Delete old versions of GCC.

Change-Id: I710f125d905290e1024cbd67f48299861790c66c

1 files changed, 0 insertions, 1601 deletions

diff --git a/gcc-4.4.0/gcc/tree-ssa-loop-prefetch.c b/gcc-4.4.0/gcc/tree-ssa-loop-prefetch.c
deleted file mode 100644
index d0e460cf9..000000000
--- a/gcc-4.4.0/gcc/tree-ssa-loop-prefetch.c
+++ /dev/null
@@ -1,1601 +0,0 @@
-/* Array prefetching.
-   Copyright (C) 2005, 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 "varray.h"
-#include "expr.h"
-#include "tree-pass.h"
-#include "ggc.h"
-#include "insn-config.h"
-#include "recog.h"
-#include "hashtab.h"
-#include "tree-chrec.h"
-#include "tree-scalar-evolution.h"
-#include "toplev.h"
-#include "params.h"
-#include "langhooks.h"
-#include "tree-inline.h"
-#include "tree-data-ref.h"
-#include "optabs.h"
-
-/* This pass inserts prefetch instructions to optimize cache usage during
-   accesses to arrays in loops.  It processes loops sequentially and:
-
-   1) Gathers all memory references in the single loop.
-   2) For each of the references it decides when it is profitable to prefetch
-      it.  To do it, we evaluate the reuse among the accesses, and determines
-      two values: PREFETCH_BEFORE (meaning that it only makes sense to do
-      prefetching in the first PREFETCH_BEFORE iterations of the loop) and
-      PREFETCH_MOD (meaning that it only makes sense to prefetch in the
-      iterations of the loop that are zero modulo PREFETCH_MOD).  For example
-      (assuming cache line size is 64 bytes, char has size 1 byte and there
-      is no hardware sequential prefetch):
-
-      char *a;
-      for (i = 0; i < max; i++)
-	{
-	  a[255] = ...;		(0)
-	  a[i] = ...;		(1)
-	  a[i + 64] = ...;	(2)
-	  a[16*i] = ...;	(3)
-	  a[187*i] = ...;	(4)
-	  a[187*i + 50] = ...;	(5)
-	}
-
-       (0) obviously has PREFETCH_BEFORE 1
-       (1) has PREFETCH_BEFORE 64, since (2) accesses the same memory
-           location 64 iterations before it, and PREFETCH_MOD 64 (since
-	   it hits the same cache line otherwise).
-       (2) has PREFETCH_MOD 64
-       (3) has PREFETCH_MOD 4
-       (4) has PREFETCH_MOD 1.  We do not set PREFETCH_BEFORE here, since
-           the cache line accessed by (4) is the same with probability only
-	   7/32.
-       (5) has PREFETCH_MOD 1 as well.
-
-      Additionally, we use data dependence analysis to determine for each
-      reference the distance till the first reuse; this information is used
-      to determine the temporality of the issued prefetch instruction.
-
-   3) We determine how much ahead we need to prefetch.  The number of
-      iterations needed is time to fetch / time spent in one iteration of
-      the loop.  The problem is that we do not know either of these values,
-      so we just make a heuristic guess based on a magic (possibly)
-      target-specific constant and size of the loop.
-
-   4) Determine which of the references we prefetch.  We take into account
-      that there is a maximum number of simultaneous prefetches (provided
-      by machine description).  We prefetch as many prefetches as possible
-      while still within this bound (starting with those with lowest
-      prefetch_mod, since they are responsible for most of the cache
-      misses).
-      
-   5) We unroll and peel loops so that we are able to satisfy PREFETCH_MOD
-      and PREFETCH_BEFORE requirements (within some bounds), and to avoid
-      prefetching nonaccessed memory.
-      TODO -- actually implement peeling.
-      
-   6) We actually emit the prefetch instructions.  ??? Perhaps emit the
-      prefetch instructions with guards in cases where 5) was not sufficient
-      to satisfy the constraints?
-
-   Some other TODO:
-      -- write and use more general reuse analysis (that could be also used
-	 in other cache aimed loop optimizations)
-      -- make it behave sanely together with the prefetches given by user
-	 (now we just ignore them; at the very least we should avoid
-	 optimizing loops in that user put his own prefetches)
-      -- we assume cache line size alignment of arrays; this could be
-	 improved.  */
-
-/* Magic constants follow.  These should be replaced by machine specific
-   numbers.  */
-
-/* True if write can be prefetched by a read prefetch.  */
-
-#ifndef WRITE_CAN_USE_READ_PREFETCH
-#define WRITE_CAN_USE_READ_PREFETCH 1
-#endif
-
-/* True if read can be prefetched by a write prefetch. */
-
-#ifndef READ_CAN_USE_WRITE_PREFETCH
-#define READ_CAN_USE_WRITE_PREFETCH 0
-#endif
-
-/* The size of the block loaded by a single prefetch.  Usually, this is
-   the same as cache line size (at the moment, we only consider one level
-   of cache hierarchy).  */
-
-#ifndef PREFETCH_BLOCK
-#define PREFETCH_BLOCK L1_CACHE_LINE_SIZE
-#endif
-
-/* Do we have a forward hardware sequential prefetching?  */
-
-#ifndef HAVE_FORWARD_PREFETCH
-#define HAVE_FORWARD_PREFETCH 0
-#endif
-
-/* Do we have a backward hardware sequential prefetching?  */
-
-#ifndef HAVE_BACKWARD_PREFETCH
-#define HAVE_BACKWARD_PREFETCH 0
-#endif
-
-/* In some cases we are only able to determine that there is a certain
-   probability that the two accesses hit the same cache line.  In this
-   case, we issue the prefetches for both of them if this probability
-   is less then (1000 - ACCEPTABLE_MISS_RATE) per thousand.  */
-
-#ifndef ACCEPTABLE_MISS_RATE
-#define ACCEPTABLE_MISS_RATE 50
-#endif
-
-#ifndef HAVE_prefetch
-#define HAVE_prefetch 0
-#endif
-
-#define L1_CACHE_SIZE_BYTES ((unsigned) (L1_CACHE_SIZE * 1024))
-#define L2_CACHE_SIZE_BYTES ((unsigned) (L2_CACHE_SIZE * 1024))
-
-/* We consider a memory access nontemporal if it is not reused sooner than
-   after L2_CACHE_SIZE_BYTES of memory are accessed.  However, we ignore
-   accesses closer than L1_CACHE_SIZE_BYTES / NONTEMPORAL_FRACTION,
-   so that we use nontemporal prefetches e.g. if single memory location
-   is accessed several times in a single iteration of the loop.  */
-#define NONTEMPORAL_FRACTION 16
-
-/* In case we have to emit a memory fence instruction after the loop that
-   uses nontemporal stores, this defines the builtin to use.  */
-
-#ifndef FENCE_FOLLOWING_MOVNT
-#define FENCE_FOLLOWING_MOVNT NULL_TREE
-#endif
-
-/* The group of references between that reuse may occur.  */
-
-struct mem_ref_group
-{
-  tree base;			/* Base of the reference.  */
-  HOST_WIDE_INT step;		/* Step of the reference.  */
-  struct mem_ref *refs;		/* References in the group.  */
-  struct mem_ref_group *next;	/* Next group of references.  */
-};
-
-/* Assigned to PREFETCH_BEFORE when all iterations are to be prefetched.  */
-
-#define PREFETCH_ALL		(~(unsigned HOST_WIDE_INT) 0)
-
-/* The memory reference.  */
-
-struct mem_ref
-{
-  gimple stmt;			/* Statement in that the reference appears.  */
-  tree mem;			/* The reference.  */
-  HOST_WIDE_INT delta;		/* Constant offset of the reference.  */
-  struct mem_ref_group *group;	/* The group of references it belongs to.  */
-  unsigned HOST_WIDE_INT prefetch_mod;
-				/* Prefetch only each PREFETCH_MOD-th
-				   iteration.  */
-  unsigned HOST_WIDE_INT prefetch_before;
-				/* Prefetch only first PREFETCH_BEFORE
-				   iterations.  */
-  unsigned reuse_distance;	/* The amount of data accessed before the first
-				   reuse of this value.  */
-  struct mem_ref *next;		/* The next reference in the group.  */
-  unsigned write_p : 1;		/* Is it a write?  */
-  unsigned independent_p : 1;	/* True if the reference is independent on
-				   all other references inside the loop.  */
-  unsigned issue_prefetch_p : 1;	/* Should we really issue the prefetch?  */
-  unsigned storent_p : 1;	/* True if we changed the store to a
-				   nontemporal one.  */
-};
-
-/* Dumps information about reference REF to FILE.  */
-
-static void
-dump_mem_ref (FILE *file, struct mem_ref *ref)
-{
-  fprintf (file, "Reference %p:\n", (void *) ref);
-
-  fprintf (file, "  group %p (base ", (void *) ref->group);
-  print_generic_expr (file, ref->group->base, TDF_SLIM);
-  fprintf (file, ", step ");
-  fprintf (file, HOST_WIDE_INT_PRINT_DEC, ref->group->step);
-  fprintf (file, ")\n");
-
-  fprintf (file, "  delta ");
-  fprintf (file, HOST_WIDE_INT_PRINT_DEC, ref->delta);
-  fprintf (file, "\n");
-
-  fprintf (file, "  %s\n", ref->write_p ? "write" : "read");
-
-  fprintf (file, "\n");
-}
-
-/* Finds a group with BASE and STEP in GROUPS, or creates one if it does not
-   exist.  */
-
-static struct mem_ref_group *
-find_or_create_group (struct mem_ref_group **groups, tree base,
-		      HOST_WIDE_INT step)
-{
-  struct mem_ref_group *group;
-
-  for (; *groups; groups = &(*groups)->next)
-    {
-      if ((*groups)->step == step
-	  && operand_equal_p ((*groups)->base, base, 0))
-	return *groups;
-
-      /* Keep the list of groups sorted by decreasing step.  */
-      if ((*groups)->step < step)
-	break;
-    }
-
-  group = XNEW (struct mem_ref_group);
-  group->base = base;
-  group->step = step;
-  group->refs = NULL;
-  group->next = *groups;
-  *groups = group;
-
-  return group;
-}
-
-/* Records a memory reference MEM in GROUP with offset DELTA and write status
-   WRITE_P.  The reference occurs in statement STMT.  */
-
-static void
-record_ref (struct mem_ref_group *group, gimple stmt, tree mem,
-	    HOST_WIDE_INT delta, bool write_p)
-{
-  struct mem_ref **aref;
-
-  /* Do not record the same address twice.  */
-  for (aref = &group->refs; *aref; aref = &(*aref)->next)
-    {
-      /* It does not have to be possible for write reference to reuse the read
-	 prefetch, or vice versa.  */
-      if (!WRITE_CAN_USE_READ_PREFETCH
-	  && write_p
-	  && !(*aref)->write_p)
-	continue;
-      if (!READ_CAN_USE_WRITE_PREFETCH
-	  && !write_p
-	  && (*aref)->write_p)
-	continue;
-
-      if ((*aref)->delta == delta)
-	return;
-    }
-
-  (*aref) = XNEW (struct mem_ref);
-  (*aref)->stmt = stmt;
-  (*aref)->mem = mem;
-  (*aref)->delta = delta;
-  (*aref)->write_p = write_p;
-  (*aref)->prefetch_before = PREFETCH_ALL;
-  (*aref)->prefetch_mod = 1;
-  (*aref)->reuse_distance = 0;
-  (*aref)->issue_prefetch_p = false;
-  (*aref)->group = group;
-  (*aref)->next = NULL;
-  (*aref)->independent_p = false;
-  (*aref)->storent_p = false;
-
-  if (dump_file && (dump_flags & TDF_DETAILS))
-    dump_mem_ref (dump_file, *aref);
-}
-
-/* Release memory references in GROUPS.  */
-
-static void
-release_mem_refs (struct mem_ref_group *groups)
-{
-  struct mem_ref_group *next_g;
-  struct mem_ref *ref, *next_r;
-
-  for (; groups; groups = next_g)
-    {
-      next_g = groups->next;
-      for (ref = groups->refs; ref; ref = next_r)
-	{
-	  next_r = ref->next;
-	  free (ref);
-	}
-      free (groups);
-    }
-}
-
-/* A structure used to pass arguments to idx_analyze_ref.  */
-
-struct ar_data
-{
-  struct loop *loop;			/* Loop of the reference.  */
-  gimple stmt;				/* Statement of the reference.  */
-  HOST_WIDE_INT *step;			/* Step of the memory reference.  */
-  HOST_WIDE_INT *delta;			/* Offset of the memory reference.  */
-};
-
-/* Analyzes a single INDEX of a memory reference to obtain information
-   described at analyze_ref.  Callback for for_each_index.  */
-
-static bool
-idx_analyze_ref (tree base, tree *index, void *data)
-{
-  struct ar_data *ar_data = (struct ar_data *) data;
-  tree ibase, step, stepsize;
-  HOST_WIDE_INT istep, idelta = 0, imult = 1;
-  affine_iv iv;
-
-  if (TREE_CODE (base) == MISALIGNED_INDIRECT_REF
-      || TREE_CODE (base) == ALIGN_INDIRECT_REF)
-    return false;
-
-  if (!simple_iv (ar_data->loop, loop_containing_stmt (ar_data->stmt),
-		  *index, &iv, false))
-    return false;
-  ibase = iv.base;
-  step = iv.step;
-
-  if (!cst_and_fits_in_hwi (step))
-    return false;
-  istep = int_cst_value (step);
-
-  if (TREE_CODE (ibase) == POINTER_PLUS_EXPR
-      && cst_and_fits_in_hwi (TREE_OPERAND (ibase, 1)))
-    {
-      idelta = int_cst_value (TREE_OPERAND (ibase, 1));
-      ibase = TREE_OPERAND (ibase, 0);
-    }
-  if (cst_and_fits_in_hwi (ibase))
-    {
-      idelta += int_cst_value (ibase);
-      ibase = build_int_cst (TREE_TYPE (ibase), 0);
-    }
-
-  if (TREE_CODE (base) == ARRAY_REF)
-    {
-      stepsize = array_ref_element_size (base);
-      if (!cst_and_fits_in_hwi (stepsize))
-	return false;
-      imult = int_cst_value (stepsize);
-
-      istep *= imult;
-      idelta *= imult;
-    }
-
-  *ar_data->step += istep;
-  *ar_data->delta += idelta;
-  *index = ibase;
-
-  return true;
-}
-
-/* Tries to express REF_P in shape &BASE + STEP * iter + DELTA, where DELTA and
-   STEP are integer constants and iter is number of iterations of LOOP.  The
-   reference occurs in statement STMT.  Strips nonaddressable component
-   references from REF_P.  */
-
-static bool
-analyze_ref (struct loop *loop, tree *ref_p, tree *base,
-	     HOST_WIDE_INT *step, HOST_WIDE_INT *delta,
-	     gimple stmt)
-{
-  struct ar_data ar_data;
-  tree off;
-  HOST_WIDE_INT bit_offset;
-  tree ref = *ref_p;
-
-  *step = 0;
-  *delta = 0;
-
-  /* First strip off the component references.  Ignore bitfields.  */
-  if (TREE_CODE (ref) == COMPONENT_REF
-      && DECL_NONADDRESSABLE_P (TREE_OPERAND (ref, 1)))
-    ref = TREE_OPERAND (ref, 0);
-
-  *ref_p = ref;
-
-  for (; TREE_CODE (ref) == COMPONENT_REF; ref = TREE_OPERAND (ref, 0))
-    {
-      off = DECL_FIELD_BIT_OFFSET (TREE_OPERAND (ref, 1));
-      bit_offset = TREE_INT_CST_LOW (off);
-      gcc_assert (bit_offset % BITS_PER_UNIT == 0);
-      
-      *delta += bit_offset / BITS_PER_UNIT;
-    }
-
-  *base = unshare_expr (ref);
-  ar_data.loop = loop;
-  ar_data.stmt = stmt;
-  ar_data.step = step;
-  ar_data.delta = delta;
-  return for_each_index (base, idx_analyze_ref, &ar_data);
-}
-
-/* Record a memory reference REF to the list REFS.  The reference occurs in
-   LOOP in statement STMT and it is write if WRITE_P.  Returns true if the
-   reference was recorded, false otherwise.  */
-
-static bool
-gather_memory_references_ref (struct loop *loop, struct mem_ref_group **refs,
-			      tree ref, bool write_p, gimple stmt)
-{
-  tree base;
-  HOST_WIDE_INT step, delta;
-  struct mem_ref_group *agrp;
-
-  if (get_base_address (ref) == NULL)
-    return false;
-
-  if (!analyze_ref (loop, &ref, &base, &step, &delta, stmt))
-    return false;
-
-  /* Now we know that REF = &BASE + STEP * iter + DELTA, where DELTA and STEP
-     are integer constants.  */
-  agrp = find_or_create_group (refs, base, step);
-  record_ref (agrp, stmt, ref, delta, write_p);
-
-  return true;
-}
-
-/* Record the suitable memory references in LOOP.  NO_OTHER_REFS is set to
-   true if there are no other memory references inside the loop.  */
-
-static struct mem_ref_group *
-gather_memory_references (struct loop *loop, bool *no_other_refs)
-{
-  basic_block *body = get_loop_body_in_dom_order (loop);
-  basic_block bb;
-  unsigned i;
-  gimple_stmt_iterator bsi;
-  gimple stmt;
-  tree lhs, rhs;
-  struct mem_ref_group *refs = NULL;
-
-  *no_other_refs = true;
-
-  /* Scan the loop body in order, so that the former references precede the
-     later ones.  */
-  for (i = 0; i < loop->num_nodes; i++)
-    {
-      bb = body[i];
-      if (bb->loop_father != loop)
-	continue;
-
-      for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
-	{
-	  stmt = gsi_stmt (bsi);
-
-	  if (gimple_code (stmt) != GIMPLE_ASSIGN)
-	    {
-	      if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS)
-		  || (is_gimple_call (stmt)
-		      && !(gimple_call_flags (stmt) & ECF_CONST)))
-		*no_other_refs = false;
-	      continue;
-	    }
-
-	  lhs = gimple_assign_lhs (stmt);
-	  rhs = gimple_assign_rhs1 (stmt);
-
-	  if (REFERENCE_CLASS_P (rhs))
-	    *no_other_refs &= gather_memory_references_ref (loop, &refs,
-							    rhs, false, stmt);
-	  if (REFERENCE_CLASS_P (lhs))
-	    *no_other_refs &= gather_memory_references_ref (loop, &refs,
-							    lhs, true, stmt);
-	}
-    }
-  free (body);
-
-  return refs;
-}
-
-/* Prune the prefetch candidate REF using the self-reuse.  */
-
-static void
-prune_ref_by_self_reuse (struct mem_ref *ref)
-{
-  HOST_WIDE_INT step = ref->group->step;
-  bool backward = step < 0;
-
-  if (step == 0)
-    {
-      /* Prefetch references to invariant address just once.  */
-      ref->prefetch_before = 1;
-      return;
-    }
-
-  if (backward)
-    step = -step;
-
-  if (step > PREFETCH_BLOCK)
-    return;
-
-  if ((backward && HAVE_BACKWARD_PREFETCH)
-      || (!backward && HAVE_FORWARD_PREFETCH))
-    {
-      ref->prefetch_before = 1;
-      return;
-    }
-
-  ref->prefetch_mod = PREFETCH_BLOCK / step;
-}
-
-/* Divides X by BY, rounding down.  */
-
-static HOST_WIDE_INT
-ddown (HOST_WIDE_INT x, unsigned HOST_WIDE_INT by)
-{
-  gcc_assert (by > 0);
-
-  if (x >= 0)
-    return x / by;
-  else
-    return (x + by - 1) / by;
-}
-
-/* Prune the prefetch candidate REF using the reuse with BY.
-   If BY_IS_BEFORE is true, BY is before REF in the loop.  */
-
-static void
-prune_ref_by_group_reuse (struct mem_ref *ref, struct mem_ref *by,
-			  bool by_is_before)
-{
-  HOST_WIDE_INT step = ref->group->step;
-  bool backward = step < 0;
-  HOST_WIDE_INT delta_r = ref->delta, delta_b = by->delta;
-  HOST_WIDE_INT delta = delta_b - delta_r;
-  HOST_WIDE_INT hit_from;
-  unsigned HOST_WIDE_INT prefetch_before, prefetch_block;
-
-  if (delta == 0)
-    {
-      /* If the references has the same address, only prefetch the
-	 former.  */
-      if (by_is_before)
-	ref->prefetch_before = 0;
-      
-      return;
-    }
-
-  if (!step)
-    {
-      /* If the reference addresses are invariant and fall into the
-	 same cache line, prefetch just the first one.  */
-      if (!by_is_before)
-	return;
-
-      if (ddown (ref->delta, PREFETCH_BLOCK)
-	  != ddown (by->delta, PREFETCH_BLOCK))
-	return;
-
-      ref->prefetch_before = 0;
-      return;
-    }
-
-  /* Only prune the reference that is behind in the array.  */
-  if (backward)
-    {
-      if (delta > 0)
-	return;
-
-      /* Transform the data so that we may assume that the accesses
-	 are forward.  */
-      delta = - delta;
-      step = -step;
-      delta_r = PREFETCH_BLOCK - 1 - delta_r;
-      delta_b = PREFETCH_BLOCK - 1 - delta_b;
-    }
-  else
-    {
-      if (delta < 0)
-	return;
-    }
-
-  /* Check whether the two references are likely to hit the same cache
-     line, and how distant the iterations in that it occurs are from
-     each other.  */
-
-  if (step <= PREFETCH_BLOCK)
-    {
-      /* The accesses are sure to meet.  Let us check when.  */
-      hit_from = ddown (delta_b, PREFETCH_BLOCK) * PREFETCH_BLOCK;
-      prefetch_before = (hit_from - delta_r + step - 1) / step;
-
-      if (prefetch_before < ref->prefetch_before)
-	ref->prefetch_before = prefetch_before;
-
-      return;
-    }
-
-  /* A more complicated case.  First let us ensure that size of cache line
-     and step are coprime (here we assume that PREFETCH_BLOCK is a power
-     of two.  */
-  prefetch_block = PREFETCH_BLOCK;
-  while ((step & 1) == 0
-	 && prefetch_block > 1)
-    {
-      step >>= 1;
-      prefetch_block >>= 1;
-      delta >>= 1;
-    }
-
-  /* Now step > prefetch_block, and step and prefetch_block are coprime.
-     Determine the probability that the accesses hit the same cache line.  */
-
-  prefetch_before = delta / step;
-  delta %= step;
-  if ((unsigned HOST_WIDE_INT) delta
-      <= (prefetch_block * ACCEPTABLE_MISS_RATE / 1000))
-    {
-      if (prefetch_before < ref->prefetch_before)
-	ref->prefetch_before = prefetch_before;
-
-      return;
-    }
-
-  /* Try also the following iteration.  */
-  prefetch_before++;
-  delta = step - delta;
-  if ((unsigned HOST_WIDE_INT) delta
-      <= (prefetch_block * ACCEPTABLE_MISS_RATE / 1000))
-    {
-      if (prefetch_before < ref->prefetch_before)
-	ref->prefetch_before = prefetch_before;
-
-      return;
-    }
-
-  /* The ref probably does not reuse by.  */
-  return;
-}
-
-/* Prune the prefetch candidate REF using the reuses with other references
-   in REFS.  */
-
-static void
-prune_ref_by_reuse (struct mem_ref *ref, struct mem_ref *refs)
-{
-  struct mem_ref *prune_by;
-  bool before = true;
-
-  prune_ref_by_self_reuse (ref);
-
-  for (prune_by = refs; prune_by; prune_by = prune_by->next)
-    {
-      if (prune_by == ref)
-	{
-	  before = false;
-	  continue;
-	}
-
-      if (!WRITE_CAN_USE_READ_PREFETCH
-	  && ref->write_p
-	  && !prune_by->write_p)
-	continue;
-      if (!READ_CAN_USE_WRITE_PREFETCH
-	  && !ref->write_p
-	  && prune_by->write_p)
-	continue;
-
-      prune_ref_by_group_reuse (ref, prune_by, before);
-    }
-}
-
-/* Prune the prefetch candidates in GROUP using the reuse analysis.  */
-
-static void
-prune_group_by_reuse (struct mem_ref_group *group)
-{
-  struct mem_ref *ref_pruned;
-
-  for (ref_pruned = group->refs; ref_pruned; ref_pruned = ref_pruned->next)
-    {
-      prune_ref_by_reuse (ref_pruned, group->refs);
-
-      if (dump_file && (dump_flags & TDF_DETAILS))
-	{
-	  fprintf (dump_file, "Reference %p:", (void *) ref_pruned);
-
-	  if (ref_pruned->prefetch_before == PREFETCH_ALL
-	      && ref_pruned->prefetch_mod == 1)
-	    fprintf (dump_file, " no restrictions");
-	  else if (ref_pruned->prefetch_before == 0)
-	    fprintf (dump_file, " do not prefetch");
-	  else if (ref_pruned->prefetch_before <= ref_pruned->prefetch_mod)
-	    fprintf (dump_file, " prefetch once");
-	  else
-	    {
-	      if (ref_pruned->prefetch_before != PREFETCH_ALL)
-		{
-		  fprintf (dump_file, " prefetch before ");
-		  fprintf (dump_file, HOST_WIDE_INT_PRINT_DEC,
-			   ref_pruned->prefetch_before);
-		}
-	      if (ref_pruned->prefetch_mod != 1)
-		{
-		  fprintf (dump_file, " prefetch mod ");
-		  fprintf (dump_file, HOST_WIDE_INT_PRINT_DEC,
-			   ref_pruned->prefetch_mod);
-		}
-	    }
-	  fprintf (dump_file, "\n");
-	}
-    }
-}
-
-/* Prune the list of prefetch candidates GROUPS using the reuse analysis.  */
-
-static void
-prune_by_reuse (struct mem_ref_group *groups)
-{
-  for (; groups; groups = groups->next)
-    prune_group_by_reuse (groups);
-}
-
-/* Returns true if we should issue prefetch for REF.  */
-
-static bool
-should_issue_prefetch_p (struct mem_ref *ref)
-{
-  /* For now do not issue prefetches for only first few of the
-     iterations.  */
-  if (ref->prefetch_before != PREFETCH_ALL)
-    return false;
-
-  /* Do not prefetch nontemporal stores.  */
-  if (ref->storent_p)
-    return false;
-
-  return true;
-}
-
-/* Decide which of the prefetch candidates in GROUPS to prefetch.
-   AHEAD is the number of iterations to prefetch ahead (which corresponds
-   to the number of simultaneous instances of one prefetch running at a
-   time).  UNROLL_FACTOR is the factor by that the loop is going to be
-   unrolled.  Returns true if there is anything to prefetch.  */
-
-static bool
-schedule_prefetches (struct mem_ref_group *groups, unsigned unroll_factor,
-		     unsigned ahead)
-{
-  unsigned remaining_prefetch_slots, n_prefetches, prefetch_slots;
-  unsigned slots_per_prefetch;
-  struct mem_ref *ref;
-  bool any = false;
-
-  /* At most SIMULTANEOUS_PREFETCHES should be running at the same time.  */
-  remaining_prefetch_slots = SIMULTANEOUS_PREFETCHES;
-
-  /* The prefetch will run for AHEAD iterations of the original loop, i.e.,
-     AHEAD / UNROLL_FACTOR iterations of the unrolled loop.  In each iteration,
-     it will need a prefetch slot.  */
-  slots_per_prefetch = (ahead + unroll_factor / 2) / unroll_factor;
-  if (dump_file && (dump_flags & TDF_DETAILS))
-    fprintf (dump_file, "Each prefetch instruction takes %u prefetch slots.\n",
-	     slots_per_prefetch);
-
-  /* For now we just take memory references one by one and issue
-     prefetches for as many as possible.  The groups are sorted
-     starting with the largest step, since the references with
-     large step are more likely to cause many cache misses.  */
-
-  for (; groups; groups = groups->next)
-    for (ref = groups->refs; ref; ref = ref->next)
-      {
-	if (!should_issue_prefetch_p (ref))
-	  continue;
-
-	/* If we need to prefetch the reference each PREFETCH_MOD iterations,
-	   and we unroll the loop UNROLL_FACTOR times, we need to insert
-	   ceil (UNROLL_FACTOR / PREFETCH_MOD) instructions in each
-	   iteration.  */
-	n_prefetches = ((unroll_factor + ref->prefetch_mod - 1)
-			/ ref->prefetch_mod);
-	prefetch_slots = n_prefetches * slots_per_prefetch;
-
-	/* If more than half of the prefetches would be lost anyway, do not
-	   issue the prefetch.  */
-	if (2 * remaining_prefetch_slots < prefetch_slots)
-	  continue;
-
-	ref->issue_prefetch_p = true;
-
-	if (remaining_prefetch_slots <= prefetch_slots)
-	  return true;
-	remaining_prefetch_slots -= prefetch_slots;
-	any = true;
-      }
-
-  return any;
-}
-
-/* Determine whether there is any reference suitable for prefetching
-   in GROUPS.  */
-
-static bool
-anything_to_prefetch_p (struct mem_ref_group *groups)
-{
-  struct mem_ref *ref;
-
-  for (; groups; groups = groups->next)
-    for (ref = groups->refs; ref; ref = ref->next)
-      if (should_issue_prefetch_p (ref))
-	return true;
-
-  return false;
-}
-
-/* Issue prefetches for the reference REF into loop as decided before.
-   HEAD is the number of iterations to prefetch ahead.  UNROLL_FACTOR
-   is the factor by which LOOP was unrolled.  */
-
-static void
-issue_prefetch_ref (struct mem_ref *ref, unsigned unroll_factor, unsigned ahead)
-{
-  HOST_WIDE_INT delta;
-  tree addr, addr_base, write_p, local;
-  gimple prefetch;
-  gimple_stmt_iterator bsi;
-  unsigned n_prefetches, ap;
-  bool nontemporal = ref->reuse_distance >= L2_CACHE_SIZE_BYTES;
-
-  if (dump_file && (dump_flags & TDF_DETAILS))
-    fprintf (dump_file, "Issued%s prefetch for %p.\n",
-	     nontemporal ? " nontemporal" : "",
-	     (void *) ref);
-
-  bsi = gsi_for_stmt (ref->stmt);
-
-  n_prefetches = ((unroll_factor + ref->prefetch_mod - 1)
-		  / ref->prefetch_mod);
-  addr_base = build_fold_addr_expr_with_type (ref->mem, ptr_type_node);
-  addr_base = force_gimple_operand_gsi (&bsi, unshare_expr (addr_base),
-					true, NULL, true, GSI_SAME_STMT);
-  write_p = ref->write_p ? integer_one_node : integer_zero_node;
-  local = build_int_cst (integer_type_node, nontemporal ? 0 : 3);
-
-  for (ap = 0; ap < n_prefetches; ap++)
-    {
-      /* Determine the address to prefetch.  */
-      delta = (ahead + ap * ref->prefetch_mod) * ref->group->step;
-      addr = fold_build2 (POINTER_PLUS_EXPR, ptr_type_node,
-			  addr_base, size_int (delta));
-      addr = force_gimple_operand_gsi (&bsi, unshare_expr (addr), true, NULL,
-				       true, GSI_SAME_STMT);
-
-      /* Create the prefetch instruction.  */
-      prefetch = gimple_build_call (built_in_decls[BUILT_IN_PREFETCH],
-				    3, addr, write_p, local);
-      gsi_insert_before (&bsi, prefetch, GSI_SAME_STMT);
-    }
-}
-
-/* Issue prefetches for the references in GROUPS into loop as decided before.
-   HEAD is the number of iterations to prefetch ahead.  UNROLL_FACTOR is the
-   factor by that LOOP was unrolled.  */
-
-static void
-issue_prefetches (struct mem_ref_group *groups,
-		  unsigned unroll_factor, unsigned ahead)
-{
-  struct mem_ref *ref;
-
-  for (; groups; groups = groups->next)
-    for (ref = groups->refs; ref; ref = ref->next)
-      if (ref->issue_prefetch_p)
-	issue_prefetch_ref (ref, unroll_factor, ahead);
-}
-
-/* Returns true if REF is a memory write for that a nontemporal store insn
-   can be used.  */
-
-static bool
-nontemporal_store_p (struct mem_ref *ref)
-{
-  enum machine_mode mode;
-  enum insn_code code;
-
-  /* REF must be a write that is not reused.  We require it to be independent
-     on all other memory references in the loop, as the nontemporal stores may
-     be reordered with respect to other memory references.  */
-  if (!ref->write_p
-      || !ref->independent_p
-      || ref->reuse_distance < L2_CACHE_SIZE_BYTES)
-    return false;
-
-  /* Check that we have the storent instruction for the mode.  */
-  mode = TYPE_MODE (TREE_TYPE (ref->mem));
-  if (mode == BLKmode)
-    return false;
-
-  code = optab_handler (storent_optab, mode)->insn_code;
-  return code != CODE_FOR_nothing;
-}
-
-/* If REF is a nontemporal store, we mark the corresponding modify statement
-   and return true.  Otherwise, we return false.  */
-
-static bool
-mark_nontemporal_store (struct mem_ref *ref)
-{
-  if (!nontemporal_store_p (ref))
-    return false;
-
-  if (dump_file && (dump_flags & TDF_DETAILS))
-    fprintf (dump_file, "Marked reference %p as a nontemporal store.\n",
-	     (void *) ref);
-
-  gimple_assign_set_nontemporal_move (ref->stmt, true);
-  ref->storent_p = true;
-
-  return true;
-}
-
-/* Issue a memory fence instruction after LOOP.  */
-
-static void
-emit_mfence_after_loop (struct loop *loop)
-{
-  VEC (edge, heap) *exits = get_loop_exit_edges (loop);
-  edge exit;
-  gimple call;
-  gimple_stmt_iterator bsi;
-  unsigned i;
-
-  for (i = 0; VEC_iterate (edge, exits, i, exit); i++)
-    {
-      call = gimple_build_call (FENCE_FOLLOWING_MOVNT, 0);
-
-      if (!single_pred_p (exit->dest)
-	  /* If possible, we prefer not to insert the fence on other paths
-	     in cfg.  */
-	  && !(exit->flags & EDGE_ABNORMAL))
-	split_loop_exit_edge (exit);
-      bsi = gsi_after_labels (exit->dest);
-
-      gsi_insert_before (&bsi, call, GSI_NEW_STMT);
-      mark_virtual_ops_for_renaming (call);
-    }
-
-  VEC_free (edge, heap, exits);
-  update_ssa (TODO_update_ssa_only_virtuals);
-}
-
-/* Returns true if we can use storent in loop, false otherwise.  */
-
-static bool
-may_use_storent_in_loop_p (struct loop *loop)
-{
-  bool ret = true;
-
-  if (loop->inner != NULL)
-    return false;
-
-  /* If we must issue a mfence insn after using storent, check that there
-     is a suitable place for it at each of the loop exits.  */
-  if (FENCE_FOLLOWING_MOVNT != NULL_TREE)
-    {
-      VEC (edge, heap) *exits = get_loop_exit_edges (loop);
-      unsigned i;
-      edge exit;
-
-      for (i = 0; VEC_iterate (edge, exits, i, exit); i++)
-	if ((exit->flags & EDGE_ABNORMAL)
-	    && exit->dest == EXIT_BLOCK_PTR)
-	  ret = false;
-
-      VEC_free (edge, heap, exits);
-    }
-
-  return ret;
-}
-
-/* Marks nontemporal stores in LOOP.  GROUPS contains the description of memory
-   references in the loop.  */
-
-static void
-mark_nontemporal_stores (struct loop *loop, struct mem_ref_group *groups)
-{
-  struct mem_ref *ref;
-  bool any = false;
-
-  if (!may_use_storent_in_loop_p (loop))
-    return;
-
-  for (; groups; groups = groups->next)
-    for (ref = groups->refs; ref; ref = ref->next)
-      any |= mark_nontemporal_store (ref);
-
-  if (any && FENCE_FOLLOWING_MOVNT != NULL_TREE)
-    emit_mfence_after_loop (loop);
-}
-
-/* Determines whether we can profitably unroll LOOP FACTOR times, and if
-   this is the case, fill in DESC by the description of number of
-   iterations.  */
-
-static bool
-should_unroll_loop_p (struct loop *loop, struct tree_niter_desc *desc,
-		      unsigned factor)
-{
-  if (!can_unroll_loop_p (loop, factor, desc))
-    return false;
-
-  /* We only consider loops without control flow for unrolling.  This is not
-     a hard restriction -- tree_unroll_loop works with arbitrary loops
-     as well; but the unrolling/prefetching is usually more profitable for
-     loops consisting of a single basic block, and we want to limit the
-     code growth.  */
-  if (loop->num_nodes > 2)
-    return false;
-
-  return true;
-}
-
-/* Determine the coefficient by that unroll LOOP, from the information
-   contained in the list of memory references REFS.  Description of
-   umber of iterations of LOOP is stored to DESC.  NINSNS is the number of
-   insns of the LOOP.  EST_NITER is the estimated number of iterations of
-   the loop, or -1 if no estimate is available.  */
-
-static unsigned
-determine_unroll_factor (struct loop *loop, struct mem_ref_group *refs,
-			 unsigned ninsns, struct tree_niter_desc *desc,
-			 HOST_WIDE_INT est_niter)
-{
-  unsigned upper_bound;
-  unsigned nfactor, factor, mod_constraint;
-  struct mem_ref_group *agp;
-  struct mem_ref *ref;
-
-  /* First check whether the loop is not too large to unroll.  We ignore
-     PARAM_MAX_UNROLL_TIMES, because for small loops, it prevented us
-     from unrolling them enough to make exactly one cache line covered by each
-     iteration.  Also, the goal of PARAM_MAX_UNROLL_TIMES is to prevent
-     us from unrolling the loops too many times in cases where we only expect
-     gains from better scheduling and decreasing loop overhead, which is not
-     the case here.  */
-  upper_bound = PARAM_VALUE (PARAM_MAX_UNROLLED_INSNS) / ninsns;
-
-  /* If we unrolled the loop more times than it iterates, the unrolled version
-     of the loop would be never entered.  */
-  if (est_niter >= 0 && est_niter < (HOST_WIDE_INT) upper_bound)
-    upper_bound = est_niter;
-
-  if (upper_bound <= 1)
-    return 1;
-
-  /* Choose the factor so that we may prefetch each cache just once,
-     but bound the unrolling by UPPER_BOUND.  */
-  factor = 1;
-  for (agp = refs; agp; agp = agp->next)
-    for (ref = agp->refs; ref; ref = ref->next)
-      if (should_issue_prefetch_p (ref))
-	{
-	  mod_constraint = ref->prefetch_mod;
-	  nfactor = least_common_multiple (mod_constraint, factor);
-	  if (nfactor <= upper_bound)
-	    factor = nfactor;
-	}
-
-  if (!should_unroll_loop_p (loop, desc, factor))
-    return 1;
-
-  return factor;
-}
-
-/* Returns the total volume of the memory references REFS, taking into account
-   reuses in the innermost loop and cache line size.  TODO -- we should also
-   take into account reuses across the iterations of the loops in the loop
-   nest.  */
-
-static unsigned
-volume_of_references (struct mem_ref_group *refs)
-{
-  unsigned volume = 0;
-  struct mem_ref_group *gr;
-  struct mem_ref *ref;
-
-  for (gr = refs; gr; gr = gr->next)
-    for (ref = gr->refs; ref; ref = ref->next)
-      {
-	/* Almost always reuses another value?  */
-	if (ref->prefetch_before != PREFETCH_ALL)
-	  continue;
-
-	/* If several iterations access the same cache line, use the size of
-	   the line divided by this number.  Otherwise, a cache line is
-	   accessed in each iteration.  TODO -- in the latter case, we should
-	   take the size of the reference into account, rounding it up on cache
-	   line size multiple.  */
-	volume += L1_CACHE_LINE_SIZE / ref->prefetch_mod;
-      }
-  return volume;
-}
-
-/* Returns the volume of memory references accessed across VEC iterations of
-   loops, whose sizes are described in the LOOP_SIZES array.  N is the number
-   of the loops in the nest (length of VEC and LOOP_SIZES vectors).  */
-
-static unsigned
-volume_of_dist_vector (lambda_vector vec, unsigned *loop_sizes, unsigned n)
-{
-  unsigned i;
-
-  for (i = 0; i < n; i++)
-    if (vec[i] != 0)
-      break;
-
-  if (i == n)
-    return 0;
-
-  gcc_assert (vec[i] > 0);
-
-  /* We ignore the parts of the distance vector in subloops, since usually
-     the numbers of iterations are much smaller.  */
-  return loop_sizes[i] * vec[i];
-}
-
-/* Add the steps of ACCESS_FN multiplied by STRIDE to the array STRIDE
-   at the position corresponding to the loop of the step.  N is the depth
-   of the considered loop nest, and, LOOP is its innermost loop.  */
-
-static void
-add_subscript_strides (tree access_fn, unsigned stride,
-		       HOST_WIDE_INT *strides, unsigned n, struct loop *loop)
-{
-  struct loop *aloop;
-  tree step;
-  HOST_WIDE_INT astep;
-  unsigned min_depth = loop_depth (loop) - n;
-
-  while (TREE_CODE (access_fn) == POLYNOMIAL_CHREC)
-    {
-      aloop = get_chrec_loop (access_fn);
-      step = CHREC_RIGHT (access_fn);
-      access_fn = CHREC_LEFT (access_fn);
-
-      if ((unsigned) loop_depth (aloop) <= min_depth)
-	continue;
-
-      if (host_integerp (step, 0))
-	astep = tree_low_cst (step, 0);
-      else
-	astep = L1_CACHE_LINE_SIZE;
-
-      strides[n - 1 - loop_depth (loop) + loop_depth (aloop)] += astep * stride;
-
-    }
-}
-
-/* Returns the volume of memory references accessed between two consecutive
-   self-reuses of the reference DR.  We consider the subscripts of DR in N
-   loops, and LOOP_SIZES contains the volumes of accesses in each of the
-   loops.  LOOP is the innermost loop of the current loop nest.  */
-
-static unsigned
-self_reuse_distance (data_reference_p dr, unsigned *loop_sizes, unsigned n,
-		     struct loop *loop)
-{
-  tree stride, access_fn;
-  HOST_WIDE_INT *strides, astride;
-  VEC (tree, heap) *access_fns;
-  tree ref = DR_REF (dr);
-  unsigned i, ret = ~0u;
-
-  /* In the following example:
-
-     for (i = 0; i < N; i++)
-       for (j = 0; j < N; j++)
-         use (a[j][i]);
-     the same cache line is accessed each N steps (except if the change from
-     i to i + 1 crosses the boundary of the cache line).  Thus, for self-reuse,
-     we cannot rely purely on the results of the data dependence analysis.
-
-     Instead, we compute the stride of the reference in each loop, and consider
-     the innermost loop in that the stride is less than cache size.  */
-
-  strides = XCNEWVEC (HOST_WIDE_INT, n);
-  access_fns = DR_ACCESS_FNS (dr);
-
-  for (i = 0; VEC_iterate (tree, access_fns, i, access_fn); i++)
-    {
-      /* Keep track of the reference corresponding to the subscript, so that we
-	 know its stride.  */
-      while (handled_component_p (ref) && TREE_CODE (ref) != ARRAY_REF)
-	ref = TREE_OPERAND (ref, 0);
-      
-      if (TREE_CODE (ref) == ARRAY_REF)
-	{
-	  stride = TYPE_SIZE_UNIT (TREE_TYPE (ref));
-	  if (host_integerp (stride, 1))
-	    astride = tree_low_cst (stride, 1);
-	  else
-	    astride = L1_CACHE_LINE_SIZE;
-
-	  ref = TREE_OPERAND (ref, 0);
-	}
-      else
-	astride = 1;
-
-      add_subscript_strides (access_fn, astride, strides, n, loop);
-    }
-
-  for (i = n; i-- > 0; )
-    {
-      unsigned HOST_WIDE_INT s;
-
-      s = strides[i] < 0 ?  -strides[i] : strides[i];
-
-      if (s < (unsigned) L1_CACHE_LINE_SIZE
-	  && (loop_sizes[i]
-	      > (unsigned) (L1_CACHE_SIZE_BYTES / NONTEMPORAL_FRACTION)))
-	{
-	  ret = loop_sizes[i];
-	  break;
-	}
-    }
-
-  free (strides);
-  return ret;
-}
-
-/* Determines the distance till the first reuse of each reference in REFS
-   in the loop nest of LOOP.  NO_OTHER_REFS is true if there are no other
-   memory references in the loop.  */
-
-static void
-determine_loop_nest_reuse (struct loop *loop, struct mem_ref_group *refs,
-			   bool no_other_refs)
-{
-  struct loop *nest, *aloop;
-  VEC (data_reference_p, heap) *datarefs = NULL;
-  VEC (ddr_p, heap) *dependences = NULL;
-  struct mem_ref_group *gr;
-  struct mem_ref *ref, *refb;
-  VEC (loop_p, heap) *vloops = NULL;
-  unsigned *loop_data_size;
-  unsigned i, j, n;
-  unsigned volume, dist, adist;
-  HOST_WIDE_INT vol;
-  data_reference_p dr;
-  ddr_p dep;
-
-  if (loop->inner)
-    return;
-
-  /* Find the outermost loop of the loop nest of loop (we require that
-     there are no sibling loops inside the nest).  */
-  nest = loop;
-  while (1)
-    {
-      aloop = loop_outer (nest);
-
-      if (aloop == current_loops->tree_root
-	  || aloop->inner->next)
-	break;
-
-      nest = aloop;
-    }
-
-  /* For each loop, determine the amount of data accessed in each iteration.
-     We use this to estimate whether the reference is evicted from the
-     cache before its reuse.  */
-  find_loop_nest (nest, &vloops);
-  n = VEC_length (loop_p, vloops);
-  loop_data_size = XNEWVEC (unsigned, n);
-  volume = volume_of_references (refs);
-  i = n;
-  while (i-- != 0)
-    {
-      loop_data_size[i] = volume;
-      /* Bound the volume by the L2 cache size, since above this bound,
-	 all dependence distances are equivalent.  */
-      if (volume > L2_CACHE_SIZE_BYTES)
-	continue;
-
-      aloop = VEC_index (loop_p, vloops, i);
-      vol = estimated_loop_iterations_int (aloop, false);
-      if (vol < 0)
-	vol = expected_loop_iterations (aloop);
-      volume *= vol;
-    }
-
-  /* Prepare the references in the form suitable for data dependence
-     analysis.  We ignore unanalyzable data references (the results
-     are used just as a heuristics to estimate temporality of the
-     references, hence we do not need to worry about correctness).  */
-  for (gr = refs; gr; gr = gr->next)
-    for (ref = gr->refs; ref; ref = ref->next)
-      {
-	dr = create_data_ref (nest, ref->mem, ref->stmt, !ref->write_p);
-
-	if (dr)
-	  {
-	    ref->reuse_distance = volume;
-	    dr->aux = ref;
-	    VEC_safe_push (data_reference_p, heap, datarefs, dr);
-	  }
-	else
-	  no_other_refs = false;
-      }
-
-  for (i = 0; VEC_iterate (data_reference_p, datarefs, i, dr); i++)
-    {
-      dist = self_reuse_distance (dr, loop_data_size, n, loop);
-      ref = (struct mem_ref *) dr->aux;
-      if (ref->reuse_distance > dist)
-	ref->reuse_distance = dist;
-
-      if (no_other_refs)
-	ref->independent_p = true;
-    }
-
-  compute_all_dependences (datarefs, &dependences, vloops, true);
-
-  for (i = 0; VEC_iterate (ddr_p, dependences, i, dep); i++)
-    {
-      if (DDR_ARE_DEPENDENT (dep) == chrec_known)
-	continue;
-
-      ref = (struct mem_ref *) DDR_A (dep)->aux;
-      refb = (struct mem_ref *) DDR_B (dep)->aux;
-
-      if (DDR_ARE_DEPENDENT (dep) == chrec_dont_know
-	  || DDR_NUM_DIST_VECTS (dep) == 0)
-	{
-	  /* If the dependence cannot be analyzed, assume that there might be
-	     a reuse.  */
-	  dist = 0;
-      
-	  ref->independent_p = false;
-	  refb->independent_p = false;
-	}
-      else
-	{
-	  /* The distance vectors are normalized to be always lexicographically
-	     positive, hence we cannot tell just from them whether DDR_A comes
-	     before DDR_B or vice versa.  However, it is not important,
-	     anyway -- if DDR_A is close to DDR_B, then it is either reused in
-	     DDR_B (and it is not nontemporal), or it reuses the value of DDR_B
-	     in cache (and marking it as nontemporal would not affect
-	     anything).  */
-
-	  dist = volume;
-	  for (j = 0; j < DDR_NUM_DIST_VECTS (dep); j++)
-	    {
-	      adist = volume_of_dist_vector (DDR_DIST_VECT (dep, j),
-					     loop_data_size, n);
-
-	      /* If this is a dependence in the innermost loop (i.e., the
-		 distances in all superloops are zero) and it is not
-		 the trivial self-dependence with distance zero, record that
-		 the references are not completely independent.  */
-	      if (lambda_vector_zerop (DDR_DIST_VECT (dep, j), n - 1)
-		  && (ref != refb
-		      || DDR_DIST_VECT (dep, j)[n-1] != 0))
-		{
-		  ref->independent_p = false;
-		  refb->independent_p = false;
-		}
-
-	      /* Ignore accesses closer than
-		 L1_CACHE_SIZE_BYTES / NONTEMPORAL_FRACTION,
-	      	 so that we use nontemporal prefetches e.g. if single memory
-		 location is accessed several times in a single iteration of
-		 the loop.  */
-	      if (adist < L1_CACHE_SIZE_BYTES / NONTEMPORAL_FRACTION)
-		continue;
-
-	      if (adist < dist)
-		dist = adist;
-	    }
-	}
-
-      if (ref->reuse_distance > dist)
-	ref->reuse_distance = dist;
-      if (refb->reuse_distance > dist)
-	refb->reuse_distance = dist;
-    }
-
-  free_dependence_relations (dependences);
-  free_data_refs (datarefs);
-  free (loop_data_size);
-
-  if (dump_file && (dump_flags & TDF_DETAILS))
-    {
-      fprintf (dump_file, "Reuse distances:\n");
-      for (gr = refs; gr; gr = gr->next)
-	for (ref = gr->refs; ref; ref = ref->next)
-	  fprintf (dump_file, " ref %p distance %u\n",
-		   (void *) ref, ref->reuse_distance);
-    }
-}
-
-/* Issue prefetch instructions for array references in LOOP.  Returns
-   true if the LOOP was unrolled.  */
-
-static bool
-loop_prefetch_arrays (struct loop *loop)
-{
-  struct mem_ref_group *refs;
-  unsigned ahead, ninsns, time, unroll_factor;
-  HOST_WIDE_INT est_niter;
-  struct tree_niter_desc desc;
-  bool unrolled = false, no_other_refs;
-
-  if (optimize_loop_nest_for_size_p (loop))
-    {
-      if (dump_file && (dump_flags & TDF_DETAILS))
-	fprintf (dump_file, "  ignored (cold area)\n");
-      return false;
-    }
-
-  /* Step 1: gather the memory references.  */
-  refs = gather_memory_references (loop, &no_other_refs);
-
-  /* Step 2: estimate the reuse effects.  */
-  prune_by_reuse (refs);
-
-  if (!anything_to_prefetch_p (refs))
-    goto fail;
-
-  determine_loop_nest_reuse (loop, refs, no_other_refs);
-
-  /* Step 3: determine the ahead and unroll factor.  */
-
-  /* FIXME: the time should be weighted by the probabilities of the blocks in
-     the loop body.  */
-  time = tree_num_loop_insns (loop, &eni_time_weights);
-  ahead = (PREFETCH_LATENCY + time - 1) / time;
-  est_niter = estimated_loop_iterations_int (loop, false);
-
-  /* The prefetches will run for AHEAD iterations of the original loop.  Unless
-     the loop rolls at least AHEAD times, prefetching the references does not
-     make sense.  */
-  if (est_niter >= 0 && est_niter <= (HOST_WIDE_INT) ahead)
-    {
-      if (dump_file && (dump_flags & TDF_DETAILS))
-	fprintf (dump_file,
-		 "Not prefetching -- loop estimated to roll only %d times\n",
-		 (int) est_niter);
-      goto fail;
-    }
-
-  mark_nontemporal_stores (loop, refs);
-
-  ninsns = tree_num_loop_insns (loop, &eni_size_weights);
-  unroll_factor = determine_unroll_factor (loop, refs, ninsns, &desc,
-					   est_niter);
-  if (dump_file && (dump_flags & TDF_DETAILS))
-    fprintf (dump_file, "Ahead %d, unroll factor %d\n", ahead, unroll_factor);
-
-  /* Step 4: what to prefetch?  */
-  if (!schedule_prefetches (refs, unroll_factor, ahead))
-    goto fail;
-
-  /* Step 5: unroll the loop.  TODO -- peeling of first and last few
-     iterations so that we do not issue superfluous prefetches.  */
-  if (unroll_factor != 1)
-    {
-      tree_unroll_loop (loop, unroll_factor,
-			single_dom_exit (loop), &desc);
-      unrolled = true;
-    }
-
-  /* Step 6: issue the prefetches.  */
-  issue_prefetches (refs, unroll_factor, ahead);
-
-fail:
-  release_mem_refs (refs);
-  return unrolled;
-}
-
-/* Issue prefetch instructions for array references in loops.  */
-
-unsigned int
-tree_ssa_prefetch_arrays (void)
-{
-  loop_iterator li;
-  struct loop *loop;
-  bool unrolled = false;
-  int todo_flags = 0;
-
-  if (!HAVE_prefetch
-      /* It is possible to ask compiler for say -mtune=i486 -march=pentium4.
-	 -mtune=i486 causes us having PREFETCH_BLOCK 0, since this is part
-	 of processor costs and i486 does not have prefetch, but
-	 -march=pentium4 causes HAVE_prefetch to be true.  Ugh.  */
-      || PREFETCH_BLOCK == 0)
-    return 0;
-
-  if (dump_file && (dump_flags & TDF_DETAILS))
-    {
-      fprintf (dump_file, "Prefetching parameters:\n");
-      fprintf (dump_file, "    simultaneous prefetches: %d\n",
-	       SIMULTANEOUS_PREFETCHES);
-      fprintf (dump_file, "    prefetch latency: %d\n", PREFETCH_LATENCY);
-      fprintf (dump_file, "    prefetch block size: %d\n", PREFETCH_BLOCK);
-      fprintf (dump_file, "    L1 cache size: %d lines, %d kB\n",
-	       L1_CACHE_SIZE_BYTES / L1_CACHE_LINE_SIZE, L1_CACHE_SIZE);
-      fprintf (dump_file, "    L1 cache line size: %d\n", L1_CACHE_LINE_SIZE);
-      fprintf (dump_file, "    L2 cache size: %d kB\n", L2_CACHE_SIZE);
-      fprintf (dump_file, "\n");
-    }
-
-  initialize_original_copy_tables ();
-
-  if (!built_in_decls[BUILT_IN_PREFETCH])
-    {
-      tree type = build_function_type (void_type_node,
-				       tree_cons (NULL_TREE,
-						  const_ptr_type_node,
-						  NULL_TREE));
-      tree decl = add_builtin_function ("__builtin_prefetch", type,
-					BUILT_IN_PREFETCH, BUILT_IN_NORMAL,
-					NULL, NULL_TREE);
-      DECL_IS_NOVOPS (decl) = true;
-      built_in_decls[BUILT_IN_PREFETCH] = decl;
-    }
-
-  /* We assume that size of cache line is a power of two, so verify this
-     here.  */
-  gcc_assert ((PREFETCH_BLOCK & (PREFETCH_BLOCK - 1)) == 0);
-
-  FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST)
-    {
-      if (dump_file && (dump_flags & TDF_DETAILS))
-	fprintf (dump_file, "Processing loop %d:\n", loop->num);
-
-      unrolled |= loop_prefetch_arrays (loop);
-
-      if (dump_file && (dump_flags & TDF_DETAILS))
-	fprintf (dump_file, "\n\n");
-    }
-
-  if (unrolled)
-    {
-      scev_reset ();
-      todo_flags |= TODO_cleanup_cfg;
-    }
-
-  free_original_copy_tables ();
-  return todo_flags;
-}