--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/tree-ssa-loop-im.c	Fri Jul 17 14:47:48 2009 +0900
@@ -0,0 +1,2309 @@
+/* Loop invariant motion.
+   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 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 "rtl.h"
+#include "tm_p.h"
+#include "hard-reg-set.h"
+#include "basic-block.h"
+#include "output.h"
+#include "diagnostic.h"
+#include "tree-flow.h"
+#include "tree-dump.h"
+#include "timevar.h"
+#include "cfgloop.h"
+#include "domwalk.h"
+#include "params.h"
+#include "tree-pass.h"
+#include "flags.h"
+#include "real.h"
+#include "hashtab.h"
+#include "tree-affine.h"
+#include "pointer-set.h"
+#include "tree-ssa-propagate.h"
+
+/* TODO:  Support for predicated code motion.  I.e.
+
+   while (1)
+     {
+       if (cond)
+	 {
+	   a = inv;
+	   something;
+	 }
+     }
+
+   Where COND and INV are is 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;
+     }  */
+
+/* A type for the list of statements that have to be moved in order to be able
+   to hoist an invariant computation.  */
+
+struct depend
+{
+  gimple stmt;
+  struct depend *next;
+};
+
+/* 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.  */
+
+  struct depend *depends;	/* List 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;
+
+DEF_VEC_P(mem_ref_loc_p);
+DEF_VEC_ALLOC_P(mem_ref_loc_p, heap);
+
+/* The list of memory reference locations in a loop.  */
+
+typedef struct mem_ref_locs
+{
+  VEC (mem_ref_loc_p, heap) *locs;
+} *mem_ref_locs_p;
+
+DEF_VEC_P(mem_ref_locs_p);
+DEF_VEC_ALLOC_P(mem_ref_locs_p, heap);
+
+/* Description of a memory reference.  */
+
+typedef struct mem_ref
+{
+  tree mem;			/* The memory itself.  */
+  unsigned id;			/* ID assigned to the memory reference
+				   (its index in memory_accesses.refs_list)  */
+  hashval_t hash;		/* Its hash value.  */
+  bitmap stored;		/* The set of loops in that this memory location
+				   is stored to.  */
+  VEC (mem_ref_locs_p, heap) *accesses_in_loop;
+				/* The locations of the accesses.  Vector
+				   indexed by the loop number.  */
+  bitmap vops;			/* Vops corresponding to this memory
+				   location.  */
+
+  /* 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 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 dep_loop;		/* The complement of INDEP_LOOP.  */
+
+  bitmap indep_ref;		/* The set of memory references on that
+				   this reference is independent.  */
+  bitmap dep_ref;		/* The complement of DEP_REF.  */
+} *mem_ref_p;
+
+DEF_VEC_P(mem_ref_p);
+DEF_VEC_ALLOC_P(mem_ref_p, heap);
+
+DEF_VEC_P(bitmap);
+DEF_VEC_ALLOC_P(bitmap, heap);
+
+DEF_VEC_P(htab_t);
+DEF_VEC_ALLOC_P(htab_t, heap);
+
+/* Description of memory accesses in loops.  */
+
+static struct
+{
+  /* The hash table of memory references accessed in loops.  */
+  htab_t refs;
+
+  /* The list of memory references.  */
+  VEC (mem_ref_p, heap) *refs_list;
+
+  /* The set of memory references accessed in each loop.  */
+  VEC (bitmap, heap) *refs_in_loop;
+
+  /* The set of memory references accessed in each loop, including
+     subloops.  */
+  VEC (bitmap, heap) *all_refs_in_loop;
+
+  /* The set of virtual operands clobbered in a given loop.  */
+  VEC (bitmap, heap) *clobbered_vops;
+
+  /* Map from the pair (loop, virtual operand) to the set of refs that
+     touch the virtual operand in the loop.  */
+  VEC (htab_t, heap) *vop_ref_map;
+
+  /* Cache for expanding memory addresses.  */
+  struct pointer_map_t *ttae_cache;
+} memory_accesses;
+
+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 that execution of the header guarantees that the
+   block will be executed.  */
+#define ALWAYS_EXECUTED_IN(BB) ((struct loop *) (BB)->aux)
+
+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)
+{
+  struct depend *dep, *next;
+
+  for (dep = data->depends; dep; dep = next)
+    {
+      next = dep->next;
+      free (dep);
+    }
+  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;
+}
+
+/* Calls CBCK for each index in memory reference ADDR_P.  There are two
+   kinds situations handled; in each of these cases, the memory reference
+   and DATA are passed to the callback:
+   
+   Access to an array: ARRAY_{RANGE_}REF (base, index).  In this case we also
+   pass the pointer to the index to the callback.
+
+   Pointer dereference: INDIRECT_REF (addr).  In this case we also pass the
+   pointer to addr to the callback.
+   
+   If the callback returns false, the whole search stops and false is returned.
+   Otherwise the function returns true after traversing through the whole
+   reference *ADDR_P.  */
+
+bool
+for_each_index (tree *addr_p, bool (*cbck) (tree, tree *, void *), void *data)
+{
+  tree *nxt, *idx;
+
+  for (; ; addr_p = nxt)
+    {
+      switch (TREE_CODE (*addr_p))
+	{
+	case SSA_NAME:
+	  return cbck (*addr_p, addr_p, data);
+
+	case MISALIGNED_INDIRECT_REF:
+	case ALIGN_INDIRECT_REF:
+	case INDIRECT_REF:
+	  nxt = &TREE_OPERAND (*addr_p, 0);
+	  return cbck (*addr_p, nxt, data);
+
+	case BIT_FIELD_REF:
+	case VIEW_CONVERT_EXPR:
+	case REALPART_EXPR:
+	case IMAGPART_EXPR:
+	  nxt = &TREE_OPERAND (*addr_p, 0);
+	  break;
+
+	case COMPONENT_REF:
+	  /* If the component has varying offset, it behaves like index
+	     as well.  */
+	  idx = &TREE_OPERAND (*addr_p, 2);
+	  if (*idx
+	      && !cbck (*addr_p, idx, data))
+	    return false;
+
+	  nxt = &TREE_OPERAND (*addr_p, 0);
+	  break;
+
+	case ARRAY_REF:
+	case ARRAY_RANGE_REF:
+	  nxt = &TREE_OPERAND (*addr_p, 0);
+	  if (!cbck (*addr_p, &TREE_OPERAND (*addr_p, 1), data))
+	    return false;
+	  break;
+
+	case VAR_DECL:
+	case PARM_DECL:
+	case STRING_CST:
+	case RESULT_DECL:
+	case VECTOR_CST:
+	case COMPLEX_CST:
+	case INTEGER_CST:
+	case REAL_CST:
+	case FIXED_CST:
+	case CONSTRUCTOR:
+	  return true;
+
+	case ADDR_EXPR:
+	  gcc_assert (is_gimple_min_invariant (*addr_p));
+	  return true;
+
+	case TARGET_MEM_REF:
+	  idx = &TMR_BASE (*addr_p);
+	  if (*idx
+	      && !cbck (*addr_p, idx, data))
+	    return false;
+	  idx = &TMR_INDEX (*addr_p);
+	  if (*idx
+	      && !cbck (*addr_p, idx, data))
+	    return false;
+	  return true;
+
+	default:
+    	  gcc_unreachable ();
+	}
+    }
+}
+
+/* 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_get_lhs (stmt) == NULL_TREE)
+    return MOVE_IMPOSSIBLE;
+
+  if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_VIRTUAL_DEFS))
+    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;
+
+  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 depend *dep;
+  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;
+
+  dep = XNEW (struct depend);
+  dep->stmt = def_stmt;
+  dep->next = data->depends;
+  data->depends = dep;
+
+  return true;
+}
+
+/* Returns an estimate for a cost of statement STMT.  TODO -- the values here
+   are just ad-hoc constants.  The estimates should be based on target-specific
+   values.  */
+
+static unsigned
+stmt_cost (gimple stmt)
+{
+  tree fndecl;
+  unsigned cost = 1;
+
+  /* Always try to create possibilities for unswitching.  */
+  if (gimple_code (stmt) == GIMPLE_COND)
+    return LIM_EXPENSIVE;
+
+  /* Hoisting memory references out should almost surely be a win.  */
+  if (gimple_references_memory_p (stmt))
+    cost += 20;
+
+  if (is_gimple_call (stmt))
+    {
+      /* We should be hoisting calls if possible.  */
+
+      /* 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 cost + 20;
+    }
+
+  if (gimple_code (stmt) != GIMPLE_ASSIGN)
+    return cost;
+
+  switch (gimple_assign_rhs_code (stmt))
+    {
+    case MULT_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.  */
+      cost += 20;
+      break;
+
+    case LSHIFT_EXPR:
+    case RSHIFT_EXPR:
+      cost += 20;
+      break;
+
+    default:
+      break;
+    }
+
+  return cost;
+}
+
+/* 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 (bitmap_bit_p (ref->stored, loop->num))
+    return NULL;
+
+  for (aloop = outer;
+       aloop != loop;
+       aloop = superloop_at_depth (loop, loop_depth (aloop) + 1))
+    if (!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;
+  enum tree_code code;
+
+  /* Recognize MEM = (SSA_NAME | invariant) and SSA_NAME = MEM patterns.  */
+  if (gimple_code (stmt) != GIMPLE_ASSIGN)
+    return NULL;
+
+  code = gimple_assign_rhs_code (stmt);
+
+  lhs = gimple_assign_lhs_ptr (stmt);
+
+  if (TREE_CODE (*lhs) == SSA_NAME)
+    {
+      if (get_gimple_rhs_class (code) != GIMPLE_SINGLE_RHS
+	  || !is_gimple_addressable (gimple_assign_rhs1 (stmt)))
+	return NULL;
+
+      *is_store = false;
+      return gimple_assign_rhs1_ptr (stmt);
+    }
+  else if (code == SSA_NAME
+	   || (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS
+	       && is_gimple_min_invariant (gimple_assign_rhs1 (stmt))))
+    {
+      *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 = (mem_ref_p) htab_find_with_hash (memory_accesses.refs, *mem, hash);
+
+  gcc_assert (ref != NULL);
+  return ref;
+}
+
+/* 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;
+
+  FOR_EACH_SSA_TREE_OPERAND (val, stmt, iter, SSA_OP_USE)
+    if (!add_dependency (val, lim_data, loop, true))
+      return false;
+
+  if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_VIRTUAL_USES))
+    {
+      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
+	{
+	  FOR_EACH_SSA_TREE_OPERAND (val, stmt, iter, SSA_OP_VIRTUAL_USES)
+	    {
+	      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 depend *dep;
+  struct lim_aux_data *lim_data;
+
+  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 (dep = lim_data->depends; dep; dep = dep->next)
+    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 var, name, lhs, type;
+  tree real_one;
+
+  stmt = gsi_stmt (*bsi);
+  lhs = gimple_assign_lhs (stmt);
+  type = TREE_TYPE (lhs);
+
+  var = create_tmp_var (type, "reciptmp");
+  add_referenced_var (var);
+  DECL_GIMPLE_REG_P (var) = 1;
+
+  /* For vectors, create a VECTOR_CST full of 1's.  */
+  if (TREE_CODE (type) == VECTOR_TYPE)
+    {
+      int i, len;
+      tree list = NULL_TREE;
+      real_one = build_real (TREE_TYPE (type), dconst1);
+      len = TYPE_VECTOR_SUBPARTS (type);
+      for (i = 0; i < len; i++)
+	list = tree_cons (NULL, real_one, list);
+      real_one = build_vector (type, list);
+    }
+  else
+    real_one = build_real (type, dconst1);
+
+  stmt1 = gimple_build_assign_with_ops (RDIV_EXPR,
+		var, real_one, gimple_assign_rhs2 (stmt));
+  name = make_ssa_name (var, stmt1);
+  gimple_assign_set_lhs (stmt1, name);
+
+  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_replace (bsi, stmt1, true);
+  gsi_insert_after (bsi, stmt2, GSI_NEW_STMT);
+
+  /* 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, var, 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)
+    {
+      /* 1 << B */
+      var = create_tmp_var (TREE_TYPE (a), "shifttmp");
+      add_referenced_var (var);
+      t = fold_build2 (LSHIFT_EXPR, TREE_TYPE (a),
+		       build_int_cst (TREE_TYPE (a), 1), b);
+      stmt1 = gimple_build_assign (var, t);
+      name = make_ssa_name (var, stmt1);
+      gimple_assign_set_lhs (stmt1, name);
+
+      /* A & (1 << B) */
+      t = fold_build2 (BIT_AND_EXPR, TREE_TYPE (a), a, name);
+      stmt2 = gimple_build_assign (var, t);
+      name = make_ssa_name (var, stmt2);
+      gimple_assign_set_lhs (stmt2, name);
+
+      /* 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));
+
+      gsi_insert_before (bsi, stmt1, GSI_SAME_STMT);
+      gsi_replace (bsi, stmt2, true);
+
+      return stmt1;
+    }
+
+  return stmt;
+}
+
+
+/* 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 walk_dominator_tree.  */
+
+static void
+determine_invariantness_stmt (struct dom_walk_data *dw_data ATTRIBUTE_UNUSED,
+			      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));
+
+  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);
+    }
+}
+
+/* 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.  */
+
+static void
+determine_invariantness (void)
+{
+  struct dom_walk_data walk_data;
+
+  memset (&walk_data, 0, sizeof (struct dom_walk_data));
+  walk_data.dom_direction = CDI_DOMINATORS;
+  walk_data.before_dom_children_before_stmts = determine_invariantness_stmt;
+
+  init_walk_dominator_tree (&walk_data);
+  walk_dominator_tree (&walk_data, ENTRY_BLOCK_PTR);
+  fini_walk_dominator_tree (&walk_data);
+}
+
+/* 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.  */
+
+static void
+move_computations_stmt (struct dom_walk_data *dw_data ATTRIBUTE_UNUSED,
+			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_bb (bb); !gsi_end_p (bsi); )
+    {
+      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);
+	}
+
+      mark_virtual_ops_for_renaming (stmt);
+      gsi_insert_on_edge (loop_preheader_edge (level), stmt);
+      gsi_remove (&bsi, false);
+    }
+}
+
+/* Hoist the statements out of the loops prescribed by data stored in
+   LIM_DATA structures associated with each statement.*/
+
+static void
+move_computations (void)
+{
+  struct dom_walk_data walk_data;
+
+  memset (&walk_data, 0, sizeof (struct dom_walk_data));
+  walk_data.dom_direction = CDI_DOMINATORS;
+  walk_data.before_dom_children_before_stmts = move_computations_stmt;
+
+  init_walk_dominator_tree (&walk_data);
+  walk_dominator_tree (&walk_data, ENTRY_BLOCK_PTR);
+  fini_walk_dominator_tree (&walk_data);
+
+  gsi_commit_edge_inserts ();
+  if (need_ssa_update_p ())
+    rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
+}
+
+/* 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 hash function for struct mem_ref object OBJ.  */
+
+static hashval_t
+memref_hash (const void *obj)
+{
+  const struct mem_ref *const mem = (const struct mem_ref *) obj;
+
+  return mem->hash;
+}
+
+/* An equality function for struct mem_ref object OBJ1 with
+   memory reference OBJ2.  */
+
+static int
+memref_eq (const void *obj1, const void *obj2)
+{
+  const struct mem_ref *const mem1 = (const struct mem_ref *) obj1;
+
+  return operand_equal_p (mem1->mem, (const_tree) obj2, 0);
+}
+
+/* Releases list of memory reference locations ACCS.  */
+
+static void
+free_mem_ref_locs (mem_ref_locs_p accs)
+{
+  unsigned i;
+  mem_ref_loc_p loc;
+
+  if (!accs)
+    return;
+
+  for (i = 0; VEC_iterate (mem_ref_loc_p, accs->locs, i, loc); i++)
+    free (loc);
+  VEC_free (mem_ref_loc_p, heap, accs->locs);
+  free (accs);
+}
+
+/* A function to free the mem_ref object OBJ.  */
+
+static void
+memref_free (void *obj)
+{
+  struct mem_ref *const mem = (struct mem_ref *) obj;
+  unsigned i;
+  mem_ref_locs_p accs;
+
+  BITMAP_FREE (mem->stored);
+  BITMAP_FREE (mem->indep_loop);
+  BITMAP_FREE (mem->dep_loop);
+  BITMAP_FREE (mem->indep_ref);
+  BITMAP_FREE (mem->dep_ref);
+
+  for (i = 0; VEC_iterate (mem_ref_locs_p, mem->accesses_in_loop, i, accs); i++)
+    free_mem_ref_locs (accs);
+  VEC_free (mem_ref_locs_p, heap, mem->accesses_in_loop);
+
+  BITMAP_FREE (mem->vops);
+  free (mem);
+}
+
+/* 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 = XNEW (struct mem_ref);
+  ref->mem = mem;
+  ref->id = id;
+  ref->hash = hash;
+  ref->stored = BITMAP_ALLOC (NULL);
+  ref->indep_loop = BITMAP_ALLOC (NULL);
+  ref->dep_loop = BITMAP_ALLOC (NULL);
+  ref->indep_ref = BITMAP_ALLOC (NULL);
+  ref->dep_ref = BITMAP_ALLOC (NULL);
+  ref->accesses_in_loop = NULL;
+  ref->vops = BITMAP_ALLOC (NULL);
+
+  return ref;
+}
+
+/* Allocates and returns the new list of locations.  */
+
+static mem_ref_locs_p
+mem_ref_locs_alloc (void)
+{
+  mem_ref_locs_p accs = XNEW (struct mem_ref_locs);
+  accs->locs = NULL;
+  return accs;
+}
+
+/* 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, struct loop *loop, gimple stmt, tree *loc)
+{
+  mem_ref_loc_p aref = XNEW (struct mem_ref_loc);
+  mem_ref_locs_p accs;
+  bitmap ril = VEC_index (bitmap, memory_accesses.refs_in_loop, loop->num);
+
+  if (VEC_length (mem_ref_locs_p, ref->accesses_in_loop)
+      <= (unsigned) loop->num)
+    VEC_safe_grow_cleared (mem_ref_locs_p, heap, ref->accesses_in_loop,
+			   loop->num + 1);
+  accs = VEC_index (mem_ref_locs_p, ref->accesses_in_loop, loop->num);
+  if (!accs)
+    {
+      accs = mem_ref_locs_alloc ();
+      VEC_replace (mem_ref_locs_p, ref->accesses_in_loop, loop->num, accs);
+    }
+
+  aref->stmt = stmt;
+  aref->ref = loc;
+
+  VEC_safe_push (mem_ref_loc_p, heap, accs->locs, aref);
+  bitmap_set_bit (ril, ref->id);
+}
+
+/* Marks reference REF as stored in LOOP.  */
+
+static void
+mark_ref_stored (mem_ref_p ref, struct loop *loop)
+{
+  for (;
+       loop != current_loops->tree_root
+       && !bitmap_bit_p (ref->stored, loop->num);
+       loop = loop_outer (loop))
+    bitmap_set_bit (ref->stored, loop->num);
+}
+
+/* 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;
+  PTR *slot;
+  mem_ref_p ref;
+  ssa_op_iter oi;
+  tree vname;
+  bool is_stored;
+  bitmap clvops;
+  unsigned id;
+
+  if (ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS))
+    return;
+
+  mem = simple_mem_ref_in_stmt (stmt, &is_stored);
+  if (!mem)
+    goto fail;
+
+  hash = iterative_hash_expr (*mem, 0);
+  slot = htab_find_slot_with_hash (memory_accesses.refs, *mem, hash, INSERT);
+
+  if (*slot)
+    {
+      ref = (mem_ref_p) *slot;
+      id = ref->id;
+    }
+  else
+    {
+      id = VEC_length (mem_ref_p, memory_accesses.refs_list);
+      ref = mem_ref_alloc (*mem, hash, id);
+      VEC_safe_push (mem_ref_p, heap, memory_accesses.refs_list, ref);
+      *slot = ref;
+
+      if (dump_file && (dump_flags & TDF_DETAILS))
+	{
+	  fprintf (dump_file, "Memory reference %u: ", id);
+	  print_generic_expr (dump_file, ref->mem, TDF_SLIM);
+	  fprintf (dump_file, "\n");
+	}
+    }
+  if (is_stored)
+    mark_ref_stored (ref, loop);
+
+  FOR_EACH_SSA_TREE_OPERAND (vname, stmt, oi, SSA_OP_VIRTUAL_USES)
+    bitmap_set_bit (ref->vops, DECL_UID (SSA_NAME_VAR (vname)));
+  record_mem_ref_loc (ref, loop, stmt, mem);
+  return;
+
+fail:
+  clvops = VEC_index (bitmap, memory_accesses.clobbered_vops, loop->num);
+  FOR_EACH_SSA_TREE_OPERAND (vname, stmt, oi, SSA_OP_VIRTUAL_USES)
+    bitmap_set_bit (clvops, DECL_UID (SSA_NAME_VAR (vname)));
+}
+
+/* Gathers memory references in loops.  */
+
+static void
+gather_mem_refs_in_loops (void)
+{
+  gimple_stmt_iterator bsi;
+  basic_block bb;
+  struct loop *loop;
+  loop_iterator li;
+  bitmap clvo, clvi;
+  bitmap lrefs, alrefs, alrefso;
+
+  FOR_EACH_BB (bb)
+    {
+      loop = bb->loop_father;
+      if (loop == current_loops->tree_root)
+	continue;
+
+      for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
+	gather_mem_refs_stmt (loop, gsi_stmt (bsi));
+    }
+
+  /* Propagate the information about clobbered vops and accessed memory
+     references up the loop hierarchy.  */
+  FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST)
+    {
+      lrefs = VEC_index (bitmap, memory_accesses.refs_in_loop, loop->num);
+      alrefs = VEC_index (bitmap, memory_accesses.all_refs_in_loop, loop->num);
+      bitmap_ior_into (alrefs, lrefs);
+
+      if (loop_outer (loop) == current_loops->tree_root)
+	continue;
+
+      clvi = VEC_index (bitmap, memory_accesses.clobbered_vops, loop->num);
+      clvo = VEC_index (bitmap, memory_accesses.clobbered_vops,
+			loop_outer (loop)->num);
+      bitmap_ior_into (clvo, clvi);
+
+      alrefso = VEC_index (bitmap, memory_accesses.all_refs_in_loop,
+			   loop_outer (loop)->num);
+      bitmap_ior_into (alrefso, alrefs);
+    }
+}
+
+/* Element of the hash table that maps vops to memory references.  */
+
+struct vop_to_refs_elt
+{
+  /* DECL_UID of the vop.  */
+  unsigned uid;
+
+  /* List of the all references.  */
+  bitmap refs_all;
+
+  /* List of stored references.  */
+  bitmap refs_stored;
+};
+
+/* A hash function for struct vop_to_refs_elt object OBJ.  */
+
+static hashval_t
+vtoe_hash (const void *obj)
+{
+  const struct vop_to_refs_elt *const vtoe =
+    (const struct vop_to_refs_elt *) obj;
+
+  return vtoe->uid;
+}
+
+/* An equality function for struct vop_to_refs_elt object OBJ1 with
+   uid of a vop OBJ2.  */
+
+static int
+vtoe_eq (const void *obj1, const void *obj2)
+{
+  const struct vop_to_refs_elt *const vtoe =
+    (const struct vop_to_refs_elt *) obj1;
+  const unsigned *const uid = (const unsigned *) obj2;
+
+  return vtoe->uid == *uid;
+}
+
+/* A function to free the struct vop_to_refs_elt object.  */
+
+static void
+vtoe_free (void *obj)
+{
+  struct vop_to_refs_elt *const vtoe =
+    (struct vop_to_refs_elt *) obj;
+
+  BITMAP_FREE (vtoe->refs_all);
+  BITMAP_FREE (vtoe->refs_stored);
+  free (vtoe);
+}
+
+/* Records REF to hashtable VOP_TO_REFS for the index VOP.  STORED is true
+   if the reference REF is stored.  */
+
+static void
+record_vop_access (htab_t vop_to_refs, unsigned vop, unsigned ref, bool stored)
+{
+  void **slot = htab_find_slot_with_hash (vop_to_refs, &vop, vop, INSERT);
+  struct vop_to_refs_elt *vtoe;
+
+  if (!*slot)
+    {
+      vtoe = XNEW (struct vop_to_refs_elt);
+      vtoe->uid = vop;
+      vtoe->refs_all = BITMAP_ALLOC (NULL);
+      vtoe->refs_stored = BITMAP_ALLOC (NULL);
+      *slot = vtoe;
+    }
+  else
+    vtoe = (struct vop_to_refs_elt *) *slot;
+
+  bitmap_set_bit (vtoe->refs_all, ref);
+  if (stored)
+    bitmap_set_bit (vtoe->refs_stored, ref);
+}
+
+/* Returns the set of references that access VOP according to the table
+   VOP_TO_REFS.  */
+
+static bitmap
+get_vop_accesses (htab_t vop_to_refs, unsigned vop)
+{
+  struct vop_to_refs_elt *const vtoe =
+    (struct vop_to_refs_elt *) htab_find_with_hash (vop_to_refs, &vop, vop);
+  return vtoe->refs_all;
+}
+
+/* Returns the set of stores that access VOP according to the table
+   VOP_TO_REFS.  */
+
+static bitmap
+get_vop_stores (htab_t vop_to_refs, unsigned vop)
+{
+  struct vop_to_refs_elt *const vtoe =
+    (struct vop_to_refs_elt *) htab_find_with_hash (vop_to_refs, &vop, vop);
+  return vtoe->refs_stored;
+}
+
+/* Adds REF to mapping from virtual operands to references in LOOP.  */
+
+static void
+add_vop_ref_mapping (struct loop *loop, mem_ref_p ref)
+{
+  htab_t map = VEC_index (htab_t, memory_accesses.vop_ref_map, loop->num);
+  bool stored = bitmap_bit_p (ref->stored, loop->num);
+  bitmap clobbers = VEC_index (bitmap, memory_accesses.clobbered_vops,
+			       loop->num);
+  bitmap_iterator bi;
+  unsigned vop;
+
+  EXECUTE_IF_AND_COMPL_IN_BITMAP (ref->vops, clobbers, 0, vop, bi)
+    {
+      record_vop_access (map, vop, ref->id, stored);
+    }
+}
+
+/* Create a mapping from virtual operands to references that touch them
+   in LOOP.  */
+
+static void
+create_vop_ref_mapping_loop (struct loop *loop)
+{
+  bitmap refs = VEC_index (bitmap, memory_accesses.refs_in_loop, loop->num);
+  struct loop *sloop;
+  bitmap_iterator bi;
+  unsigned i;
+  mem_ref_p ref;
+
+  EXECUTE_IF_SET_IN_BITMAP (refs, 0, i, bi)
+    {
+      ref = VEC_index (mem_ref_p, memory_accesses.refs_list, i);
+      for (sloop = loop; sloop != current_loops->tree_root; sloop = loop_outer (sloop))
+	add_vop_ref_mapping (sloop, ref);
+    }
+}
+
+/* For each non-clobbered virtual operand and each loop, record the memory
+   references in this loop that touch the operand.  */
+
+static void
+create_vop_ref_mapping (void)
+{
+  loop_iterator li;
+  struct loop *loop;
+
+  FOR_EACH_LOOP (li, loop, 0)
+    {
+      create_vop_ref_mapping_loop (loop);
+    }
+}
+
+/* Gathers information about memory accesses in the loops.  */
+
+static void
+analyze_memory_references (void)
+{
+  unsigned i;
+  bitmap empty;
+  htab_t hempty;
+
+  memory_accesses.refs
+	  = htab_create (100, memref_hash, memref_eq, memref_free);
+  memory_accesses.refs_list = NULL;
+  memory_accesses.refs_in_loop = VEC_alloc (bitmap, heap,
+					    number_of_loops ());
+  memory_accesses.all_refs_in_loop = VEC_alloc (bitmap, heap,
+						number_of_loops ());
+  memory_accesses.clobbered_vops = VEC_alloc (bitmap, heap,
+					      number_of_loops ());
+  memory_accesses.vop_ref_map = VEC_alloc (htab_t, heap,
+					   number_of_loops ());
+
+  for (i = 0; i < number_of_loops (); i++)
+    {
+      empty = BITMAP_ALLOC (NULL);
+      VEC_quick_push (bitmap, memory_accesses.refs_in_loop, empty);
+      empty = BITMAP_ALLOC (NULL);
+      VEC_quick_push (bitmap, memory_accesses.all_refs_in_loop, empty);
+      empty = BITMAP_ALLOC (NULL);
+      VEC_quick_push (bitmap, memory_accesses.clobbered_vops, empty);
+      hempty = htab_create (10, vtoe_hash, vtoe_eq, vtoe_free);
+      VEC_quick_push (htab_t, memory_accesses.vop_ref_map, hempty);
+    }
+
+  memory_accesses.ttae_cache = NULL;
+
+  gather_mem_refs_in_loops ();
+  create_vop_ref_mapping ();
+}
+
+/* Returns true if a region of size SIZE1 at position 0 and a region of
+   size SIZE2 at position DIFF cannot overlap.  */
+
+static bool
+cannot_overlap_p (aff_tree *diff, double_int size1, double_int size2)
+{
+  double_int d, bound;
+
+  /* Unless the difference is a constant, we fail.  */
+  if (diff->n != 0)
+    return false;
+
+  d = diff->offset;
+  if (double_int_negative_p (d))
+    {
+      /* The second object is before the first one, we succeed if the last
+	 element of the second object is before the start of the first one.  */
+      bound = double_int_add (d, double_int_add (size2, double_int_minus_one));
+      return double_int_negative_p (bound);
+    }
+  else
+    {
+      /* We succeed if the second object starts after the first one ends.  */
+      return double_int_scmp (size1, d) <= 0;
+    }
+}
+
+/* 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 (tree mem1, tree 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 (mem1, mem2))
+    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, &off1, &size1);
+  get_inner_reference_aff (mem2, &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 (cannot_overlap_p (&off2, size1, size2))
+    return false;
+
+  return true;
+}
+
+/* Rewrites location LOC by TMP_VAR.  */
+
+static void
+rewrite_mem_ref_loc (mem_ref_loc_p loc, tree tmp_var)
+{
+  mark_virtual_ops_for_renaming (loc->stmt);
+  *loc->ref = tmp_var;
+  update_stmt (loc->stmt);
+}
+
+/* Adds all locations of REF in LOOP and its subloops to LOCS.  */
+
+static void
+get_all_locs_in_loop (struct loop *loop, mem_ref_p ref,
+		      VEC (mem_ref_loc_p, heap) **locs)
+{
+  mem_ref_locs_p accs;
+  unsigned i;
+  mem_ref_loc_p loc;
+  bitmap refs = VEC_index (bitmap, memory_accesses.all_refs_in_loop,
+			   loop->num);
+  struct loop *subloop;
+
+  if (!bitmap_bit_p (refs, ref->id))
+    return;
+
+  if (VEC_length (mem_ref_locs_p, ref->accesses_in_loop)
+      > (unsigned) loop->num)
+    {
+      accs = VEC_index (mem_ref_locs_p, ref->accesses_in_loop, loop->num);
+      if (accs)
+	{
+	  for (i = 0; VEC_iterate (mem_ref_loc_p, accs->locs, i, loc); i++)
+	    VEC_safe_push (mem_ref_loc_p, heap, *locs, loc);
+	}
+    }
+
+  for (subloop = loop->inner; subloop != NULL; subloop = subloop->next)
+    get_all_locs_in_loop (subloop, ref, locs);
+}
+
+/* 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)
+{
+  unsigned i;
+  mem_ref_loc_p loc;
+  VEC (mem_ref_loc_p, heap) *locs = NULL;
+
+  get_all_locs_in_loop (loop, ref, &locs);
+  for (i = 0; VEC_iterate (mem_ref_loc_p, locs, i, loc); i++)
+    rewrite_mem_ref_loc (loc, tmp_var);
+  VEC_free (mem_ref_loc_p, heap, locs);
+}
+
+/* The name and the length of the currently generated variable
+   for lsm.  */
+#define MAX_LSM_NAME_LENGTH 40
+static char lsm_tmp_name[MAX_LSM_NAME_LENGTH + 1];
+static int lsm_tmp_name_length;
+
+/* Adds S to lsm_tmp_name.  */
+
+static void
+lsm_tmp_name_add (const char *s)
+{
+  int l = strlen (s) + lsm_tmp_name_length;
+  if (l > MAX_LSM_NAME_LENGTH)
+    return;
+
+  strcpy (lsm_tmp_name + lsm_tmp_name_length, s);
+  lsm_tmp_name_length = l;
+}
+
+/* Stores the name for temporary variable that replaces REF to
+   lsm_tmp_name.  */
+
+static void
+gen_lsm_tmp_name (tree ref)
+{
+  const char *name;
+
+  switch (TREE_CODE (ref))
+    {
+    case MISALIGNED_INDIRECT_REF:
+    case ALIGN_INDIRECT_REF:
+    case INDIRECT_REF:
+      gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
+      lsm_tmp_name_add ("_");
+      break;
+
+    case BIT_FIELD_REF:
+    case VIEW_CONVERT_EXPR:
+    case ARRAY_RANGE_REF:
+      gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
+      break;
+
+    case REALPART_EXPR:
+      gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
+      lsm_tmp_name_add ("_RE");
+      break;
+      
+    case IMAGPART_EXPR:
+      gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
+      lsm_tmp_name_add ("_IM");
+      break;
+
+    case COMPONENT_REF:
+      gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
+      lsm_tmp_name_add ("_");
+      name = get_name (TREE_OPERAND (ref, 1));
+      if (!name)
+	name = "F";
+      lsm_tmp_name_add ("_");
+      lsm_tmp_name_add (name);
+
+    case ARRAY_REF:
+      gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
+      lsm_tmp_name_add ("_I");
+      break;
+
+    case SSA_NAME:
+      ref = SSA_NAME_VAR (ref);
+      /* Fallthru.  */
+
+    case VAR_DECL:
+    case PARM_DECL:
+      name = get_name (ref);
+      if (!name)
+	name = "D";
+      lsm_tmp_name_add (name);
+      break;
+
+    case STRING_CST:
+      lsm_tmp_name_add ("S");
+      break;
+
+    case RESULT_DECL:
+      lsm_tmp_name_add ("R");
+      break;
+
+    default:
+      gcc_unreachable ();
+    }
+}
+
+/* Determines name for temporary variable that replaces REF.
+   The name is accumulated into the lsm_tmp_name variable.
+   N is added to the name of the temporary.  */
+
+char *
+get_lsm_tmp_name (tree ref, unsigned n)
+{
+  char ns[2];
+
+  lsm_tmp_name_length = 0;
+  gen_lsm_tmp_name (ref);
+  lsm_tmp_name_add ("_lsm");
+  if (n < 10)
+    {
+      ns[0] = '0' + n;
+      ns[1] = 0;
+      lsm_tmp_name_add (ns);
+    }
+  return lsm_tmp_name;
+}
+
+/* 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, heap) *exits, mem_ref_p ref)
+{
+  tree tmp_var;
+  unsigned i;
+  gimple load, store;
+  struct fmt_data fmt_data;
+  edge ex;
+  struct lim_aux_data *lim_data;
+
+  if (dump_file && (dump_flags & TDF_DETAILS))
+    {
+      fprintf (dump_file, "Executing store motion of ");
+      print_generic_expr (dump_file, ref->mem, 0);
+      fprintf (dump_file, " from loop %d\n", loop->num);
+    }
+
+  tmp_var = make_rename_temp (TREE_TYPE (ref->mem),
+			      get_lsm_tmp_name (ref->mem, ~0));
+
+  fmt_data.loop = loop;
+  fmt_data.orig_loop = loop;
+  for_each_index (&ref->mem, force_move_till, &fmt_data);
+
+  rewrite_mem_refs (loop, ref, tmp_var);
+
+  /* Emit the load & stores.  */
+  load = gimple_build_assign (tmp_var, unshare_expr (ref->mem));
+  lim_data = init_lim_data (load);
+  lim_data->max_loop = loop;
+  lim_data->tgt_loop = loop;
+
+  /* Put this into the latch, so that we are sure it will be processed after
+     all dependencies.  */
+  gsi_insert_on_edge (loop_latch_edge (loop), load);
+
+  for (i = 0; VEC_iterate (edge, exits, i, ex); i++)
+    {
+      store = gimple_build_assign (unshare_expr (ref->mem), tmp_var);
+      gsi_insert_on_edge (ex, store);
+    }
+}
+
+/* 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, heap) *exits)
+{
+  mem_ref_p ref;
+  unsigned  i;
+  bitmap_iterator bi;
+
+  EXECUTE_IF_SET_IN_BITMAP (mem_refs, 0, i, bi)
+    {
+      ref = VEC_index (mem_ref_p, memory_accesses.refs_list, i);
+      execute_sm (loop, exits, ref);
+    }
+}
+
+/* Returns true if REF is always accessed in LOOP.  */
+
+static bool
+ref_always_accessed_p (struct loop *loop, mem_ref_p ref)
+{
+  VEC (mem_ref_loc_p, heap) *locs = NULL;
+  unsigned i;
+  mem_ref_loc_p loc;
+  bool ret = false;
+  struct loop *must_exec;
+
+  get_all_locs_in_loop (loop, ref, &locs);
+  for (i = 0; VEC_iterate (mem_ref_loc_p, locs, i, loc); i++)
+    {
+      if (!get_lim_data (loc->stmt))
+	continue;
+
+      must_exec = get_lim_data (loc->stmt)->always_executed_in;
+      if (!must_exec)
+	continue;
+
+      if (must_exec == loop
+	  || flow_loop_nested_p (must_exec, loop))
+	{
+	  ret = true;
+	  break;
+	}
+    }
+  VEC_free (mem_ref_loc_p, heap, locs);
+
+  return ret;
+}
+
+/* Returns true if REF1 and REF2 are independent.  */
+
+static bool
+refs_independent_p (mem_ref_p ref1, mem_ref_p ref2)
+{
+  if (ref1 == ref2
+      || bitmap_bit_p (ref1->indep_ref, ref2->id))
+    return true;
+  if (bitmap_bit_p (ref1->dep_ref, ref2->id))
+    return false;
+
+  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->mem, ref2->mem,
+			    &memory_accesses.ttae_cache))
+    {
+      bitmap_set_bit (ref1->dep_ref, ref2->id);
+      bitmap_set_bit (ref2->dep_ref, ref1->id);
+      if (dump_file && (dump_flags & TDF_DETAILS))
+	fprintf (dump_file, "dependent.\n");
+      return false;
+    }
+  else
+    {
+      bitmap_set_bit (ref1->indep_ref, ref2->id);
+      bitmap_set_bit (ref2->indep_ref, ref1->id);
+      if (dump_file && (dump_flags & TDF_DETAILS))
+	fprintf (dump_file, "independent.\n");
+      return true;
+    }
+}
+
+/* Records the information whether REF is independent in LOOP (according
+   to INDEP).  */
+
+static void
+record_indep_loop (struct loop *loop, mem_ref_p ref, bool indep)
+{
+  if (indep)
+    bitmap_set_bit (ref->indep_loop, loop->num);
+  else
+    bitmap_set_bit (ref->dep_loop, loop->num);
+}
+
+/* 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)
+{
+  bitmap clobbers, refs_to_check, refs;
+  unsigned i;
+  bitmap_iterator bi;
+  bool ret = true, stored = bitmap_bit_p (ref->stored, loop->num);
+  htab_t map;
+  mem_ref_p aref;
+
+  /* If the reference is clobbered, it is not independent.  */
+  clobbers = VEC_index (bitmap, memory_accesses.clobbered_vops, loop->num);
+  if (bitmap_intersect_p (ref->vops, clobbers))
+    return false;
+
+  refs_to_check = BITMAP_ALLOC (NULL);
+
+  map = VEC_index (htab_t, memory_accesses.vop_ref_map, loop->num);
+  EXECUTE_IF_AND_COMPL_IN_BITMAP (ref->vops, clobbers, 0, i, bi)
+    {
+      if (stored)
+	refs = get_vop_accesses (map, i);
+      else
+	refs = get_vop_stores (map, i);
+
+      bitmap_ior_into (refs_to_check, refs);
+    }
+
+  EXECUTE_IF_SET_IN_BITMAP (refs_to_check, 0, i, bi)
+    {
+      aref = VEC_index (mem_ref_p, memory_accesses.refs_list, i);
+      if (!refs_independent_p (ref, aref))
+	{
+	  ret = false;
+	  record_indep_loop (loop, aref, false);
+	  break;
+	}
+    }
+
+  BITMAP_FREE (refs_to_check);
+  return ret;
+}
+
+/* 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 (struct loop *loop, mem_ref_p ref)
+{
+  bool ret;
+
+  if (bitmap_bit_p (ref->indep_loop, loop->num))
+    return true;
+  if (bitmap_bit_p (ref->dep_loop, loop->num))
+    return false;
+
+  ret = ref_indep_loop_p_1 (loop, ref);
+
+  if (dump_file && (dump_flags & TDF_DETAILS))
+    fprintf (dump_file, "Querying dependencies of ref %u in loop %d: %s\n",
+	     ref->id, loop->num, ret ? "independent" : "dependent");
+
+  record_indep_loop (loop, ref, ret);
+
+  return ret;
+}
+
+/* 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)
+{
+  /* Unless the reference is stored in the loop, there is nothing to do.  */
+  if (!bitmap_bit_p (ref->stored, loop->num))
+    return false;
+
+  /* It should be movable.  */
+  if (!is_gimple_reg_type (TREE_TYPE (ref->mem))
+      || TREE_THIS_VOLATILE (ref->mem)
+      || !for_each_index (&ref->mem, may_move_till, loop))
+    return false;
+
+  /* If it can trap, it must be always executed in LOOP.  */
+  if (tree_could_trap_p (ref->mem)
+      && !ref_always_accessed_p (loop, ref))
+    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 = VEC_index (bitmap, memory_accesses.all_refs_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 = VEC_index (mem_ref_p, 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, heap) *exits)
+{
+  unsigned i;
+  edge ex;
+
+  for (i = 0; VEC_iterate (edge, exits, i, ex); i++)
+    if (ex->flags & EDGE_ABNORMAL)
+      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, heap) *exits = get_loop_exit_edges (loop);
+  struct loop *subloop;
+  bitmap sm_in_loop = BITMAP_ALLOC (NULL);
+
+  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);
+    }
+  VEC_free (edge, heap, exits);
+
+  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 (NULL);
+
+  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 (struct loop *loop, sbitmap contains_call)
+{
+  basic_block bb = NULL, *bbs, last = NULL;
+  unsigned i;
+  edge e;
+  struct loop *inn_loop = loop;
+
+  if (!loop->header->aux)
+    {
+      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 (TEST_BIT (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)
+	{
+	  last->aux = 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 (loop, contains_call);
+}
+
+/* Compute the global information needed by the loop invariant motion pass.  */
+
+static void
+tree_ssa_lim_initialize (void)
+{
+  sbitmap contains_call = sbitmap_alloc (last_basic_block);
+  gimple_stmt_iterator bsi;
+  struct loop *loop;
+  basic_block bb;
+
+  sbitmap_zero (contains_call);
+  FOR_EACH_BB (bb)
+    {
+      for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
+	{
+	  if (nonpure_call_p (gsi_stmt (bsi)))
+	    break;
+	}
+
+      if (!gsi_end_p (bsi))
+	SET_BIT (contains_call, bb->index);
+    }
+
+  for (loop = current_loops->tree_root->inner; loop; loop = loop->next)
+    fill_always_executed_in (loop, contains_call);
+
+  sbitmap_free (contains_call);
+
+  lim_aux_data_map = pointer_map_create ();
+}
+
+/* Cleans up after the invariant motion pass.  */
+
+static void
+tree_ssa_lim_finalize (void)
+{
+  basic_block bb;
+  unsigned i;
+  bitmap b;
+  htab_t h;
+
+  FOR_EACH_BB (bb)
+    {
+      bb->aux = NULL;
+    }
+
+  pointer_map_destroy (lim_aux_data_map);
+
+  VEC_free (mem_ref_p, heap, memory_accesses.refs_list);
+  htab_delete (memory_accesses.refs);
+
+  for (i = 0; VEC_iterate (bitmap, memory_accesses.refs_in_loop, i, b); i++)
+    BITMAP_FREE (b);
+  VEC_free (bitmap, heap, memory_accesses.refs_in_loop);
+
+  for (i = 0; VEC_iterate (bitmap, memory_accesses.all_refs_in_loop, i, b); i++)
+    BITMAP_FREE (b);
+  VEC_free (bitmap, heap, memory_accesses.all_refs_in_loop);
+
+  for (i = 0; VEC_iterate (bitmap, memory_accesses.clobbered_vops, i, b); i++)
+    BITMAP_FREE (b);
+  VEC_free (bitmap, heap, memory_accesses.clobbered_vops);
+
+  for (i = 0; VEC_iterate (htab_t, memory_accesses.vop_ref_map, i, h); i++)
+    htab_delete (h);
+  VEC_free (htab_t, heap, memory_accesses.vop_ref_map);
+
+  if (memory_accesses.ttae_cache)
+    pointer_map_destroy (memory_accesses.ttae_cache);
+}
+
+/* Moves invariants from loops.  Only "expensive" invariants are moved out --
+   i.e. those that are likely to be win regardless of the register pressure.  */
+
+void
+tree_ssa_lim (void)
+{
+  tree_ssa_lim_initialize ();
+
+  /* Gathers information about memory accesses in the loops.  */
+  analyze_memory_references ();
+
+  /* For each statement determine the outermost loop in that it is
+     invariant and cost for computing the invariant.  */
+  determine_invariantness ();
+
+  /* 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.  */
+  move_computations ();
+
+  tree_ssa_lim_finalize ();
+}