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Re: [patch][RFA] Remove compute_sets and CUIDs from gcse.c, and use DF instead


On Tue, Apr 14, 2009 at 10:31 AM, Richard Guenther
<richard.guenther@gmail.com> wrote:
> On Mon, Apr 13, 2009 at 7:05 PM, Steven Bosscher <stevenb.gcc@gmail.com> wrote:
>> Hi,
>>
>> This patch is the first step of DF-ifying gcse.c. ?Pretty straight-forward:
>>
>> * replace CUIDs with DF_INSN_LUIDs
>> * replace compute_sets with the existing DF insn operand caches
>>
>> Bootstrapped&tested on ia64-unknown-linux-gnu.
>> OK for trunk?
>
> Ok without the ??? STEVEN ??? in
>
> - ? ? ?/* ??? When we allocate this at the start of the function,
> - ? ? ? ?the comment says that "this data is kept accurate during
> - ? ? ? ?each pass". ?Apparently this is not so? ?FIXME. ?*/
> - ? ? ?free_reg_set_mem ();
> - ? ? ?alloc_reg_set_mem (max_reg_num ());
> - ? ? ?compute_sets ();
> + ? ? ?df_analyze (); /* ??? STEVEN ??? */
>
> ;)
>
> Thanks,
> Richard.

Right. Oops :-)

Anyway, some changes happened since I tested it first, and that caused
some new failures.

It turns out that this these
 new failures were caused by the same issue that I had trouble with
while converting other passes to DF (the passes in regrename.c):
df_insn_rescan loses the DF_INSN_LUID of a rescanned insn, even if the
insn is not new.  I already talked about this with Kenny, like, a year
ago (?).  We should just keep the same LUID around if an insn is only
being rescanned.

I'm committing that bit as obvious, along with the gcse.c patch.

Ciao!
Steven



	* df-scan.c (df_insn_rescan): Salvage insn's LUID if the insn is
	not new but only being rescanned.
	* gcse.c (uid_cuid, max_uid, INSN_CUID, max_cuid, struct reg_set,
	reg_set_table, REG_SET_TABLE_SLOP, reg_set_in_block,
	alloc_reg_set_mem, free_reg_set_mem, record_one_set,
	record_set_info, compute_set, grealloc): Remove.
	(recompute_all_luids): New function.
	(gcse_main): Don't compute sets, and don't do related memory
	allocations/free-ing.  If something changed before the end of the
	pass, update LUIDs using recompute_all_luids.
	(alloc_gcse_mem): Don't compute LUIDs.  Don't allocate reg_set memory.
	(free_gcse_mem): Don't free it either.
	(oprs_unchanged_p, load_killed_in_block, record_last_reg_set_info):
	Use the df insn LUIDs.
	(load_killed_in_block): Likewise.
	(compute_hash_table_work): Don't compute reg_set_in_block.
	(compute_transp): Use DF_REG_DEF_CHAINs.
	(local_cprop_pass): Don't use compute_sets and related functions.
	(one_cprop_pass, pre_gcse, one_pre_gcse_pass, one_code_hoisting_pass):
	Use get_max_uid() instead of max_cuid.
	(insert_insn_end_basic_block, pre_insert_copy_insn,
	update_ld_motion_stores): Don't try to
	keep reg_set tables up to date.
	(pre_insert_copies): Use df insn LUIDs.
	(sbitmap pre_redundant_insns): Replace with uses of INSN_DELETED_P.
	(reg_set_info): Don't use extra bitmap argument.
	(compute_store_table): Don't compute reg_set_in_block.  Use DF scan
	information to compute regs_set_in_block.
	(free_store_memory, store_motion): Don't nullify reg_set_in_block.
	(bypass_jumps): Don't use compute_sets and friends.

Index: df-scan.c
===================================================================
--- df-scan.c	(revision 146741)
+++ df-scan.c	(working copy)
@@ -1258,6 +1258,7 @@ df_insn_rescan (rtx insn)
   bitmap_clear_bit (df->insns_to_notes_rescan, uid);
   if (insn_info)
     {
+      int luid;
       bool the_same = df_insn_refs_verify (&collection_rec, bb, insn, false);
       /* If there's no change, return false. */
       if (the_same)
@@ -1270,9 +1271,12 @@ df_insn_rescan (rtx insn)
       if (dump_file)
 	fprintf (dump_file, "rescanning insn with uid = %d.\n", uid);

-      /* There's change - we need to delete the existing info. */
+      /* There's change - we need to delete the existing info.
+	 Since the insn isn't moved, we can salvage its LUID.  */
+      luid = DF_INSN_LUID (insn);
       df_insn_delete (NULL, uid);
       df_insn_create_insn_record (insn);
+      DF_INSN_LUID (insn) = luid;
     }
   else
     {
Index: gcse.c
===================================================================
--- gcse.c	(revision 146741)
+++ gcse.c	(working copy)
@@ -27,9 +27,6 @@ along with GCC; see the file COPYING3.  If not see
    - a store to the same address as a load does not kill the load if the
      source of the store is also the destination of the load.  Handling this
      allows more load motion, particularly out of loops.
-   - ability to realloc sbitmap vectors would allow one initial computation
-     of reg_set_in_block with only subsequent additions, rather than
-     recomputing it for each pass

 */

@@ -373,70 +370,11 @@ static struct hash_table expr_hash_table;
 /* Copy propagation hash table.  */
 static struct hash_table set_hash_table;

-/* Mapping of uids to cuids.
-   Only real insns get cuids.  */
-static int *uid_cuid;
-
-/* Highest UID in UID_CUID.  */
-static int max_uid;
-
-/* Get the cuid of an insn.  */
-#ifdef ENABLE_CHECKING
-#define INSN_CUID(INSN) \
-  (gcc_assert (INSN_UID (INSN) <= max_uid), uid_cuid[INSN_UID (INSN)])
-#else
-#define INSN_CUID(INSN) (uid_cuid[INSN_UID (INSN)])
-#endif
-
-/* Number of cuids.  */
-static int max_cuid;
-
 /* Maximum register number in function prior to doing gcse + 1.
    Registers created during this pass have regno >= max_gcse_regno.
    This is named with "gcse" to not collide with global of same name.  */
 static unsigned int max_gcse_regno;

-/* Table of registers that are modified.
-
-   For each register, each element is a list of places where the pseudo-reg
-   is set.
-
-   For simplicity, GCSE is done on sets of pseudo-regs only.  PRE GCSE only
-   requires knowledge of which blocks kill which regs [and thus could use
-   a bitmap instead of the lists `reg_set_table' uses].
-
-   `reg_set_table' and could be turned into an array of bitmaps (num-bbs x
-   num-regs) [however perhaps it may be useful to keep the data as is].  One
-   advantage of recording things this way is that `reg_set_table' is fairly
-   sparse with respect to pseudo regs but for hard regs could be fairly dense
-   [relatively speaking].  And recording sets of pseudo-regs in lists speeds
-   up functions like compute_transp since in the case of pseudo-regs we only
-   need to iterate over the number of times a pseudo-reg is set, not over the
-   number of basic blocks [clearly there is a bit of a slow down in the cases
-   where a pseudo is set more than once in a block, however it is believed
-   that the net effect is to speed things up].  This isn't done for hard-regs
-   because recording call-clobbered hard-regs in `reg_set_table' at each
-   function call can consume a fair bit of memory, and iterating over
-   hard-regs stored this way in compute_transp will be more expensive.  */
-
-typedef struct reg_set
-{
-  /* The next setting of this register.  */
-  struct reg_set *next;
-  /* The index of the block where it was set.  */
-  int bb_index;
-} reg_set;
-
-static reg_set **reg_set_table;
-
-/* Size of `reg_set_table'.
-   The table starts out at max_gcse_regno + slop, and is enlarged as
-   necessary.  */
-static int reg_set_table_size;
-
-/* Amount to grow `reg_set_table' by when it's full.  */
-#define REG_SET_TABLE_SLOP 100
-
 /* This is a list of expressions which are MEMs and will be used by load
    or store motion.
    Load motion tracks MEMs which aren't killed by
@@ -476,13 +414,6 @@ static htab_t pre_ldst_table = NULL;
    the start of the basic block.  */
 static regset reg_set_bitmap;

-/* For each block, a bitmap of registers set in the block.
-   This is used by compute_transp.
-   It is computed during hash table computation and not by compute_sets
-   as it includes registers added since the last pass (or between cprop and
-   gcse) and it's currently not easy to realloc sbitmap vectors.  */
-static sbitmap *reg_set_in_block;
-
 /* Array, indexed by basic block number for a list of insns which modify
    memory within that block.  */
 static rtx * modify_mem_list;
@@ -519,17 +450,12 @@ static int global_copy_prop_count;
 static sbitmap *ae_kill, *ae_gen;
 
 static void compute_can_copy (void);
+static void recompute_all_luids (void);
 static void *gmalloc (size_t) ATTRIBUTE_MALLOC;
 static void *gcalloc (size_t, size_t) ATTRIBUTE_MALLOC;
-static void *grealloc (void *, size_t);
 static void *gcse_alloc (unsigned long);
 static void alloc_gcse_mem (void);
 static void free_gcse_mem (void);
-static void alloc_reg_set_mem (int);
-static void free_reg_set_mem (void);
-static void record_one_set (int, rtx);
-static void record_set_info (rtx, const_rtx, void *);
-static void compute_sets (void);
 static void hash_scan_insn (rtx, struct hash_table *);
 static void hash_scan_set (rtx, rtx, struct hash_table *);
 static void hash_scan_clobber (rtx, rtx, struct hash_table *);
@@ -655,11 +581,9 @@ static bool is_too_expensive (const char *);

 #define GNEWVEC(T, N)		((T *) gmalloc (sizeof (T) * (N)))
 #define GCNEWVEC(T, N)		((T *) gcalloc ((N), sizeof (T)))
-#define GRESIZEVEC(T, P, N)	((T *) grealloc ((void *) (P), sizeof (T) * (N)))

 #define GNEWVAR(T, S)		((T *) gmalloc ((S)))
 #define GCNEWVAR(T, S)		((T *) gcalloc (1, (S)))
-#define GRESIZEVAR(T, P, S)	((T *) grealloc ((P), (S)))

 #define GOBNEW(T)		((T *) gcse_alloc (sizeof (T)))
 #define GOBNEWVAR(T, S)		((T *) gcse_alloc ((S)))
@@ -705,21 +629,6 @@ gcse_main (rtx f ATTRIBUTE_UNUSED)
   /* We need alias.  */
   init_alias_analysis ();

-  /* Record where pseudo-registers are set.  This data is kept accurate
-     during each pass.  ??? We could also record hard-reg information here
-     [since it's unchanging], however it is currently done during hash table
-     computation.
-
-     It may be tempting to compute MEM set information here too, but MEM sets
-     will be subject to code motion one day and thus we need to compute
-     information about memory sets when we build the hash tables.
-
-     ??? Actually, we already know the information that compute_sets computes
-     because it is available from DF.  FIXME.  */
-
-  alloc_reg_set_mem (max_gcse_regno);
-  compute_sets ();
-
   gcse_obstack_bottom = GOBNEWVAR (char, 1);
   changed = 0;

@@ -736,6 +645,8 @@ gcse_main (rtx f ATTRIBUTE_UNUSED)
     {
       timevar_push (TV_CPROP1);
       changed = one_cprop_pass (1, false, false);
+      if (changed)
+        recompute_all_luids ();
       timevar_pop (TV_CPROP1);
     }

@@ -757,12 +668,7 @@ gcse_main (rtx f ATTRIBUTE_UNUSED)
 	  canon_modify_mem_list = GCNEWVEC (rtx, last_basic_block);
 	}

-      /* ??? When we allocate this at the start of the function,
-	 the comment says that "this data is kept accurate during
-	 each pass".  Apparently this is not so?  FIXME.  */
-      free_reg_set_mem ();
-      alloc_reg_set_mem (max_reg_num ());
-      compute_sets ();
+      df_analyze ();
       run_jump_opt_after_gcse = 1;
       timevar_pop (TV_PRE);
     }
@@ -799,7 +705,9 @@ gcse_main (rtx f ATTRIBUTE_UNUSED)

       /* This time, go ahead and allow cprop to alter jumps.  */
       timevar_push (TV_CPROP2);
-      one_cprop_pass (2, true, true);
+      changed = one_cprop_pass (2, true, true);
+      if (changed)
+        recompute_all_luids ();
       timevar_pop (TV_CPROP2);
       free_gcse_mem ();
     }
@@ -812,7 +720,6 @@ gcse_main (rtx f ATTRIBUTE_UNUSED)
     }

   obstack_free (&gcse_obstack, NULL);
-  free_reg_set_mem ();

   /* We are finished with alias.
      ??? Actually we recompute alias in store_motion.  */
@@ -882,6 +789,20 @@ can_copy_p (enum machine_mode mode)

   return can_copy[mode] != 0;
 }
+
+/* Recompute the DF LUIDs for all basic blocks.  If a sub-pass in this
+   file changes something, we have to recompute them for the next pass.
+   FIXME: If we would track which basic blocks we touch, we could
+	  update LUIDs in only those basic blocks.  */
+
+static void
+recompute_all_luids (void)
+{
+  basic_block bb;
+  FOR_EACH_BB (bb)
+    df_recompute_luids (bb);
+}
+
 
 /* Cover function to xmalloc to record bytes allocated.  */

@@ -901,16 +822,6 @@ gcalloc (size_t nelem, size_t elsize)
   return xcalloc (nelem, elsize);
 }

-/* Cover function to xrealloc.
-   We don't record the additional size since we don't know it.
-   It won't affect memory usage stats much anyway.  */
-
-static void *
-grealloc (void *ptr, size_t size)
-{
-  return xrealloc (ptr, size);
-}
-
 /* Cover function to obstack_alloc.  */

 static void *
@@ -920,43 +831,15 @@ gcse_alloc (unsigned long size)
   return obstack_alloc (&gcse_obstack, size);
 }

-/* Allocate memory for the cuid mapping array,
-   and reg/memory set tracking tables.
-
+/* Allocate memory for the reg/memory set tracking tables.
    This is called at the start of each pass.  */

 static void
 alloc_gcse_mem (void)
 {
-  int i;
-  basic_block bb;
-  rtx insn;
-
-  /* Find the largest UID and create a mapping from UIDs to CUIDs.
-     CUIDs are like UIDs except they increase monotonically, have no gaps,
-     and only apply to real insns.
-     (Actually, there are gaps, for insn that are not inside a basic block.
-     but we should never see those anyway, so this is OK.)  */
-
-  max_uid = get_max_uid ();
-  uid_cuid = GCNEWVEC (int, max_uid + 1);
-  i = 0;
-  FOR_EACH_BB (bb)
-    FOR_BB_INSNS (bb, insn)
-      {
-	if (INSN_P (insn))
-	  uid_cuid[INSN_UID (insn)] = i++;
-	else
-	  uid_cuid[INSN_UID (insn)] = i;
-      }
-
-  max_cuid = i;
-
   /* Allocate vars to track sets of regs.  */
   reg_set_bitmap = BITMAP_ALLOC (NULL);

-  /* Allocate vars to track sets of regs, memory per block.  */
-  reg_set_in_block = sbitmap_vector_alloc (last_basic_block, max_gcse_regno);
   /* Allocate array to keep a list of insns which modify memory in each
      basic block.  */
   modify_mem_list = GCNEWVEC (rtx, last_basic_block);
@@ -970,11 +853,6 @@ alloc_gcse_mem (void)
 static void
 free_gcse_mem (void)
 {
-  free (uid_cuid);
-
-  BITMAP_FREE (reg_set_bitmap);
-
-  sbitmap_vector_free (reg_set_in_block);
   free_modify_mem_tables ();
   BITMAP_FREE (modify_mem_list_set);
   BITMAP_FREE (blocks_with_calls);
@@ -1073,85 +951,6 @@ compute_local_properties (sbitmap *transp, sbitmap
     }
 }
 
-/* Register set information.
-
-   `reg_set_table' records where each register is set or otherwise
-   modified.  */
-
-static struct obstack reg_set_obstack;
-
-static void
-alloc_reg_set_mem (int n_regs)
-{
-  reg_set_table_size = n_regs + REG_SET_TABLE_SLOP;
-  reg_set_table = GCNEWVEC (struct reg_set *, reg_set_table_size);
-
-  gcc_obstack_init (&reg_set_obstack);
-}
-
-static void
-free_reg_set_mem (void)
-{
-  free (reg_set_table);
-  obstack_free (&reg_set_obstack, NULL);
-}
-
-/* Record REGNO in the reg_set table.  */
-
-static void
-record_one_set (int regno, rtx insn)
-{
-  /* Allocate a new reg_set element and link it onto the list.  */
-  struct reg_set *new_reg_info;
-
-  /* If the table isn't big enough, enlarge it.  */
-  if (regno >= reg_set_table_size)
-    {
-      int new_size = regno + REG_SET_TABLE_SLOP;
-
-      reg_set_table = GRESIZEVEC (struct reg_set *, reg_set_table, new_size);
-      memset (reg_set_table + reg_set_table_size, 0,
-	      (new_size - reg_set_table_size) * sizeof (struct reg_set *));
-      reg_set_table_size = new_size;
-    }
-
-  new_reg_info = XOBNEW (&reg_set_obstack, struct reg_set);
-  bytes_used += sizeof (struct reg_set);
-  new_reg_info->bb_index = BLOCK_NUM (insn);
-  new_reg_info->next = reg_set_table[regno];
-  reg_set_table[regno] = new_reg_info;
-}
-
-/* Called from compute_sets via note_stores to handle one SET or CLOBBER in
-   an insn.  The DATA is really the instruction in which the SET is
-   occurring.  */
-
-static void
-record_set_info (rtx dest, const_rtx setter ATTRIBUTE_UNUSED, void *data)
-{
-  rtx record_set_insn = (rtx) data;
-
-  if (REG_P (dest) && REGNO (dest) >= FIRST_PSEUDO_REGISTER)
-    record_one_set (REGNO (dest), record_set_insn);
-}
-
-/* Scan the function and record each set of each pseudo-register.
-
-   This is called once, at the start of the gcse pass.  See the comments for
-   `reg_set_table' for further documentation.  */
-
-static void
-compute_sets (void)
-{
-  basic_block bb;
-  rtx insn;
-
-  FOR_EACH_BB (bb)
-    FOR_BB_INSNS (bb, insn)
-      if (INSN_P (insn))
-	note_stores (PATTERN (insn), record_set_info, insn);
-}
-
 /* Hash table support.  */

 struct reg_avail_info
@@ -1257,13 +1056,13 @@ oprs_unchanged_p (const_rtx x, const_rtx insn, int
 	if (info->last_bb != current_bb)
 	  return 1;
 	if (avail_p)
-	  return info->last_set < INSN_CUID (insn);
+	  return info->last_set < DF_INSN_LUID (insn);
 	else
-	  return info->first_set >= INSN_CUID (insn);
+	  return info->first_set >= DF_INSN_LUID (insn);
       }

     case MEM:
-      if (load_killed_in_block_p (current_bb, INSN_CUID (insn),
+      if (load_killed_in_block_p (current_bb, DF_INSN_LUID (insn),
 				  x, avail_p))
 	return 0;
       else
@@ -1362,7 +1161,7 @@ mems_conflict_for_gcse_p (rtx dest, const_rtx sett
 }

 /* Return nonzero if the expression in X (a memory reference) is killed
-   in block BB before or after the insn with the CUID in UID_LIMIT.
+   in block BB before or after the insn with the LUID in UID_LIMIT.
    AVAIL_P is nonzero for kills after UID_LIMIT, and zero for kills
    before UID_LIMIT.

@@ -1383,9 +1182,9 @@ load_killed_in_block_p (const_basic_block bb, int
       rtx setter;
       /* Ignore entries in the list that do not apply.  */
       if ((avail_p
-	   && INSN_CUID (XEXP (list_entry, 0)) < uid_limit)
+	   && DF_INSN_LUID (XEXP (list_entry, 0)) < uid_limit)
 	  || (! avail_p
-	      && INSN_CUID (XEXP (list_entry, 0)) > uid_limit))
+	      && DF_INSN_LUID (XEXP (list_entry, 0)) > uid_limit))
 	{
 	  list_entry = XEXP (list_entry, 1);
 	  continue;
@@ -1923,23 +1722,19 @@ dump_hash_table (FILE *file, const char *name, str
    is set and is used to compute "availability".

    last_bb records the block for which first_set and last_set are
-   valid, as a quick test to invalidate them.
+   valid, as a quick test to invalidate them.  */

-   reg_set_in_block records whether the register is set in the block
-   and is used to compute "transparency".  */
-
 static void
 record_last_reg_set_info (rtx insn, int regno)
 {
   struct reg_avail_info *info = &reg_avail_info[regno];
-  int cuid = INSN_CUID (insn);
+  int luid = DF_INSN_LUID (insn);

-  info->last_set = cuid;
+  info->last_set = luid;
   if (info->last_bb != current_bb)
     {
       info->last_bb = current_bb;
-      info->first_set = cuid;
-      SET_BIT (reg_set_in_block[current_bb->index], regno);
+      info->first_set = luid;
     }
 }

@@ -2046,12 +1841,6 @@ compute_hash_table_work (struct hash_table *table)
 {
   unsigned int i;

-  /* While we compute the hash table we also compute a bit array of which
-     registers are set in which blocks.
-     ??? This isn't needed during const/copy propagation, but it's cheap to
-     compute.  Later.  */
-  sbitmap_vector_zero (reg_set_in_block, last_basic_block);
-
   /* re-Cache any INSN_LIST nodes we have allocated.  */
   clear_modify_mem_tables ();
   /* Some working arrays used to track first and last set in each block.  */
@@ -2066,10 +1855,7 @@ compute_hash_table_work (struct hash_table *table)
       unsigned int regno;

       /* First pass over the instructions records information used to
-	 determine when registers and memory are first and last set.
-	 ??? hard-reg reg_set_in_block computation
-	 could be moved to compute_sets since they currently don't change.  */
-
+	 determine when registers and memory are first and last set.  */
       FOR_BB_INSNS (current_bb, insn)
 	{
 	  if (! INSN_P (insn))
@@ -2274,7 +2060,7 @@ oprs_not_set_p (const_rtx x, const_rtx insn)

     case MEM:
       if (load_killed_in_block_p (BLOCK_FOR_INSN (insn),
-				  INSN_CUID (insn), x, 0))
+				  DF_INSN_LUID (insn), x, 0))
 	return 0;
       else
 	return oprs_not_set_p (XEXP (x, 0), insn);
@@ -2429,9 +2215,7 @@ static void
 compute_transp (const_rtx x, int indx, sbitmap *bmap, int set_p)
 {
   int i, j;
-  basic_block bb;
   enum rtx_code code;
-  reg_set *r;
   const char *fmt;

   /* repeat is used to turn tail-recursion into iteration since GCC
@@ -2447,31 +2231,19 @@ compute_transp (const_rtx x, int indx, sbitmap *bm
     case REG:
       if (set_p)
 	{
-	  if (REGNO (x) < FIRST_PSEUDO_REGISTER)
-	    {
-	      FOR_EACH_BB (bb)
-		if (TEST_BIT (reg_set_in_block[bb->index], REGNO (x)))
-		  SET_BIT (bmap[bb->index], indx);
-	    }
-	  else
-	    {
-	      for (r = reg_set_table[REGNO (x)]; r != NULL; r = r->next)
-		SET_BIT (bmap[r->bb_index], indx);
-	    }
+	  df_ref def;
+	  for (def = DF_REG_DEF_CHAIN (REGNO (x));
+	       def;
+	       def = DF_REF_NEXT_REG (def))
+	    SET_BIT (bmap[DF_REF_BB (def)->index], indx);
 	}
       else
 	{
-	  if (REGNO (x) < FIRST_PSEUDO_REGISTER)
-	    {
-	      FOR_EACH_BB (bb)
-		if (TEST_BIT (reg_set_in_block[bb->index], REGNO (x)))
-		  RESET_BIT (bmap[bb->index], indx);
-	    }
-	  else
-	    {
-	      for (r = reg_set_table[REGNO (x)]; r != NULL; r = r->next)
-		RESET_BIT (bmap[r->bb_index], indx);
-	    }
+	  df_ref def;
+	  for (def = DF_REG_DEF_CHAIN (REGNO (x));
+	       def;
+	       def = DF_REF_NEXT_REG (def))
+	    RESET_BIT (bmap[DF_REF_BB (def)->index], indx);
 	}

       return;
@@ -3188,12 +2960,7 @@ local_cprop_pass (bool alter_jumps)

   /* Global analysis may get into infinite loops for unreachable blocks.  */
   if (changed && alter_jumps)
-    {
-      delete_unreachable_blocks ();
-      free_reg_set_mem ();
-      alloc_reg_set_mem (max_reg_num ());
-      compute_sets ();
-    }
+    delete_unreachable_blocks ();
 }

 /* Forward propagate copies.  This includes copies and constants.  Return
@@ -3359,7 +3126,7 @@ one_cprop_pass (int pass, bool cprop_jumps, bool b
   implicit_sets = XCNEWVEC (rtx, last_basic_block);
   find_implicit_sets ();

-  alloc_hash_table (max_cuid, &set_hash_table, 1);
+  alloc_hash_table (get_max_uid (), &set_hash_table, 1);
   compute_hash_table (&set_hash_table);

   /* Free implicit_sets before peak usage.  */
@@ -3720,9 +3487,6 @@ static sbitmap *pre_delete_map;
 /* Contains the edge_list returned by pre_edge_lcm.  */
 static struct edge_list *edge_list;

-/* Redundant insns.  */
-static sbitmap pre_redundant_insns;
-
 /* Allocate vars used for PRE analysis.  */

 static void
@@ -4045,10 +3809,7 @@ insert_insn_end_basic_block (struct expr *expr, ba
   while (1)
     {
       if (INSN_P (pat))
-	{
-	  add_label_notes (PATTERN (pat), new_insn);
-	  note_stores (PATTERN (pat), record_set_info, pat);
-	}
+	add_label_notes (PATTERN (pat), new_insn);
       if (pat == pat_end)
 	break;
       pat = NEXT_INSN (pat);
@@ -4221,17 +3982,11 @@ pre_insert_copy_insn (struct expr *expr, rtx insn)
         {
           new_insn = gen_move_insn (old_reg, reg);
           new_insn = emit_insn_after (new_insn, insn);
-
-          /* Keep register set table up to date.  */
-          record_one_set (regno, insn);
         }
       else
         {
           new_insn = gen_move_insn (reg, old_reg);
           new_insn = emit_insn_after (new_insn, insn);
-
-          /* Keep register set table up to date.  */
-          record_one_set (regno, new_insn);
         }
     }
   else /* This is possible only in case of a store to memory.  */
@@ -4244,9 +3999,6 @@ pre_insert_copy_insn (struct expr *expr, rtx insn)
         new_insn = emit_insn_before (new_insn, insn);
       else
         new_insn = emit_insn_after (new_insn, insn);
-
-      /* Keep register set table up to date.  */
-      record_one_set (regno, new_insn);
     }

   gcse_create_count++;
@@ -4303,7 +4055,7 @@ pre_insert_copies (void)
 		  continue;

 		/* Don't handle this one if it's a redundant one.  */
-		if (TEST_BIT (pre_redundant_insns, INSN_CUID (insn)))
+		if (INSN_DELETED_P (insn))
 		  continue;

 		/* Or if the expression doesn't reach the deleted one.  */
@@ -4400,7 +4152,6 @@ pre_delete (void)
 		gcse_emit_move_after (expr->reaching_reg, SET_DEST (set), insn);
 		delete_insn (insn);
 		occr->deleted_p = 1;
-		SET_BIT (pre_redundant_insns, INSN_CUID (insn));
 		changed = 1;
 		gcse_subst_count++;

@@ -4455,10 +4206,6 @@ pre_gcse (void)
     for (expr = expr_hash_table.table[i]; expr != NULL; expr =
expr->next_same_hash)
       index_map[expr->bitmap_index] = expr;

-  /* Reset bitmap used to track which insns are redundant.  */
-  pre_redundant_insns = sbitmap_alloc (max_cuid);
-  sbitmap_zero (pre_redundant_insns);
-
   /* Delete the redundant insns first so that
      - we know what register to use for the new insns and for the other
        ones with reaching expressions
@@ -4477,7 +4224,6 @@ pre_gcse (void)
     }

   free (index_map);
-  sbitmap_free (pre_redundant_insns);
   return changed;
 }

@@ -4493,7 +4239,7 @@ one_pre_gcse_pass (int pass)
   gcse_subst_count = 0;
   gcse_create_count = 0;

-  alloc_hash_table (max_cuid, &expr_hash_table, 0);
+  alloc_hash_table (get_max_uid (), &expr_hash_table, 0);
   add_noreturn_fake_exit_edges ();
   if (flag_gcse_lm)
     compute_ld_motion_mems ();
@@ -4947,7 +4693,7 @@ one_code_hoisting_pass (void)
 {
   int changed = 0;

-  alloc_hash_table (max_cuid, &expr_hash_table, 0);
+  alloc_hash_table (get_max_uid (), &expr_hash_table, 0);
   compute_hash_table (&expr_hash_table);
   if (dump_file)
     dump_hash_table (dump_file, "Code Hosting Expressions", &expr_hash_table);
@@ -5393,10 +5139,9 @@ update_ld_motion_stores (struct expr * expr)
 	      fprintf (dump_file, "\n");
 	    }

-	  copy = gen_move_insn ( reg, copy_rtx (SET_SRC (pat)));
+	  copy = gen_move_insn (reg, copy_rtx (SET_SRC (pat)));
 	  new_rtx = emit_insn_before (copy, insn);
-	  record_one_set (REGNO (reg), new_rtx);
-	  SET_SRC (pat) = reg;
+	  SET_SRC (pat) = reg;
 	  df_insn_rescan (insn);

 	  /* un-recognize this pattern since it's probably different now.  */
@@ -5430,19 +5175,13 @@ static int num_stores;

 static void
 reg_set_info (rtx dest, const_rtx setter ATTRIBUTE_UNUSED,
-	      void *data)
+	      void *data ATTRIBUTE_UNUSED)
 {
-  sbitmap bb_reg = (sbitmap) data;
-
   if (GET_CODE (dest) == SUBREG)
     dest = SUBREG_REG (dest);

   if (REG_P (dest))
-    {
-      regvec[REGNO (dest)] = INSN_UID (compute_store_table_current_insn);
-      if (bb_reg)
-	SET_BIT (bb_reg, REGNO (dest));
-    }
+    regvec[REGNO (dest)] = INSN_UID (compute_store_table_current_insn);
 }

 /* Clear any mark that says that this insn sets dest.  Called from
@@ -5705,9 +5444,6 @@ compute_store_table (void)

   max_gcse_regno = max_reg_num ();

-  reg_set_in_block = sbitmap_vector_alloc (last_basic_block,
-						       max_gcse_regno);
-  sbitmap_vector_zero (reg_set_in_block, last_basic_block);
   pre_ldst_mems = 0;
   pre_ldst_table = htab_create (13, pre_ldst_expr_hash,
 				pre_ldst_expr_eq, NULL);
@@ -5729,15 +5465,12 @@ compute_store_table (void)
 	    {
 	      for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
 		if (TEST_HARD_REG_BIT (regs_invalidated_by_call, regno))
-		  {
-		    last_set_in[regno] = INSN_UID (insn);
-		    SET_BIT (reg_set_in_block[bb->index], regno);
-		  }
+		  last_set_in[regno] = INSN_UID (insn);
 	    }

 	  pat = PATTERN (insn);
 	  compute_store_table_current_insn = insn;
-	  note_stores (pat, reg_set_info, reg_set_in_block[bb->index]);
+	  note_stores (pat, reg_set_info, NULL);
 	}

       /* Now find the stores.  */
@@ -6029,7 +5762,6 @@ build_store_vectors (void)
   int *regs_set_in_block;
   rtx insn, st;
   struct ls_expr * ptr;
-  unsigned regno;

   /* Build the gen_vector. This is any store in the table which is not killed
      by aliasing later in its block.  */
@@ -6078,8 +5810,17 @@ build_store_vectors (void)

   FOR_EACH_BB (bb)
     {
-      for (regno = 0; regno < max_gcse_regno; regno++)
-	regs_set_in_block[regno] = TEST_BIT (reg_set_in_block[bb->index], regno);
+      FOR_BB_INSNS (bb, insn)
+	if (INSN_P (insn))
+	  {
+	    df_ref *def_rec;
+	    for (def_rec = DF_INSN_DEFS (insn); *def_rec; def_rec++)
+	      {
+		unsigned int ref_regno = DF_REF_REGNO (*def_rec);
+		if (ref_regno < max_gcse_regno)
+		  regs_set_in_block[DF_REF_REGNO (*def_rec)] = 1;
+	      }
+	  }

       for (ptr = first_ls_expr (); ptr != NULL; ptr = next_ls_expr (ptr))
 	{
@@ -6395,11 +6136,9 @@ free_store_memory (void)
     sbitmap_vector_free (pre_insert_map);
   if (pre_delete_map)
     sbitmap_vector_free (pre_delete_map);
-  if (reg_set_in_block)
-    sbitmap_vector_free (reg_set_in_block);

   ae_gen = ae_kill = transp = st_antloc = NULL;
-  pre_insert_map = pre_delete_map = reg_set_in_block = NULL;
+  pre_insert_map = pre_delete_map = NULL;
 }

 /* Perform store motion. Much like gcse, except we move expressions the
@@ -6427,7 +6166,6 @@ store_motion (void)
     {
       htab_delete (pre_ldst_table);
       pre_ldst_table = NULL;
-      sbitmap_vector_free (reg_set_in_block);
       end_alias_analysis ();
       return;
     }
@@ -6512,18 +6250,6 @@ bypass_jumps (void)
   /* We need alias.  */
   init_alias_analysis ();

-  /* Record where pseudo-registers are set.  This data is kept accurate
-     during each pass.  ??? We could also record hard-reg information here
-     [since it's unchanging], however it is currently done during hash table
-     computation.
-
-     It may be tempting to compute MEM set information here too, but MEM sets
-     will be subject to code motion one day and thus we need to compute
-     information about memory sets when we build the hash tables.  */
-
-  alloc_reg_set_mem (max_gcse_regno);
-  compute_sets ();
-
   max_gcse_regno = max_reg_num ();
   alloc_gcse_mem ();
   changed = one_cprop_pass (3, true, true);
@@ -6537,7 +6263,6 @@ bypass_jumps (void)
     }

   obstack_free (&gcse_obstack, NULL);
-  free_reg_set_mem ();

   /* We are finished with alias.  */
   end_alias_analysis ();


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