpvar, op1, op2);
+ op = make_ssa_name (tmpvar, sum);
+ gimple_assign_set_lhs (sum, op);
+
+ /* Find an insertion place and insert. */
+ if (TREE_CODE (op1) == SSA_NAME)
+ op1def = SSA_NAME_DEF_STMT (op1);
+ if (TREE_CODE (op2) == SSA_NAME)
+ op2def = SSA_NAME_DEF_STMT (op2);
+ if ((!op1def || gimple_nop_p (op1def))
+ && (!op2def || gimple_nop_p (op2def)))
+ {
+ gsi = gsi_start_bb (single_succ (ENTRY_BLOCK_PTR));
+ gsi_insert_before (&gsi, sum, GSI_NEW_STMT);
+ }
+ else if ((!op1def || gimple_nop_p (op1def))
+ || (op2def && !gimple_nop_p (op2def)
+ && stmt_dominates_stmt_p (op1def, op2def)))
+ {
+ if (gimple_code (op2def) == GIMPLE_PHI)
+ {
+ gsi = gsi_start_bb (gimple_bb (op2def));
+ gsi_insert_before (&gsi, sum, GSI_NEW_STMT);
+ }
+ else
+ {
+ if (!stmt_ends_bb_p (op2def))
+ {
+ gsi = gsi_for_stmt (op2def);
+ gsi_insert_after (&gsi, sum, GSI_NEW_STMT);
+ }
+ else
+ {
+ edge e;
+ edge_iterator ei;
+
+ FOR_EACH_EDGE (e, ei, gimple_bb (op2def)->succs)
+ if (e->flags & EDGE_FALLTHRU)
+ gsi_insert_on_edge_immediate (e, sum);
+ }
+ }
+ }
+ else
+ {
+ if (gimple_code (op1def) == GIMPLE_PHI)
+ {
+ gsi = gsi_start_bb (gimple_bb (op1def));
+ gsi_insert_before (&gsi, sum, GSI_NEW_STMT);
+ }
+ else
+ {
+ if (!stmt_ends_bb_p (op1def))
+ {
+ gsi = gsi_for_stmt (op1def);
+ gsi_insert_after (&gsi, sum, GSI_NEW_STMT);
+ }
+ else
+ {
+ edge e;
+ edge_iterator ei;
+
+ FOR_EACH_EDGE (e, ei, gimple_bb (op1def)->succs)
+ if (e->flags & EDGE_FALLTHRU)
+ gsi_insert_on_edge_immediate (e, sum);
+ }
+ }
+ }
+ update_stmt (sum);
+
+ return sum;
+}
+
+/* Perform un-distribution of divisions and multiplications.
+ A * X + B * X is transformed into (A + B) * X and A / X + B / X
+ to (A + B) / X for real X.
+
+ The algorithm is organized as follows.
+
+ - First we walk the addition chain *OPS looking for summands that
+ are defined by a multiplication or a real division. This results
+ in the candidates bitmap with relevant indices into *OPS.
+
+ - Second we build the chains of multiplications or divisions for
+ these candidates, counting the number of occurences of (operand, code)
+ pairs in all of the candidates chains.
+
+ - Third we sort the (operand, code) pairs by number of occurence and
+ process them starting with the pair with the most uses.
+
+ * For each such pair we walk the candidates again to build a
+ second candidate bitmap noting all multiplication/division chains
+ that have at least one occurence of (operand, code).
+
+ * We build an alternate addition chain only covering these
+ candidates with one (operand, code) operation removed from their
+ multiplication/division chain.
+
+ * The first candidate gets replaced by the alternate addition chain
+ multiplied/divided by the operand.
+
+ * All candidate chains get disabled for further processing and
+ processing of (operand, code) pairs continues.
+
+ The alternate addition chains built are re-processed by the main
+ reassociation algorithm which allows optimizing a * x * y + b * y * x
+ to (a + b ) * x * y in one invocation of the reassociation pass. */
+
+static bool
+undistribute_ops_list (enum tree_code opcode,
+ VEC (operand_entry_t, heap) **ops, struct loop *loop)
+{
+ unsigned int length = VEC_length (operand_entry_t, *ops);
+ operand_entry_t oe1;
+ unsigned i, j;
+ sbitmap candidates, candidates2;
+ unsigned nr_candidates, nr_candidates2;
+ sbitmap_iterator sbi0;
+ VEC (operand_entry_t, heap) **subops;
+ htab_t ctable;
+ bool changed = false;
+
+ if (length <= 1
+ || opcode != PLUS_EXPR)
+ return false;
+
+ /* Build a list of candidates to process. */
+ candidates = sbitmap_alloc (length);
+ sbitmap_zero (candidates);
+ nr_candidates = 0;
+ for (i = 0; VEC_iterate (operand_entry_t, *ops, i, oe1); ++i)
+ {
+ enum tree_code dcode;
+ gimple oe1def;
+
+ if (TREE_CODE (oe1->op) != SSA_NAME)
+ continue;
+ oe1def = SSA_NAME_DEF_STMT (oe1->op);
+ if (!is_gimple_assign (oe1def))
+ continue;
+ dcode = gimple_assign_rhs_code (oe1def);
+ if ((dcode != MULT_EXPR
+ && dcode != RDIV_EXPR)
+ || !is_reassociable_op (oe1def, dcode, loop))
+ continue;
+
+ SET_BIT (candidates, i);
+ nr_candidates++;
+ }
+
+ if (nr_candidates < 2)
+ {
+ sbitmap_free (candidates);
+ return false;
+ }
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "searching for un-distribute opportunities ");
+ print_generic_expr (dump_file,
+ VEC_index (operand_entry_t, *ops,
+ sbitmap_first_set_bit (candidates))->op, 0);
+ fprintf (dump_file, " %d\n", nr_candidates);
+ }
+
+ /* Build linearized sub-operand lists and the counting table. */
+ cvec = NULL;
+ ctable = htab_create (15, oecount_hash, oecount_eq, NULL);
+ subops = XCNEWVEC (VEC (operand_entry_t, heap) *,
+ VEC_length (operand_entry_t, *ops));
+ EXECUTE_IF_SET_IN_SBITMAP (candidates, 0, i, sbi0)
+ {
+ gimple oedef;
+ enum tree_code oecode;
+ unsigned j;
+
+ oedef = SSA_NAME_DEF_STMT (VEC_index (operand_entry_t, *ops, i)->op);
+ oecode = gimple_assign_rhs_code (oedef);
+ linearize_expr_tree (&subops[i], oedef,
+ associative_tree_code (oecode), false);
+
+ for (j = 0; VEC_iterate (operand_entry_t, subops[i], j, oe1); ++j)
+ {
+ oecount c;
+ void **slot;
+ size_t idx;
+ c.oecode = oecode;
+ c.cnt = 1;
+ c.op = oe1->op;
+ VEC_safe_push (oecount, heap, cvec, &c);
+ idx = VEC_length (oecount, cvec) + 41;
+ slot = htab_find_slot (ctable, (void *)idx, INSERT);
+ if (!*slot)
+ {
+ *slot = (void *)idx;
+ }
+ else
+ {
+ VEC_pop (oecount, cvec);
+ VEC_index (oecount, cvec, (size_t)*slot - 42)->cnt++;
+ }
+ }
+ }
+ htab_delete (ctable);
+
+ /* Sort the counting table. */
+ qsort (VEC_address (oecount, cvec), VEC_length (oecount, cvec),
+ sizeof (oecount), oecount_cmp);
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ oecount *c;
+ fprintf (dump_file, "Candidates:\n");
+ for (j = 0; VEC_iterate (oecount, cvec, j, c); ++j)
+ {
+ fprintf (dump_file, " %u %s: ", c->cnt,
+ c->oecode == MULT_EXPR
+ ? "*" : c->oecode == RDIV_EXPR ? "/" : "?");
+ print_generic_expr (dump_file, c->op, 0);
+ fprintf (dump_file, "\n");
+ }
+ }
+
+ /* Process the (operand, code) pairs in order of most occurence. */
+ candidates2 = sbitmap_alloc (length);
+ while (!VEC_empty (oecount, cvec))
+ {
+ oecount *c = VEC_last (oecount, cvec);
+ if (c->cnt < 2)
+ break;
+
+ /* Now collect the operands in the outer chain that contain
+ the common operand in their inner chain. */
+ sbitmap_zero (candidates2);
+ nr_candidates2 = 0;
+ EXECUTE_IF_SET_IN_SBITMAP (candidates, 0, i, sbi0)
+ {
+ gimple oedef;
+ enum tree_code oecode;
+ unsigned j;
+ tree op = VEC_index (operand_entry_t, *ops, i)->op;
+
+ /* If we undistributed in this chain already this may be
+ a constant. */
+ if (TREE_CODE (op) != SSA_NAME)
+ continue;
+
+ oedef = SSA_NAME_DEF_STMT (op);
+ oecode = gimple_assign_rhs_code (oedef);
+ if (oecode != c->oecode)
+ continue;
+
+ for (j = 0; VEC_iterate (operand_entry_t, subops[i], j, oe1); ++j)
+ {
+ if (oe1->op == c->op)
+ {
+ SET_BIT (candidates2, i);
+ ++nr_candidates2;
+ break;
+ }
+ }
+ }
+
+ if (nr_candidates2 >= 2)
+ {
+ operand_entry_t oe1, oe2;
+ tree tmpvar;
+ gimple prod;
+ int first = sbitmap_first_set_bit (candidates2);
+
+ /* Build the new addition chain. */
+ oe1 = VEC_index (operand_entry_t, *ops, first);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Building (");
+ print_generic_expr (dump_file, oe1->op, 0);
+ }
+ tmpvar = create_tmp_var (TREE_TYPE (oe1->op), NULL);
+ add_referenced_var (tmpvar);
+ zero_one_operation (&oe1->op, c->oecode, c->op);
+ EXECUTE_IF_SET_IN_SBITMAP (candidates2, first+1, i, sbi0)
+ {
+ gimple sum;
+ oe2 = VEC_index (operand_entry_t, *ops, i);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, " + ");
+ print_generic_expr (dump_file, oe2->op, 0);
+ }
+ zero_one_operation (&oe2->op, c->oecode, c->op);
+ sum = build_and_add_sum (tmpvar, oe1->op, oe2->op, opcode);
+ oe2->op = fold_convert (TREE_TYPE (oe2->op), integer_zero_node);
+ oe2->rank = 0;
+ oe1->op = gimple_get_lhs (sum);
+ }
+
+ /* Apply the multiplication/division. */
+ prod = build_and_add_sum (tmpvar, oe1->op, c->op, c->oecode);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, ") %s ", c->oecode == MULT_EXPR ? "*" : "/");
+ print_generic_expr (dump_file, c->op, 0);
+ fprintf (dump_file, "\n");
+ }
+
+ /* Record it in the addition chain and disable further
+ undistribution with this op. */
+ oe1->op = gimple_assign_lhs (prod);
+ oe1->rank = get_rank (oe1->op);
+ VEC_free (operand_entry_t, heap, subops[first]);
+
+ changed = true;
+ }
+
+ VEC_pop (oecount, cvec);
+ }
+
+ for (i = 0; i < VEC_length (operand_entry_t, *ops); ++i)
+ VEC_free (operand_entry_t, heap, subops[i]);
+ free (subops);
+ VEC_free (oecount, heap, cvec);
+ sbitmap_free (candidates);
+ sbitmap_free (candidates2);
+
+ return changed;
+}
+
+
+/* Perform various identities and other optimizations on the list of
+ operand entries, stored in OPS. The tree code for the binary
+ operation between all the operands is OPCODE. */
+
+static void
+optimize_ops_list (enum tree_code opcode,
+ VEC (operand_entry_t, heap) **ops)
+{
+ unsigned int length = VEC_length (operand_entry_t, *ops);
+ unsigned int i;
+ operand_entry_t oe;
+ operand_entry_t oelast = NULL;
+ bool iterate = false;
+
+ if (length == 1)
+ return;
+
+ oelast = VEC_last (operand_entry_t, *ops);
+
+ /* If the last two are constants, pop the constants off, merge them
+ and try the next two. */
+ if (oelast->rank == 0 && is_gimple_min_invariant (oelast->op))
+ {
+ operand_entry_t oelm1 = VEC_index (operand_entry_t, *ops, length - 2);
+
+ if (oelm1->rank == 0
+ && is_gimple_min_invariant (oelm1->op)
+ && useless_type_conversion_p (TREE_TYPE (oelm1->op),
+ TREE_TYPE (oelast->op)))
+ {
+ tree folded = fold_binary (opcode, TREE_TYPE (oelm1->op),
+ oelm1->op, oelast->op);
+
+ if (folded && is_gimple_min_invariant (folded))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Merging constants\n");
+
+ VEC_pop (operand_entry_t, *ops);
+ VEC_pop (operand_entry_t, *ops);
+
+ add_to_ops_vec (ops, folded);
+ reassociate_stats.constants_eliminated++;
+
+ optimize_ops_list (opcode, ops);
+ return;
+ }
+ }
+ }
+
+ eliminate_using_constants (opcode, ops);
+ oelast = NULL;
+
+ for (i = 0; VEC_iterate (operand_entry_t, *ops, i, oe);)
+ {
+ bool done = false;
+
+ if (eliminate_not_pairs (opcode, ops, i, oe))
+ return;
+ if (eliminate_duplicate_pair (opcode, ops, &done, i, oe, oelast)
+ || (!done && eliminate_plus_minus_pair (opcode, ops, i, oe)))
+ {
+ if (done)
+ return;
+ iterate = true;
+ oelast = NULL;
+ continue;
+ }
+ oelast = oe;
+ i++;
+ }
+
+ length = VEC_length (operand_entry_t, *ops);
+ oelast = VEC_last (operand_entry_t, *ops);
+
+ if (iterate)
+ optimize_ops_list (opcode, ops);
+}
+
+/* Return true if OPERAND is defined by a PHI node which uses the LHS
+ of STMT in it's operands. This is also known as a "destructive
+ update" operation. */
+
+static bool
+is_phi_for_stmt (gimple stmt, tree operand)
+{
+ gimple def_stmt;
+ tree lhs;
+ use_operand_p arg_p;
+ ssa_op_iter i;
+
+ if (TREE_CODE (operand) != SSA_NAME)
+ return false;
+
+ lhs = gimple_assign_lhs (stmt);
+
+ def_stmt = SSA_NAME_DEF_STMT (operand);
+ if (gimple_code (def_stmt) != GIMPLE_PHI)
+ return false;
+
+ FOR_EACH_PHI_ARG (arg_p, def_stmt, i, SSA_OP_USE)
+ if (lhs == USE_FROM_PTR (arg_p))
+ return true;
+ return false;
+}
+
+/* Remove def stmt of VAR if VAR has zero uses and recurse
+ on rhs1 operand if so. */
+
+static void
+remove_visited_stmt_chain (tree var)
+{
+ gimple stmt;
+ gimple_stmt_iterator gsi;
+
+ while (1)
+ {
+ if (TREE_CODE (var) != SSA_NAME || !has_zero_uses (var))
+ return;
+ stmt = SSA_NAME_DEF_STMT (var);
+ if (!is_gimple_assign (stmt)
+ || !gimple_visited_p (stmt))
+ return;
+ var = gimple_assign_rhs1 (stmt);
+ gsi = gsi_for_stmt (stmt);
+ gsi_remove (&gsi, true);
+ release_defs (stmt);
+ }
+}
+
+/* Recursively rewrite our linearized statements so that the operators
+ match those in OPS[OPINDEX], putting the computation in rank
+ order. */
+
+static void
+rewrite_expr_tree (gimple stmt, unsigned int opindex,
+ VEC(operand_entry_t, heap) * ops, bool moved)
+{
+ tree rhs1 = gimple_assign_rhs1 (stmt);
+ tree rhs2 = gimple_assign_rhs2 (stmt);
+ operand_entry_t oe;
+
+ /* If we have three operands left, then we want to make sure the one
+ that gets the double binary op are the ones with the same rank.
+
+ The alternative we try is to see if this is a destructive
+ update style statement, which is like:
+ b = phi (a, ...)
+ a = c + b;
+ In that case, we want to use the destructive update form to
+ expose the possible vectorizer sum reduction opportunity.
+ In that case, the third operand will be the phi node.
+
+ We could, of course, try to be better as noted above, and do a
+ lot of work to try to find these opportunities in >3 operand
+ cases, but it is unlikely to be worth it. */
+ if (opindex + 3 == VEC_length (operand_entry_t, ops))
+ {
+ operand_entry_t oe1, oe2, oe3;
+
+ oe1 = VEC_index (operand_entry_t, ops, opindex);
+ oe2 = VEC_index (operand_entry_t, ops, opindex + 1);
+ oe3 = VEC_index (operand_entry_t, ops, opindex + 2);
+
+ if ((oe1->rank == oe2->rank
+ && oe2->rank != oe3->rank)
+ || (is_phi_for_stmt (stmt, oe3->op)
+ && !is_phi_for_stmt (stmt, oe1->op)
+ && !is_phi_for_stmt (stmt, oe2->op)))
+ {
+ struct operand_entry temp = *oe3;
+ oe3->op = oe1->op;
+ oe3->rank = oe1->rank;
+ oe1->op = temp.op;
+ oe1->rank= temp.rank;
+ }
+ else if ((oe1->rank == oe3->rank
+ && oe2->rank != oe3->rank)
+ || (is_phi_for_stmt (stmt, oe2->op)
+ && !is_phi_for_stmt (stmt, oe1->op)
+ && !is_phi_for_stmt (stmt, oe3->op)))
+ {
+ struct operand_entry temp = *oe2;
+ oe2->op = oe1->op;
+ oe2->rank = oe1->rank;
+ oe1->op = temp.op;
+ oe1->rank= temp.rank;
+ }
+ }
+
+ /* The final recursion case for this function is that you have
+ exactly two operations left.
+ If we had one exactly one op in the entire list to start with, we
+ would have never called this function, and the tail recursion
+ rewrites them one at a time. */
+ if (opindex + 2 == VEC_length (operand_entry_t, ops))
+ {
+ operand_entry_t oe1, oe2;
+
+ oe1 = VEC_index (operand_entry_t, ops, opindex);
+ oe2 = VEC_index (operand_entry_t, ops, opindex + 1);
+
+ if (rhs1 != oe1->op || rhs2 != oe2->op)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Transforming ");
+ print_gimple_stmt (dump_file, stmt, 0, 0);
+ }
+
+ gimple_assign_set_rhs1 (stmt, oe1->op);
+ gimple_assign_set_rhs2 (stmt, oe2->op);
+ update_stmt (stmt);
+ if (rhs1 != oe1->op && rhs1 != oe2->op)
+ remove_visited_stmt_chain (rhs1);
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, " into ");
+ print_gimple_stmt (dump_file, stmt, 0, 0);
+ }
+
+ }
+ return;
+ }
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