gcc.c-torture/execute/builtins/pr93262-chk.c: Remove return statement

[thirdparty/gcc.git] / gcc / config / riscv / riscv-vsetvl.cc

/* VSETVL pass for RISC-V 'V' Extension for GNU compiler.
   Copyright (C) 2022-2023 Free Software Foundation, Inc.
   Contributed by Juzhe Zhong (juzhe.zhong@rivai.ai), RiVAI Technologies Ltd.

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/>.  */

/* The values of the vl and vtype registers will affect the behavior of RVV
   insns. That is, when we need to execute an RVV instruction, we need to set
   the correct vl and vtype values by executing the vsetvl instruction before.
   Executing the fewest number of vsetvl instructions while keeping the behavior
   the same is the problem this pass is trying to solve. This vsetvl pass is
   divided into 5 phases:

     - Phase 1 (fuse local vsetvl infos): traverses each Basic Block, parses
       each instruction in it that affects vl and vtype state and generates an
       array of vsetvl_info objects. Then traverse the vsetvl_info array from
       front to back and perform fusion according to the fusion rules. The fused
       vsetvl infos are stored in the vsetvl_block_info object's `infos` field.

     - Phase 2 (earliest fuse global vsetvl infos): The header_info and
       footer_info of vsetvl_block_info are used as expressions, and the
       earliest of each expression is computed. Based on the earliest
       information, try to lift up the corresponding vsetvl info to the src
       basic block of the edge (mainly to reduce the total number of vsetvl
       instructions, this uplift will cause some execution paths to execute
       vsetvl instructions that shouldn't be there).

     - Phase 3 (pre global vsetvl info): The header_info and footer_info of
       vsetvl_block_info are used as expressions, and the LCM algorithm is used
       to compute the header_info that needs to be deleted and the one that
       needs to be inserted in some edges.

     - Phase 4 (emit vsetvl insns) : Based on the fusion result of Phase 1 and
       the deletion and insertion information of Phase 3, the mandatory vsetvl
       instruction insertion, modification and deletion are performed.

     - Phase 5 (cleanup): Clean up the avl operand in the RVV operator
       instruction and cleanup the unused dest operand of the vsetvl insn.

     After the Phase 1 a virtual CFG of vsetvl_info is generated. The virtual
     basic block is represented by vsetvl_block_info, and the virtual vsetvl
     statements inside are represented by vsetvl_info. The later phases 2 and 3
     are constantly modifying and adjusting this virtual CFG. Phase 4 performs
     insertion, modification and deletion of vsetvl instructions based on the
     optimized virtual CFG. The Phase 1, 2 and 3 do not involve modifications to
     the RTL.
*/

#define IN_TARGET_CODE 1
#define INCLUDE_ALGORITHM
#define INCLUDE_FUNCTIONAL

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "backend.h"
#include "rtl.h"
#include "target.h"
#include "tree-pass.h"
#include "df.h"
#include "rtl-ssa.h"
#include "cfgcleanup.h"
#include "insn-config.h"
#include "insn-attr.h"
#include "insn-opinit.h"
#include "tm-constrs.h"
#include "cfgrtl.h"
#include "cfganal.h"
#include "lcm.h"
#include "predict.h"
#include "profile-count.h"
#include "gcse.h"

using namespace rtl_ssa;
using namespace riscv_vector;

/* Set the bitmap DST to the union of SRC of predecessors of
   basic block B.
   It's a bit different from bitmap_union_of_preds in cfganal.cc. This function
   takes into account the case where pred is ENTRY basic block. The main reason
   for this difference is to make it easier to insert some special value into
   the ENTRY base block. For example, vsetvl_info with a status of UNKNOW.  */
static void
bitmap_union_of_preds_with_entry (sbitmap dst, sbitmap *src, basic_block b)
{
  unsigned int set_size = dst->size;
  edge e;
  unsigned ix;

  for (ix = 0; ix < EDGE_COUNT (b->preds); ix++)
    {
      e = EDGE_PRED (b, ix);
      bitmap_copy (dst, src[e->src->index]);
      break;
    }

  if (ix == EDGE_COUNT (b->preds))
    bitmap_clear (dst);
  else
    for (ix++; ix < EDGE_COUNT (b->preds); ix++)
      {
	unsigned int i;
	SBITMAP_ELT_TYPE *p, *r;

	e = EDGE_PRED (b, ix);
	p = src[e->src->index]->elms;
	r = dst->elms;
	for (i = 0; i < set_size; i++)
	  *r++ |= *p++;
      }
}

/* Compute the reaching defintion in and out based on the gen and KILL
   informations in each Base Blocks.
   This function references the compute_avaiable implementation in lcm.cc  */
static void
compute_reaching_defintion (sbitmap *gen, sbitmap *kill, sbitmap *in,
			    sbitmap *out)
{
  edge e;
  basic_block *worklist, *qin, *qout, *qend, bb;
  unsigned int qlen;
  edge_iterator ei;

  /* Allocate a worklist array/queue.  Entries are only added to the
     list if they were not already on the list.  So the size is
     bounded by the number of basic blocks.  */
  qin = qout = worklist
    = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS);

  /* Put every block on the worklist; this is necessary because of the
     optimistic initialization of AVOUT above.  Use reverse postorder
     to make the forward dataflow problem require less iterations.  */
  int *rpo = XNEWVEC (int, n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS);
  int n = pre_and_rev_post_order_compute_fn (cfun, NULL, rpo, false);
  for (int i = 0; i < n; ++i)
    {
      bb = BASIC_BLOCK_FOR_FN (cfun, rpo[i]);
      *qin++ = bb;
      bb->aux = bb;
    }
  free (rpo);

  qin = worklist;
  qend = &worklist[n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS];
  qlen = n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS;

  /* Mark blocks which are successors of the entry block so that we
     can easily identify them below.  */
  FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR_FOR_FN (cfun)->succs)
    e->dest->aux = ENTRY_BLOCK_PTR_FOR_FN (cfun);

  /* Iterate until the worklist is empty.  */
  while (qlen)
    {
      /* Take the first entry off the worklist.  */
      bb = *qout++;
      qlen--;

      if (qout >= qend)
	qout = worklist;

      /* Do not clear the aux field for blocks which are successors of the
	 ENTRY block.  That way we never add then to the worklist again.  */
      if (bb->aux != ENTRY_BLOCK_PTR_FOR_FN (cfun))
	bb->aux = NULL;

      bitmap_union_of_preds_with_entry (in[bb->index], out, bb);

      if (bitmap_ior_and_compl (out[bb->index], gen[bb->index], in[bb->index],
				kill[bb->index]))
	/* If the out state of this block changed, then we need
	   to add the successors of this block to the worklist
	   if they are not already on the worklist.  */
	FOR_EACH_EDGE (e, ei, bb->succs)
	  if (!e->dest->aux && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun))
	    {
	      *qin++ = e->dest;
	      e->dest->aux = e;
	      qlen++;

	      if (qin >= qend)
		qin = worklist;
	    }
    }

  clear_aux_for_edges ();
  clear_aux_for_blocks ();
  free (worklist);
}

/* Classification of vsetvl instruction.  */
enum vsetvl_type
{
  VSETVL_NORMAL,
  VSETVL_VTYPE_CHANGE_ONLY,
  VSETVL_DISCARD_RESULT,
  NUM_VSETVL_TYPE
};

enum emit_type
{
  /* emit_insn directly.  */
  EMIT_DIRECT,
  EMIT_BEFORE,
  EMIT_AFTER,
};

/* dump helper functions */
static const char *
vlmul_to_str (vlmul_type vlmul)
{
  switch (vlmul)
    {
    case LMUL_1:
      return "m1";
    case LMUL_2:
      return "m2";
    case LMUL_4:
      return "m4";
    case LMUL_8:
      return "m8";
    case LMUL_RESERVED:
      return "INVALID LMUL";
    case LMUL_F8:
      return "mf8";
    case LMUL_F4:
      return "mf4";
    case LMUL_F2:
      return "mf2";

    default:
      gcc_unreachable ();
    }
}

static const char *
policy_to_str (bool agnostic_p)
{
  return agnostic_p ? "agnostic" : "undisturbed";
}

static bool
vlmax_avl_p (rtx x)
{
  return x && rtx_equal_p (x, RVV_VLMAX);
}

/* Return true if it is an RVV instruction depends on VTYPE global
   status register.  */
static bool
has_vtype_op (rtx_insn *rinsn)
{
  return recog_memoized (rinsn) >= 0 && get_attr_has_vtype_op (rinsn);
}

/* Return true if it is an RVV instruction depends on VL global
   status register.  */
static bool
has_vl_op (rtx_insn *rinsn)
{
  return recog_memoized (rinsn) >= 0 && get_attr_has_vl_op (rinsn);
}

/* Return true if the instruction ignores VLMUL field of VTYPE.  */
static bool
ignore_vlmul_insn_p (rtx_insn *rinsn)
{
  return get_attr_type (rinsn) == TYPE_VIMOVVX
	 || get_attr_type (rinsn) == TYPE_VFMOVVF
	 || get_attr_type (rinsn) == TYPE_VIMOVXV
	 || get_attr_type (rinsn) == TYPE_VFMOVFV;
}

/* Return true if the instruction is scalar move instruction.  */
static bool
scalar_move_insn_p (rtx_insn *rinsn)
{
  return get_attr_type (rinsn) == TYPE_VIMOVXV
	 || get_attr_type (rinsn) == TYPE_VFMOVFV;
}

/* Return true if the instruction is fault first load instruction.  */
static bool
fault_first_load_p (rtx_insn *rinsn)
{
  return recog_memoized (rinsn) >= 0
	 && (get_attr_type (rinsn) == TYPE_VLDFF
	     || get_attr_type (rinsn) == TYPE_VLSEGDFF);
}

/* Return true if the instruction is read vl instruction.  */
static bool
read_vl_insn_p (rtx_insn *rinsn)
{
  return recog_memoized (rinsn) >= 0 && get_attr_type (rinsn) == TYPE_RDVL;
}

/* Return true if it is a vsetvl instruction.  */
static bool
vector_config_insn_p (rtx_insn *rinsn)
{
  return recog_memoized (rinsn) >= 0 && get_attr_type (rinsn) == TYPE_VSETVL;
}

/* Return true if it is vsetvldi or vsetvlsi.  */
static bool
vsetvl_insn_p (rtx_insn *rinsn)
{
  if (!rinsn || !vector_config_insn_p (rinsn))
    return false;
  return (INSN_CODE (rinsn) == CODE_FOR_vsetvldi
	  || INSN_CODE (rinsn) == CODE_FOR_vsetvlsi);
}

/* Return true if it is vsetvl zero, rs1.  */
static bool
vsetvl_discard_result_insn_p (rtx_insn *rinsn)
{
  if (!vector_config_insn_p (rinsn))
    return false;
  return (INSN_CODE (rinsn) == CODE_FOR_vsetvl_discard_resultdi
	  || INSN_CODE (rinsn) == CODE_FOR_vsetvl_discard_resultsi);
}

static bool
real_insn_and_same_bb_p (const insn_info *insn, const bb_info *bb)
{
  return insn != nullptr && insn->is_real () && insn->bb () == bb;
}

/* Helper function to get VL operand for VLMAX insn.  */
static rtx
get_vl (rtx_insn *rinsn)
{
  if (has_vl_op (rinsn))
    {
      extract_insn_cached (rinsn);
      return recog_data.operand[get_attr_vl_op_idx (rinsn)];
    }
  return SET_DEST (XVECEXP (PATTERN (rinsn), 0, 0));
}

/* Helper function to get AVL operand.  */
static rtx
get_avl (rtx_insn *rinsn)
{
  if (vsetvl_insn_p (rinsn) || vsetvl_discard_result_insn_p (rinsn))
    return XVECEXP (SET_SRC (XVECEXP (PATTERN (rinsn), 0, 0)), 0, 0);

  if (!has_vl_op (rinsn))
    return NULL_RTX;
  if (get_attr_avl_type (rinsn) == VLMAX)
    return RVV_VLMAX;
  extract_insn_cached (rinsn);
  return recog_data.operand[get_attr_vl_op_idx (rinsn)];
}

/* Helper function to get SEW operand. We always have SEW value for
   all RVV instructions that have VTYPE OP.  */
static uint8_t
get_sew (rtx_insn *rinsn)
{
  return get_attr_sew (rinsn);
}

/* Helper function to get VLMUL operand. We always have VLMUL value for
   all RVV instructions that have VTYPE OP. */
static enum vlmul_type
get_vlmul (rtx_insn *rinsn)
{
  return (enum vlmul_type) get_attr_vlmul (rinsn);
}

/* Get default tail policy.  */
static bool
get_default_ta ()
{
  /* For the instruction that doesn't require TA, we still need a default value
     to emit vsetvl. We pick up the default value according to prefer policy. */
  return (bool) (get_prefer_tail_policy () & 0x1
		 || (get_prefer_tail_policy () >> 1 & 0x1));
}

/* Get default mask policy.  */
static bool
get_default_ma ()
{
  /* For the instruction that doesn't require MA, we still need a default value
     to emit vsetvl. We pick up the default value according to prefer policy. */
  return (bool) (get_prefer_mask_policy () & 0x1
		 || (get_prefer_mask_policy () >> 1 & 0x1));
}

/* Helper function to get TA operand.  */
static bool
tail_agnostic_p (rtx_insn *rinsn)
{
  /* If it doesn't have TA, we return agnostic by default.  */
  extract_insn_cached (rinsn);
  int ta = get_attr_ta (rinsn);
  return ta == INVALID_ATTRIBUTE ? get_default_ta () : IS_AGNOSTIC (ta);
}

/* Helper function to get MA operand.  */
static bool
mask_agnostic_p (rtx_insn *rinsn)
{
  /* If it doesn't have MA, we return agnostic by default.  */
  extract_insn_cached (rinsn);
  int ma = get_attr_ma (rinsn);
  return ma == INVALID_ATTRIBUTE ? get_default_ma () : IS_AGNOSTIC (ma);
}

/* Return true if FN has a vector instruction that use VL/VTYPE.  */
static bool
has_vector_insn (function *fn)
{
  basic_block cfg_bb;
  rtx_insn *rinsn;
  FOR_ALL_BB_FN (cfg_bb, fn)
    FOR_BB_INSNS (cfg_bb, rinsn)
      if (NONDEBUG_INSN_P (rinsn) && has_vtype_op (rinsn))
	return true;
  return false;
}

static vlmul_type
calculate_vlmul (unsigned int sew, unsigned int ratio)
{
  const vlmul_type ALL_LMUL[]
    = {LMUL_1, LMUL_2, LMUL_4, LMUL_8, LMUL_F8, LMUL_F4, LMUL_F2};
  for (const vlmul_type vlmul : ALL_LMUL)
    if (calculate_ratio (sew, vlmul) == ratio)
      return vlmul;
  return LMUL_RESERVED;
}

/* Get the currently supported maximum sew used in the int rvv instructions. */
static uint8_t
get_max_int_sew ()
{
  if (TARGET_VECTOR_ELEN_64)
    return 64;
  else if (TARGET_VECTOR_ELEN_32)
    return 32;
  gcc_unreachable ();
}

/* Get the currently supported maximum sew used in the float rvv instructions.
 */
static uint8_t
get_max_float_sew ()
{
  if (TARGET_VECTOR_ELEN_FP_64)
    return 64;
  else if (TARGET_VECTOR_ELEN_FP_32)
    return 32;
  else if (TARGET_VECTOR_ELEN_FP_16)
    return 16;
  gcc_unreachable ();
}

/* Count the number of REGNO in RINSN.  */
static int
count_regno_occurrences (rtx_insn *rinsn, unsigned int regno)
{
  int count = 0;
  extract_insn (rinsn);
  for (int i = 0; i < recog_data.n_operands; i++)
    if (refers_to_regno_p (regno, recog_data.operand[i]))
      count++;
  return count;
}

enum def_type
{
  REAL_SET = 1 << 0,
  PHI_SET = 1 << 1,
  BB_HEAD_SET = 1 << 2,
  BB_END_SET = 1 << 3,
  /* ??? TODO: In RTL_SSA framework, we have REAL_SET,
     PHI_SET, BB_HEAD_SET, BB_END_SET and
     CLOBBER_DEF def_info types. Currently,
     we conservatively do not optimize clobber
     def since we don't see the case that we
     need to optimize it.  */
  CLOBBER_DEF = 1 << 4
};

static bool
insn_should_be_added_p (const insn_info *insn, unsigned int types)
{
  if (insn->is_real () && (types & REAL_SET))
    return true;
  if (insn->is_phi () && (types & PHI_SET))
    return true;
  if (insn->is_bb_head () && (types & BB_HEAD_SET))
    return true;
  if (insn->is_bb_end () && (types & BB_END_SET))
    return true;
  return false;
}

static const hash_set<use_info *>
get_all_real_uses (insn_info *insn, unsigned regno)
{
  gcc_assert (insn->is_real ());

  hash_set<use_info *> uses;
  auto_vec<phi_info *> work_list;
  hash_set<phi_info *> visited_list;

  for (def_info *def : insn->defs ())
    {
      if (!def->is_reg () || def->regno () != regno)
	continue;
      set_info *set = safe_dyn_cast<set_info *> (def);
      if (!set)
	continue;
      for (use_info *use : set->nondebug_insn_uses ())
	if (use->insn ()->is_real ())
	  uses.add (use);
      for (use_info *use : set->phi_uses ())
	work_list.safe_push (use->phi ());
    }

  while (!work_list.is_empty ())
    {
      phi_info *phi = work_list.pop ();
      visited_list.add (phi);

      for (use_info *use : phi->nondebug_insn_uses ())
	if (use->insn ()->is_real ())
	  uses.add (use);
      for (use_info *use : phi->phi_uses ())
	if (!visited_list.contains (use->phi ()))
	  work_list.safe_push (use->phi ());
    }
  return uses;
}

/* Recursively find all define instructions. The kind of instruction is
   specified by the DEF_TYPE.  */
static hash_set<set_info *>
get_all_sets (phi_info *phi, unsigned int types)
{
  hash_set<set_info *> insns;
  auto_vec<phi_info *> work_list;
  hash_set<phi_info *> visited_list;
  if (!phi)
    return hash_set<set_info *> ();
  work_list.safe_push (phi);

  while (!work_list.is_empty ())
    {
      phi_info *phi = work_list.pop ();
      visited_list.add (phi);
      for (use_info *use : phi->inputs ())
	{
	  def_info *def = use->def ();
	  set_info *set = safe_dyn_cast<set_info *> (def);
	  if (!set)
	    return hash_set<set_info *> ();

	  gcc_assert (!set->insn ()->is_debug_insn ());

	  if (insn_should_be_added_p (set->insn (), types))
	    insns.add (set);
	  if (set->insn ()->is_phi ())
	    {
	      phi_info *new_phi = as_a<phi_info *> (set);
	      if (!visited_list.contains (new_phi))
		work_list.safe_push (new_phi);
	    }
	}
    }
  return insns;
}

static hash_set<set_info *>
get_all_sets (set_info *set, bool /* get_real_inst */ real_p,
	      bool /*get_phi*/ phi_p, bool /* get_function_parameter*/ param_p)
{
  if (real_p && phi_p && param_p)
    return get_all_sets (safe_dyn_cast<phi_info *> (set),
			 REAL_SET | PHI_SET | BB_HEAD_SET | BB_END_SET);

  else if (real_p && param_p)
    return get_all_sets (safe_dyn_cast<phi_info *> (set),
			 REAL_SET | BB_HEAD_SET | BB_END_SET);

  else if (real_p)
    return get_all_sets (safe_dyn_cast<phi_info *> (set), REAL_SET);
  return hash_set<set_info *> ();
}

static bool
source_equal_p (insn_info *insn1, insn_info *insn2)
{
  if (!insn1 || !insn2)
    return false;
  rtx_insn *rinsn1 = insn1->rtl ();
  rtx_insn *rinsn2 = insn2->rtl ();
  if (!rinsn1 || !rinsn2)
    return false;

  rtx note1 = find_reg_equal_equiv_note (rinsn1);
  rtx note2 = find_reg_equal_equiv_note (rinsn2);
  if (note1 && note2 && rtx_equal_p (note1, note2))
    return true;
  return false;
}

static insn_info *
extract_single_source (set_info *set)
{
  if (!set)
    return nullptr;
  if (set->insn ()->is_real ())
    return set->insn ();
  if (!set->insn ()->is_phi ())
    return nullptr;
  hash_set<set_info *> sets = get_all_sets (set, true, false, true);

  insn_info *first_insn = (*sets.begin ())->insn ();
  if (first_insn->is_artificial ())
    return nullptr;
  for (const set_info *set : sets)
    {
      /* If there is a head or end insn, we conservative return
	 NULL so that VSETVL PASS will insert vsetvl directly.  */
      if (set->insn ()->is_artificial ())
	return nullptr;
      if (set != *sets.begin () && !source_equal_p (set->insn (), first_insn))
	return nullptr;
    }

  return first_insn;
}

static bool
same_equiv_note_p (set_info *set1, set_info *set2)
{
  insn_info *insn1 = extract_single_source (set1);
  insn_info *insn2 = extract_single_source (set2);
  if (!insn1 || !insn2)
    return false;
  return source_equal_p (insn1, insn2);
}

static unsigned
get_expr_id (unsigned bb_index, unsigned regno, unsigned num_bbs)
{
  return regno * num_bbs + bb_index;
}
static unsigned
get_regno (unsigned expr_id, unsigned num_bb)
{
  return expr_id / num_bb;
}
static unsigned
get_bb_index (unsigned expr_id, unsigned num_bb)
{
  return expr_id % num_bb;
}

/* Return true if the SET result is not used by any instructions.  */
static bool
has_no_uses (basic_block cfg_bb, rtx_insn *rinsn, int regno)
{
  if (bitmap_bit_p (df_get_live_out (cfg_bb), regno))
    return false;

  rtx_insn *iter;
  for (iter = NEXT_INSN (rinsn); iter && iter != NEXT_INSN (BB_END (cfg_bb));
       iter = NEXT_INSN (iter))
    if (df_find_use (iter, regno_reg_rtx[regno]))
      return false;

  return true;
}

/* Change insn and Assert the change always happens.  */
static void
validate_change_or_fail (rtx object, rtx *loc, rtx new_rtx, bool in_group)
{
  bool change_p = validate_change (object, loc, new_rtx, in_group);
  gcc_assert (change_p);
}

/* This flags indicates the minimum demand of the vl and vtype values by the
   RVV instruction. For example, DEMAND_RATIO_P indicates that this RVV
   instruction only needs the SEW/LMUL ratio to remain the same, and does not
   require SEW and LMUL to be fixed.
   Therefore, if the former RVV instruction needs DEMAND_RATIO_P and the latter
   instruction needs DEMAND_SEW_LMUL_P and its SEW/LMUL is the same as that of
   the former instruction, then we can make the minimu demand of the former
   instruction strict to DEMAND_SEW_LMUL_P, and its required SEW and LMUL are
   the SEW and LMUL of the latter instruction, and the vsetvl instruction
   generated according to the new demand can also be used for the latter
   instruction, so there is no need to insert a separate vsetvl instruction for
   the latter instruction.  */
enum demand_flags : unsigned
{
  DEMAND_EMPTY_P = 0,
  DEMAND_SEW_P = 1 << 0,
  DEMAND_LMUL_P = 1 << 1,
  DEMAND_RATIO_P = 1 << 2,
  DEMAND_GE_SEW_P = 1 << 3,
  DEMAND_TAIL_POLICY_P = 1 << 4,
  DEMAND_MASK_POLICY_P = 1 << 5,
  DEMAND_AVL_P = 1 << 6,
  DEMAND_NON_ZERO_AVL_P = 1 << 7,
};

/* We split the demand information into three parts. They are sew and lmul
   related (sew_lmul_demand_type), tail and mask policy related
   (policy_demand_type) and avl related (avl_demand_type). Then we define three
   interfaces avaiable_with, compatible_p and merge. avaiable_with is
   used to determine whether the two vsetvl infos prev_info and next_info are
   available or not. If prev_info is available for next_info, it means that the
   RVV insn corresponding to next_info on the path from prev_info to next_info
   can be used without inserting a separate vsetvl instruction. compatible_p
   is used to determine whether prev_info is compatible with next_info, and if
   so, merge can be used to merge the stricter demand information from
   next_info into prev_info so that prev_info becomes available to next_info.
 */

enum class sew_lmul_demand_type : unsigned
{
  sew_lmul = demand_flags::DEMAND_SEW_P | demand_flags::DEMAND_LMUL_P,
  ratio_only = demand_flags::DEMAND_RATIO_P,
  sew_only = demand_flags::DEMAND_SEW_P,
  ge_sew = demand_flags::DEMAND_GE_SEW_P,
  ratio_and_ge_sew
  = demand_flags::DEMAND_RATIO_P | demand_flags::DEMAND_GE_SEW_P,
};

enum class policy_demand_type : unsigned
{
  tail_mask_policy
  = demand_flags::DEMAND_TAIL_POLICY_P | demand_flags::DEMAND_MASK_POLICY_P,
  tail_policy_only = demand_flags::DEMAND_TAIL_POLICY_P,
  mask_policy_only = demand_flags::DEMAND_MASK_POLICY_P,
  ignore_policy = demand_flags::DEMAND_EMPTY_P,
};

enum class avl_demand_type : unsigned
{
  avl = demand_flags::DEMAND_AVL_P,
  non_zero_avl = demand_flags::DEMAND_NON_ZERO_AVL_P,
  ignore_avl = demand_flags::DEMAND_EMPTY_P,
};

class vsetvl_info
{
private:
  insn_info *m_insn;
  bb_info *m_bb;
  rtx m_avl;
  rtx m_vl;
  set_info *m_avl_def;
  uint8_t m_sew;
  uint8_t m_max_sew;
  vlmul_type m_vlmul;
  uint8_t m_ratio;
  bool m_ta;
  bool m_ma;

  sew_lmul_demand_type m_sew_lmul_demand;
  policy_demand_type m_policy_demand;
  avl_demand_type m_avl_demand;

  enum class state_type
  {
    UNINITIALIZED,
    VALID,
    UNKNOWN,
    EMPTY,
  };
  state_type m_state;

  bool m_delete;
  bool m_change_vtype_only;
  insn_info *m_read_vl_insn;
  bool m_vl_used_by_non_rvv_insn;

public:
  vsetvl_info ()
    : m_insn (nullptr), m_bb (nullptr), m_avl (NULL_RTX), m_vl (NULL_RTX),
      m_avl_def (nullptr), m_sew (0), m_max_sew (0), m_vlmul (LMUL_RESERVED),
      m_ratio (0), m_ta (false), m_ma (false),
      m_sew_lmul_demand (sew_lmul_demand_type::sew_lmul),
      m_policy_demand (policy_demand_type::tail_mask_policy),
      m_avl_demand (avl_demand_type::avl), m_state (state_type::UNINITIALIZED),
      m_delete (false), m_change_vtype_only (false), m_read_vl_insn (nullptr),
      m_vl_used_by_non_rvv_insn (false)
  {}

  vsetvl_info (insn_info *insn) : vsetvl_info () { parse_insn (insn); }

  vsetvl_info (rtx_insn *insn) : vsetvl_info () { parse_insn (insn); }

  void set_avl (rtx avl) { m_avl = avl; }
  void set_vl (rtx vl) { m_vl = vl; }
  void set_avl_def (set_info *avl_def) { m_avl_def = avl_def; }
  void set_sew (uint8_t sew) { m_sew = sew; }
  void set_vlmul (vlmul_type vlmul) { m_vlmul = vlmul; }
  void set_ratio (uint8_t ratio) { m_ratio = ratio; }
  void set_ta (bool ta) { m_ta = ta; }
  void set_ma (bool ma) { m_ma = ma; }
  void set_delete () { m_delete = true; }
  void set_bb (bb_info *bb) { m_bb = bb; }
  void set_max_sew (uint8_t max_sew) { m_max_sew = max_sew; }
  void set_change_vtype_only () { m_change_vtype_only = true; }
  void set_read_vl_insn (insn_info *insn) { m_read_vl_insn = insn; }

  rtx get_avl () const { return m_avl; }
  rtx get_vl () const { return m_vl; }
  set_info *get_avl_def () const { return m_avl_def; }
  uint8_t get_sew () const { return m_sew; }
  vlmul_type get_vlmul () const { return m_vlmul; }
  uint8_t get_ratio () const { return m_ratio; }
  bool get_ta () const { return m_ta; }
  bool get_ma () const { return m_ma; }
  insn_info *get_insn () const { return m_insn; }
  bool delete_p () const { return m_delete; }
  bb_info *get_bb () const { return m_bb; }
  uint8_t get_max_sew () const { return m_max_sew; }
  insn_info *get_read_vl_insn () const { return m_read_vl_insn; }
  bool vl_use_by_non_rvv_insn_p () const { return m_vl_used_by_non_rvv_insn; }

  bool has_imm_avl () const { return m_avl && CONST_INT_P (m_avl); }
  bool has_vlmax_avl () const { return vlmax_avl_p (m_avl); }
  bool has_nonvlmax_reg_avl () const
  {
    return m_avl && REG_P (m_avl) && !has_vlmax_avl ();
  }
  bool has_non_zero_avl () const
  {
    if (has_imm_avl ())
      return INTVAL (m_avl) > 0;
    return has_vlmax_avl ();
  }
  bool has_vl () const
  {
    /* The VL operand can only be either a NULL_RTX or a register.   */
    gcc_assert (!m_vl || REG_P (m_vl));
    return m_vl != NULL_RTX;
  }
  bool has_same_ratio (const vsetvl_info &other) const
  {
    return get_ratio () == other.get_ratio ();
  }

  /* The block of INSN isn't always same as the block of the VSETVL_INFO,
      meaning we may have 'get_insn ()->bb () != get_bb ()'.

	E.g.  BB 2 (Empty) ---> BB 3 (VALID, has rvv insn 1)

     BB 2 has empty VSETVL_INFO, wheras BB 3 has VSETVL_INFO that satisfies
     get_insn ()->bb () == get_bb (). In earliest fusion, we may fuse bb 3 and
     bb 2 so that the 'get_bb ()' of BB2 VSETVL_INFO will be BB2 wheras the
     'get_insn ()' of BB2 VSETVL INFO will be the rvv insn 1 (which is located
     at BB3).  */
  bool insn_inside_bb_p () const { return get_insn ()->bb () == get_bb (); }
  void update_avl (const vsetvl_info &other)
  {
    m_avl = other.get_avl ();
    m_vl = other.get_vl ();
    m_avl_def = other.get_avl_def ();
  }

  bool uninit_p () const { return m_state == state_type::UNINITIALIZED; }
  bool valid_p () const { return m_state == state_type::VALID; }
  bool unknown_p () const { return m_state == state_type::UNKNOWN; }
  bool empty_p () const { return m_state == state_type::EMPTY; }
  bool change_vtype_only_p () const { return m_change_vtype_only; }

  void set_valid () { m_state = state_type::VALID; }
  void set_unknown () { m_state = state_type::UNKNOWN; }
  void set_empty () { m_state = state_type::EMPTY; }

  void set_sew_lmul_demand (sew_lmul_demand_type demand)
  {
    m_sew_lmul_demand = demand;
  }
  void set_policy_demand (policy_demand_type demand)
  {
    m_policy_demand = demand;
  }
  void set_avl_demand (avl_demand_type demand) { m_avl_demand = demand; }

  sew_lmul_demand_type get_sew_lmul_demand () const
  {
    return m_sew_lmul_demand;
  }
  policy_demand_type get_policy_demand () const { return m_policy_demand; }
  avl_demand_type get_avl_demand () const { return m_avl_demand; }

  void normalize_demand (unsigned demand_flags)
  {
    switch (demand_flags
	    & (DEMAND_SEW_P | DEMAND_LMUL_P | DEMAND_RATIO_P | DEMAND_GE_SEW_P))
      {
      case (unsigned) sew_lmul_demand_type::sew_lmul:
	m_sew_lmul_demand = sew_lmul_demand_type::sew_lmul;
	break;
      case (unsigned) sew_lmul_demand_type::ratio_only:
	m_sew_lmul_demand = sew_lmul_demand_type::ratio_only;
	break;
      case (unsigned) sew_lmul_demand_type::sew_only:
	m_sew_lmul_demand = sew_lmul_demand_type::sew_only;
	break;
      case (unsigned) sew_lmul_demand_type::ge_sew:
	m_sew_lmul_demand = sew_lmul_demand_type::ge_sew;
	break;
      case (unsigned) sew_lmul_demand_type::ratio_and_ge_sew:
	m_sew_lmul_demand = sew_lmul_demand_type::ratio_and_ge_sew;
	break;
      default:
	gcc_unreachable ();
      }

    switch (demand_flags & (DEMAND_TAIL_POLICY_P | DEMAND_MASK_POLICY_P))
      {
      case (unsigned) policy_demand_type::tail_mask_policy:
	m_policy_demand = policy_demand_type::tail_mask_policy;
	break;
      case (unsigned) policy_demand_type::tail_policy_only:
	m_policy_demand = policy_demand_type::tail_policy_only;
	break;
      case (unsigned) policy_demand_type::mask_policy_only:
	m_policy_demand = policy_demand_type::mask_policy_only;
	break;
      case (unsigned) policy_demand_type::ignore_policy:
	m_policy_demand = policy_demand_type::ignore_policy;
	break;
      default:
	gcc_unreachable ();
      }

    switch (demand_flags & (DEMAND_AVL_P | DEMAND_NON_ZERO_AVL_P))
      {
      case (unsigned) avl_demand_type::avl:
	m_avl_demand = avl_demand_type::avl;
	break;
      case (unsigned) avl_demand_type::non_zero_avl:
	m_avl_demand = avl_demand_type::non_zero_avl;
	break;
      case (unsigned) avl_demand_type::ignore_avl:
	m_avl_demand = avl_demand_type::ignore_avl;
	break;
      default:
	gcc_unreachable ();
      }
  }

  void parse_insn (rtx_insn *rinsn)
  {
    if (!NONDEBUG_INSN_P (rinsn))
      return;
    if (optimize == 0 && !has_vtype_op (rinsn))
      return;
    gcc_assert (!vsetvl_discard_result_insn_p (rinsn));
    set_valid ();
    extract_insn_cached (rinsn);
    m_avl = ::get_avl (rinsn);
    if (has_vlmax_avl () || vsetvl_insn_p (rinsn))
      m_vl = ::get_vl (rinsn);
    m_sew = ::get_sew (rinsn);
    m_vlmul = ::get_vlmul (rinsn);
    m_ta = tail_agnostic_p (rinsn);
    m_ma = mask_agnostic_p (rinsn);
  }

  void parse_insn (insn_info *insn)
  {
    m_insn = insn;
    m_bb = insn->bb ();
    /* Return if it is debug insn for the consistency with optimize == 0.  */
    if (insn->is_debug_insn ())
      return;

    /* We set it as unknown since we don't what will happen in CALL or ASM.  */
    if (insn->is_call () || insn->is_asm ())
      {
	set_unknown ();
	return;
      }

    /* If this is something that updates VL/VTYPE that we don't know about, set
       the state to unknown.  */
    if (!vector_config_insn_p (insn->rtl ()) && !has_vtype_op (insn->rtl ())
	&& (find_access (insn->defs (), VL_REGNUM)
	    || find_access (insn->defs (), VTYPE_REGNUM)))
      {
	set_unknown ();
	return;
      }

    if (!vector_config_insn_p (insn->rtl ()) && !has_vtype_op (insn->rtl ()))
      /* uninitialized */
      return;

    set_valid ();

    m_avl = ::get_avl (insn->rtl ());
    if (m_avl)
      {
	if (vsetvl_insn_p (insn->rtl ()) || has_vlmax_avl ())
	  m_vl = ::get_vl (insn->rtl ());

	if (has_nonvlmax_reg_avl ())
	  m_avl_def = find_access (insn->uses (), REGNO (m_avl))->def ();
      }

    m_sew = ::get_sew (insn->rtl ());
    m_vlmul = ::get_vlmul (insn->rtl ());
    m_ratio = get_attr_ratio (insn->rtl ());
    /* when get_attr_ratio is invalid, this kind of instructions
       doesn't care about ratio. However, we still need this value
       in demand info backward analysis.  */
    if (m_ratio == INVALID_ATTRIBUTE)
      m_ratio = calculate_ratio (m_sew, m_vlmul);
    m_ta = tail_agnostic_p (insn->rtl ());
    m_ma = mask_agnostic_p (insn->rtl ());

    /* If merge operand is undef value, we prefer agnostic.  */
    int merge_op_idx = get_attr_merge_op_idx (insn->rtl ());
    if (merge_op_idx != INVALID_ATTRIBUTE
	&& satisfies_constraint_vu (recog_data.operand[merge_op_idx]))
      {
	m_ta = true;
	m_ma = true;
      }

    /* Determine the demand info of the RVV insn.  */
    m_max_sew = get_max_int_sew ();
    unsigned demand_flags = 0;
    if (vector_config_insn_p (insn->rtl ()))
      {
	demand_flags |= demand_flags::DEMAND_AVL_P;
	demand_flags |= demand_flags::DEMAND_RATIO_P;
      }
    else
      {
	if (has_vl_op (insn->rtl ()))
	  {
	    if (scalar_move_insn_p (insn->rtl ()))
	      {
		/* If the avl for vmv.s.x comes from the vsetvl instruction, we
		   don't know if the avl is non-zero, so it is set to
		   DEMAND_AVL_P for now. it may be corrected to
		   DEMAND_NON_ZERO_AVL_P later when more information is
		   available.
		 */
		if (has_non_zero_avl ())
		  demand_flags |= demand_flags::DEMAND_NON_ZERO_AVL_P;
		else
		  demand_flags |= demand_flags::DEMAND_AVL_P;
	      }
	    else
	      demand_flags |= demand_flags::DEMAND_AVL_P;
	  }

	if (get_attr_ratio (insn->rtl ()) != INVALID_ATTRIBUTE)
	  demand_flags |= demand_flags::DEMAND_RATIO_P;
	else
	  {
	    if (scalar_move_insn_p (insn->rtl ()) && m_ta)
	      {
		demand_flags |= demand_flags::DEMAND_GE_SEW_P;
		m_max_sew = get_attr_type (insn->rtl ()) == TYPE_VFMOVFV
			      ? get_max_float_sew ()
			      : get_max_int_sew ();
	      }
	    else
	      demand_flags |= demand_flags::DEMAND_SEW_P;

	    if (!ignore_vlmul_insn_p (insn->rtl ()))
	      demand_flags |= demand_flags::DEMAND_LMUL_P;
	  }

	if (!m_ta)
	  demand_flags |= demand_flags::DEMAND_TAIL_POLICY_P;
	if (!m_ma)
	  demand_flags |= demand_flags::DEMAND_MASK_POLICY_P;
      }

    normalize_demand (demand_flags);

    /* Optimize AVL from the vsetvl instruction.  */
    insn_info *def_insn = extract_single_source (get_avl_def ());
    if (def_insn && vsetvl_insn_p (def_insn->rtl ()))
      {
	vsetvl_info def_info = vsetvl_info (def_insn);
	if ((scalar_move_insn_p (insn->rtl ())
	     || def_info.get_ratio () == get_ratio ())
	    && (def_info.has_vlmax_avl () || def_info.has_imm_avl ()))
	  {
	    update_avl (def_info);
	    if (scalar_move_insn_p (insn->rtl ()) && has_non_zero_avl ())
	      m_avl_demand = avl_demand_type::non_zero_avl;
	  }
      }

    /* Determine if dest operand(vl) has been used by non-RVV instructions.  */
    if (has_vl ())
      {
	const hash_set<use_info *> vl_uses
	  = get_all_real_uses (get_insn (), REGNO (get_vl ()));
	for (use_info *use : vl_uses)
	  {
	    gcc_assert (use->insn ()->is_real ());
	    rtx_insn *rinsn = use->insn ()->rtl ();
	    if (!has_vl_op (rinsn)
		|| count_regno_occurrences (rinsn, REGNO (get_vl ())) != 1)
	      {
		m_vl_used_by_non_rvv_insn = true;
		break;
	      }
	    rtx avl = ::get_avl (rinsn);
	    if (!avl || REGNO (get_vl ()) != REGNO (avl))
	      {
		m_vl_used_by_non_rvv_insn = true;
		break;
	      }
	  }
      }

    /* Collect the read vl insn for the fault-only-first rvv loads.  */
    if (fault_first_load_p (insn->rtl ()))
      {
	for (insn_info *i = insn->next_nondebug_insn ();
	     i->bb () == insn->bb (); i = i->next_nondebug_insn ())
	  {
	    if (find_access (i->defs (), VL_REGNUM))
	      break;
	    if (i->rtl () && read_vl_insn_p (i->rtl ()))
	      {
		m_read_vl_insn = i;
		break;
	      }
	  }
      }
  }

  /* Returns the corresponding vsetvl rtx pat.  */
  rtx get_vsetvl_pat (bool ignore_vl = false) const
  {
    rtx avl = get_avl ();
    /* if optimization == 0 and the instruction is vmv.x.s/vfmv.f.s,
       set the value of avl to (const_int 0) so that VSETVL PASS will
       insert vsetvl correctly.*/
    if (!get_avl ())
      avl = GEN_INT (0);
    rtx sew = gen_int_mode (get_sew (), Pmode);
    rtx vlmul = gen_int_mode (get_vlmul (), Pmode);
    rtx ta = gen_int_mode (get_ta (), Pmode);
    rtx ma = gen_int_mode (get_ma (), Pmode);

    if (change_vtype_only_p ())
      return gen_vsetvl_vtype_change_only (sew, vlmul, ta, ma);
    else if (has_vl () && !ignore_vl)
      return gen_vsetvl (Pmode, get_vl (), avl, sew, vlmul, ta, ma);
    else
      return gen_vsetvl_discard_result (Pmode, avl, sew, vlmul, ta, ma);
  }

  bool operator== (const vsetvl_info &other) const
  {
    gcc_assert (!uninit_p () && !other.uninit_p ()
		&& "Uninitialization should not happen");

    if (empty_p ())
      return other.empty_p ();
    if (unknown_p ())
      return other.unknown_p ();

    return get_insn () == other.get_insn () && get_bb () == other.get_bb ()
	   && get_avl () == other.get_avl () && get_vl () == other.get_vl ()
	   && get_avl_def () == other.get_avl_def ()
	   && get_sew () == other.get_sew ()
	   && get_vlmul () == other.get_vlmul () && get_ta () == other.get_ta ()
	   && get_ma () == other.get_ma ()
	   && get_avl_demand () == other.get_avl_demand ()
	   && get_sew_lmul_demand () == other.get_sew_lmul_demand ()
	   && get_policy_demand () == other.get_policy_demand ();
  }

  void dump (FILE *file, const char *indent = "") const
  {
    if (uninit_p ())
      {
	fprintf (file, "UNINITIALIZED.\n");
	return;
      }
    else if (unknown_p ())
      {
	fprintf (file, "UNKNOWN.\n");
	return;
      }
    else if (empty_p ())
      {
	fprintf (file, "EMPTY.\n");
	return;
      }
    else if (valid_p ())
      fprintf (file, "VALID (insn %u, bb %u)%s\n", get_insn ()->uid (),
	       get_bb ()->index (), delete_p () ? " (deleted)" : "");
    else
      gcc_unreachable ();

    fprintf (file, "%sDemand fields:", indent);
    if (m_sew_lmul_demand == sew_lmul_demand_type::sew_lmul)
      fprintf (file, " demand_sew_lmul");
    else if (m_sew_lmul_demand == sew_lmul_demand_type::ratio_only)
      fprintf (file, " demand_ratio_only");
    else if (m_sew_lmul_demand == sew_lmul_demand_type::sew_only)
      fprintf (file, " demand_sew_only");
    else if (m_sew_lmul_demand == sew_lmul_demand_type::ge_sew)
      fprintf (file, " demand_ge_sew");
    else if (m_sew_lmul_demand == sew_lmul_demand_type::ratio_and_ge_sew)
      fprintf (file, " demand_ratio_and_ge_sew");

    if (m_policy_demand == policy_demand_type::tail_mask_policy)
      fprintf (file, " demand_tail_mask_policy");
    else if (m_policy_demand == policy_demand_type::tail_policy_only)
      fprintf (file, " demand_tail_policy_only");
    else if (m_policy_demand == policy_demand_type::mask_policy_only)
      fprintf (file, " demand_mask_policy_only");

    if (m_avl_demand == avl_demand_type::avl)
      fprintf (file, " demand_avl");
    else if (m_avl_demand == avl_demand_type::non_zero_avl)
      fprintf (file, " demand_non_zero_avl");
    fprintf (file, "\n");

    fprintf (file, "%sSEW=%d, ", indent, get_sew ());
    fprintf (file, "VLMUL=%s, ", vlmul_to_str (get_vlmul ()));
    fprintf (file, "RATIO=%d, ", get_ratio ());
    fprintf (file, "MAX_SEW=%d\n", get_max_sew ());

    fprintf (file, "%sTAIL_POLICY=%s, ", indent, policy_to_str (get_ta ()));
    fprintf (file, "MASK_POLICY=%s\n", policy_to_str (get_ma ()));

    fprintf (file, "%sAVL=", indent);
    print_rtl_single (file, get_avl ());
    fprintf (file, "%sVL=", indent);
    print_rtl_single (file, get_vl ());
    if (change_vtype_only_p ())
      fprintf (file, "%schange vtype only\n", indent);
    if (get_read_vl_insn ())
      fprintf (file, "%sread_vl_insn: insn %u\n", indent,
	       get_read_vl_insn ()->uid ());
    if (vl_use_by_non_rvv_insn_p ())
      fprintf (file, "%suse_by_non_rvv_insn=true\n", indent);
  }
};

class vsetvl_block_info
{
public:
  /* The static execute probability of the demand info.  */
  profile_probability probability;

  auto_vec<vsetvl_info> local_infos;
  vsetvl_info global_info;
  bb_info *bb;

  bool full_available;

  vsetvl_block_info () : bb (nullptr), full_available (false)
  {
    local_infos.safe_grow_cleared (0);
    global_info.set_empty ();
  }
  vsetvl_block_info (const vsetvl_block_info &other)
    : probability (other.probability), local_infos (other.local_infos.copy ()),
      global_info (other.global_info), bb (other.bb)
  {}

  vsetvl_info &get_entry_info ()
  {
    gcc_assert (!empty_p ());
    return local_infos.is_empty () ? global_info : local_infos[0];
  }
  vsetvl_info &get_exit_info ()
  {
    gcc_assert (!empty_p ());
    return local_infos.is_empty () ? global_info
				   : local_infos[local_infos.length () - 1];
  }
  const vsetvl_info &get_entry_info () const
  {
    gcc_assert (!empty_p ());
    return local_infos.is_empty () ? global_info : local_infos[0];
  }
  const vsetvl_info &get_exit_info () const
  {
    gcc_assert (!empty_p ());
    return local_infos.is_empty () ? global_info
				   : local_infos[local_infos.length () - 1];
  }

  bool empty_p () const { return local_infos.is_empty () && !has_info (); }
  bool has_info () const { return !global_info.empty_p (); }
  void set_info (const vsetvl_info &info)
  {
    gcc_assert (local_infos.is_empty ());
    global_info = info;
    global_info.set_bb (bb);
  }
  void set_empty_info () { global_info.set_empty (); }
};

/* Demand system is the RVV-based VSETVL info analysis tools wrapper.
   It defines compatible rules for SEW/LMUL, POLICY and AVL.
   Also, it provides 3 iterfaces avaiable_p, compatible_p and
   merge for the VSETVL PASS analysis and optimization.

     - avaiable_p: Determine whether the next info can get the
       avaiable VSETVL status from previous info.
       e.g. bb 2 (demand SEW = 32, LMUL = M2) -> bb 3 (demand RATIO = 16).
       Since bb 2 demand info (SEW/LMUL = 32/2 = 16) satisfies the bb 3
       demand, the VSETVL instruction in bb 3 can be elided.
       avaiable_p (previous, next) is true in such situation.
     - compatible_p: Determine whether prev_info is compatible with next_info
       so that we can have a new merged info that is avaiable to both of them.
     - merge: Merge the stricter demand information from
       next_info into prev_info so that prev_info becomes available to
       next_info.  */
class demand_system
{
private:
  sbitmap *m_avl_def_in;
  sbitmap *m_avl_def_out;

  /* predictors.  */

  inline bool always_true (const vsetvl_info &prev ATTRIBUTE_UNUSED,
			   const vsetvl_info &next ATTRIBUTE_UNUSED)
  {
    return true;
  }
  inline bool always_false (const vsetvl_info &prev ATTRIBUTE_UNUSED,
			    const vsetvl_info &next ATTRIBUTE_UNUSED)
  {
    return false;
  }

  /* predictors for sew and lmul */

  inline bool lmul_eq_p (const vsetvl_info &prev, const vsetvl_info &next)
  {
    return prev.get_vlmul () == next.get_vlmul ();
  }
  inline bool sew_eq_p (const vsetvl_info &prev, const vsetvl_info &next)
  {
    return prev.get_sew () == next.get_sew ();
  }
  inline bool sew_lmul_eq_p (const vsetvl_info &prev, const vsetvl_info &next)
  {
    return lmul_eq_p (prev, next) && sew_eq_p (prev, next);
  }
  inline bool sew_ge_p (const vsetvl_info &prev, const vsetvl_info &next)
  {
    return prev.get_sew () == next.get_sew ()
	   || (next.get_ta () && prev.get_sew () > next.get_sew ());
  }
  inline bool sew_le_p (const vsetvl_info &prev, const vsetvl_info &next)
  {
    return prev.get_sew () == next.get_sew ()
	   || (prev.get_ta () && prev.get_sew () < next.get_sew ());
  }
  inline bool prev_sew_le_next_max_sew_p (const vsetvl_info &prev,
					  const vsetvl_info &next)
  {
    return prev.get_sew () <= next.get_max_sew ();
  }
  inline bool next_sew_le_prev_max_sew_p (const vsetvl_info &prev,
					  const vsetvl_info &next)
  {
    return next.get_sew () <= prev.get_max_sew ();
  }
  inline bool max_sew_overlap_p (const vsetvl_info &prev,
				 const vsetvl_info &next)
  {
    return !(prev.get_sew () > next.get_max_sew ()
	     || next.get_sew () > prev.get_max_sew ());
  }
  inline bool ratio_eq_p (const vsetvl_info &prev, const vsetvl_info &next)
  {
    return prev.has_same_ratio (next);
  }
  inline bool prev_ratio_valid_for_next_sew_p (const vsetvl_info &prev,
					       const vsetvl_info &next)
  {
    return prev.get_ratio () >= (next.get_sew () / 8);
  }
  inline bool next_ratio_valid_for_prev_sew_p (const vsetvl_info &prev,
					       const vsetvl_info &next)
  {
    return next.get_ratio () >= (prev.get_sew () / 8);
  }

  inline bool sew_ge_and_ratio_eq_p (const vsetvl_info &prev,
				     const vsetvl_info &next)
  {
    return sew_ge_p (prev, next) && ratio_eq_p (prev, next);
  }
  inline bool sew_ge_and_prev_sew_le_next_max_sew_p (const vsetvl_info &prev,
						     const vsetvl_info &next)
  {
    return sew_ge_p (prev, next) && prev_sew_le_next_max_sew_p (prev, next);
  }
  inline bool
  sew_ge_and_prev_sew_le_next_max_sew_and_next_ratio_valid_for_prev_sew_p (
    const vsetvl_info &prev, const vsetvl_info &next)
  {
    return sew_ge_p (prev, next) && prev_sew_le_next_max_sew_p (prev, next)
	   && next_ratio_valid_for_prev_sew_p (prev, next);
  }
  inline bool sew_le_and_next_sew_le_prev_max_sew_p (const vsetvl_info &prev,
						     const vsetvl_info &next)
  {
    return sew_le_p (prev, next) && next_sew_le_prev_max_sew_p (prev, next);
  }
  inline bool
  max_sew_overlap_and_next_ratio_valid_for_prev_sew_p (const vsetvl_info &prev,
						       const vsetvl_info &next)
  {
    return next_ratio_valid_for_prev_sew_p (prev, next)
	   && max_sew_overlap_p (prev, next);
  }
  inline bool
  sew_le_and_next_sew_le_prev_max_sew_and_ratio_eq_p (const vsetvl_info &prev,
						      const vsetvl_info &next)
  {
    return sew_le_p (prev, next) && ratio_eq_p (prev, next)
	   && next_sew_le_prev_max_sew_p (prev, next);
  }
  inline bool
  max_sew_overlap_and_prev_ratio_valid_for_next_sew_p (const vsetvl_info &prev,
						       const vsetvl_info &next)
  {
    return prev_ratio_valid_for_next_sew_p (prev, next)
	   && max_sew_overlap_p (prev, next);
  }
  inline bool
  sew_le_and_next_sew_le_prev_max_sew_and_prev_ratio_valid_for_next_sew_p (
    const vsetvl_info &prev, const vsetvl_info &next)
  {
    return sew_le_p (prev, next) && prev_ratio_valid_for_next_sew_p (prev, next)
	   && next_sew_le_prev_max_sew_p (prev, next);
  }
  inline bool max_sew_overlap_and_ratio_eq_p (const vsetvl_info &prev,
					      const vsetvl_info &next)
  {
    return ratio_eq_p (prev, next) && max_sew_overlap_p (prev, next);
  }

  /* predictors for tail and mask policy */

  inline bool tail_policy_eq_p (const vsetvl_info &prev,
				const vsetvl_info &next)
  {
    return prev.get_ta () == next.get_ta ();
  }
  inline bool mask_policy_eq_p (const vsetvl_info &prev,
				const vsetvl_info &next)
  {
    return prev.get_ma () == next.get_ma ();
  }
  inline bool tail_mask_policy_eq_p (const vsetvl_info &prev,
				     const vsetvl_info &next)
  {
    return tail_policy_eq_p (prev, next) && mask_policy_eq_p (prev, next);
  }

  /* predictors for avl */

  inline bool modify_or_use_vl_p (insn_info *i, const vsetvl_info &info)
  {
    return info.has_vl ()
	   && (find_access (i->uses (), REGNO (info.get_vl ()))
	       || find_access (i->defs (), REGNO (info.get_vl ())));
  }
  inline bool modify_avl_p (insn_info *i, const vsetvl_info &info)
  {
    return info.has_nonvlmax_reg_avl ()
	   && find_access (i->defs (), REGNO (info.get_avl ()));
  }

  inline bool modify_reg_between_p (insn_info *prev_insn, insn_info *curr_insn,
				    unsigned regno)
  {
    gcc_assert (prev_insn->compare_with (curr_insn) < 0);
    for (insn_info *i = curr_insn->prev_nondebug_insn (); i != prev_insn;
	 i = i->prev_nondebug_insn ())
      {
	// no def of regno
	if (find_access (i->defs (), regno))
	  return true;
      }
    return false;
  }

  inline bool reg_avl_equal_p (const vsetvl_info &prev, const vsetvl_info &next)
  {
    if (!prev.has_nonvlmax_reg_avl () || !next.has_nonvlmax_reg_avl ())
      return false;

    if (same_equiv_note_p (prev.get_avl_def (), next.get_avl_def ()))
      return true;

    if (REGNO (prev.get_avl ()) != REGNO (next.get_avl ()))
      return false;

    insn_info *prev_insn = prev.get_insn ();
    if (prev.get_bb () != prev_insn->bb ())
      prev_insn = prev.get_bb ()->end_insn ();

    insn_info *next_insn = next.get_insn ();
    if (next.get_bb () != next_insn->bb ())
      next_insn = next.get_bb ()->end_insn ();

    return avl_vl_unmodified_between_p (prev_insn, next_insn, next, false);
  }

  inline bool avl_equal_p (const vsetvl_info &prev, const vsetvl_info &next)
  {
    gcc_assert (prev.valid_p () && next.valid_p ());

    if (prev.get_ratio () != next.get_ratio ())
      return false;

    if (next.has_vl () && next.vl_use_by_non_rvv_insn_p ())
      return false;

    if (vector_config_insn_p (prev.get_insn ()->rtl ()) && next.get_avl_def ()
	&& next.get_avl_def ()->insn () == prev.get_insn ())
      return true;

    if (prev.get_read_vl_insn ())
      {
	if (!next.has_nonvlmax_reg_avl () || !next.get_avl_def ())
	  return false;
	insn_info *avl_def_insn = extract_single_source (next.get_avl_def ());
	return avl_def_insn == prev.get_read_vl_insn ();
      }

    if (prev == next && prev.has_nonvlmax_reg_avl ())
      {
	insn_info *insn = prev.get_insn ();
	bb_info *bb = insn->bb ();
	for (insn_info *i = insn; real_insn_and_same_bb_p (i, bb);
	     i = i->next_nondebug_insn ())
	  if (find_access (i->defs (), REGNO (prev.get_avl ())))
	    return false;
      }

    if (prev.has_vlmax_avl () && next.has_vlmax_avl ())
      return true;
    else if (prev.has_imm_avl () && next.has_imm_avl ())
      return INTVAL (prev.get_avl ()) == INTVAL (next.get_avl ());
    else if (prev.has_vl () && next.has_nonvlmax_reg_avl ()
	     && REGNO (prev.get_vl ()) == REGNO (next.get_avl ()))
      {
	insn_info *prev_insn = prev.insn_inside_bb_p ()
				 ? prev.get_insn ()
				 : prev.get_bb ()->end_insn ();

	insn_info *next_insn = next.insn_inside_bb_p ()
				 ? next.get_insn ()
				 : next.get_bb ()->end_insn ();
	return avl_vl_unmodified_between_p (prev_insn, next_insn, next, false);
      }
    else if (prev.has_nonvlmax_reg_avl () && next.has_nonvlmax_reg_avl ())
      return reg_avl_equal_p (prev, next);

    return false;
  }
  inline bool avl_equal_or_prev_avl_non_zero_p (const vsetvl_info &prev,
						const vsetvl_info &next)
  {
    return avl_equal_p (prev, next) || prev.has_non_zero_avl ();
  }

  inline bool can_use_next_avl_p (const vsetvl_info &prev,
				  const vsetvl_info &next)
  {
    if (!next.has_nonvlmax_reg_avl () && !next.has_vl ())
      return true;

    insn_info *prev_insn = prev.get_insn ();
    if (prev.get_bb () != prev_insn->bb ())
      prev_insn = prev.get_bb ()->end_insn ();

    insn_info *next_insn = next.get_insn ();
    if (next.get_bb () != next_insn->bb ())
      next_insn = next.get_bb ()->end_insn ();

    return avl_vl_unmodified_between_p (prev_insn, next_insn, next);
  }

  inline bool avl_equal_or_next_avl_non_zero_and_can_use_next_avl_p (
    const vsetvl_info &prev, const vsetvl_info &next)
  {
    return avl_equal_p (prev, next)
	   || (next.has_non_zero_avl () && can_use_next_avl_p (prev, next));
  }

  /* modifiers  */

  inline void nop (const vsetvl_info &prev ATTRIBUTE_UNUSED,
		   const vsetvl_info &next ATTRIBUTE_UNUSED)
  {}

  /* modifiers for sew and lmul */

  inline void use_min_of_max_sew (vsetvl_info &prev, const vsetvl_info &next)
  {
    prev.set_max_sew (MIN (prev.get_max_sew (), next.get_max_sew ()));
  }
  inline void use_next_sew (vsetvl_info &prev, const vsetvl_info &next)
  {
    prev.set_sew (next.get_sew ());
    use_min_of_max_sew (prev, next);
  }
  inline void use_max_sew (vsetvl_info &prev, const vsetvl_info &next)
  {
    auto max_sew = std::max (prev.get_sew (), next.get_sew ());
    prev.set_sew (max_sew);
    use_min_of_max_sew (prev, next);
  }
  inline void use_next_sew_lmul (vsetvl_info &prev, const vsetvl_info &next)
  {
    use_next_sew (prev, next);
    prev.set_vlmul (next.get_vlmul ());
    prev.set_ratio (next.get_ratio ());
  }
  inline void use_next_sew_with_prev_ratio (vsetvl_info &prev,
					    const vsetvl_info &next)
  {
    use_next_sew (prev, next);
    prev.set_vlmul (calculate_vlmul (next.get_sew (), prev.get_ratio ()));
  }
  inline void modify_lmul_with_next_ratio (vsetvl_info &prev,
					   const vsetvl_info &next)
  {
    prev.set_vlmul (calculate_vlmul (prev.get_sew (), next.get_ratio ()));
    prev.set_ratio (next.get_ratio ());
  }

  inline void use_max_sew_and_lmul_with_next_ratio (vsetvl_info &prev,
						    const vsetvl_info &next)
  {
    prev.set_vlmul (calculate_vlmul (prev.get_sew (), next.get_ratio ()));
    use_max_sew (prev, next);
    prev.set_ratio (next.get_ratio ());
  }

  inline void use_max_sew_and_lmul_with_prev_ratio (vsetvl_info &prev,
						    const vsetvl_info &next)
  {
    auto max_sew = std::max (prev.get_sew (), next.get_sew ());
    prev.set_vlmul (calculate_vlmul (max_sew, prev.get_ratio ()));
    prev.set_sew (max_sew);
  }

  /* modifiers for tail and mask policy */

  inline void use_tail_policy (vsetvl_info &prev, const vsetvl_info &next)
  {
    if (!next.get_ta ())
      prev.set_ta (next.get_ta ());
  }
  inline void use_mask_policy (vsetvl_info &prev, const vsetvl_info &next)
  {
    if (!next.get_ma ())
      prev.set_ma (next.get_ma ());
  }
  inline void use_tail_mask_policy (vsetvl_info &prev, const vsetvl_info &next)
  {
    use_tail_policy (prev, next);
    use_mask_policy (prev, next);
  }

  /* modifiers for avl */

  inline void use_next_avl (vsetvl_info &prev, const vsetvl_info &next)
  {
    gcc_assert (can_use_next_avl_p (prev, next));
    prev.update_avl (next);
  }

  inline void use_next_avl_when_not_equal (vsetvl_info &prev,
					   const vsetvl_info &next)
  {
    if (avl_equal_p (prev, next))
      return;
    gcc_assert (next.has_non_zero_avl ());
    use_next_avl (prev, next);
  }

public:
  demand_system () : m_avl_def_in (nullptr), m_avl_def_out (nullptr) {}

  void set_avl_in_out_data (sbitmap *m_avl_def_in, sbitmap *m_avl_def_out)
  {
    m_avl_def_in = m_avl_def_in;
    m_avl_def_out = m_avl_def_out;
  }

  /* Can we move vsetvl info between prev_insn and next_insn safe? */
  bool avl_vl_unmodified_between_p (insn_info *prev_insn, insn_info *next_insn,
				    const vsetvl_info &info,
				    bool ignore_vl = false)
  {
    gcc_assert ((ignore_vl && info.has_nonvlmax_reg_avl ())
		|| (info.has_nonvlmax_reg_avl () || info.has_vl ()));

    gcc_assert (!prev_insn->is_debug_insn () && !next_insn->is_debug_insn ());
    if (prev_insn->bb () == next_insn->bb ()
	&& prev_insn->compare_with (next_insn) < 0)
      {
	for (insn_info *i = next_insn->prev_nondebug_insn (); i != prev_insn;
	     i = i->prev_nondebug_insn ())
	  {
	    // no def amd use of vl
	    if (!ignore_vl && modify_or_use_vl_p (i, info))
	      return false;

	    // no def of avl
	    if (modify_avl_p (i, info))
	      return false;
	  }
	return true;
      }
    else
      {
	if (!ignore_vl && info.has_vl ())
	  {
	    bitmap live_out = df_get_live_out (prev_insn->bb ()->cfg_bb ());
	    if (bitmap_bit_p (live_out, REGNO (info.get_vl ())))
	      return false;
	  }

	if (info.has_nonvlmax_reg_avl () && m_avl_def_in && m_avl_def_out)
	  {
	    bool has_avl_out = false;
	    unsigned regno = REGNO (info.get_avl ());
	    unsigned expr_id;
	    sbitmap_iterator sbi;
	    EXECUTE_IF_SET_IN_BITMAP (m_avl_def_out[prev_insn->bb ()->index ()],
				      0, expr_id, sbi)
	      {
		if (get_regno (expr_id, last_basic_block_for_fn (cfun))
		    != regno)
		  continue;
		has_avl_out = true;
		if (!bitmap_bit_p (m_avl_def_in[next_insn->bb ()->index ()],
				   expr_id))
		  return false;
	      }
	    if (!has_avl_out)
	      return false;
	  }

	for (insn_info *i = next_insn; i != next_insn->bb ()->head_insn ();
	     i = i->prev_nondebug_insn ())
	  {
	    // no def amd use of vl
	    if (!ignore_vl && modify_or_use_vl_p (i, info))
	      return false;

	    // no def of avl
	    if (modify_avl_p (i, info))
	      return false;
	  }

	for (insn_info *i = prev_insn->bb ()->end_insn (); i != prev_insn;
	     i = i->prev_nondebug_insn ())
	  {
	    // no def amd use of vl
	    if (!ignore_vl && modify_or_use_vl_p (i, info))
	      return false;

	    // no def of avl
	    if (modify_avl_p (i, info))
	      return false;
	  }
      }
    return true;
  }

  bool sew_lmul_compatible_p (const vsetvl_info &prev, const vsetvl_info &next)
  {
    gcc_assert (prev.valid_p () && next.valid_p ());
    sew_lmul_demand_type prev_flags = prev.get_sew_lmul_demand ();
    sew_lmul_demand_type next_flags = next.get_sew_lmul_demand ();
#define DEF_SEW_LMUL_RULE(PREV_FLAGS, NEXT_FLAGS, NEW_FLAGS, COMPATIBLE_P,     \
			  AVAILABLE_P, FUSE)                                   \
  if (prev_flags == sew_lmul_demand_type::PREV_FLAGS                           \
      && next_flags == sew_lmul_demand_type::NEXT_FLAGS)                       \
    return COMPATIBLE_P (prev, next);

#include "riscv-vsetvl.def"

    gcc_unreachable ();
  }

  bool sew_lmul_available_p (const vsetvl_info &prev, const vsetvl_info &next)
  {
    gcc_assert (prev.valid_p () && next.valid_p ());
    sew_lmul_demand_type prev_flags = prev.get_sew_lmul_demand ();
    sew_lmul_demand_type next_flags = next.get_sew_lmul_demand ();
#define DEF_SEW_LMUL_RULE(PREV_FLAGS, NEXT_FLAGS, NEW_FLAGS, COMPATIBLE_P,     \
			  AVAILABLE_P, FUSE)                                   \
  if (prev_flags == sew_lmul_demand_type::PREV_FLAGS                           \
      && next_flags == sew_lmul_demand_type::NEXT_FLAGS)                       \
    return AVAILABLE_P (prev, next);

#include "riscv-vsetvl.def"

    gcc_unreachable ();
  }

  void merge_sew_lmul (vsetvl_info &prev, const vsetvl_info &next)
  {
    gcc_assert (prev.valid_p () && next.valid_p ());
    sew_lmul_demand_type prev_flags = prev.get_sew_lmul_demand ();
    sew_lmul_demand_type next_flags = next.get_sew_lmul_demand ();
#define DEF_SEW_LMUL_RULE(PREV_FLAGS, NEXT_FLAGS, NEW_FLAGS, COMPATIBLE_P,     \
			  AVAILABLE_P, FUSE)                                   \
  if (prev_flags == sew_lmul_demand_type::PREV_FLAGS                           \
      && next_flags == sew_lmul_demand_type::NEXT_FLAGS)                       \
    {                                                                          \
      gcc_assert (COMPATIBLE_P (prev, next));                                  \
      FUSE (prev, next);                                                       \
      prev.set_sew_lmul_demand (sew_lmul_demand_type::NEW_FLAGS);              \
      return;                                                                  \
    }

#include "riscv-vsetvl.def"

    gcc_unreachable ();
  }

  bool policy_compatible_p (const vsetvl_info &prev, const vsetvl_info &next)
  {
    gcc_assert (prev.valid_p () && next.valid_p ());
    policy_demand_type prev_flags = prev.get_policy_demand ();
    policy_demand_type next_flags = next.get_policy_demand ();
#define DEF_POLICY_RULE(PREV_FLAGS, NEXT_FLAGS, NEW_FLAGS, COMPATIBLE_P,       \
			AVAILABLE_P, FUSE)                                     \
  if (prev_flags == policy_demand_type::PREV_FLAGS                             \
      && next_flags == policy_demand_type::NEXT_FLAGS)                         \
    return COMPATIBLE_P (prev, next);

#include "riscv-vsetvl.def"

    gcc_unreachable ();
  }

  bool policy_available_p (const vsetvl_info &prev, const vsetvl_info &next)
  {
    gcc_assert (prev.valid_p () && next.valid_p ());
    policy_demand_type prev_flags = prev.get_policy_demand ();
    policy_demand_type next_flags = next.get_policy_demand ();
#define DEF_POLICY_RULE(PREV_FLAGS, NEXT_FLAGS, NEW_FLAGS, COMPATIBLE_P,       \
			AVAILABLE_P, FUSE)                                     \
  if (prev_flags == policy_demand_type::PREV_FLAGS                             \
      && next_flags == policy_demand_type::NEXT_FLAGS)                         \
    return AVAILABLE_P (prev, next);

#include "riscv-vsetvl.def"

    gcc_unreachable ();
  }

  void merge_policy (vsetvl_info &prev, const vsetvl_info &next)
  {
    gcc_assert (prev.valid_p () && next.valid_p ());
    policy_demand_type prev_flags = prev.get_policy_demand ();
    policy_demand_type next_flags = next.get_policy_demand ();
#define DEF_POLICY_RULE(PREV_FLAGS, NEXT_FLAGS, NEW_FLAGS, COMPATIBLE_P,       \
			AVAILABLE_P, FUSE)                                     \
  if (prev_flags == policy_demand_type::PREV_FLAGS                             \
      && next_flags == policy_demand_type::NEXT_FLAGS)                         \
    {                                                                          \
      gcc_assert (COMPATIBLE_P (prev, next));                                  \
      FUSE (prev, next);                                                       \
      prev.set_policy_demand (policy_demand_type::NEW_FLAGS);                  \
      return;                                                                  \
    }

#include "riscv-vsetvl.def"

    gcc_unreachable ();
  }

  bool avl_compatible_p (const vsetvl_info &prev, const vsetvl_info &next)
  {
    gcc_assert (prev.valid_p () && next.valid_p ());
    avl_demand_type prev_flags = prev.get_avl_demand ();
    avl_demand_type next_flags = next.get_avl_demand ();
#define DEF_AVL_RULE(PREV_FLAGS, NEXT_FLAGS, NEW_FLAGS, COMPATIBLE_P,          \
		     AVAILABLE_P, FUSE)                                        \
  if (prev_flags == avl_demand_type::PREV_FLAGS                                \
      && next_flags == avl_demand_type::NEXT_FLAGS)                            \
    return COMPATIBLE_P (prev, next);

#include "riscv-vsetvl.def"

    gcc_unreachable ();
  }

  bool avl_available_p (const vsetvl_info &prev, const vsetvl_info &next)
  {
    gcc_assert (prev.valid_p () && next.valid_p ());
    avl_demand_type prev_flags = prev.get_avl_demand ();
    avl_demand_type next_flags = next.get_avl_demand ();
#define DEF_AVL_RULE(PREV_FLAGS, NEXT_FLAGS, NEW_FLAGS, COMPATIBLE_P,          \
		     AVAILABLE_P, FUSE)                                        \
  if (prev_flags == avl_demand_type::PREV_FLAGS                                \
      && next_flags == avl_demand_type::NEXT_FLAGS)                            \
    return AVAILABLE_P (prev, next);

#include "riscv-vsetvl.def"

    gcc_unreachable ();
  }

  void merge_avl (vsetvl_info &prev, const vsetvl_info &next)
  {
    gcc_assert (prev.valid_p () && next.valid_p ());
    avl_demand_type prev_flags = prev.get_avl_demand ();
    avl_demand_type next_flags = next.get_avl_demand ();
#define DEF_AVL_RULE(PREV_FLAGS, NEXT_FLAGS, NEW_FLAGS, COMPATIBLE_P,          \
		     AVAILABLE_P, FUSE)                                        \
  if (prev_flags == avl_demand_type::PREV_FLAGS                                \
      && next_flags == avl_demand_type::NEXT_FLAGS)                            \
    {                                                                          \
      gcc_assert (COMPATIBLE_P (prev, next));                                  \
      FUSE (prev, next);                                                       \
      prev.set_avl_demand (avl_demand_type::NEW_FLAGS);                        \
      return;                                                                  \
    }

#include "riscv-vsetvl.def"

    gcc_unreachable ();
  }

  bool compatible_p (const vsetvl_info &prev, const vsetvl_info &next)
  {
    bool compatible_p = sew_lmul_compatible_p (prev, next)
			&& policy_compatible_p (prev, next)
			&& avl_compatible_p (prev, next);
    return compatible_p;
  }

  bool available_p (const vsetvl_info &prev, const vsetvl_info &next)
  {
    bool available_p = sew_lmul_available_p (prev, next)
		       && policy_available_p (prev, next)
		       && avl_available_p (prev, next);
    gcc_assert (!available_p || compatible_p (prev, next));
    return available_p;
  }

  void merge (vsetvl_info &prev, const vsetvl_info &next)
  {
    gcc_assert (compatible_p (prev, next));
    merge_sew_lmul (prev, next);
    merge_policy (prev, next);
    merge_avl (prev, next);
    gcc_assert (available_p (prev, next));
  }
};


class pre_vsetvl
{
private:
  demand_system m_dem;
  auto_vec<vsetvl_block_info> m_vector_block_infos;

  /* data for avl reaching defintion.  */
  sbitmap m_avl_regs;
  sbitmap *m_avl_def_in;
  sbitmap *m_avl_def_out;
  sbitmap *m_reg_def_loc;

  /* data for vsetvl info reaching defintion.  */
  vsetvl_info m_unknow_info;
  auto_vec<vsetvl_info *> m_vsetvl_def_exprs;
  sbitmap *m_vsetvl_def_in;
  sbitmap *m_vsetvl_def_out;

  /* data for lcm */
  auto_vec<vsetvl_info *> m_exprs;
  sbitmap *m_avloc;
  sbitmap *m_avin;
  sbitmap *m_avout;
  sbitmap *m_kill;
  sbitmap *m_antloc;
  sbitmap *m_transp;
  sbitmap *m_insert;
  sbitmap *m_del;
  struct edge_list *m_edges;

  auto_vec<vsetvl_info> m_delete_list;

  vsetvl_block_info &get_block_info (const bb_info *bb)
  {
    return m_vector_block_infos[bb->index ()];
  }
  const vsetvl_block_info &get_block_info (const basic_block bb) const
  {
    return m_vector_block_infos[bb->index];
  }

  vsetvl_block_info &get_block_info (const basic_block bb)
  {
    return m_vector_block_infos[bb->index];
  }

  void add_expr (auto_vec<vsetvl_info *> &m_exprs, vsetvl_info &info)
  {
    for (vsetvl_info *item : m_exprs)
      {
	if (*item == info)
	  return;
      }
    m_exprs.safe_push (&info);
  }

  unsigned get_expr_index (auto_vec<vsetvl_info *> &m_exprs,
			   const vsetvl_info &info)
  {
    for (size_t i = 0; i < m_exprs.length (); i += 1)
      {
	if (*m_exprs[i] == info)
	  return i;
      }
    gcc_unreachable ();
  }

  bool anticpatable_exp_p (const vsetvl_info &header_info)
  {
    if (!header_info.has_nonvlmax_reg_avl () && !header_info.has_vl ())
      return true;

    bb_info *bb = header_info.get_bb ();
    insn_info *prev_insn = bb->head_insn ();
    insn_info *next_insn = header_info.insn_inside_bb_p ()
			     ? header_info.get_insn ()
			     : header_info.get_bb ()->end_insn ();

    return m_dem.avl_vl_unmodified_between_p (prev_insn, next_insn,
					      header_info);
  }

  bool available_exp_p (const vsetvl_info &prev_info,
			const vsetvl_info &next_info)
  {
    return m_dem.available_p (prev_info, next_info);
  }

  void compute_probabilities ()
  {
    edge e;
    edge_iterator ei;

    for (const bb_info *bb : crtl->ssa->bbs ())
      {
	basic_block cfg_bb = bb->cfg_bb ();
	auto &curr_prob = get_block_info (cfg_bb).probability;

	/* GCC assume entry block (bb 0) are always so
	   executed so set its probability as "always".  */
	if (ENTRY_BLOCK_PTR_FOR_FN (cfun) == cfg_bb)
	  curr_prob = profile_probability::always ();
	/* Exit block (bb 1) is the block we don't need to process.  */
	if (EXIT_BLOCK_PTR_FOR_FN (cfun) == cfg_bb)
	  continue;

	gcc_assert (curr_prob.initialized_p ());
	FOR_EACH_EDGE (e, ei, cfg_bb->succs)
	  {
	    auto &new_prob = get_block_info (e->dest).probability;
	    /* Normally, the edge probability should be initialized.
	       However, some special testing code which is written in
	       GIMPLE IR style force the edge probility uninitialized,
	       we conservatively set it as never so that it will not
	       affect PRE (Phase 3 && Phse 4).  */
	    if (!e->probability.initialized_p ())
	      new_prob = profile_probability::never ();
	    else if (!new_prob.initialized_p ())
	      new_prob = curr_prob * e->probability;
	    else if (new_prob == profile_probability::always ())
	      continue;
	    else
	      new_prob += curr_prob * e->probability;
	  }
      }
  }

  void insert_vsetvl_insn (enum emit_type emit_type, const vsetvl_info &info)
  {
    rtx pat = info.get_vsetvl_pat ();
    rtx_insn *rinsn = info.get_insn ()->rtl ();

    if (emit_type == EMIT_DIRECT)
      {
	emit_insn (pat);
	if (dump_file)
	  {
	    fprintf (dump_file, "  Insert vsetvl insn %d:\n",
		     INSN_UID (get_last_insn ()));
	    print_rtl_single (dump_file, get_last_insn ());
	  }
      }
    else if (emit_type == EMIT_BEFORE)
      {
	emit_insn_before (pat, rinsn);
	if (dump_file)
	  {
	    fprintf (dump_file, "  Insert vsetvl insn before insn %d:\n",
		     INSN_UID (rinsn));
	    print_rtl_single (dump_file, PREV_INSN (rinsn));
	  }
      }
    else
      {
	emit_insn_after (pat, rinsn);
	if (dump_file)
	  {
	    fprintf (dump_file, "  Insert vsetvl insn after insn %d:\n",
		     INSN_UID (rinsn));
	    print_rtl_single (dump_file, NEXT_INSN (rinsn));
	  }
      }
  }

  void change_vsetvl_insn (const vsetvl_info &info)
  {
    rtx_insn *rinsn = info.get_insn ()->rtl ();
    rtx new_pat = info.get_vsetvl_pat ();

    if (dump_file)
      {
	fprintf (dump_file, "  Change insn %d from:\n", INSN_UID (rinsn));
	print_rtl_single (dump_file, rinsn);
      }

    validate_change_or_fail (rinsn, &PATTERN (rinsn), new_pat, false);

    if (dump_file)
      {
	fprintf (dump_file, "\n  to:\n");
	print_rtl_single (dump_file, rinsn);
      }
  }

  void remove_vsetvl_insn (const vsetvl_info &info)
  {
    rtx_insn *rinsn = info.get_insn ()->rtl ();
    if (dump_file)
      {
	fprintf (dump_file, "  Eliminate insn %d:\n", INSN_UID (rinsn));
	print_rtl_single (dump_file, rinsn);
      }
    if (in_sequence_p ())
      remove_insn (rinsn);
    else
      delete_insn (rinsn);
  }

  bool successors_probability_equal_p (const basic_block cfg_bb) const
  {
    edge e;
    edge_iterator ei;
    profile_probability prob = profile_probability::uninitialized ();
    FOR_EACH_EDGE (e, ei, cfg_bb->succs)
      {
	if (prob == profile_probability::uninitialized ())
	  prob = m_vector_block_infos[e->dest->index].probability;
	else if (prob == m_vector_block_infos[e->dest->index].probability)
	  continue;
	else
	  /* We pick the highest probability among those incompatible VSETVL
	     infos. When all incompatible VSTEVL infos have same probability, we
	     don't pick any of them.  */
	  return false;
      }
    return true;
  }

  bool preds_has_same_avl_p (const vsetvl_info &curr_info)
  {
    gcc_assert (
      !bitmap_empty_p (m_vsetvl_def_in[curr_info.get_bb ()->index ()]));

    unsigned expr_index;
    sbitmap_iterator sbi;
    EXECUTE_IF_SET_IN_BITMAP (m_vsetvl_def_in[curr_info.get_bb ()->index ()], 0,
			      expr_index, sbi)
      {
	const vsetvl_info &prev_info = *m_vsetvl_def_exprs[expr_index];
	if (!prev_info.valid_p ()
	    || !m_dem.avl_available_p (prev_info, curr_info))
	  return false;
      }

    return true;
  }

public:
  pre_vsetvl ()
    : m_avl_def_in (nullptr), m_avl_def_out (nullptr),
      m_vsetvl_def_in (nullptr), m_vsetvl_def_out (nullptr), m_avloc (nullptr),
      m_avin (nullptr), m_avout (nullptr), m_kill (nullptr), m_antloc (nullptr),
      m_transp (nullptr), m_insert (nullptr), m_del (nullptr), m_edges (nullptr)
  {
    /* Initialization of RTL_SSA.  */
    calculate_dominance_info (CDI_DOMINATORS);
    df_analyze ();
    crtl->ssa = new function_info (cfun);
    m_vector_block_infos.safe_grow_cleared (last_basic_block_for_fn (cfun));
    compute_probabilities ();
    m_unknow_info.set_unknown ();
  }

  void finish ()
  {
    free_dominance_info (CDI_DOMINATORS);
    if (crtl->ssa->perform_pending_updates ())
      cleanup_cfg (0);
    delete crtl->ssa;
    crtl->ssa = nullptr;

    if (m_avl_regs)
      sbitmap_free (m_avl_regs);
    if (m_reg_def_loc)
      sbitmap_vector_free (m_reg_def_loc);

    if (m_avl_def_in)
      sbitmap_vector_free (m_avl_def_in);
    if (m_avl_def_out)
      sbitmap_vector_free (m_avl_def_out);

    if (m_vsetvl_def_in)
      sbitmap_vector_free (m_vsetvl_def_in);
    if (m_vsetvl_def_out)
      sbitmap_vector_free (m_vsetvl_def_out);

    if (m_avloc)
      sbitmap_vector_free (m_avloc);
    if (m_kill)
      sbitmap_vector_free (m_kill);
    if (m_antloc)
      sbitmap_vector_free (m_antloc);
    if (m_transp)
      sbitmap_vector_free (m_transp);
    if (m_insert)
      sbitmap_vector_free (m_insert);
    if (m_del)
      sbitmap_vector_free (m_del);
    if (m_avin)
      sbitmap_vector_free (m_avin);
    if (m_avout)
      sbitmap_vector_free (m_avout);

    if (m_edges)
      free_edge_list (m_edges);
  }

  void compute_avl_def_data ();
  void compute_vsetvl_def_data ();
  void compute_lcm_local_properties ();

  void fuse_local_vsetvl_info ();
  bool earliest_fuse_vsetvl_info ();
  void pre_global_vsetvl_info ();
  void emit_vsetvl ();
  void cleaup ();
  void remove_avl_operand ();
  void remove_unused_dest_operand ();

  void dump (FILE *file, const char *title) const
  {
    fprintf (file, "\nVSETVL infos after %s\n\n", title);
    for (const bb_info *bb : crtl->ssa->bbs ())
      {
	const auto &block_info = m_vector_block_infos[bb->index ()];
	fprintf (file, "  bb %d:\n", bb->index ());
	fprintf (file, "    probability: ");
	block_info.probability.dump (file);
	fprintf (file, "\n");
	if (!block_info.empty_p ())
	  {
	    fprintf (file, "    Header vsetvl info:");
	    block_info.get_entry_info ().dump (file, "      ");
	    fprintf (file, "    Footer vsetvl info:");
	    block_info.get_exit_info ().dump (file, "      ");
	    for (const auto &info : block_info.local_infos)
	      {
		fprintf (file,
			 "    insn %d vsetvl info:", info.get_insn ()->uid ());
		info.dump (file, "      ");
	      }
	  }
      }
  }
};

void
pre_vsetvl::compute_avl_def_data ()
{
  if (bitmap_empty_p (m_avl_regs))
    return;

  unsigned num_regs = GP_REG_LAST + 1;
  unsigned num_bbs = last_basic_block_for_fn (cfun);

  sbitmap *avl_def_loc_temp = sbitmap_vector_alloc (num_bbs, num_regs);
  for (const bb_info *bb : crtl->ssa->bbs ())
    {
      bitmap_and (avl_def_loc_temp[bb->index ()], m_avl_regs,
		  m_reg_def_loc[bb->index ()]);

      vsetvl_block_info &block_info = get_block_info (bb);
      if (block_info.has_info ())
	{
	  vsetvl_info &footer_info = block_info.get_exit_info ();
	  gcc_assert (footer_info.valid_p ());
	  if (footer_info.has_vl ())
	    bitmap_set_bit (avl_def_loc_temp[bb->index ()],
			    REGNO (footer_info.get_vl ()));
	}
    }

  if (m_avl_def_in)
    sbitmap_vector_free (m_avl_def_in);
  if (m_avl_def_out)
    sbitmap_vector_free (m_avl_def_out);

  unsigned num_exprs = num_bbs * num_regs;
  sbitmap *avl_def_loc = sbitmap_vector_alloc (num_bbs, num_exprs);
  sbitmap *m_kill = sbitmap_vector_alloc (num_bbs, num_exprs);
  m_avl_def_in = sbitmap_vector_alloc (num_bbs, num_exprs);
  m_avl_def_out = sbitmap_vector_alloc (num_bbs, num_exprs);

  bitmap_vector_clear (avl_def_loc, num_bbs);
  bitmap_vector_clear (m_kill, num_bbs);
  bitmap_vector_clear (m_avl_def_out, num_bbs);

  unsigned regno;
  sbitmap_iterator sbi;
  for (const bb_info *bb : crtl->ssa->bbs ())
    EXECUTE_IF_SET_IN_BITMAP (avl_def_loc_temp[bb->index ()], 0, regno, sbi)
      {
	bitmap_set_bit (avl_def_loc[bb->index ()],
			get_expr_id (bb->index (), regno, num_bbs));
	bitmap_set_range (m_kill[bb->index ()], regno * num_bbs, num_bbs);
      }

  basic_block entry = ENTRY_BLOCK_PTR_FOR_FN (cfun);
  EXECUTE_IF_SET_IN_BITMAP (m_avl_regs, 0, regno, sbi)
    bitmap_set_bit (m_avl_def_out[entry->index],
		    get_expr_id (entry->index, regno, num_bbs));

  compute_reaching_defintion (avl_def_loc, m_kill, m_avl_def_in, m_avl_def_out);

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file,
	       "  Compute avl reaching defition data (num_bbs %d, num_regs "
	       "%d):\n\n",
	       num_bbs, num_regs);
      fprintf (dump_file, "    avl_regs: ");
      dump_bitmap_file (dump_file, m_avl_regs);
      fprintf (dump_file, "\n    bitmap data:\n");
      for (const bb_info *bb : crtl->ssa->bbs ())
	{
	  unsigned int i = bb->index ();
	  fprintf (dump_file, "      BB %u:\n", i);
	  fprintf (dump_file, "        avl_def_loc:");
	  unsigned expr_id;
	  sbitmap_iterator sbi;
	  EXECUTE_IF_SET_IN_BITMAP (avl_def_loc[i], 0, expr_id, sbi)
	    {
	      fprintf (dump_file, " (r%u,bb%u)", get_regno (expr_id, num_bbs),
		       get_bb_index (expr_id, num_bbs));
	    }
	  fprintf (dump_file, "\n        kill:");
	  EXECUTE_IF_SET_IN_BITMAP (m_kill[i], 0, expr_id, sbi)
	    {
	      fprintf (dump_file, " (r%u,bb%u)", get_regno (expr_id, num_bbs),
		       get_bb_index (expr_id, num_bbs));
	    }
	  fprintf (dump_file, "\n        avl_def_in:");
	  EXECUTE_IF_SET_IN_BITMAP (m_avl_def_in[i], 0, expr_id, sbi)
	    {
	      fprintf (dump_file, " (r%u,bb%u)", get_regno (expr_id, num_bbs),
		       get_bb_index (expr_id, num_bbs));
	    }
	  fprintf (dump_file, "\n        avl_def_out:");
	  EXECUTE_IF_SET_IN_BITMAP (m_avl_def_out[i], 0, expr_id, sbi)
	    {
	      fprintf (dump_file, " (r%u,bb%u)", get_regno (expr_id, num_bbs),
		       get_bb_index (expr_id, num_bbs));
	    }
	  fprintf (dump_file, "\n");
	}
    }

  sbitmap_vector_free (avl_def_loc);
  sbitmap_vector_free (m_kill);
  sbitmap_vector_free (avl_def_loc_temp);

  m_dem.set_avl_in_out_data (m_avl_def_in, m_avl_def_out);
}

void
pre_vsetvl::compute_vsetvl_def_data ()
{
  m_vsetvl_def_exprs.truncate (0);
  add_expr (m_vsetvl_def_exprs, m_unknow_info);
  for (const bb_info *bb : crtl->ssa->bbs ())
    {
      vsetvl_block_info &block_info = get_block_info (bb);
      if (block_info.empty_p ())
	continue;
      vsetvl_info &footer_info = block_info.get_exit_info ();
      gcc_assert (footer_info.valid_p () || footer_info.unknown_p ());
      add_expr (m_vsetvl_def_exprs, footer_info);
    }

  if (m_vsetvl_def_in)
    sbitmap_vector_free (m_vsetvl_def_in);
  if (m_vsetvl_def_out)
    sbitmap_vector_free (m_vsetvl_def_out);

  sbitmap *def_loc = sbitmap_vector_alloc (last_basic_block_for_fn (cfun),
					   m_vsetvl_def_exprs.length ());
  sbitmap *m_kill = sbitmap_vector_alloc (last_basic_block_for_fn (cfun),
					  m_vsetvl_def_exprs.length ());

  m_vsetvl_def_in = sbitmap_vector_alloc (last_basic_block_for_fn (cfun),
					  m_vsetvl_def_exprs.length ());
  m_vsetvl_def_out = sbitmap_vector_alloc (last_basic_block_for_fn (cfun),
					   m_vsetvl_def_exprs.length ());

  bitmap_vector_clear (def_loc, last_basic_block_for_fn (cfun));
  bitmap_vector_clear (m_kill, last_basic_block_for_fn (cfun));
  bitmap_vector_clear (m_vsetvl_def_out, last_basic_block_for_fn (cfun));

  for (const bb_info *bb : crtl->ssa->bbs ())
    {
      vsetvl_block_info &block_info = get_block_info (bb);
      if (block_info.empty_p ())
	{
	  for (unsigned i = 0; i < m_vsetvl_def_exprs.length (); i += 1)
	    {
	      const vsetvl_info &info = *m_vsetvl_def_exprs[i];
	      if (!info.has_nonvlmax_reg_avl ())
		continue;
	      unsigned int regno;
	      sbitmap_iterator sbi;
	      EXECUTE_IF_SET_IN_BITMAP (m_reg_def_loc[bb->index ()], 0, regno,
					sbi)
		if (regno == REGNO (info.get_avl ()))
		  {
		    bitmap_set_bit (m_kill[bb->index ()], i);
		    bitmap_set_bit (def_loc[bb->index ()],
				    get_expr_index (m_vsetvl_def_exprs,
						    m_unknow_info));
		  }
	    }
	  continue;
	}

      vsetvl_info &footer_info = block_info.get_exit_info ();
      bitmap_ones (m_kill[bb->index ()]);
      bitmap_set_bit (def_loc[bb->index ()],
		      get_expr_index (m_vsetvl_def_exprs, footer_info));
    }

  /* Set the def_out of the ENTRY basic block to m_unknow_info expr.  */
  basic_block entry = ENTRY_BLOCK_PTR_FOR_FN (cfun);
  bitmap_set_bit (m_vsetvl_def_out[entry->index],
		  get_expr_index (m_vsetvl_def_exprs, m_unknow_info));

  compute_reaching_defintion (def_loc, m_kill, m_vsetvl_def_in,
			      m_vsetvl_def_out);

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file,
	       "\n  Compute vsetvl info reaching defition data:\n\n");
      fprintf (dump_file, "    Expression List (%d):\n",
	       m_vsetvl_def_exprs.length ());
      for (unsigned i = 0; i < m_vsetvl_def_exprs.length (); i++)
	{
	  const auto &info = *m_vsetvl_def_exprs[i];
	  fprintf (dump_file, "      Expr[%u]: ", i);
	  info.dump (dump_file, "        ");
	}
      fprintf (dump_file, "\n    bitmap data:\n");
      for (const bb_info *bb : crtl->ssa->bbs ())
	{
	  unsigned int i = bb->index ();
	  fprintf (dump_file, "      BB %u:\n", i);
	  fprintf (dump_file, "        def_loc: ");
	  dump_bitmap_file (dump_file, def_loc[i]);
	  fprintf (dump_file, "        kill: ");
	  dump_bitmap_file (dump_file, m_kill[i]);
	  fprintf (dump_file, "        vsetvl_def_in: ");
	  dump_bitmap_file (dump_file, m_vsetvl_def_in[i]);
	  fprintf (dump_file, "        vsetvl_def_out: ");
	  dump_bitmap_file (dump_file, m_vsetvl_def_out[i]);
	}
    }

  for (const bb_info *bb : crtl->ssa->bbs ())
    {
      vsetvl_block_info &block_info = get_block_info (bb);
      if (block_info.empty_p ())
	continue;
      vsetvl_info &curr_info = block_info.get_entry_info ();
      if (!curr_info.valid_p ())
	continue;

      unsigned int expr_index;
      sbitmap_iterator sbi;
      gcc_assert (
	!bitmap_empty_p (m_vsetvl_def_in[curr_info.get_bb ()->index ()]));
      bool full_available = true;
      EXECUTE_IF_SET_IN_BITMAP (m_vsetvl_def_in[bb->index ()], 0, expr_index,
				sbi)
	{
	  vsetvl_info &prev_info = *m_vsetvl_def_exprs[expr_index];
	  if (!prev_info.valid_p ()
	      || !m_dem.available_p (prev_info, curr_info))
	    {
	      full_available = false;
	      break;
	    }
	}
      block_info.full_available = full_available;
    }

  sbitmap_vector_free (def_loc);
  sbitmap_vector_free (m_kill);
}

/* Compute the local properties of each recorded expression.

   Local properties are those that are defined by the block, irrespective of
   other blocks.

   An expression is transparent in a block if its operands are not modified
   in the block.

   An expression is computed (locally available) in a block if it is computed
   at least once and expression would contain the same value if the
   computation was moved to the end of the block.

   An expression is locally anticipatable in a block if it is computed at
   least once and expression would contain the same value if the computation
   was moved to the beginning of the block.  */
void
pre_vsetvl::compute_lcm_local_properties ()
{
  m_exprs.truncate (0);
  for (const bb_info *bb : crtl->ssa->bbs ())
    {
      vsetvl_block_info &block_info = get_block_info (bb);
      if (block_info.empty_p ())
	continue;
      vsetvl_info &header_info = block_info.get_entry_info ();
      vsetvl_info &footer_info = block_info.get_exit_info ();
      gcc_assert (footer_info.valid_p () || footer_info.unknown_p ());
      add_expr (m_exprs, header_info);
      add_expr (m_exprs, footer_info);
    }

  int num_exprs = m_exprs.length ();
  if (m_avloc)
    sbitmap_vector_free (m_avloc);
  if (m_kill)
    sbitmap_vector_free (m_kill);
  if (m_antloc)
    sbitmap_vector_free (m_antloc);
  if (m_transp)
    sbitmap_vector_free (m_transp);
  if (m_avin)
    sbitmap_vector_free (m_avin);
  if (m_avout)
    sbitmap_vector_free (m_avout);

  m_avloc = sbitmap_vector_alloc (last_basic_block_for_fn (cfun), num_exprs);
  m_kill = sbitmap_vector_alloc (last_basic_block_for_fn (cfun), num_exprs);
  m_antloc = sbitmap_vector_alloc (last_basic_block_for_fn (cfun), num_exprs);
  m_transp = sbitmap_vector_alloc (last_basic_block_for_fn (cfun), num_exprs);
  m_avin = sbitmap_vector_alloc (last_basic_block_for_fn (cfun), num_exprs);
  m_avout = sbitmap_vector_alloc (last_basic_block_for_fn (cfun), num_exprs);

  bitmap_vector_clear (m_avloc, last_basic_block_for_fn (cfun));
  bitmap_vector_clear (m_antloc, last_basic_block_for_fn (cfun));
  bitmap_vector_clear (m_transp, last_basic_block_for_fn (cfun));

  /* -  If T is locally available at the end of a block, then T' must be
	available at the end of the same block. Since some optimization has
	occurred earlier, T' might not be locally available, however, it must
	have been previously computed on all paths. As a formula, T at AVLOC(B)
	implies that T' at AVOUT(B).
	An "available occurrence" is one that is the last occurrence in the
	basic block and the operands are not modified by following statements in
	the basic block [including this insn].

     -  If T is locally anticipated at the beginning of a block, then either
	T', is locally anticipated or it is already available from previous
	blocks. As a formula, this means that T at ANTLOC(B) implies that T' at
	ANTLOC(B) at AVIN(B).
	An "anticipatable occurrence" is one that is the first occurrence in the
	basic block, the operands are not modified in the basic block prior
	to the occurrence and the output is not used between the start of
	the block and the occurrence.  */
  for (const bb_info *bb : crtl->ssa->bbs ())
    {
      unsigned bb_index = bb->index ();
      vsetvl_block_info &block_info = get_block_info (bb);

      /* Compute m_transp */
      if (block_info.empty_p ())
	{
	  bitmap_ones (m_transp[bb_index]);
	  for (int i = 0; i < num_exprs; i += 1)
	    {
	      const vsetvl_info &info = *m_exprs[i];
	      if (!info.has_nonvlmax_reg_avl () && !info.has_vl ())
		continue;

	      unsigned int regno;
	      sbitmap_iterator sbi;
	      EXECUTE_IF_SET_IN_BITMAP (m_reg_def_loc[bb->index ()], 0, regno,
					sbi)
		{
		  if (regno == REGNO (info.get_avl ()))
		    bitmap_clear_bit (m_transp[bb->index ()], i);
		}

	      for (const insn_info *insn : bb->real_nondebug_insns ())
		{
		  if ((info.has_nonvlmax_reg_avl ()
		       && find_access (insn->defs (), REGNO (info.get_avl ())))
		      || (info.has_vl ()
			  && find_access (insn->uses (),
					  REGNO (info.get_vl ()))))
		    {
		      bitmap_clear_bit (m_transp[bb_index], i);
		      break;
		    }
		}
	    }

	  continue;
	}

      vsetvl_info &header_info = block_info.get_entry_info ();
      vsetvl_info &footer_info = block_info.get_exit_info ();

      if (header_info.valid_p ()
	  && (anticpatable_exp_p (header_info) || block_info.full_available))
	bitmap_set_bit (m_antloc[bb_index],
			get_expr_index (m_exprs, header_info));

      if (footer_info.valid_p ())
	for (int i = 0; i < num_exprs; i += 1)
	  {
	    const vsetvl_info &info = *m_exprs[i];
	    if (!info.valid_p ())
	      continue;
	    if (available_exp_p (footer_info, info))
	      bitmap_set_bit (m_avloc[bb_index], i);
	  }
    }

  for (const bb_info *bb : crtl->ssa->bbs ())
    {
      unsigned bb_index = bb->index ();
      bitmap_ior (m_kill[bb_index], m_transp[bb_index], m_avloc[bb_index]);
      bitmap_not (m_kill[bb_index], m_kill[bb_index]);
    }

  for (const bb_info *bb : crtl->ssa->bbs ())
    {
      unsigned bb_index = bb->index ();
      edge e;
      edge_iterator ei;
      FOR_EACH_EDGE (e, ei, bb->cfg_bb ()->preds)
	if (e->flags & EDGE_COMPLEX)
	  {
	    bitmap_clear (m_antloc[bb_index]);
	    bitmap_clear (m_transp[bb_index]);
	  }
    }
}

void
pre_vsetvl::fuse_local_vsetvl_info ()
{
  m_reg_def_loc
    = sbitmap_vector_alloc (last_basic_block_for_fn (cfun), GP_REG_LAST + 1);
  bitmap_vector_clear (m_reg_def_loc, last_basic_block_for_fn (cfun));
  bitmap_ones (m_reg_def_loc[ENTRY_BLOCK_PTR_FOR_FN (cfun)->index]);

  for (bb_info *bb : crtl->ssa->bbs ())
    {
      auto &block_info = get_block_info (bb);
      block_info.bb = bb;
      if (dump_file && (dump_flags & TDF_DETAILS))
	{
	  fprintf (dump_file, "  Try fuse basic block %d\n", bb->index ());
	}
      auto_vec<vsetvl_info> infos;
      for (insn_info *insn : bb->real_nondebug_insns ())
	{
	  vsetvl_info curr_info = vsetvl_info (insn);
	  if (curr_info.valid_p () || curr_info.unknown_p ())
	    infos.safe_push (curr_info);

	  /* Collecting GP registers modified by the current bb.  */
	  if (insn->is_real ())
	    for (def_info *def : insn->defs ())
	      if (def->is_reg () && GP_REG_P (def->regno ()))
		bitmap_set_bit (m_reg_def_loc[bb->index ()], def->regno ());
	}

      vsetvl_info prev_info = vsetvl_info ();
      prev_info.set_empty ();
      for (auto &curr_info : infos)
	{
	  if (prev_info.empty_p ())
	    prev_info = curr_info;
	  else if ((curr_info.unknown_p () && prev_info.valid_p ())
		   || (curr_info.valid_p () && prev_info.unknown_p ()))
	    {
	      block_info.local_infos.safe_push (prev_info);
	      prev_info = curr_info;
	    }
	  else if (curr_info.valid_p () && prev_info.valid_p ())
	    {
	      if (m_dem.available_p (prev_info, curr_info))
		{
		  if (dump_file && (dump_flags & TDF_DETAILS))
		    {
		      fprintf (dump_file,
			       "    Ignore curr info since prev info "
			       "available with it:\n");
		      fprintf (dump_file, "      prev_info: ");
		      prev_info.dump (dump_file, "        ");
		      fprintf (dump_file, "      curr_info: ");
		      curr_info.dump (dump_file, "        ");
		      fprintf (dump_file, "\n");
		    }
		  if (!curr_info.vl_use_by_non_rvv_insn_p ()
		      && vsetvl_insn_p (curr_info.get_insn ()->rtl ()))
		    m_delete_list.safe_push (curr_info);

		  if (curr_info.get_read_vl_insn ())
		    prev_info.set_read_vl_insn (curr_info.get_read_vl_insn ());
		}
	      else if (m_dem.compatible_p (prev_info, curr_info))
		{
		  if (dump_file && (dump_flags & TDF_DETAILS))
		    {
		      fprintf (dump_file, "    Fuse curr info since prev info "
					  "compatible with it:\n");
		      fprintf (dump_file, "      prev_info: ");
		      prev_info.dump (dump_file, "        ");
		      fprintf (dump_file, "      curr_info: ");
		      curr_info.dump (dump_file, "        ");
		    }
		  m_dem.merge (prev_info, curr_info);
		  if (curr_info.get_read_vl_insn ())
		    prev_info.set_read_vl_insn (curr_info.get_read_vl_insn ());
		  if (dump_file && (dump_flags & TDF_DETAILS))
		    {
		      fprintf (dump_file, "      prev_info after fused: ");
		      prev_info.dump (dump_file, "        ");
		      fprintf (dump_file, "\n");
		    }
		}
	      else
		{
		  if (dump_file && (dump_flags & TDF_DETAILS))
		    {
		      fprintf (dump_file,
			       "    Cannot fuse uncompatible infos:\n");
		      fprintf (dump_file, "      prev_info: ");
		      prev_info.dump (dump_file, "       ");
		      fprintf (dump_file, "      curr_info: ");
		      curr_info.dump (dump_file, "       ");
		    }
		  block_info.local_infos.safe_push (prev_info);
		  prev_info = curr_info;
		}
	    }
	}

      if (prev_info.valid_p () || prev_info.unknown_p ())
	block_info.local_infos.safe_push (prev_info);
    }

  m_avl_regs = sbitmap_alloc (GP_REG_LAST + 1);
  bitmap_clear (m_avl_regs);
  for (const bb_info *bb : crtl->ssa->bbs ())
    {
      vsetvl_block_info &block_info = get_block_info (bb);
      if (block_info.empty_p ())
	continue;

      vsetvl_info &header_info = block_info.get_entry_info ();
      if (header_info.valid_p () && header_info.has_nonvlmax_reg_avl ())
	{
	  gcc_assert (GP_REG_P (REGNO (header_info.get_avl ())));
	  bitmap_set_bit (m_avl_regs, REGNO (header_info.get_avl ()));
	}
    }
}


bool
pre_vsetvl::earliest_fuse_vsetvl_info ()
{
  compute_avl_def_data ();
  compute_vsetvl_def_data ();
  compute_lcm_local_properties ();

  unsigned num_exprs = m_exprs.length ();
  struct edge_list *m_edges = create_edge_list ();
  unsigned num_edges = NUM_EDGES (m_edges);
  sbitmap *antin
    = sbitmap_vector_alloc (last_basic_block_for_fn (cfun), num_exprs);
  sbitmap *antout
    = sbitmap_vector_alloc (last_basic_block_for_fn (cfun), num_exprs);

  sbitmap *earliest = sbitmap_vector_alloc (num_edges, num_exprs);

  compute_available (m_avloc, m_kill, m_avout, m_avin);
  compute_antinout_edge (m_antloc, m_transp, antin, antout);
  compute_earliest (m_edges, num_exprs, antin, antout, m_avout, m_kill,
		    earliest);

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "\n  Compute LCM earliest insert data:\n\n");
      fprintf (dump_file, "    Expression List (%u):\n", num_exprs);
      for (unsigned i = 0; i < num_exprs; i++)
	{
	  const auto &info = *m_exprs[i];
	  fprintf (dump_file, "      Expr[%u]: ", i);
	  info.dump (dump_file, "        ");
	}
      fprintf (dump_file, "\n    bitmap data:\n");
      for (const bb_info *bb : crtl->ssa->bbs ())
	{
	  unsigned int i = bb->index ();
	  fprintf (dump_file, "      BB %u:\n", i);
	  fprintf (dump_file, "        avloc: ");
	  dump_bitmap_file (dump_file, m_avloc[i]);
	  fprintf (dump_file, "        kill: ");
	  dump_bitmap_file (dump_file, m_kill[i]);
	  fprintf (dump_file, "        antloc: ");
	  dump_bitmap_file (dump_file, m_antloc[i]);
	  fprintf (dump_file, "        transp: ");
	  dump_bitmap_file (dump_file, m_transp[i]);

	  fprintf (dump_file, "        avin: ");
	  dump_bitmap_file (dump_file, m_avin[i]);
	  fprintf (dump_file, "        avout: ");
	  dump_bitmap_file (dump_file, m_avout[i]);
	  fprintf (dump_file, "        antin: ");
	  dump_bitmap_file (dump_file, antin[i]);
	  fprintf (dump_file, "        antout: ");
	  dump_bitmap_file (dump_file, antout[i]);
	}
      fprintf (dump_file, "\n");
      fprintf (dump_file, "      earliest:\n");
      for (unsigned ed = 0; ed < num_edges; ed++)
	{
	  edge eg = INDEX_EDGE (m_edges, ed);

	  if (bitmap_empty_p (earliest[ed]))
	    continue;
	  fprintf (dump_file, "        Edge(bb %u -> bb %u): ", eg->src->index,
		   eg->dest->index);
	  dump_bitmap_file (dump_file, earliest[ed]);
	}
      fprintf (dump_file, "\n");
    }

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "    Fused global info result:\n");
    }

  bool changed = false;
  for (unsigned ed = 0; ed < num_edges; ed++)
    {
      sbitmap e = earliest[ed];
      if (bitmap_empty_p (e))
	continue;

      unsigned int expr_index;
      sbitmap_iterator sbi;
      EXECUTE_IF_SET_IN_BITMAP (e, 0, expr_index, sbi)
	{
	  vsetvl_info &curr_info = *m_exprs[expr_index];
	  if (!curr_info.valid_p ())
	    continue;

	  edge eg = INDEX_EDGE (m_edges, ed);
	  if (eg->probability == profile_probability::never ())
	    continue;
	  if (eg->src == ENTRY_BLOCK_PTR_FOR_FN (cfun)
	      || eg->dest == EXIT_BLOCK_PTR_FOR_FN (cfun))
	    continue;

	  vsetvl_block_info &src_block_info = get_block_info (eg->src);
	  vsetvl_block_info &dest_block_info = get_block_info (eg->dest);

	  if (src_block_info.probability
	      == profile_probability::uninitialized ())
	    continue;

	  if (src_block_info.empty_p ())
	    {
	      vsetvl_info new_curr_info = curr_info;
	      new_curr_info.set_bb (crtl->ssa->bb (eg->dest));
	      bool has_compatible_p = false;
	      unsigned int def_expr_index;
	      sbitmap_iterator sbi2;
	      EXECUTE_IF_SET_IN_BITMAP (
		m_vsetvl_def_in[new_curr_info.get_bb ()->index ()], 0,
		def_expr_index, sbi2)
		{
		  vsetvl_info &prev_info = *m_vsetvl_def_exprs[def_expr_index];
		  if (!prev_info.valid_p ())
		    continue;
		  if (m_dem.compatible_p (prev_info, new_curr_info))
		    {
		      has_compatible_p = true;
		      break;
		    }
		}
	      if (!has_compatible_p)
		{
		  if (dump_file && (dump_flags & TDF_DETAILS))
		    {
		      fprintf (dump_file,
			       "      Forbidden lift up vsetvl info into bb %u "
			       "since there is no vsetvl info that reaching in "
			       "is compatible with it:",
			       eg->src->index);
		      curr_info.dump (dump_file, "        ");
		    }
		  continue;
		}

	      if (dump_file && (dump_flags & TDF_DETAILS))
		{
		  fprintf (dump_file,
			   "      Set empty bb %u to info:", eg->src->index);
		  curr_info.dump (dump_file, "        ");
		}
	      src_block_info.set_info (curr_info);
	      src_block_info.probability = dest_block_info.probability;
	      changed = true;
	    }
	  else if (src_block_info.has_info ())
	    {
	      vsetvl_info &prev_info = src_block_info.get_exit_info ();
	      gcc_assert (prev_info.valid_p ());

	      if (m_dem.compatible_p (prev_info, curr_info))
		{
		  if (dump_file && (dump_flags & TDF_DETAILS))
		    {
		      fprintf (dump_file, "    Fuse curr info since prev info "
					  "compatible with it:\n");
		      fprintf (dump_file, "      prev_info: ");
		      prev_info.dump (dump_file, "        ");
		      fprintf (dump_file, "      curr_info: ");
		      curr_info.dump (dump_file, "        ");
		    }
		  m_dem.merge (prev_info, curr_info);
		  if (dump_file && (dump_flags & TDF_DETAILS))
		    {
		      fprintf (dump_file, "      prev_info after fused: ");
		      prev_info.dump (dump_file, "        ");
		      fprintf (dump_file, "\n");
		    }
		  changed = true;
		  if (src_block_info.has_info ())
		    src_block_info.probability += dest_block_info.probability;
		}
	      else if (src_block_info.has_info ()
		       && !m_dem.compatible_p (prev_info, curr_info))
		{
		  /* Cancel lift up if probabilities are equal.  */
		  if (successors_probability_equal_p (eg->src))
		    {
		      if (dump_file && (dump_flags & TDF_DETAILS))
			{
			  fprintf (dump_file,
				   "      Change empty bb %u to from:",
				   eg->src->index);
			  prev_info.dump (dump_file, "        ");
			  fprintf (dump_file,
				   "        to (higher probability):");
			  curr_info.dump (dump_file, "        ");
			}
		      src_block_info.set_empty_info ();
		      src_block_info.probability
			= profile_probability::uninitialized ();
		      changed = true;
		    }
		  /* Choose the one with higher probability. */
		  else if (dest_block_info.probability
			   > src_block_info.probability)
		    {
		      if (dump_file && (dump_flags & TDF_DETAILS))
			{
			  fprintf (dump_file,
				   "      Change empty bb %u to from:",
				   eg->src->index);
			  prev_info.dump (dump_file, "        ");
			  fprintf (dump_file,
				   "        to (higher probability):");
			  curr_info.dump (dump_file, "        ");
			}
		      src_block_info.set_info (curr_info);
		      src_block_info.probability = dest_block_info.probability;
		      changed = true;
		    }
		}
	    }
	  else
	    {
	      vsetvl_info &prev_info = src_block_info.get_exit_info ();
	      if (!prev_info.valid_p ()
		  || m_dem.available_p (prev_info, curr_info))
		continue;

	      if (m_dem.compatible_p (prev_info, curr_info))
		{
		  if (dump_file && (dump_flags & TDF_DETAILS))
		    {
		      fprintf (dump_file, "    Fuse curr info since prev info "
					  "compatible with it:\n");
		      fprintf (dump_file, "      prev_info: ");
		      prev_info.dump (dump_file, "        ");
		      fprintf (dump_file, "      curr_info: ");
		      curr_info.dump (dump_file, "        ");
		    }
		  m_dem.merge (prev_info, curr_info);
		  if (dump_file && (dump_flags & TDF_DETAILS))
		    {
		      fprintf (dump_file, "      prev_info after fused: ");
		      prev_info.dump (dump_file, "        ");
		      fprintf (dump_file, "\n");
		    }
		  changed = true;
		}
	    }
	}
    }

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "\n");
    }

  sbitmap_vector_free (antin);
  sbitmap_vector_free (antout);
  sbitmap_vector_free (earliest);
  free_edge_list (m_edges);

  return changed;
}

void
pre_vsetvl::pre_global_vsetvl_info ()
{
  compute_avl_def_data ();
  compute_vsetvl_def_data ();
  compute_lcm_local_properties ();

  unsigned num_exprs = m_exprs.length ();
  m_edges = pre_edge_lcm_avs (num_exprs, m_transp, m_avloc, m_antloc, m_kill,
			      m_avin, m_avout, &m_insert, &m_del);
  unsigned num_edges = NUM_EDGES (m_edges);

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "\n  Compute LCM insert and delete data:\n\n");
      fprintf (dump_file, "    Expression List (%u):\n", num_exprs);
      for (unsigned i = 0; i < num_exprs; i++)
	{
	  const auto &info = *m_exprs[i];
	  fprintf (dump_file, "      Expr[%u]: ", i);
	  info.dump (dump_file, "        ");
	}
      fprintf (dump_file, "\n    bitmap data:\n");
      for (const bb_info *bb : crtl->ssa->bbs ())
	{
	  unsigned i = bb->index ();
	  fprintf (dump_file, "      BB %u:\n", i);
	  fprintf (dump_file, "        avloc: ");
	  dump_bitmap_file (dump_file, m_avloc[i]);
	  fprintf (dump_file, "        kill: ");
	  dump_bitmap_file (dump_file, m_kill[i]);
	  fprintf (dump_file, "        antloc: ");
	  dump_bitmap_file (dump_file, m_antloc[i]);
	  fprintf (dump_file, "        transp: ");
	  dump_bitmap_file (dump_file, m_transp[i]);

	  fprintf (dump_file, "        avin: ");
	  dump_bitmap_file (dump_file, m_avin[i]);
	  fprintf (dump_file, "        avout: ");
	  dump_bitmap_file (dump_file, m_avout[i]);
	  fprintf (dump_file, "        del: ");
	  dump_bitmap_file (dump_file, m_del[i]);
	}
      fprintf (dump_file, "\n");
      fprintf (dump_file, "      insert:\n");
      for (unsigned ed = 0; ed < num_edges; ed++)
	{
	  edge eg = INDEX_EDGE (m_edges, ed);

	  if (bitmap_empty_p (m_insert[ed]))
	    continue;
	  fprintf (dump_file, "        Edge(bb %u -> bb %u): ", eg->src->index,
		   eg->dest->index);
	  dump_bitmap_file (dump_file, m_insert[ed]);
	}
    }

  /* Remove vsetvl infos as LCM suggest */
  for (const bb_info *bb : crtl->ssa->bbs ())
    {
      sbitmap d = m_del[bb->index ()];
      if (bitmap_count_bits (d) == 0)
	continue;
      gcc_assert (bitmap_count_bits (d) == 1);
      unsigned expr_index = bitmap_first_set_bit (d);
      vsetvl_info &info = *m_exprs[expr_index];
      gcc_assert (info.valid_p ());
      gcc_assert (info.get_bb () == bb);
      const vsetvl_block_info &block_info = get_block_info (info.get_bb ());
      gcc_assert (block_info.get_entry_info () == info);
      info.set_delete ();
    }

  for (const bb_info *bb : crtl->ssa->bbs ())
    {
      vsetvl_block_info &block_info = get_block_info (bb);
      if (block_info.empty_p ())
	continue;
      vsetvl_info &curr_info = block_info.get_entry_info ();
      if (curr_info.delete_p ())
	{
	  if (block_info.local_infos.is_empty ())
	    continue;
	  curr_info = block_info.local_infos[0];
	}
      if (curr_info.valid_p () && !curr_info.vl_use_by_non_rvv_insn_p ()
	  && preds_has_same_avl_p (curr_info))
	curr_info.set_change_vtype_only ();

      vsetvl_info prev_info = vsetvl_info ();
      prev_info.set_empty ();
      for (auto &curr_info : block_info.local_infos)
	{
	  if (prev_info.valid_p () && curr_info.valid_p ()
	      && m_dem.avl_available_p (prev_info, curr_info))
	    curr_info.set_change_vtype_only ();
	  prev_info = curr_info;
	}
    }
}

void
pre_vsetvl::emit_vsetvl ()
{
  bool need_commit = false;

  for (const bb_info *bb : crtl->ssa->bbs ())
    {
      for (const auto &curr_info : get_block_info (bb).local_infos)
	{
	  insn_info *insn = curr_info.get_insn ();
	  if (curr_info.delete_p ())
	    {
	      if (vsetvl_insn_p (insn->rtl ()))
		remove_vsetvl_insn (curr_info);
	      continue;
	    }
	  else if (curr_info.valid_p ())
	    {
	      if (vsetvl_insn_p (insn->rtl ()))
		{
		  const vsetvl_info temp = vsetvl_info (insn);
		  if (!(curr_info == temp))
		    {
		      if (dump_file)
			{
			  fprintf (dump_file, "\n  Change vsetvl info from: ");
			  temp.dump (dump_file, "    ");
			  fprintf (dump_file, "  to: ");
			  curr_info.dump (dump_file, "    ");
			}
		      change_vsetvl_insn (curr_info);
		    }
		}
	      else
		{
		  if (dump_file)
		    {
		      fprintf (dump_file,
			       "\n  Insert vsetvl info before insn %d: ",
			       insn->uid ());
		      curr_info.dump (dump_file, "    ");
		    }
		  insert_vsetvl_insn (EMIT_BEFORE, curr_info);
		}
	    }
	}
    }

  for (const vsetvl_info &item : m_delete_list)
    {
      gcc_assert (vsetvl_insn_p (item.get_insn ()->rtl ()));
      remove_vsetvl_insn (item);
    }

  /* m_insert vsetvl as LCM suggest. */
  for (int ed = 0; ed < NUM_EDGES (m_edges); ed++)
    {
      edge eg = INDEX_EDGE (m_edges, ed);
      sbitmap i = m_insert[ed];
      if (bitmap_count_bits (i) < 1)
	continue;

      if (bitmap_count_bits (i) > 1)
	/* For code with infinite loop (e.g. pr61634.c), The data flow is
	   completely wrong.  */
	continue;

      gcc_assert (bitmap_count_bits (i) == 1);
      unsigned expr_index = bitmap_first_set_bit (i);
      const vsetvl_info &info = *m_exprs[expr_index];
      gcc_assert (info.valid_p ());
      if (dump_file)
	{
	  fprintf (dump_file,
		   "\n  Insert vsetvl info at edge(bb %u -> bb %u): ",
		   eg->src->index, eg->dest->index);
	  info.dump (dump_file, "    ");
	}
      rtl_profile_for_edge (eg);
      start_sequence ();

      insert_vsetvl_insn (EMIT_DIRECT, info);
      rtx_insn *rinsn = get_insns ();
      end_sequence ();
      default_rtl_profile ();

      /* We should not get an abnormal edge here.  */
      gcc_assert (!(eg->flags & EDGE_ABNORMAL));
      need_commit = true;
      insert_insn_on_edge (rinsn, eg);
    }

  /* Insert vsetvl info that was not deleted after lift up.  */
  for (const bb_info *bb : crtl->ssa->bbs ())
    {
      const vsetvl_block_info &block_info = get_block_info (bb);
      if (!block_info.has_info ())
	continue;

      const vsetvl_info &footer_info = block_info.get_exit_info ();

      if (footer_info.delete_p ())
	continue;

      edge eg;
      edge_iterator eg_iterator;
      FOR_EACH_EDGE (eg, eg_iterator, bb->cfg_bb ()->succs)
	{
	  gcc_assert (!(eg->flags & EDGE_ABNORMAL));
	  if (dump_file)
	    {
	      fprintf (
		dump_file,
		"\n  Insert missed vsetvl info at edge(bb %u -> bb %u): ",
		eg->src->index, eg->dest->index);
	      footer_info.dump (dump_file, "    ");
	    }
	  start_sequence ();
	  insert_vsetvl_insn (EMIT_DIRECT, footer_info);
	  rtx_insn *rinsn = get_insns ();
	  end_sequence ();
	  default_rtl_profile ();
	  insert_insn_on_edge (rinsn, eg);
	  need_commit = true;
	}
    }

  if (need_commit)
    commit_edge_insertions ();
}

void
pre_vsetvl::cleaup ()
{
  remove_avl_operand ();
  remove_unused_dest_operand ();
}

void
pre_vsetvl::remove_avl_operand ()
{
  basic_block cfg_bb;
  rtx_insn *rinsn;
  FOR_ALL_BB_FN (cfg_bb, cfun)
    FOR_BB_INSNS (cfg_bb, rinsn)
      if (NONDEBUG_INSN_P (rinsn) && has_vl_op (rinsn)
	  && REG_P (get_vl (rinsn)))
	{
	  rtx avl = get_vl (rinsn);
	  if (count_regno_occurrences (rinsn, REGNO (avl)) == 1)
	    {
	      rtx new_pat;
	      if (fault_first_load_p (rinsn))
		new_pat
		  = simplify_replace_rtx (PATTERN (rinsn), avl, const0_rtx);
	      else
		{
		  rtx set = single_set (rinsn);
		  rtx src
		    = simplify_replace_rtx (SET_SRC (set), avl, const0_rtx);
		  new_pat = gen_rtx_SET (SET_DEST (set), src);
		}
	      if (dump_file)
		{
		  fprintf (dump_file, "  Cleanup insn %u's avl operand:\n",
			   INSN_UID (rinsn));
		  print_rtl_single (dump_file, rinsn);
		}
	      validate_change_or_fail (rinsn, &PATTERN (rinsn), new_pat, false);
	    }
	}
}

void
pre_vsetvl::remove_unused_dest_operand ()
{
  df_analyze ();
  basic_block cfg_bb;
  rtx_insn *rinsn;
  FOR_ALL_BB_FN (cfg_bb, cfun)
    FOR_BB_INSNS (cfg_bb, rinsn)
      if (NONDEBUG_INSN_P (rinsn) && vsetvl_insn_p (rinsn))
	{
	  rtx vl = get_vl (rinsn);
	  vsetvl_info info = vsetvl_info (rinsn);
	  if (has_no_uses (cfg_bb, rinsn, REGNO (vl)))
	    if (!info.has_vlmax_avl ())
	      {
		rtx new_pat = info.get_vsetvl_pat (true);
		if (dump_file)
		  {
		    fprintf (dump_file,
			     "  Remove vsetvl insn %u's dest(vl) operand since "
			     "it unused:\n",
			     INSN_UID (rinsn));
		    print_rtl_single (dump_file, rinsn);
		  }
		validate_change_or_fail (rinsn, &PATTERN (rinsn), new_pat,
					 false);
	      }
	}
}

const pass_data pass_data_vsetvl = {
  RTL_PASS,	 /* type */
  "vsetvl",	 /* name */
  OPTGROUP_NONE, /* optinfo_flags */
  TV_NONE,	 /* tv_id */
  0,		 /* properties_required */
  0,		 /* properties_provided */
  0,		 /* properties_destroyed */
  0,		 /* todo_flags_start */
  0,		 /* todo_flags_finish */
};

class pass_vsetvl : public rtl_opt_pass
{
private:
  void simple_vsetvl ();
  void lazy_vsetvl ();

public:
  pass_vsetvl (gcc::context *ctxt) : rtl_opt_pass (pass_data_vsetvl, ctxt) {}

  /* opt_pass methods: */
  virtual bool gate (function *) final override { return TARGET_VECTOR; }
  virtual unsigned int execute (function *) final override;
}; // class pass_vsetvl

void
pass_vsetvl::simple_vsetvl ()
{
  if (dump_file)
    fprintf (dump_file, "\nEntering Simple VSETVL PASS\n");

  basic_block cfg_bb;
  rtx_insn *rinsn;
  FOR_ALL_BB_FN (cfg_bb, cfun)
    {
      FOR_BB_INSNS (cfg_bb, rinsn)
	{
	  if (!NONDEBUG_INSN_P (rinsn))
	    continue;
	  if (has_vtype_op (rinsn))
	    {
	      const auto &info = vsetvl_info (rinsn);
	      rtx pat = info.get_vsetvl_pat ();
	      emit_insn_before (pat, rinsn);
	      if (dump_file)
		{
		  fprintf (dump_file, "  Insert vsetvl insn before insn %d:\n",
			   INSN_UID (rinsn));
		  print_rtl_single (dump_file, PREV_INSN (rinsn));
		}
	    }
	}
    }
}

/* Lazy vsetvl insertion for optimize > 0. */
void
pass_vsetvl::lazy_vsetvl ()
{
  if (dump_file)
    fprintf (dump_file, "\nEntering Lazy VSETVL PASS\n\n");

  pre_vsetvl pre = pre_vsetvl ();

  if (dump_file)
    fprintf (dump_file, "\nPhase 1: Fuse local vsetvl infos.\n\n");
  pre.fuse_local_vsetvl_info ();
  if (dump_file && (dump_flags & TDF_DETAILS))
    pre.dump (dump_file, "phase 1");

  /* Phase 2:  Fuse header and footer vsetvl infos between basic blocks.  */
  if (dump_file)
    fprintf (dump_file, "\nPhase 2: Lift up vsetvl info.\n\n");
  bool changed;
  int fused_count = 0;
  do
    {
      if (dump_file)
	fprintf (dump_file, "  Try lift up %d.\n\n", fused_count);
      changed = pre.earliest_fuse_vsetvl_info ();
      fused_count += 1;
  } while (changed);

  if (dump_file && (dump_flags & TDF_DETAILS))
    pre.dump (dump_file, "phase 2");

  /* Phase 3: Reducing redundant vsetvl infos using LCM.  */
  if (dump_file)
    fprintf (dump_file, "\nPhase 3: Reduce global vsetvl infos.\n\n");
  pre.pre_global_vsetvl_info ();
  if (dump_file && (dump_flags & TDF_DETAILS))
    pre.dump (dump_file, "phase 3");

  /* Phase 4: Insert, modify and remove vsetvl insns.  */
  if (dump_file)
    fprintf (dump_file,
	     "\nPhase 4: Insert, modify and remove vsetvl insns.\n\n");
  pre.emit_vsetvl ();

  /* Phase 5: Cleaup */
  if (dump_file)
    fprintf (dump_file, "\nPhase 5: Cleaup\n\n");
  pre.cleaup ();

  pre.finish ();
}

/* Main entry point for this pass.  */
unsigned int
pass_vsetvl::execute (function *)
{
  if (n_basic_blocks_for_fn (cfun) <= 0)
    return 0;

  /* The RVV instruction may change after split which is not a stable
     instruction. We need to split it here to avoid potential issue
     since the VSETVL PASS is insert before split PASS.  */
  split_all_insns ();

  /* Early return for there is no vector instructions.  */
  if (!has_vector_insn (cfun))
    return 0;

  if (!optimize)
    simple_vsetvl ();
  else
    lazy_vsetvl ();

  return 0;
}

rtl_opt_pass *
make_pass_vsetvl (gcc::context *ctxt)
{
  return new pass_vsetvl (ctxt);
}