Initial checkin of GCC 4.9.0 from trunk (r208799).

Change-Id: I48a3c08bb98542aa215912a75f03c0890e497dba

1 files changed, 2586 insertions, 0 deletions

diff --git a/gcc-4.9/gcc/tree-ssa-loop-im.c b/gcc-4.9/gcc/tree-ssa-loop-im.c
new file mode 100644
index 000000000..c75f25749
--- /dev/null
+++ b/gcc-4.9/gcc/tree-ssa-loop-im.c
@@ -0,0 +1,2586 @@
+/* Loop invariant motion.
+   Copyright (C) 2003-2014 Free Software Foundation, Inc.
+
+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
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "tree.h"
+#include "tm_p.h"
+#include "basic-block.h"
+#include "gimple-pretty-print.h"
+#include "pointer-set.h"
+#include "hash-table.h"
+#include "tree-ssa-alias.h"
+#include "internal-fn.h"
+#include "tree-eh.h"
+#include "gimple-expr.h"
+#include "is-a.h"
+#include "gimple.h"
+#include "gimplify.h"
+#include "gimple-iterator.h"
+#include "gimple-ssa.h"
+#include "tree-cfg.h"
+#include "tree-phinodes.h"
+#include "ssa-iterators.h"
+#include "stringpool.h"
+#include "tree-ssanames.h"
+#include "tree-ssa-loop-manip.h"
+#include "tree-ssa-loop.h"
+#include "tree-into-ssa.h"
+#include "cfgloop.h"
+#include "domwalk.h"
+#include "params.h"
+#include "tree-pass.h"
+#include "flags.h"
+#include "tree-affine.h"
+#include "tree-ssa-propagate.h"
+#include "trans-mem.h"
+#include "gimple-fold.h"
+
+/* TODO:  Support for predicated code motion.  I.e.
+
+   while (1)
+     {
+       if (cond)
+	 {
+	   a = inv;
+	   something;
+	 }
+     }
+
+   Where COND and INV are invariants, but evaluating INV may trap or be
+   invalid from some other reason if !COND.  This may be transformed to
+
+   if (cond)
+     a = inv;
+   while (1)
+     {
+       if (cond)
+	 something;
+     }  */
+
+/* The auxiliary data kept for each statement.  */
+
+struct lim_aux_data
+{
+  struct loop *max_loop;	/* The outermost loop in that the statement
+				   is invariant.  */
+
+  struct loop *tgt_loop;	/* The loop out of that we want to move the
+				   invariant.  */
+
+  struct loop *always_executed_in;
+				/* The outermost loop for that we are sure
+				   the statement is executed if the loop
+				   is entered.  */
+
+  unsigned cost;		/* Cost of the computation performed by the
+				   statement.  */
+
+  vec<gimple> depends;		/* Vector of statements that must be also
+				   hoisted out of the loop when this statement
+				   is hoisted; i.e. those that define the
+				   operands of the statement and are inside of
+				   the MAX_LOOP loop.  */
+};
+
+/* Maps statements to their lim_aux_data.  */
+
+static struct pointer_map_t *lim_aux_data_map;
+
+/* Description of a memory reference location.  */
+
+typedef struct mem_ref_loc
+{
+  tree *ref;			/* The reference itself.  */
+  gimple stmt;			/* The statement in that it occurs.  */
+} *mem_ref_loc_p;
+
+
+/* Description of a memory reference.  */
+
+typedef struct mem_ref
+{
+  unsigned id;			/* ID assigned to the memory reference
+				   (its index in memory_accesses.refs_list)  */
+  hashval_t hash;		/* Its hash value.  */
+
+  /* The memory access itself and associated caching of alias-oracle
+     query meta-data.  */
+  ao_ref mem;
+
+  bitmap stored;		/* The set of loops in that this memory location
+				   is stored to.  */
+  vec<mem_ref_loc>		accesses_in_loop;
+				/* The locations of the accesses.  Vector
+				   indexed by the loop number.  */
+
+  /* The following sets are computed on demand.  We keep both set and
+     its complement, so that we know whether the information was
+     already computed or not.  */
+  bitmap_head indep_loop;	/* The set of loops in that the memory
+				   reference is independent, meaning:
+				   If it is stored in the loop, this store
+				     is independent on all other loads and
+				     stores.
+				   If it is only loaded, then it is independent
+				     on all stores in the loop.  */
+  bitmap_head dep_loop;		/* The complement of INDEP_LOOP.  */
+} *mem_ref_p;
+
+/* We use two bits per loop in the ref->{in,}dep_loop bitmaps, the first
+   to record (in)dependence against stores in the loop and its subloops, the
+   second to record (in)dependence against all references in the loop
+   and its subloops.  */
+#define LOOP_DEP_BIT(loopnum, storedp) (2 * (loopnum) + (storedp ? 1 : 0))
+
+/* Mem_ref hashtable helpers.  */
+
+struct mem_ref_hasher : typed_noop_remove <mem_ref>
+{
+  typedef mem_ref value_type;
+  typedef tree_node compare_type;
+  static inline hashval_t hash (const value_type *);
+  static inline bool equal (const value_type *, const compare_type *);
+};
+
+/* A hash function for struct mem_ref object OBJ.  */
+
+inline hashval_t
+mem_ref_hasher::hash (const value_type *mem)
+{
+  return mem->hash;
+}
+
+/* An equality function for struct mem_ref object MEM1 with
+   memory reference OBJ2.  */
+
+inline bool
+mem_ref_hasher::equal (const value_type *mem1, const compare_type *obj2)
+{
+  return operand_equal_p (mem1->mem.ref, (const_tree) obj2, 0);
+}
+
+
+/* Description of memory accesses in loops.  */
+
+static struct
+{
+  /* The hash table of memory references accessed in loops.  */
+  hash_table <mem_ref_hasher> refs;
+
+  /* The list of memory references.  */
+  vec<mem_ref_p> refs_list;
+
+  /* The set of memory references accessed in each loop.  */
+  vec<bitmap_head> refs_in_loop;
+
+  /* The set of memory references stored in each loop.  */
+  vec<bitmap_head> refs_stored_in_loop;
+
+  /* The set of memory references stored in each loop, including subloops .  */
+  vec<bitmap_head> all_refs_stored_in_loop;
+
+  /* Cache for expanding memory addresses.  */
+  struct pointer_map_t *ttae_cache;
+} memory_accesses;
+
+/* Obstack for the bitmaps in the above data structures.  */
+static bitmap_obstack lim_bitmap_obstack;
+static obstack mem_ref_obstack;
+
+static bool ref_indep_loop_p (struct loop *, mem_ref_p);
+
+/* Minimum cost of an expensive expression.  */
+#define LIM_EXPENSIVE ((unsigned) PARAM_VALUE (PARAM_LIM_EXPENSIVE))
+
+/* The outermost loop for which execution of the header guarantees that the
+   block will be executed.  */
+#define ALWAYS_EXECUTED_IN(BB) ((struct loop *) (BB)->aux)
+#define SET_ALWAYS_EXECUTED_IN(BB, VAL) ((BB)->aux = (void *) (VAL))
+
+/* ID of the shared unanalyzable mem.  */
+#define UNANALYZABLE_MEM_ID 0
+
+/* Whether the reference was analyzable.  */
+#define MEM_ANALYZABLE(REF) ((REF)->id != UNANALYZABLE_MEM_ID)
+
+static struct lim_aux_data *
+init_lim_data (gimple stmt)
+{
+  void **p = pointer_map_insert (lim_aux_data_map, stmt);
+
+  *p = XCNEW (struct lim_aux_data);
+  return (struct lim_aux_data *) *p;
+}
+
+static struct lim_aux_data *
+get_lim_data (gimple stmt)
+{
+  void **p = pointer_map_contains (lim_aux_data_map, stmt);
+  if (!p)
+    return NULL;
+
+  return (struct lim_aux_data *) *p;
+}
+
+/* Releases the memory occupied by DATA.  */
+
+static void
+free_lim_aux_data (struct lim_aux_data *data)
+{
+  data->depends.release ();
+  free (data);
+}
+
+static void
+clear_lim_data (gimple stmt)
+{
+  void **p = pointer_map_contains (lim_aux_data_map, stmt);
+  if (!p)
+    return;
+
+  free_lim_aux_data ((struct lim_aux_data *) *p);
+  *p = NULL;
+}
+
+
+/* The possibilities of statement movement.  */
+enum move_pos
+  {
+    MOVE_IMPOSSIBLE,		/* No movement -- side effect expression.  */
+    MOVE_PRESERVE_EXECUTION,	/* Must not cause the non-executed statement
+				   become executed -- memory accesses, ... */
+    MOVE_POSSIBLE		/* Unlimited movement.  */
+  };
+
+
+/* If it is possible to hoist the statement STMT unconditionally,
+   returns MOVE_POSSIBLE.
+   If it is possible to hoist the statement STMT, but we must avoid making
+   it executed if it would not be executed in the original program (e.g.
+   because it may trap), return MOVE_PRESERVE_EXECUTION.
+   Otherwise return MOVE_IMPOSSIBLE.  */
+
+enum move_pos
+movement_possibility (gimple stmt)
+{
+  tree lhs;
+  enum move_pos ret = MOVE_POSSIBLE;
+
+  if (flag_unswitch_loops
+      && gimple_code (stmt) == GIMPLE_COND)
+    {
+      /* If we perform unswitching, force the operands of the invariant
+	 condition to be moved out of the loop.  */
+      return MOVE_POSSIBLE;
+    }
+
+  if (gimple_code (stmt) == GIMPLE_PHI
+      && gimple_phi_num_args (stmt) <= 2
+      && !virtual_operand_p (gimple_phi_result (stmt))
+      && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_phi_result (stmt)))
+    return MOVE_POSSIBLE;
+
+  if (gimple_get_lhs (stmt) == NULL_TREE)
+    return MOVE_IMPOSSIBLE;
+
+  if (gimple_vdef (stmt))
+    return MOVE_IMPOSSIBLE;
+
+  if (stmt_ends_bb_p (stmt)
+      || gimple_has_volatile_ops (stmt)
+      || gimple_has_side_effects (stmt)
+      || stmt_could_throw_p (stmt))
+    return MOVE_IMPOSSIBLE;
+
+  if (is_gimple_call (stmt))
+    {
+      /* While pure or const call is guaranteed to have no side effects, we
+	 cannot move it arbitrarily.  Consider code like
+
+	 char *s = something ();
+
+	 while (1)
+	   {
+	     if (s)
+	       t = strlen (s);
+	     else
+	       t = 0;
+	   }
+
+	 Here the strlen call cannot be moved out of the loop, even though
+	 s is invariant.  In addition to possibly creating a call with
+	 invalid arguments, moving out a function call that is not executed
+	 may cause performance regressions in case the call is costly and
+	 not executed at all.  */
+      ret = MOVE_PRESERVE_EXECUTION;
+      lhs = gimple_call_lhs (stmt);
+    }
+  else if (is_gimple_assign (stmt))
+    lhs = gimple_assign_lhs (stmt);
+  else
+    return MOVE_IMPOSSIBLE;
+
+  if (TREE_CODE (lhs) == SSA_NAME
+      && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
+    return MOVE_IMPOSSIBLE;
+
+  if (TREE_CODE (lhs) != SSA_NAME
+      || gimple_could_trap_p (stmt))
+    return MOVE_PRESERVE_EXECUTION;
+
+  /* Non local loads in a transaction cannot be hoisted out.  Well,
+     unless the load happens on every path out of the loop, but we
+     don't take this into account yet.  */
+  if (flag_tm
+      && gimple_in_transaction (stmt)
+      && gimple_assign_single_p (stmt))
+    {
+      tree rhs = gimple_assign_rhs1 (stmt);
+      if (DECL_P (rhs) && is_global_var (rhs))
+	{
+	  if (dump_file)
+	    {
+	      fprintf (dump_file, "Cannot hoist conditional load of ");
+	      print_generic_expr (dump_file, rhs, TDF_SLIM);
+	      fprintf (dump_file, " because it is in a transaction.\n");
+	    }
+	  return MOVE_IMPOSSIBLE;
+	}
+    }
+
+  return ret;
+}
+
+/* Suppose that operand DEF is used inside the LOOP.  Returns the outermost
+   loop to that we could move the expression using DEF if it did not have
+   other operands, i.e. the outermost loop enclosing LOOP in that the value
+   of DEF is invariant.  */
+
+static struct loop *
+outermost_invariant_loop (tree def, struct loop *loop)
+{
+  gimple def_stmt;
+  basic_block def_bb;
+  struct loop *max_loop;
+  struct lim_aux_data *lim_data;
+
+  if (!def)
+    return superloop_at_depth (loop, 1);
+
+  if (TREE_CODE (def) != SSA_NAME)
+    {
+      gcc_assert (is_gimple_min_invariant (def));
+      return superloop_at_depth (loop, 1);
+    }
+
+  def_stmt = SSA_NAME_DEF_STMT (def);
+  def_bb = gimple_bb (def_stmt);
+  if (!def_bb)
+    return superloop_at_depth (loop, 1);
+
+  max_loop = find_common_loop (loop, def_bb->loop_father);
+
+  lim_data = get_lim_data (def_stmt);
+  if (lim_data != NULL && lim_data->max_loop != NULL)
+    max_loop = find_common_loop (max_loop,
+				 loop_outer (lim_data->max_loop));
+  if (max_loop == loop)
+    return NULL;
+  max_loop = superloop_at_depth (loop, loop_depth (max_loop) + 1);
+
+  return max_loop;
+}
+
+/* DATA is a structure containing information associated with a statement
+   inside LOOP.  DEF is one of the operands of this statement.
+
+   Find the outermost loop enclosing LOOP in that value of DEF is invariant
+   and record this in DATA->max_loop field.  If DEF itself is defined inside
+   this loop as well (i.e. we need to hoist it out of the loop if we want
+   to hoist the statement represented by DATA), record the statement in that
+   DEF is defined to the DATA->depends list.  Additionally if ADD_COST is true,
+   add the cost of the computation of DEF to the DATA->cost.
+
+   If DEF is not invariant in LOOP, return false.  Otherwise return TRUE.  */
+
+static bool
+add_dependency (tree def, struct lim_aux_data *data, struct loop *loop,
+		bool add_cost)
+{
+  gimple def_stmt = SSA_NAME_DEF_STMT (def);
+  basic_block def_bb = gimple_bb (def_stmt);
+  struct loop *max_loop;
+  struct lim_aux_data *def_data;
+
+  if (!def_bb)
+    return true;
+
+  max_loop = outermost_invariant_loop (def, loop);
+  if (!max_loop)
+    return false;
+
+  if (flow_loop_nested_p (data->max_loop, max_loop))
+    data->max_loop = max_loop;
+
+  def_data = get_lim_data (def_stmt);
+  if (!def_data)
+    return true;
+
+  if (add_cost
+      /* Only add the cost if the statement defining DEF is inside LOOP,
+	 i.e. if it is likely that by moving the invariants dependent
+	 on it, we will be able to avoid creating a new register for
+	 it (since it will be only used in these dependent invariants).  */
+      && def_bb->loop_father == loop)
+    data->cost += def_data->cost;
+
+  data->depends.safe_push (def_stmt);
+
+  return true;
+}
+
+/* Returns an estimate for a cost of statement STMT.  The values here
+   are just ad-hoc constants, similar to costs for inlining.  */
+
+static unsigned
+stmt_cost (gimple stmt)
+{
+  /* Always try to create possibilities for unswitching.  */
+  if (gimple_code (stmt) == GIMPLE_COND
+      || gimple_code (stmt) == GIMPLE_PHI)
+    return LIM_EXPENSIVE;
+
+  /* We should be hoisting calls if possible.  */
+  if (is_gimple_call (stmt))
+    {
+      tree fndecl;
+
+      /* Unless the call is a builtin_constant_p; this always folds to a
+	 constant, so moving it is useless.  */
+      fndecl = gimple_call_fndecl (stmt);
+      if (fndecl
+	  && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
+	  && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
+	return 0;
+
+      return LIM_EXPENSIVE;
+    }
+
+  /* Hoisting memory references out should almost surely be a win.  */
+  if (gimple_references_memory_p (stmt))
+    return LIM_EXPENSIVE;
+
+  if (gimple_code (stmt) != GIMPLE_ASSIGN)
+    return 1;
+
+  switch (gimple_assign_rhs_code (stmt))
+    {
+    case MULT_EXPR:
+    case WIDEN_MULT_EXPR:
+    case WIDEN_MULT_PLUS_EXPR:
+    case WIDEN_MULT_MINUS_EXPR:
+    case DOT_PROD_EXPR:
+    case FMA_EXPR:
+    case TRUNC_DIV_EXPR:
+    case CEIL_DIV_EXPR:
+    case FLOOR_DIV_EXPR:
+    case ROUND_DIV_EXPR:
+    case EXACT_DIV_EXPR:
+    case CEIL_MOD_EXPR:
+    case FLOOR_MOD_EXPR:
+    case ROUND_MOD_EXPR:
+    case TRUNC_MOD_EXPR:
+    case RDIV_EXPR:
+      /* Division and multiplication are usually expensive.  */
+      return LIM_EXPENSIVE;
+
+    case LSHIFT_EXPR:
+    case RSHIFT_EXPR:
+    case WIDEN_LSHIFT_EXPR:
+    case LROTATE_EXPR:
+    case RROTATE_EXPR:
+      /* Shifts and rotates are usually expensive.  */
+      return LIM_EXPENSIVE;
+
+    case CONSTRUCTOR:
+      /* Make vector construction cost proportional to the number
+         of elements.  */
+      return CONSTRUCTOR_NELTS (gimple_assign_rhs1 (stmt));
+
+    case SSA_NAME:
+    case PAREN_EXPR:
+      /* Whether or not something is wrapped inside a PAREN_EXPR
+         should not change move cost.  Nor should an intermediate
+	 unpropagated SSA name copy.  */
+      return 0;
+
+    default:
+      return 1;
+    }
+}
+
+/* Finds the outermost loop between OUTER and LOOP in that the memory reference
+   REF is independent.  If REF is not independent in LOOP, NULL is returned
+   instead.  */
+
+static struct loop *
+outermost_indep_loop (struct loop *outer, struct loop *loop, mem_ref_p ref)
+{
+  struct loop *aloop;
+
+  if (ref->stored && bitmap_bit_p (ref->stored, loop->num))
+    return NULL;
+
+  for (aloop = outer;
+       aloop != loop;
+       aloop = superloop_at_depth (loop, loop_depth (aloop) + 1))
+    if ((!ref->stored || !bitmap_bit_p (ref->stored, aloop->num))
+	&& ref_indep_loop_p (aloop, ref))
+      return aloop;
+
+  if (ref_indep_loop_p (loop, ref))
+    return loop;
+  else
+    return NULL;
+}
+
+/* If there is a simple load or store to a memory reference in STMT, returns
+   the location of the memory reference, and sets IS_STORE according to whether
+   it is a store or load.  Otherwise, returns NULL.  */
+
+static tree *
+simple_mem_ref_in_stmt (gimple stmt, bool *is_store)
+{
+  tree *lhs, *rhs;
+
+  /* Recognize SSA_NAME = MEM and MEM = (SSA_NAME | invariant) patterns.  */
+  if (!gimple_assign_single_p (stmt))
+    return NULL;
+
+  lhs = gimple_assign_lhs_ptr (stmt);
+  rhs = gimple_assign_rhs1_ptr (stmt);
+
+  if (TREE_CODE (*lhs) == SSA_NAME && gimple_vuse (stmt))
+    {
+      *is_store = false;
+      return rhs;
+    }
+  else if (gimple_vdef (stmt)
+	   && (TREE_CODE (*rhs) == SSA_NAME || is_gimple_min_invariant (*rhs)))
+    {
+      *is_store = true;
+      return lhs;
+    }
+  else
+    return NULL;
+}
+
+/* Returns the memory reference contained in STMT.  */
+
+static mem_ref_p
+mem_ref_in_stmt (gimple stmt)
+{
+  bool store;
+  tree *mem = simple_mem_ref_in_stmt (stmt, &store);
+  hashval_t hash;
+  mem_ref_p ref;
+
+  if (!mem)
+    return NULL;
+  gcc_assert (!store);
+
+  hash = iterative_hash_expr (*mem, 0);
+  ref = memory_accesses.refs.find_with_hash (*mem, hash);
+
+  gcc_assert (ref != NULL);
+  return ref;
+}
+
+/* From a controlling predicate in DOM determine the arguments from
+   the PHI node PHI that are chosen if the predicate evaluates to
+   true and false and store them to *TRUE_ARG_P and *FALSE_ARG_P if
+   they are non-NULL.  Returns true if the arguments can be determined,
+   else return false.  */
+
+static bool
+extract_true_false_args_from_phi (basic_block dom, gimple phi,
+				  tree *true_arg_p, tree *false_arg_p)
+{
+  basic_block bb = gimple_bb (phi);
+  edge true_edge, false_edge, tem;
+  tree arg0 = NULL_TREE, arg1 = NULL_TREE;
+
+  /* We have to verify that one edge into the PHI node is dominated
+     by the true edge of the predicate block and the other edge
+     dominated by the false edge.  This ensures that the PHI argument
+     we are going to take is completely determined by the path we
+     take from the predicate block.
+     We can only use BB dominance checks below if the destination of
+     the true/false edges are dominated by their edge, thus only
+     have a single predecessor.  */
+  extract_true_false_edges_from_block (dom, &true_edge, &false_edge);
+  tem = EDGE_PRED (bb, 0);
+  if (tem == true_edge
+      || (single_pred_p (true_edge->dest)
+	  && (tem->src == true_edge->dest
+	      || dominated_by_p (CDI_DOMINATORS,
+				 tem->src, true_edge->dest))))
+    arg0 = PHI_ARG_DEF (phi, tem->dest_idx);
+  else if (tem == false_edge
+	   || (single_pred_p (false_edge->dest)
+	       && (tem->src == false_edge->dest
+		   || dominated_by_p (CDI_DOMINATORS,
+				      tem->src, false_edge->dest))))
+    arg1 = PHI_ARG_DEF (phi, tem->dest_idx);
+  else
+    return false;
+  tem = EDGE_PRED (bb, 1);
+  if (tem == true_edge
+      || (single_pred_p (true_edge->dest)
+	  && (tem->src == true_edge->dest
+	      || dominated_by_p (CDI_DOMINATORS,
+				 tem->src, true_edge->dest))))
+    arg0 = PHI_ARG_DEF (phi, tem->dest_idx);
+  else if (tem == false_edge
+	   || (single_pred_p (false_edge->dest)
+	       && (tem->src == false_edge->dest
+		   || dominated_by_p (CDI_DOMINATORS,
+				      tem->src, false_edge->dest))))
+    arg1 = PHI_ARG_DEF (phi, tem->dest_idx);
+  else
+    return false;
+  if (!arg0 || !arg1)
+    return false;
+
+  if (true_arg_p)
+    *true_arg_p = arg0;
+  if (false_arg_p)
+    *false_arg_p = arg1;
+
+  return true;
+}
+
+/* Determine the outermost loop to that it is possible to hoist a statement
+   STMT and store it to LIM_DATA (STMT)->max_loop.  To do this we determine
+   the outermost loop in that the value computed by STMT is invariant.
+   If MUST_PRESERVE_EXEC is true, additionally choose such a loop that
+   we preserve the fact whether STMT is executed.  It also fills other related
+   information to LIM_DATA (STMT).
+
+   The function returns false if STMT cannot be hoisted outside of the loop it
+   is defined in, and true otherwise.  */
+
+static bool
+determine_max_movement (gimple stmt, bool must_preserve_exec)
+{
+  basic_block bb = gimple_bb (stmt);
+  struct loop *loop = bb->loop_father;
+  struct loop *level;
+  struct lim_aux_data *lim_data = get_lim_data (stmt);
+  tree val;
+  ssa_op_iter iter;
+
+  if (must_preserve_exec)
+    level = ALWAYS_EXECUTED_IN (bb);
+  else
+    level = superloop_at_depth (loop, 1);
+  lim_data->max_loop = level;
+
+  if (gimple_code (stmt) == GIMPLE_PHI)
+    {
+      use_operand_p use_p;
+      unsigned min_cost = UINT_MAX;
+      unsigned total_cost = 0;
+      struct lim_aux_data *def_data;
+
+      /* We will end up promoting dependencies to be unconditionally
+	 evaluated.  For this reason the PHI cost (and thus the
+	 cost we remove from the loop by doing the invariant motion)
+	 is that of the cheapest PHI argument dependency chain.  */
+      FOR_EACH_PHI_ARG (use_p, stmt, iter, SSA_OP_USE)
+	{
+	  val = USE_FROM_PTR (use_p);
+	  if (TREE_CODE (val) != SSA_NAME)
+	    continue;
+	  if (!add_dependency (val, lim_data, loop, false))
+	    return false;
+	  def_data = get_lim_data (SSA_NAME_DEF_STMT (val));
+	  if (def_data)
+	    {
+	      min_cost = MIN (min_cost, def_data->cost);
+	      total_cost += def_data->cost;
+	    }
+	}
+
+      lim_data->cost += min_cost;
+
+      if (gimple_phi_num_args (stmt) > 1)
+	{
+	  basic_block dom = get_immediate_dominator (CDI_DOMINATORS, bb);
+	  gimple cond;
+	  if (gsi_end_p (gsi_last_bb (dom)))
+	    return false;
+	  cond = gsi_stmt (gsi_last_bb (dom));
+	  if (gimple_code (cond) != GIMPLE_COND)
+	    return false;
+	  /* Verify that this is an extended form of a diamond and
+	     the PHI arguments are completely controlled by the
+	     predicate in DOM.  */
+	  if (!extract_true_false_args_from_phi (dom, stmt, NULL, NULL))
+	    return false;
+
+	  /* Fold in dependencies and cost of the condition.  */
+	  FOR_EACH_SSA_TREE_OPERAND (val, cond, iter, SSA_OP_USE)
+	    {
+	      if (!add_dependency (val, lim_data, loop, false))
+		return false;
+	      def_data = get_lim_data (SSA_NAME_DEF_STMT (val));
+	      if (def_data)
+		total_cost += def_data->cost;
+	    }
+
+	  /* We want to avoid unconditionally executing very expensive
+	     operations.  As costs for our dependencies cannot be
+	     negative just claim we are not invariand for this case.
+	     We also are not sure whether the control-flow inside the
+	     loop will vanish.  */
+	  if (total_cost - min_cost >= 2 * LIM_EXPENSIVE
+	      && !(min_cost != 0
+		   && total_cost / min_cost <= 2))
+	    return false;
+
+	  /* Assume that the control-flow in the loop will vanish.
+	     ???  We should verify this and not artificially increase
+	     the cost if that is not the case.  */
+	  lim_data->cost += stmt_cost (stmt);
+	}
+
+      return true;
+    }
+  else
+    FOR_EACH_SSA_TREE_OPERAND (val, stmt, iter, SSA_OP_USE)
+      if (!add_dependency (val, lim_data, loop, true))
+	return false;
+
+  if (gimple_vuse (stmt))
+    {
+      mem_ref_p ref = mem_ref_in_stmt (stmt);
+
+      if (ref)
+	{
+	  lim_data->max_loop
+		  = outermost_indep_loop (lim_data->max_loop, loop, ref);
+	  if (!lim_data->max_loop)
+	    return false;
+	}
+      else
+	{
+	  if ((val = gimple_vuse (stmt)) != NULL_TREE)
+	    {
+	      if (!add_dependency (val, lim_data, loop, false))
+		return false;
+	    }
+	}
+    }
+
+  lim_data->cost += stmt_cost (stmt);
+
+  return true;
+}
+
+/* Suppose that some statement in ORIG_LOOP is hoisted to the loop LEVEL,
+   and that one of the operands of this statement is computed by STMT.
+   Ensure that STMT (together with all the statements that define its
+   operands) is hoisted at least out of the loop LEVEL.  */
+
+static void
+set_level (gimple stmt, struct loop *orig_loop, struct loop *level)
+{
+  struct loop *stmt_loop = gimple_bb (stmt)->loop_father;
+  struct lim_aux_data *lim_data;
+  gimple dep_stmt;
+  unsigned i;
+
+  stmt_loop = find_common_loop (orig_loop, stmt_loop);
+  lim_data = get_lim_data (stmt);
+  if (lim_data != NULL && lim_data->tgt_loop != NULL)
+    stmt_loop = find_common_loop (stmt_loop,
+				  loop_outer (lim_data->tgt_loop));
+  if (flow_loop_nested_p (stmt_loop, level))
+    return;
+
+  gcc_assert (level == lim_data->max_loop
+	      || flow_loop_nested_p (lim_data->max_loop, level));
+
+  lim_data->tgt_loop = level;
+  FOR_EACH_VEC_ELT (lim_data->depends, i, dep_stmt)
+    set_level (dep_stmt, orig_loop, level);
+}
+
+/* Determines an outermost loop from that we want to hoist the statement STMT.
+   For now we chose the outermost possible loop.  TODO -- use profiling
+   information to set it more sanely.  */
+
+static void
+set_profitable_level (gimple stmt)
+{
+  set_level (stmt, gimple_bb (stmt)->loop_father, get_lim_data (stmt)->max_loop);
+}
+
+/* Returns true if STMT is a call that has side effects.  */
+
+static bool
+nonpure_call_p (gimple stmt)
+{
+  if (gimple_code (stmt) != GIMPLE_CALL)
+    return false;
+
+  return gimple_has_side_effects (stmt);
+}
+
+/* Rewrite a/b to a*(1/b).  Return the invariant stmt to process.  */
+
+static gimple
+rewrite_reciprocal (gimple_stmt_iterator *bsi)
+{
+  gimple stmt, stmt1, stmt2;
+  tree name, lhs, type;
+  tree real_one;
+  gimple_stmt_iterator gsi;
+
+  stmt = gsi_stmt (*bsi);
+  lhs = gimple_assign_lhs (stmt);
+  type = TREE_TYPE (lhs);
+
+  real_one = build_one_cst (type);
+
+  name = make_temp_ssa_name (type, NULL, "reciptmp");
+  stmt1 = gimple_build_assign_with_ops (RDIV_EXPR, name, real_one,
+					gimple_assign_rhs2 (stmt));
+
+  stmt2 = gimple_build_assign_with_ops (MULT_EXPR, lhs, name,
+					gimple_assign_rhs1 (stmt));
+
+  /* Replace division stmt with reciprocal and multiply stmts.
+     The multiply stmt is not invariant, so update iterator
+     and avoid rescanning.  */
+  gsi = *bsi;
+  gsi_insert_before (bsi, stmt1, GSI_NEW_STMT);
+  gsi_replace (&gsi, stmt2, true);
+
+  /* Continue processing with invariant reciprocal statement.  */
+  return stmt1;
+}
+
+/* Check if the pattern at *BSI is a bittest of the form
+   (A >> B) & 1 != 0 and in this case rewrite it to A & (1 << B) != 0.  */
+
+static gimple
+rewrite_bittest (gimple_stmt_iterator *bsi)
+{
+  gimple stmt, use_stmt, stmt1, stmt2;
+  tree lhs, name, t, a, b;
+  use_operand_p use;
+
+  stmt = gsi_stmt (*bsi);
+  lhs = gimple_assign_lhs (stmt);
+
+  /* Verify that the single use of lhs is a comparison against zero.  */
+  if (TREE_CODE (lhs) != SSA_NAME
+      || !single_imm_use (lhs, &use, &use_stmt)
+      || gimple_code (use_stmt) != GIMPLE_COND)
+    return stmt;
+  if (gimple_cond_lhs (use_stmt) != lhs
+      || (gimple_cond_code (use_stmt) != NE_EXPR
+	  && gimple_cond_code (use_stmt) != EQ_EXPR)
+      || !integer_zerop (gimple_cond_rhs (use_stmt)))
+    return stmt;
+
+  /* Get at the operands of the shift.  The rhs is TMP1 & 1.  */
+  stmt1 = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt));
+  if (gimple_code (stmt1) != GIMPLE_ASSIGN)
+    return stmt;
+
+  /* There is a conversion in between possibly inserted by fold.  */
+  if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt1)))
+    {
+      t = gimple_assign_rhs1 (stmt1);
+      if (TREE_CODE (t) != SSA_NAME
+	  || !has_single_use (t))
+	return stmt;
+      stmt1 = SSA_NAME_DEF_STMT (t);
+      if (gimple_code (stmt1) != GIMPLE_ASSIGN)
+	return stmt;
+    }
+
+  /* Verify that B is loop invariant but A is not.  Verify that with
+     all the stmt walking we are still in the same loop.  */
+  if (gimple_assign_rhs_code (stmt1) != RSHIFT_EXPR
+      || loop_containing_stmt (stmt1) != loop_containing_stmt (stmt))
+    return stmt;
+
+  a = gimple_assign_rhs1 (stmt1);
+  b = gimple_assign_rhs2 (stmt1);
+
+  if (outermost_invariant_loop (b, loop_containing_stmt (stmt1)) != NULL
+      && outermost_invariant_loop (a, loop_containing_stmt (stmt1)) == NULL)
+    {
+      gimple_stmt_iterator rsi;
+
+      /* 1 << B */
+      t = fold_build2 (LSHIFT_EXPR, TREE_TYPE (a),
+		       build_int_cst (TREE_TYPE (a), 1), b);
+      name = make_temp_ssa_name (TREE_TYPE (a), NULL, "shifttmp");
+      stmt1 = gimple_build_assign (name, t);
+
+      /* A & (1 << B) */
+      t = fold_build2 (BIT_AND_EXPR, TREE_TYPE (a), a, name);
+      name = make_temp_ssa_name (TREE_TYPE (a), NULL, "shifttmp");
+      stmt2 = gimple_build_assign (name, t);
+
+      /* Replace the SSA_NAME we compare against zero.  Adjust
+	 the type of zero accordingly.  */
+      SET_USE (use, name);
+      gimple_cond_set_rhs (use_stmt, build_int_cst_type (TREE_TYPE (name), 0));
+
+      /* Don't use gsi_replace here, none of the new assignments sets
+	 the variable originally set in stmt.  Move bsi to stmt1, and
+	 then remove the original stmt, so that we get a chance to
+	 retain debug info for it.  */
+      rsi = *bsi;
+      gsi_insert_before (bsi, stmt1, GSI_NEW_STMT);
+      gsi_insert_before (&rsi, stmt2, GSI_SAME_STMT);
+      gsi_remove (&rsi, true);
+
+      return stmt1;
+    }
+
+  return stmt;
+}
+
+/* For each statement determines the outermost loop in that it is invariant,
+   -   statements on whose motion it depends and the cost of the computation.
+   -   This information is stored to the LIM_DATA structure associated with
+   -   each statement.  */
+class invariantness_dom_walker : public dom_walker
+{
+public:
+  invariantness_dom_walker (cdi_direction direction)
+    : dom_walker (direction) {}
+
+  virtual void before_dom_children (basic_block);
+};
+
+/* Determine the outermost loops in that statements in basic block BB are
+   invariant, and record them to the LIM_DATA associated with the statements.
+   Callback for dom_walker.  */
+
+void
+invariantness_dom_walker::before_dom_children (basic_block bb)
+{
+  enum move_pos pos;
+  gimple_stmt_iterator bsi;
+  gimple stmt;
+  bool maybe_never = ALWAYS_EXECUTED_IN (bb) == NULL;
+  struct loop *outermost = ALWAYS_EXECUTED_IN (bb);
+  struct lim_aux_data *lim_data;
+
+  if (!loop_outer (bb->loop_father))
+    return;
+
+  if (dump_file && (dump_flags & TDF_DETAILS))
+    fprintf (dump_file, "Basic block %d (loop %d -- depth %d):\n\n",
+	     bb->index, bb->loop_father->num, loop_depth (bb->loop_father));
+
+  /* Look at PHI nodes, but only if there is at most two.
+     ???  We could relax this further by post-processing the inserted
+     code and transforming adjacent cond-exprs with the same predicate
+     to control flow again.  */
+  bsi = gsi_start_phis (bb);
+  if (!gsi_end_p (bsi)
+      && ((gsi_next (&bsi), gsi_end_p (bsi))
+	  || (gsi_next (&bsi), gsi_end_p (bsi))))
+    for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi))
+      {
+	stmt = gsi_stmt (bsi);
+
+	pos = movement_possibility (stmt);
+	if (pos == MOVE_IMPOSSIBLE)
+	  continue;
+
+	lim_data = init_lim_data (stmt);
+	lim_data->always_executed_in = outermost;
+
+	if (!determine_max_movement (stmt, false))
+	  {
+	    lim_data->max_loop = NULL;
+	    continue;
+	  }
+
+	if (dump_file && (dump_flags & TDF_DETAILS))
+	  {
+	    print_gimple_stmt (dump_file, stmt, 2, 0);
+	    fprintf (dump_file, "  invariant up to level %d, cost %d.\n\n",
+		     loop_depth (lim_data->max_loop),
+		     lim_data->cost);
+	  }
+
+	if (lim_data->cost >= LIM_EXPENSIVE)
+	  set_profitable_level (stmt);
+      }
+
+  for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
+    {
+      stmt = gsi_stmt (bsi);
+
+      pos = movement_possibility (stmt);
+      if (pos == MOVE_IMPOSSIBLE)
+	{
+	  if (nonpure_call_p (stmt))
+	    {
+	      maybe_never = true;
+	      outermost = NULL;
+	    }
+	  /* Make sure to note always_executed_in for stores to make
+	     store-motion work.  */
+	  else if (stmt_makes_single_store (stmt))
+	    {
+	      struct lim_aux_data *lim_data = init_lim_data (stmt);
+	      lim_data->always_executed_in = outermost;
+	    }
+	  continue;
+	}
+
+      if (is_gimple_assign (stmt)
+	  && (get_gimple_rhs_class (gimple_assign_rhs_code (stmt))
+	      == GIMPLE_BINARY_RHS))
+	{
+	  tree op0 = gimple_assign_rhs1 (stmt);
+	  tree op1 = gimple_assign_rhs2 (stmt);
+	  struct loop *ol1 = outermost_invariant_loop (op1,
+					loop_containing_stmt (stmt));
+
+	  /* If divisor is invariant, convert a/b to a*(1/b), allowing reciprocal
+	     to be hoisted out of loop, saving expensive divide.  */
+	  if (pos == MOVE_POSSIBLE
+	      && gimple_assign_rhs_code (stmt) == RDIV_EXPR
+	      && flag_unsafe_math_optimizations
+	      && !flag_trapping_math
+	      && ol1 != NULL
+	      && outermost_invariant_loop (op0, ol1) == NULL)
+	    stmt = rewrite_reciprocal (&bsi);
+
+	  /* If the shift count is invariant, convert (A >> B) & 1 to
+	     A & (1 << B) allowing the bit mask to be hoisted out of the loop
+	     saving an expensive shift.  */
+	  if (pos == MOVE_POSSIBLE
+	      && gimple_assign_rhs_code (stmt) == BIT_AND_EXPR
+	      && integer_onep (op1)
+	      && TREE_CODE (op0) == SSA_NAME
+	      && has_single_use (op0))
+	    stmt = rewrite_bittest (&bsi);
+	}
+
+      lim_data = init_lim_data (stmt);
+      lim_data->always_executed_in = outermost;
+
+      if (maybe_never && pos == MOVE_PRESERVE_EXECUTION)
+	continue;
+
+      if (!determine_max_movement (stmt, pos == MOVE_PRESERVE_EXECUTION))
+	{
+	  lim_data->max_loop = NULL;
+	  continue;
+	}
+
+      if (dump_file && (dump_flags & TDF_DETAILS))
+	{
+	  print_gimple_stmt (dump_file, stmt, 2, 0);
+	  fprintf (dump_file, "  invariant up to level %d, cost %d.\n\n",
+		   loop_depth (lim_data->max_loop),
+		   lim_data->cost);
+	}
+
+      if (lim_data->cost >= LIM_EXPENSIVE)
+	set_profitable_level (stmt);
+    }
+}
+
+class move_computations_dom_walker : public dom_walker
+{
+public:
+  move_computations_dom_walker (cdi_direction direction)
+    : dom_walker (direction), todo_ (0) {}
+
+  virtual void before_dom_children (basic_block);
+
+  unsigned int todo_;
+};
+
+/* Hoist the statements in basic block BB out of the loops prescribed by
+   data stored in LIM_DATA structures associated with each statement.  Callback
+   for walk_dominator_tree.  */
+
+void
+move_computations_dom_walker::before_dom_children (basic_block bb)
+{
+  struct loop *level;
+  gimple_stmt_iterator bsi;
+  gimple stmt;
+  unsigned cost = 0;
+  struct lim_aux_data *lim_data;
+
+  if (!loop_outer (bb->loop_father))
+    return;
+
+  for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); )
+    {
+      gimple new_stmt;
+      stmt = gsi_stmt (bsi);
+
+      lim_data = get_lim_data (stmt);
+      if (lim_data == NULL)
+	{
+	  gsi_next (&bsi);
+	  continue;
+	}
+
+      cost = lim_data->cost;
+      level = lim_data->tgt_loop;
+      clear_lim_data (stmt);
+
+      if (!level)
+	{
+	  gsi_next (&bsi);
+	  continue;
+	}
+
+      if (dump_file && (dump_flags & TDF_DETAILS))
+	{
+	  fprintf (dump_file, "Moving PHI node\n");
+	  print_gimple_stmt (dump_file, stmt, 0, 0);
+	  fprintf (dump_file, "(cost %u) out of loop %d.\n\n",
+		   cost, level->num);
+	}
+
+      if (gimple_phi_num_args (stmt) == 1)
+	{
+	  tree arg = PHI_ARG_DEF (stmt, 0);
+	  new_stmt = gimple_build_assign_with_ops (TREE_CODE (arg),
+						   gimple_phi_result (stmt),
+						   arg, NULL_TREE);
+	}
+      else
+	{
+	  basic_block dom = get_immediate_dominator (CDI_DOMINATORS, bb);
+	  gimple cond = gsi_stmt (gsi_last_bb (dom));
+	  tree arg0 = NULL_TREE, arg1 = NULL_TREE, t;
+	  /* Get the PHI arguments corresponding to the true and false
+	     edges of COND.  */
+	  extract_true_false_args_from_phi (dom, stmt, &arg0, &arg1);
+	  gcc_assert (arg0 && arg1);
+	  t = build2 (gimple_cond_code (cond), boolean_type_node,
+		      gimple_cond_lhs (cond), gimple_cond_rhs (cond));
+	  new_stmt = gimple_build_assign_with_ops (COND_EXPR,
+						   gimple_phi_result (stmt),
+						   t, arg0, arg1);
+	  todo_ |= TODO_cleanup_cfg;
+	}
+      gsi_insert_on_edge (loop_preheader_edge (level), new_stmt);
+      remove_phi_node (&bsi, false);
+    }
+
+  for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); )
+    {
+      edge e;
+
+      stmt = gsi_stmt (bsi);
+
+      lim_data = get_lim_data (stmt);
+      if (lim_data == NULL)
+	{
+	  gsi_next (&bsi);
+	  continue;
+	}
+
+      cost = lim_data->cost;
+      level = lim_data->tgt_loop;
+      clear_lim_data (stmt);
+
+      if (!level)
+	{
+	  gsi_next (&bsi);
+	  continue;
+	}
+
+      /* We do not really want to move conditionals out of the loop; we just
+	 placed it here to force its operands to be moved if necessary.  */
+      if (gimple_code (stmt) == GIMPLE_COND)
+	continue;
+
+      if (dump_file && (dump_flags & TDF_DETAILS))
+	{
+	  fprintf (dump_file, "Moving statement\n");
+	  print_gimple_stmt (dump_file, stmt, 0, 0);
+	  fprintf (dump_file, "(cost %u) out of loop %d.\n\n",
+		   cost, level->num);
+	}
+
+      e = loop_preheader_edge (level);
+      gcc_assert (!gimple_vdef (stmt));
+      if (gimple_vuse (stmt))
+	{
+	  /* The new VUSE is the one from the virtual PHI in the loop
+	     header or the one already present.  */
+	  gimple_stmt_iterator gsi2;
+	  for (gsi2 = gsi_start_phis (e->dest);
+	       !gsi_end_p (gsi2); gsi_next (&gsi2))
+	    {
+	      gimple phi = gsi_stmt (gsi2);
+	      if (virtual_operand_p (gimple_phi_result (phi)))
+		{
+		  gimple_set_vuse (stmt, PHI_ARG_DEF_FROM_EDGE (phi, e));
+		  break;
+		}
+	    }
+	}
+      gsi_remove (&bsi, false);
+      /* In case this is a stmt that is not unconditionally executed
+         when the target loop header is executed and the stmt may
+	 invoke undefined integer or pointer overflow rewrite it to
+	 unsigned arithmetic.  */
+      if (is_gimple_assign (stmt)
+	  && INTEGRAL_TYPE_P (TREE_TYPE (gimple_assign_lhs (stmt)))
+	  && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (gimple_assign_lhs (stmt)))
+	  && arith_code_with_undefined_signed_overflow
+	       (gimple_assign_rhs_code (stmt))
+	  && (!ALWAYS_EXECUTED_IN (bb)
+	      || !(ALWAYS_EXECUTED_IN (bb) == level
+		   || flow_loop_nested_p (ALWAYS_EXECUTED_IN (bb), level))))
+	gsi_insert_seq_on_edge (e, rewrite_to_defined_overflow (stmt));
+      else
+	gsi_insert_on_edge (e, stmt);
+    }
+}
+
+/* Hoist the statements out of the loops prescribed by data stored in
+   LIM_DATA structures associated with each statement.*/
+
+static unsigned int
+move_computations (void)
+{
+  move_computations_dom_walker walker (CDI_DOMINATORS);
+  walker.walk (cfun->cfg->x_entry_block_ptr);
+
+  gsi_commit_edge_inserts ();
+  if (need_ssa_update_p (cfun))
+    rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
+
+  return walker.todo_;
+}
+
+/* Checks whether the statement defining variable *INDEX can be hoisted
+   out of the loop passed in DATA.  Callback for for_each_index.  */
+
+static bool
+may_move_till (tree ref, tree *index, void *data)
+{
+  struct loop *loop = (struct loop *) data, *max_loop;
+
+  /* If REF is an array reference, check also that the step and the lower
+     bound is invariant in LOOP.  */
+  if (TREE_CODE (ref) == ARRAY_REF)
+    {
+      tree step = TREE_OPERAND (ref, 3);
+      tree lbound = TREE_OPERAND (ref, 2);
+
+      max_loop = outermost_invariant_loop (step, loop);
+      if (!max_loop)
+	return false;
+
+      max_loop = outermost_invariant_loop (lbound, loop);
+      if (!max_loop)
+	return false;
+    }
+
+  max_loop = outermost_invariant_loop (*index, loop);
+  if (!max_loop)
+    return false;
+
+  return true;
+}
+
+/* If OP is SSA NAME, force the statement that defines it to be
+   moved out of the LOOP.  ORIG_LOOP is the loop in that EXPR is used.  */
+
+static void
+force_move_till_op (tree op, struct loop *orig_loop, struct loop *loop)
+{
+  gimple stmt;
+
+  if (!op
+      || is_gimple_min_invariant (op))
+    return;
+
+  gcc_assert (TREE_CODE (op) == SSA_NAME);
+
+  stmt = SSA_NAME_DEF_STMT (op);
+  if (gimple_nop_p (stmt))
+    return;
+
+  set_level (stmt, orig_loop, loop);
+}
+
+/* Forces statement defining invariants in REF (and *INDEX) to be moved out of
+   the LOOP.  The reference REF is used in the loop ORIG_LOOP.  Callback for
+   for_each_index.  */
+
+struct fmt_data
+{
+  struct loop *loop;
+  struct loop *orig_loop;
+};
+
+static bool
+force_move_till (tree ref, tree *index, void *data)
+{
+  struct fmt_data *fmt_data = (struct fmt_data *) data;
+
+  if (TREE_CODE (ref) == ARRAY_REF)
+    {
+      tree step = TREE_OPERAND (ref, 3);
+      tree lbound = TREE_OPERAND (ref, 2);
+
+      force_move_till_op (step, fmt_data->orig_loop, fmt_data->loop);
+      force_move_till_op (lbound, fmt_data->orig_loop, fmt_data->loop);
+    }
+
+  force_move_till_op (*index, fmt_data->orig_loop, fmt_data->loop);
+
+  return true;
+}
+
+/* A function to free the mem_ref object OBJ.  */
+
+static void
+memref_free (struct mem_ref *mem)
+{
+  mem->accesses_in_loop.release ();
+}
+
+/* Allocates and returns a memory reference description for MEM whose hash
+   value is HASH and id is ID.  */
+
+static mem_ref_p
+mem_ref_alloc (tree mem, unsigned hash, unsigned id)
+{
+  mem_ref_p ref = XOBNEW (&mem_ref_obstack, struct mem_ref);
+  ao_ref_init (&ref->mem, mem);
+  ref->id = id;
+  ref->hash = hash;
+  ref->stored = NULL;
+  bitmap_initialize (&ref->indep_loop, &lim_bitmap_obstack);
+  bitmap_initialize (&ref->dep_loop, &lim_bitmap_obstack);
+  ref->accesses_in_loop.create (1);
+
+  return ref;
+}
+
+/* Records memory reference location *LOC in LOOP to the memory reference
+   description REF.  The reference occurs in statement STMT.  */
+
+static void
+record_mem_ref_loc (mem_ref_p ref, gimple stmt, tree *loc)
+{
+  mem_ref_loc aref;
+  aref.stmt = stmt;
+  aref.ref = loc;
+  ref->accesses_in_loop.safe_push (aref);
+}
+
+/* Set the LOOP bit in REF stored bitmap and allocate that if
+   necessary.  Return whether a bit was changed.  */
+
+static bool
+set_ref_stored_in_loop (mem_ref_p ref, struct loop *loop)
+{
+  if (!ref->stored)
+    ref->stored = BITMAP_ALLOC (&lim_bitmap_obstack);
+  return bitmap_set_bit (ref->stored, loop->num);
+}
+
+/* Marks reference REF as stored in LOOP.  */
+
+static void
+mark_ref_stored (mem_ref_p ref, struct loop *loop)
+{
+  while (loop != current_loops->tree_root
+	 && set_ref_stored_in_loop (ref, loop))
+    loop = loop_outer (loop);
+}
+
+/* Gathers memory references in statement STMT in LOOP, storing the
+   information about them in the memory_accesses structure.  Marks
+   the vops accessed through unrecognized statements there as
+   well.  */
+
+static void
+gather_mem_refs_stmt (struct loop *loop, gimple stmt)
+{
+  tree *mem = NULL;
+  hashval_t hash;
+  mem_ref **slot;
+  mem_ref_p ref;
+  bool is_stored;
+  unsigned id;
+
+  if (!gimple_vuse (stmt))
+    return;
+
+  mem = simple_mem_ref_in_stmt (stmt, &is_stored);
+  if (!mem)
+    {
+      /* We use the shared mem_ref for all unanalyzable refs.  */
+      id = UNANALYZABLE_MEM_ID;
+      ref = memory_accesses.refs_list[id];
+      if (dump_file && (dump_flags & TDF_DETAILS))
+	{
+	  fprintf (dump_file, "Unanalyzed memory reference %u: ", id);
+	  print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
+	}
+      is_stored = gimple_vdef (stmt);
+    }
+  else
+    {
+      hash = iterative_hash_expr (*mem, 0);
+      slot = memory_accesses.refs.find_slot_with_hash (*mem, hash, INSERT);
+      if (*slot)
+	{
+	  ref = (mem_ref_p) *slot;
+	  id = ref->id;
+	}
+      else
+	{
+	  id = memory_accesses.refs_list.length ();
+	  ref = mem_ref_alloc (*mem, hash, id);
+	  memory_accesses.refs_list.safe_push (ref);
+	  *slot = ref;
+
+	  if (dump_file && (dump_flags & TDF_DETAILS))
+	    {
+	      fprintf (dump_file, "Memory reference %u: ", id);
+	      print_generic_expr (dump_file, ref->mem.ref, TDF_SLIM);
+	      fprintf (dump_file, "\n");
+	    }
+	}
+
+      record_mem_ref_loc (ref, stmt, mem);
+    }
+  bitmap_set_bit (&memory_accesses.refs_in_loop[loop->num], ref->id);
+  if (is_stored)
+    {
+      bitmap_set_bit (&memory_accesses.refs_stored_in_loop[loop->num], ref->id);
+      mark_ref_stored (ref, loop);
+    }
+  return;
+}
+
+static unsigned *bb_loop_postorder;
+
+/* qsort sort function to sort blocks after their loop fathers postorder.  */
+
+static int
+sort_bbs_in_loop_postorder_cmp (const void *bb1_, const void *bb2_)
+{
+  basic_block bb1 = *(basic_block *)const_cast<void *>(bb1_);
+  basic_block bb2 = *(basic_block *)const_cast<void *>(bb2_);
+  struct loop *loop1 = bb1->loop_father;
+  struct loop *loop2 = bb2->loop_father;
+  if (loop1->num == loop2->num)
+    return 0;
+  return bb_loop_postorder[loop1->num] < bb_loop_postorder[loop2->num] ? -1 : 1;
+}
+
+/* qsort sort function to sort ref locs after their loop fathers postorder.  */
+
+static int
+sort_locs_in_loop_postorder_cmp (const void *loc1_, const void *loc2_)
+{
+  mem_ref_loc *loc1 = (mem_ref_loc *)const_cast<void *>(loc1_);
+  mem_ref_loc *loc2 = (mem_ref_loc *)const_cast<void *>(loc2_);
+  struct loop *loop1 = gimple_bb (loc1->stmt)->loop_father;
+  struct loop *loop2 = gimple_bb (loc2->stmt)->loop_father;
+  if (loop1->num == loop2->num)
+    return 0;
+  return bb_loop_postorder[loop1->num] < bb_loop_postorder[loop2->num] ? -1 : 1;
+}
+
+/* Gathers memory references in loops.  */
+
+static void
+analyze_memory_references (void)
+{
+  gimple_stmt_iterator bsi;
+  basic_block bb, *bbs;
+  struct loop *loop, *outer;
+  unsigned i, n;
+
+#if 0
+  /* Initialize bb_loop_postorder with a mapping from loop->num to
+     its postorder index.  */
+  i = 0;
+  bb_loop_postorder = XNEWVEC (unsigned, number_of_loops (cfun));
+  FOR_EACH_LOOP (loop, LI_FROM_INNERMOST)
+    bb_loop_postorder[loop->num] = i++;
+#endif
+
+  /* Collect all basic-blocks in loops and sort them after their
+     loops postorder.  */
+  i = 0;
+  bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS);
+  FOR_EACH_BB_FN (bb, cfun)
+    if (bb->loop_father != current_loops->tree_root)
+      bbs[i++] = bb;
+  n = i;
+  qsort (bbs, n, sizeof (basic_block), sort_bbs_in_loop_postorder_cmp);
+
+  /* Visit blocks in loop postorder and assign mem-ref IDs in that order.
+     That results in better locality for all the bitmaps.  */
+  for (i = 0; i < n; ++i)
+    {
+      basic_block bb = bbs[i];
+      for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
+        gather_mem_refs_stmt (bb->loop_father, gsi_stmt (bsi));
+    }
+
+  /* Sort the location list of gathered memory references after their
+     loop postorder number.  */
+  mem_ref *ref;
+  FOR_EACH_VEC_ELT (memory_accesses.refs_list, i, ref)
+    ref->accesses_in_loop.qsort (sort_locs_in_loop_postorder_cmp);
+
+  free (bbs);
+//  free (bb_loop_postorder);
+
+  /* Propagate the information about accessed memory references up
+     the loop hierarchy.  */
+  FOR_EACH_LOOP (loop, LI_FROM_INNERMOST)
+    {
+      /* Finalize the overall touched references (including subloops).  */
+      bitmap_ior_into (&memory_accesses.all_refs_stored_in_loop[loop->num],
+		       &memory_accesses.refs_stored_in_loop[loop->num]);
+
+      /* Propagate the information about accessed memory references up
+	 the loop hierarchy.  */
+      outer = loop_outer (loop);
+      if (outer == current_loops->tree_root)
+	continue;
+
+      bitmap_ior_into (&memory_accesses.all_refs_stored_in_loop[outer->num],
+		       &memory_accesses.all_refs_stored_in_loop[loop->num]);
+    }
+}
+
+/* Returns true if MEM1 and MEM2 may alias.  TTAE_CACHE is used as a cache in
+   tree_to_aff_combination_expand.  */
+
+static bool
+mem_refs_may_alias_p (mem_ref_p mem1, mem_ref_p mem2,
+		      struct pointer_map_t **ttae_cache)
+{
+  /* Perform BASE + OFFSET analysis -- if MEM1 and MEM2 are based on the same
+     object and their offset differ in such a way that the locations cannot
+     overlap, then they cannot alias.  */
+  double_int size1, size2;
+  aff_tree off1, off2;
+
+  /* Perform basic offset and type-based disambiguation.  */
+  if (!refs_may_alias_p_1 (&mem1->mem, &mem2->mem, true))
+    return false;
+
+  /* The expansion of addresses may be a bit expensive, thus we only do
+     the check at -O2 and higher optimization levels.  */
+  if (optimize < 2)
+    return true;
+
+  get_inner_reference_aff (mem1->mem.ref, &off1, &size1);
+  get_inner_reference_aff (mem2->mem.ref, &off2, &size2);
+  aff_combination_expand (&off1, ttae_cache);
+  aff_combination_expand (&off2, ttae_cache);
+  aff_combination_scale (&off1, double_int_minus_one);
+  aff_combination_add (&off2, &off1);
+
+  if (aff_comb_cannot_overlap_p (&off2, size1, size2))
+    return false;
+
+  return true;
+}
+
+/* Compare function for bsearch searching for reference locations
+   in a loop.  */
+
+static int
+find_ref_loc_in_loop_cmp (const void *loop_, const void *loc_)
+{
+  struct loop *loop = (struct loop *)const_cast<void *>(loop_);
+  mem_ref_loc *loc = (mem_ref_loc *)const_cast<void *>(loc_);
+  struct loop *loc_loop = gimple_bb (loc->stmt)->loop_father;
+  if (loop->num  == loc_loop->num
+      || flow_loop_nested_p (loop, loc_loop))
+    return 0;
+  return (bb_loop_postorder[loop->num] < bb_loop_postorder[loc_loop->num]
+	  ? -1 : 1);
+}
+
+/* Iterates over all locations of REF in LOOP and its subloops calling
+   fn.operator() with the location as argument.  When that operator
+   returns true the iteration is stopped and true is returned.
+   Otherwise false is returned.  */
+
+template <typename FN>
+static bool
+for_all_locs_in_loop (struct loop *loop, mem_ref_p ref, FN fn)
+{
+  unsigned i;
+  mem_ref_loc_p loc;
+
+  /* Search for the cluster of locs in the accesses_in_loop vector
+     which is sorted after postorder index of the loop father.  */
+  loc = ref->accesses_in_loop.bsearch (loop, find_ref_loc_in_loop_cmp);
+  if (!loc)
+    return false;
+
+  /* We have found one location inside loop or its sub-loops.  Iterate
+     both forward and backward to cover the whole cluster.  */
+  i = loc - ref->accesses_in_loop.address ();
+  while (i > 0)
+    {
+      --i;
+      mem_ref_loc_p l = &ref->accesses_in_loop[i];
+      if (!flow_bb_inside_loop_p (loop, gimple_bb (l->stmt)))
+	break;
+      if (fn (l))
+	return true;
+    }
+  for (i = loc - ref->accesses_in_loop.address ();
+       i < ref->accesses_in_loop.length (); ++i)
+    {
+      mem_ref_loc_p l = &ref->accesses_in_loop[i];
+      if (!flow_bb_inside_loop_p (loop, gimple_bb (l->stmt)))
+	break;
+      if (fn (l))
+	return true;
+    }
+
+  return false;
+}
+
+/* Rewrites location LOC by TMP_VAR.  */
+
+struct rewrite_mem_ref_loc
+{
+  rewrite_mem_ref_loc (tree tmp_var_) : tmp_var (tmp_var_) {}
+  bool operator () (mem_ref_loc_p loc);
+  tree tmp_var;
+};
+
+bool
+rewrite_mem_ref_loc::operator () (mem_ref_loc_p loc)
+{
+  *loc->ref = tmp_var;
+  update_stmt (loc->stmt);
+  return false;
+}
+
+/* Rewrites all references to REF in LOOP by variable TMP_VAR.  */
+
+static void
+rewrite_mem_refs (struct loop *loop, mem_ref_p ref, tree tmp_var)
+{
+  for_all_locs_in_loop (loop, ref, rewrite_mem_ref_loc (tmp_var));
+}
+
+/* Stores the first reference location in LOCP.  */
+
+struct first_mem_ref_loc_1
+{
+  first_mem_ref_loc_1 (mem_ref_loc_p *locp_) : locp (locp_) {}
+  bool operator () (mem_ref_loc_p loc);
+  mem_ref_loc_p *locp;
+};
+
+bool
+first_mem_ref_loc_1::operator () (mem_ref_loc_p loc)
+{
+  *locp = loc;
+  return true;
+}
+
+/* Returns the first reference location to REF in LOOP.  */
+
+static mem_ref_loc_p
+first_mem_ref_loc (struct loop *loop, mem_ref_p ref)
+{
+  mem_ref_loc_p locp = NULL;
+  for_all_locs_in_loop (loop, ref, first_mem_ref_loc_1 (&locp));
+  return locp;
+}
+
+struct prev_flag_edges {
+  /* Edge to insert new flag comparison code.  */
+  edge append_cond_position;
+
+  /* Edge for fall through from previous flag comparison.  */
+  edge last_cond_fallthru;
+};
+
+/* Helper function for execute_sm.  Emit code to store TMP_VAR into
+   MEM along edge EX.
+
+   The store is only done if MEM has changed.  We do this so no
+   changes to MEM occur on code paths that did not originally store
+   into it.
+
+   The common case for execute_sm will transform:
+
+     for (...) {
+       if (foo)
+         stuff;
+       else
+         MEM = TMP_VAR;
+     }
+
+   into:
+
+     lsm = MEM;
+     for (...) {
+       if (foo)
+         stuff;
+       else
+         lsm = TMP_VAR;
+     }
+     MEM = lsm;
+
+  This function will generate:
+
+     lsm = MEM;
+
+     lsm_flag = false;
+     ...
+     for (...) {
+       if (foo)
+         stuff;
+       else {
+         lsm = TMP_VAR;
+         lsm_flag = true;
+       }
+     }
+     if (lsm_flag)	<--
+       MEM = lsm;	<--
+*/
+
+static void
+execute_sm_if_changed (edge ex, tree mem, tree tmp_var, tree flag)
+{
+  basic_block new_bb, then_bb, old_dest;
+  bool loop_has_only_one_exit;
+  edge then_old_edge, orig_ex = ex;
+  gimple_stmt_iterator gsi;
+  gimple stmt;
+  struct prev_flag_edges *prev_edges = (struct prev_flag_edges *) ex->aux;
+
+  /* ?? Insert store after previous store if applicable.  See note
+     below.  */
+  if (prev_edges)
+    ex = prev_edges->append_cond_position;
+
+  loop_has_only_one_exit = single_pred_p (ex->dest);
+
+  if (loop_has_only_one_exit)
+    ex = split_block_after_labels (ex->dest);
+
+  old_dest = ex->dest;
+  new_bb = split_edge (ex);
+  then_bb = create_empty_bb (new_bb);
+  if (current_loops && new_bb->loop_father)
+    add_bb_to_loop (then_bb, new_bb->loop_father);
+
+  gsi = gsi_start_bb (new_bb);
+  stmt = gimple_build_cond (NE_EXPR, flag, boolean_false_node,
+			    NULL_TREE, NULL_TREE);
+  gsi_insert_after (&gsi, stmt, GSI_CONTINUE_LINKING);
+
+  gsi = gsi_start_bb (then_bb);
+  /* Insert actual store.  */
+  stmt = gimple_build_assign (unshare_expr (mem), tmp_var);
+  gsi_insert_after (&gsi, stmt, GSI_CONTINUE_LINKING);
+
+  make_edge (new_bb, then_bb, EDGE_TRUE_VALUE);
+  make_edge (new_bb, old_dest, EDGE_FALSE_VALUE);
+  then_old_edge = make_edge (then_bb, old_dest, EDGE_FALLTHRU);
+
+  set_immediate_dominator (CDI_DOMINATORS, then_bb, new_bb);
+
+  if (prev_edges)
+    {
+      basic_block prevbb = prev_edges->last_cond_fallthru->src;
+      redirect_edge_succ (prev_edges->last_cond_fallthru, new_bb);
+      set_immediate_dominator (CDI_DOMINATORS, new_bb, prevbb);
+      set_immediate_dominator (CDI_DOMINATORS, old_dest,
+			       recompute_dominator (CDI_DOMINATORS, old_dest));
+    }
+
+  /* ?? Because stores may alias, they must happen in the exact
+     sequence they originally happened.  Save the position right after
+     the (_lsm) store we just created so we can continue appending after
+     it and maintain the original order.  */
+  {
+    struct prev_flag_edges *p;
+
+    if (orig_ex->aux)
+      orig_ex->aux = NULL;
+    alloc_aux_for_edge (orig_ex, sizeof (struct prev_flag_edges));
+    p = (struct prev_flag_edges *) orig_ex->aux;
+    p->append_cond_position = then_old_edge;
+    p->last_cond_fallthru = find_edge (new_bb, old_dest);
+    orig_ex->aux = (void *) p;
+  }
+
+  if (!loop_has_only_one_exit)
+    for (gsi = gsi_start_phis (old_dest); !gsi_end_p (gsi); gsi_next (&gsi))
+      {
+	gimple phi = gsi_stmt (gsi);
+	unsigned i;
+
+	for (i = 0; i < gimple_phi_num_args (phi); i++)
+	  if (gimple_phi_arg_edge (phi, i)->src == new_bb)
+	    {
+	      tree arg = gimple_phi_arg_def (phi, i);
+	      add_phi_arg (phi, arg, then_old_edge, UNKNOWN_LOCATION);
+	      update_stmt (phi);
+	    }
+      }
+  /* Remove the original fall through edge.  This was the
+     single_succ_edge (new_bb).  */
+  EDGE_SUCC (new_bb, 0)->flags &= ~EDGE_FALLTHRU;
+}
+
+/* When REF is set on the location, set flag indicating the store.  */
+
+struct sm_set_flag_if_changed
+{
+  sm_set_flag_if_changed (tree flag_) : flag (flag_) {}
+  bool operator () (mem_ref_loc_p loc);
+  tree flag;
+};
+
+bool
+sm_set_flag_if_changed::operator () (mem_ref_loc_p loc)
+{
+  /* Only set the flag for writes.  */
+  if (is_gimple_assign (loc->stmt)
+      && gimple_assign_lhs_ptr (loc->stmt) == loc->ref)
+    {
+      gimple_stmt_iterator gsi = gsi_for_stmt (loc->stmt);
+      gimple stmt = gimple_build_assign (flag, boolean_true_node);
+      gsi_insert_after (&gsi, stmt, GSI_CONTINUE_LINKING);
+    }
+  return false;
+}
+
+/* Helper function for execute_sm.  On every location where REF is
+   set, set an appropriate flag indicating the store.  */
+
+static tree
+execute_sm_if_changed_flag_set (struct loop *loop, mem_ref_p ref)
+{
+  tree flag;
+  char *str = get_lsm_tmp_name (ref->mem.ref, ~0, "_flag");
+  flag = create_tmp_reg (boolean_type_node, str);
+  for_all_locs_in_loop (loop, ref, sm_set_flag_if_changed (flag));
+  return flag;
+}
+
+/* Executes store motion of memory reference REF from LOOP.
+   Exits from the LOOP are stored in EXITS.  The initialization of the
+   temporary variable is put to the preheader of the loop, and assignments
+   to the reference from the temporary variable are emitted to exits.  */
+
+static void
+execute_sm (struct loop *loop, vec<edge> exits, mem_ref_p ref)
+{
+  tree tmp_var, store_flag = NULL_TREE;
+  unsigned i;
+  gimple load;
+  struct fmt_data fmt_data;
+  edge ex;
+  struct lim_aux_data *lim_data;
+  bool multi_threaded_model_p = false;
+  gimple_stmt_iterator gsi;
+
+  if (dump_file && (dump_flags & TDF_DETAILS))
+    {
+      fprintf (dump_file, "Executing store motion of ");
+      print_generic_expr (dump_file, ref->mem.ref, 0);
+      fprintf (dump_file, " from loop %d\n", loop->num);
+    }
+
+  tmp_var = create_tmp_reg (TREE_TYPE (ref->mem.ref),
+			    get_lsm_tmp_name (ref->mem.ref, ~0));
+
+  fmt_data.loop = loop;
+  fmt_data.orig_loop = loop;
+  for_each_index (&ref->mem.ref, force_move_till, &fmt_data);
+
+  if (bb_in_transaction (loop_preheader_edge (loop)->src)
+      || !PARAM_VALUE (PARAM_ALLOW_STORE_DATA_RACES))
+    multi_threaded_model_p = true;
+
+  if (multi_threaded_model_p)
+    store_flag = execute_sm_if_changed_flag_set (loop, ref);
+
+  rewrite_mem_refs (loop, ref, tmp_var);
+
+  /* Emit the load code on a random exit edge or into the latch if
+     the loop does not exit, so that we are sure it will be processed
+     by move_computations after all dependencies.  */
+  gsi = gsi_for_stmt (first_mem_ref_loc (loop, ref)->stmt);
+
+  /* FIXME/TODO: For the multi-threaded variant, we could avoid this
+     load altogether, since the store is predicated by a flag.  We
+     could, do the load only if it was originally in the loop.  */
+  load = gimple_build_assign (tmp_var, unshare_expr (ref->mem.ref));
+  lim_data = init_lim_data (load);
+  lim_data->max_loop = loop;
+  lim_data->tgt_loop = loop;
+  gsi_insert_before (&gsi, load, GSI_SAME_STMT);
+
+  if (multi_threaded_model_p)
+    {
+      load = gimple_build_assign (store_flag, boolean_false_node);
+      lim_data = init_lim_data (load);
+      lim_data->max_loop = loop;
+      lim_data->tgt_loop = loop;
+      gsi_insert_before (&gsi, load, GSI_SAME_STMT);
+    }
+
+  /* Sink the store to every exit from the loop.  */
+  FOR_EACH_VEC_ELT (exits, i, ex)
+    if (!multi_threaded_model_p)
+      {
+	gimple store;
+	store = gimple_build_assign (unshare_expr (ref->mem.ref), tmp_var);
+	gsi_insert_on_edge (ex, store);
+      }
+    else
+      execute_sm_if_changed (ex, ref->mem.ref, tmp_var, store_flag);
+}
+
+/* Hoists memory references MEM_REFS out of LOOP.  EXITS is the list of exit
+   edges of the LOOP.  */
+
+static void
+hoist_memory_references (struct loop *loop, bitmap mem_refs,
+			 vec<edge> exits)
+{
+  mem_ref_p ref;
+  unsigned  i;
+  bitmap_iterator bi;
+
+  EXECUTE_IF_SET_IN_BITMAP (mem_refs, 0, i, bi)
+    {
+      ref = memory_accesses.refs_list[i];
+      execute_sm (loop, exits, ref);
+    }
+}
+
+struct ref_always_accessed
+{
+  ref_always_accessed (struct loop *loop_, bool stored_p_)
+      : loop (loop_), stored_p (stored_p_) {}
+  bool operator () (mem_ref_loc_p loc);
+  struct loop *loop;
+  bool stored_p;
+};
+
+bool
+ref_always_accessed::operator () (mem_ref_loc_p loc)
+{
+  struct loop *must_exec;
+
+  if (!get_lim_data (loc->stmt))
+    return false;
+
+  /* If we require an always executed store make sure the statement
+     stores to the reference.  */
+  if (stored_p)
+    {
+      tree lhs = gimple_get_lhs (loc->stmt);
+      if (!lhs
+	  || lhs != *loc->ref)
+	return false;
+    }
+
+  must_exec = get_lim_data (loc->stmt)->always_executed_in;
+  if (!must_exec)
+    return false;
+
+  if (must_exec == loop
+      || flow_loop_nested_p (must_exec, loop))
+    return true;
+
+  return false;
+}
+
+/* Returns true if REF is always accessed in LOOP.  If STORED_P is true
+   make sure REF is always stored to in LOOP.  */
+
+static bool
+ref_always_accessed_p (struct loop *loop, mem_ref_p ref, bool stored_p)
+{
+  return for_all_locs_in_loop (loop, ref,
+			       ref_always_accessed (loop, stored_p));
+}
+
+/* Returns true if REF1 and REF2 are independent.  */
+
+static bool
+refs_independent_p (mem_ref_p ref1, mem_ref_p ref2)
+{
+  if (ref1 == ref2)
+    return true;
+
+  if (dump_file && (dump_flags & TDF_DETAILS))
+    fprintf (dump_file, "Querying dependency of refs %u and %u: ",
+	     ref1->id, ref2->id);
+
+  if (mem_refs_may_alias_p (ref1, ref2, &memory_accesses.ttae_cache))
+    {
+      if (dump_file && (dump_flags & TDF_DETAILS))
+	fprintf (dump_file, "dependent.\n");
+      return false;
+    }
+  else
+    {
+      if (dump_file && (dump_flags & TDF_DETAILS))
+	fprintf (dump_file, "independent.\n");
+      return true;
+    }
+}
+
+/* Mark REF dependent on stores or loads (according to STORED_P) in LOOP
+   and its super-loops.  */
+
+static void
+record_dep_loop (struct loop *loop, mem_ref_p ref, bool stored_p)
+{
+  /* We can propagate dependent-in-loop bits up the loop
+     hierarchy to all outer loops.  */
+  while (loop != current_loops->tree_root
+	 && bitmap_set_bit (&ref->dep_loop, LOOP_DEP_BIT (loop->num, stored_p)))
+    loop = loop_outer (loop);
+}
+
+/* Returns true if REF is independent on all other memory references in
+   LOOP.  */
+
+static bool
+ref_indep_loop_p_1 (struct loop *loop, mem_ref_p ref, bool stored_p)
+{
+  bitmap refs_to_check;
+  unsigned i;
+  bitmap_iterator bi;
+  mem_ref_p aref;
+
+  if (stored_p)
+    refs_to_check = &memory_accesses.refs_in_loop[loop->num];
+  else
+    refs_to_check = &memory_accesses.refs_stored_in_loop[loop->num];
+
+  if (bitmap_bit_p (refs_to_check, UNANALYZABLE_MEM_ID))
+    return false;
+
+  EXECUTE_IF_SET_IN_BITMAP (refs_to_check, 0, i, bi)
+    {
+      aref = memory_accesses.refs_list[i];
+      if (!refs_independent_p (ref, aref))
+	return false;
+    }
+
+  return true;
+}
+
+/* Returns true if REF is independent on all other memory references in
+   LOOP.  Wrapper over ref_indep_loop_p_1, caching its results.  */
+
+static bool
+ref_indep_loop_p_2 (struct loop *loop, mem_ref_p ref, bool stored_p)
+{
+  stored_p |= (ref->stored && bitmap_bit_p (ref->stored, loop->num));
+
+  if (bitmap_bit_p (&ref->indep_loop, LOOP_DEP_BIT (loop->num, stored_p)))
+    return true;
+  if (bitmap_bit_p (&ref->dep_loop, LOOP_DEP_BIT (loop->num, stored_p)))
+    return false;
+
+  struct loop *inner = loop->inner;
+  while (inner)
+    {
+      if (!ref_indep_loop_p_2 (inner, ref, stored_p))
+	return false;
+      inner = inner->next;
+    }
+
+  bool indep_p = ref_indep_loop_p_1 (loop, ref, stored_p);
+
+  if (dump_file && (dump_flags & TDF_DETAILS))
+    fprintf (dump_file, "Querying dependencies of ref %u in loop %d: %s\n",
+	     ref->id, loop->num, indep_p ? "independent" : "dependent");
+
+  /* Record the computed result in the cache.  */
+  if (indep_p)
+    {
+      if (bitmap_set_bit (&ref->indep_loop, LOOP_DEP_BIT (loop->num, stored_p))
+	  && stored_p)
+	{
+	  /* If it's independend against all refs then it's independent
+	     against stores, too.  */
+	  bitmap_set_bit (&ref->indep_loop, LOOP_DEP_BIT (loop->num, false));
+	}
+    }
+  else
+    {
+      record_dep_loop (loop, ref, stored_p);
+      if (!stored_p)
+	{
+	  /* If it's dependent against stores it's dependent against
+	     all refs, too.  */
+	  record_dep_loop (loop, ref, true);
+	}
+    }
+
+  return indep_p;
+}
+
+/* Returns true if REF is independent on all other memory references in
+   LOOP.  */
+
+static bool
+ref_indep_loop_p (struct loop *loop, mem_ref_p ref)
+{
+  gcc_checking_assert (MEM_ANALYZABLE (ref));
+
+  return ref_indep_loop_p_2 (loop, ref, false);
+}
+
+/* Returns true if we can perform store motion of REF from LOOP.  */
+
+static bool
+can_sm_ref_p (struct loop *loop, mem_ref_p ref)
+{
+  tree base;
+
+  /* Can't hoist unanalyzable refs.  */
+  if (!MEM_ANALYZABLE (ref))
+    return false;
+
+  /* It should be movable.  */
+  if (!is_gimple_reg_type (TREE_TYPE (ref->mem.ref))
+      || TREE_THIS_VOLATILE (ref->mem.ref)
+      || !for_each_index (&ref->mem.ref, may_move_till, loop))
+    return false;
+
+  /* If it can throw fail, we do not properly update EH info.  */
+  if (tree_could_throw_p (ref->mem.ref))
+    return false;
+
+  /* If it can trap, it must be always executed in LOOP.
+     Readonly memory locations may trap when storing to them, but
+     tree_could_trap_p is a predicate for rvalues, so check that
+     explicitly.  */
+  base = get_base_address (ref->mem.ref);
+  if ((tree_could_trap_p (ref->mem.ref)
+       || (DECL_P (base) && TREE_READONLY (base)))
+      && !ref_always_accessed_p (loop, ref, true))
+    return false;
+
+  /* And it must be independent on all other memory references
+     in LOOP.  */
+  if (!ref_indep_loop_p (loop, ref))
+    return false;
+
+  return true;
+}
+
+/* Marks the references in LOOP for that store motion should be performed
+   in REFS_TO_SM.  SM_EXECUTED is the set of references for that store
+   motion was performed in one of the outer loops.  */
+
+static void
+find_refs_for_sm (struct loop *loop, bitmap sm_executed, bitmap refs_to_sm)
+{
+  bitmap refs = &memory_accesses.all_refs_stored_in_loop[loop->num];
+  unsigned i;
+  bitmap_iterator bi;
+  mem_ref_p ref;
+
+  EXECUTE_IF_AND_COMPL_IN_BITMAP (refs, sm_executed, 0, i, bi)
+    {
+      ref = memory_accesses.refs_list[i];
+      if (can_sm_ref_p (loop, ref))
+	bitmap_set_bit (refs_to_sm, i);
+    }
+}
+
+/* Checks whether LOOP (with exits stored in EXITS array) is suitable
+   for a store motion optimization (i.e. whether we can insert statement
+   on its exits).  */
+
+static bool
+loop_suitable_for_sm (struct loop *loop ATTRIBUTE_UNUSED,
+		      vec<edge> exits)
+{
+  unsigned i;
+  edge ex;
+
+  FOR_EACH_VEC_ELT (exits, i, ex)
+    if (ex->flags & (EDGE_ABNORMAL | EDGE_EH))
+      return false;
+
+  return true;
+}
+
+/* Try to perform store motion for all memory references modified inside
+   LOOP.  SM_EXECUTED is the bitmap of the memory references for that
+   store motion was executed in one of the outer loops.  */
+
+static void
+store_motion_loop (struct loop *loop, bitmap sm_executed)
+{
+  vec<edge> exits = get_loop_exit_edges (loop);
+  struct loop *subloop;
+  bitmap sm_in_loop = BITMAP_ALLOC (&lim_bitmap_obstack);
+
+  if (loop_suitable_for_sm (loop, exits))
+    {
+      find_refs_for_sm (loop, sm_executed, sm_in_loop);
+      hoist_memory_references (loop, sm_in_loop, exits);
+    }
+  exits.release ();
+
+  bitmap_ior_into (sm_executed, sm_in_loop);
+  for (subloop = loop->inner; subloop != NULL; subloop = subloop->next)
+    store_motion_loop (subloop, sm_executed);
+  bitmap_and_compl_into (sm_executed, sm_in_loop);
+  BITMAP_FREE (sm_in_loop);
+}
+
+/* Try to perform store motion for all memory references modified inside
+   loops.  */
+
+static void
+store_motion (void)
+{
+  struct loop *loop;
+  bitmap sm_executed = BITMAP_ALLOC (&lim_bitmap_obstack);
+
+  for (loop = current_loops->tree_root->inner; loop != NULL; loop = loop->next)
+    store_motion_loop (loop, sm_executed);
+
+  BITMAP_FREE (sm_executed);
+  gsi_commit_edge_inserts ();
+}
+
+/* Fills ALWAYS_EXECUTED_IN information for basic blocks of LOOP, i.e.
+   for each such basic block bb records the outermost loop for that execution
+   of its header implies execution of bb.  CONTAINS_CALL is the bitmap of
+   blocks that contain a nonpure call.  */
+
+static void
+fill_always_executed_in_1 (struct loop *loop, sbitmap contains_call)
+{
+  basic_block bb = NULL, *bbs, last = NULL;
+  unsigned i;
+  edge e;
+  struct loop *inn_loop = loop;
+
+  if (ALWAYS_EXECUTED_IN (loop->header) == NULL)
+    {
+      bbs = get_loop_body_in_dom_order (loop);
+
+      for (i = 0; i < loop->num_nodes; i++)
+	{
+	  edge_iterator ei;
+	  bb = bbs[i];
+
+	  if (dominated_by_p (CDI_DOMINATORS, loop->latch, bb))
+	    last = bb;
+
+	  if (bitmap_bit_p (contains_call, bb->index))
+	    break;
+
+	  FOR_EACH_EDGE (e, ei, bb->succs)
+	    if (!flow_bb_inside_loop_p (loop, e->dest))
+	      break;
+	  if (e)
+	    break;
+
+	  /* A loop might be infinite (TODO use simple loop analysis
+	     to disprove this if possible).  */
+	  if (bb->flags & BB_IRREDUCIBLE_LOOP)
+	    break;
+
+	  if (!flow_bb_inside_loop_p (inn_loop, bb))
+	    break;
+
+	  if (bb->loop_father->header == bb)
+	    {
+	      if (!dominated_by_p (CDI_DOMINATORS, loop->latch, bb))
+		break;
+
+	      /* In a loop that is always entered we may proceed anyway.
+		 But record that we entered it and stop once we leave it.  */
+	      inn_loop = bb->loop_father;
+	    }
+	}
+
+      while (1)
+	{
+	  SET_ALWAYS_EXECUTED_IN (last, loop);
+	  if (last == loop->header)
+	    break;
+	  last = get_immediate_dominator (CDI_DOMINATORS, last);
+	}
+
+      free (bbs);
+    }
+
+  for (loop = loop->inner; loop; loop = loop->next)
+    fill_always_executed_in_1 (loop, contains_call);
+}
+
+/* Fills ALWAYS_EXECUTED_IN information for basic blocks, i.e.
+   for each such basic block bb records the outermost loop for that execution
+   of its header implies execution of bb.  */
+
+static void
+fill_always_executed_in (void)
+{
+  sbitmap contains_call = sbitmap_alloc (last_basic_block_for_fn (cfun));
+  basic_block bb;
+  struct loop *loop;
+
+  bitmap_clear (contains_call);
+  FOR_EACH_BB_FN (bb, cfun)
+    {
+      gimple_stmt_iterator gsi;
+      for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+	{
+	  if (nonpure_call_p (gsi_stmt (gsi)))
+	    break;
+	}
+
+      if (!gsi_end_p (gsi))
+	bitmap_set_bit (contains_call, bb->index);
+    }
+
+  for (loop = current_loops->tree_root->inner; loop; loop = loop->next)
+    fill_always_executed_in_1 (loop, contains_call);
+
+  sbitmap_free (contains_call);
+}
+
+
+/* Compute the global information needed by the loop invariant motion pass.  */
+
+static void
+tree_ssa_lim_initialize (void)
+{
+  struct loop *loop;
+  unsigned i;
+
+  bitmap_obstack_initialize (&lim_bitmap_obstack);
+  gcc_obstack_init (&mem_ref_obstack);
+  lim_aux_data_map = pointer_map_create ();
+
+  if (flag_tm)
+    compute_transaction_bits ();
+
+  alloc_aux_for_edges (0);
+
+  memory_accesses.refs.create (100);
+  memory_accesses.refs_list.create (100);
+  /* Allocate a special, unanalyzable mem-ref with ID zero.  */
+  memory_accesses.refs_list.quick_push
+    (mem_ref_alloc (error_mark_node, 0, UNANALYZABLE_MEM_ID));
+
+  memory_accesses.refs_in_loop.create (number_of_loops (cfun));
+  memory_accesses.refs_in_loop.quick_grow (number_of_loops (cfun));
+  memory_accesses.refs_stored_in_loop.create (number_of_loops (cfun));
+  memory_accesses.refs_stored_in_loop.quick_grow (number_of_loops (cfun));
+  memory_accesses.all_refs_stored_in_loop.create (number_of_loops (cfun));
+  memory_accesses.all_refs_stored_in_loop.quick_grow (number_of_loops (cfun));
+
+  for (i = 0; i < number_of_loops (cfun); i++)
+    {
+      bitmap_initialize (&memory_accesses.refs_in_loop[i],
+			 &lim_bitmap_obstack);
+      bitmap_initialize (&memory_accesses.refs_stored_in_loop[i],
+			 &lim_bitmap_obstack);
+      bitmap_initialize (&memory_accesses.all_refs_stored_in_loop[i],
+			 &lim_bitmap_obstack);
+    }
+
+  memory_accesses.ttae_cache = NULL;
+
+  /* Initialize bb_loop_postorder with a mapping from loop->num to
+     its postorder index.  */
+  i = 0;
+  bb_loop_postorder = XNEWVEC (unsigned, number_of_loops (cfun));
+  FOR_EACH_LOOP (loop, LI_FROM_INNERMOST)
+    bb_loop_postorder[loop->num] = i++;
+}
+
+/* Cleans up after the invariant motion pass.  */
+
+static void
+tree_ssa_lim_finalize (void)
+{
+  basic_block bb;
+  unsigned i;
+  mem_ref_p ref;
+
+  free_aux_for_edges ();
+
+  FOR_EACH_BB_FN (bb, cfun)
+    SET_ALWAYS_EXECUTED_IN (bb, NULL);
+
+  bitmap_obstack_release (&lim_bitmap_obstack);
+  pointer_map_destroy (lim_aux_data_map);
+
+  memory_accesses.refs.dispose ();
+
+  FOR_EACH_VEC_ELT (memory_accesses.refs_list, i, ref)
+    memref_free (ref);
+  memory_accesses.refs_list.release ();
+  obstack_free (&mem_ref_obstack, NULL);
+
+  memory_accesses.refs_in_loop.release ();
+  memory_accesses.refs_stored_in_loop.release ();
+  memory_accesses.all_refs_stored_in_loop.release ();
+
+  if (memory_accesses.ttae_cache)
+    free_affine_expand_cache (&memory_accesses.ttae_cache);
+
+  free (bb_loop_postorder);
+}
+
+/* Moves invariants from loops.  Only "expensive" invariants are moved out --
+   i.e. those that are likely to be win regardless of the register pressure.  */
+
+unsigned int
+tree_ssa_lim (void)
+{
+  unsigned int todo;
+
+  tree_ssa_lim_initialize ();
+
+  /* Gathers information about memory accesses in the loops.  */
+  analyze_memory_references ();
+
+  /* Fills ALWAYS_EXECUTED_IN information for basic blocks.  */
+  fill_always_executed_in ();
+
+  /* For each statement determine the outermost loop in that it is
+     invariant and cost for computing the invariant.  */
+  invariantness_dom_walker (CDI_DOMINATORS)
+    .walk (cfun->cfg->x_entry_block_ptr);
+
+  /* Execute store motion.  Force the necessary invariants to be moved
+     out of the loops as well.  */
+  store_motion ();
+
+  /* Move the expressions that are expensive enough.  */
+  todo = move_computations ();
+
+  tree_ssa_lim_finalize ();
+
+  return todo;
+}
+
+/* Loop invariant motion pass.  */
+
+static unsigned int
+tree_ssa_loop_im (void)
+{
+  if (number_of_loops (cfun) <= 1)
+    return 0;
+
+  return tree_ssa_lim ();
+}
+
+static bool
+gate_tree_ssa_loop_im (void)
+{
+  return flag_tree_loop_im != 0;
+}
+
+namespace {
+
+const pass_data pass_data_lim =
+{
+  GIMPLE_PASS, /* type */
+  "lim", /* name */
+  OPTGROUP_LOOP, /* optinfo_flags */
+  true, /* has_gate */
+  true, /* has_execute */
+  TV_LIM, /* tv_id */
+  PROP_cfg, /* properties_required */
+  0, /* properties_provided */
+  0, /* properties_destroyed */
+  0, /* todo_flags_start */
+  0, /* todo_flags_finish */
+};
+
+class pass_lim : public gimple_opt_pass
+{
+public:
+  pass_lim (gcc::context *ctxt)
+    : gimple_opt_pass (pass_data_lim, ctxt)
+  {}
+
+  /* opt_pass methods: */
+  opt_pass * clone () { return new pass_lim (m_ctxt); }
+  bool gate () { return gate_tree_ssa_loop_im (); }
+  unsigned int execute () { return tree_ssa_loop_im (); }
+
+}; // class pass_lim
+
+} // anon namespace
+
+gimple_opt_pass *
+make_pass_lim (gcc::context *ctxt)
+{
+  return new pass_lim (ctxt);
+}
+
+