[V3,02/11] RISC-V: P2: Refactor and cleanup demand system

Message ID 20231019083333.2052340-3-lehua.ding@rivai.ai
State Unresolved
Headers
Series Refactor and cleanup vsetvl pass |

Checks

Context Check Description
snail/gcc-patch-check warning Git am fail log

Commit Message

Lehua Ding Oct. 19, 2023, 8:33 a.m. UTC
  gcc/ChangeLog:

	* config/riscv/riscv-vsetvl.cc (incompatible_avl_p): Removed.
	(different_sew_p): Removed.
	(different_lmul_p): Removed.
	(different_ratio_p): Removed.
	(different_tail_policy_p): Removed.
	(different_mask_policy_p): Removed.
	(possible_zero_avl_p): Removed.
	(second_ratio_invalid_for_first_sew_p): Removed.
	(second_ratio_invalid_for_first_lmul_p): Removed.
	(float_insn_valid_sew_p): Removed.
	(second_sew_less_than_first_sew_p): Removed.
	(first_sew_less_than_second_sew_p): Removed.
	(compare_lmul): Removed.
	(second_lmul_less_than_first_lmul_p): Removed.
	(second_ratio_less_than_first_ratio_p): Removed.
	(DEF_INCOMPATIBLE_COND): Removed.
	(greatest_sew): Removed.
	(first_sew): Removed.
	(second_sew): Removed.
	(first_vlmul): Removed.
	(second_vlmul): Removed.
	(first_ratio): Removed.
	(second_ratio): Removed.
	(vlmul_for_first_sew_second_ratio): Removed.
	(vlmul_for_greatest_sew_second_ratio): Removed.
	(ratio_for_second_sew_first_vlmul): Removed.
	(DEF_SEW_LMUL_FUSE_RULE): Removed.
	(always_unavailable): Removed.
	(avl_unavailable_p): Removed.
	(sew_unavailable_p): Removed.
	(lmul_unavailable_p): Removed.
	(ge_sew_unavailable_p): Removed.
	(ge_sew_lmul_unavailable_p): Removed.
	(ge_sew_ratio_unavailable_p): Removed.
	(DEF_UNAVAILABLE_COND): Removed.
	(same_sew_lmul_demand_p): Removed.
	(propagate_avl_across_demands_p): Removed.
	(reg_available_p): Removed.
	(support_relaxed_compatible_p): Removed.
	(count_regno_occurrences): Removed.
	(demands_can_be_fused_p): Removed.
	(earliest_pred_can_be_fused_p): Removed.
	(vsetvl_dominated_by_p): Removed.
	(class demand_system): New.
	(DEF_SEW_LMUL_RULE): New.
	(DEF_POLICY_RULE): New.
	(DEF_AVL_RULE): New.

---
 gcc/config/riscv/riscv-vsetvl.cc | 1158 +++++++++++++++++-------------
 1 file changed, 668 insertions(+), 490 deletions(-)
  

Patch

diff --git a/gcc/config/riscv/riscv-vsetvl.cc b/gcc/config/riscv/riscv-vsetvl.cc
index 8908071dc0d..c9f2f653247 100644
--- a/gcc/config/riscv/riscv-vsetvl.cc
+++ b/gcc/config/riscv/riscv-vsetvl.cc
@@ -1091,496 +1091,6 @@  calculate_vlmul (unsigned int sew, unsigned int ratio)
   return LMUL_RESERVED;
 }
 
-static bool
-incompatible_avl_p (const vector_insn_info &info1,
-		    const vector_insn_info &info2)
-{
-  return !info1.compatible_avl_p (info2) && !info2.compatible_avl_p (info1);
-}
-
-static bool
-different_sew_p (const vector_insn_info &info1, const vector_insn_info &info2)
-{
-  return info1.get_sew () != info2.get_sew ();
-}
-
-static bool
-different_lmul_p (const vector_insn_info &info1, const vector_insn_info &info2)
-{
-  return info1.get_vlmul () != info2.get_vlmul ();
-}
-
-static bool
-different_ratio_p (const vector_insn_info &info1, const vector_insn_info &info2)
-{
-  return info1.get_ratio () != info2.get_ratio ();
-}
-
-static bool
-different_tail_policy_p (const vector_insn_info &info1,
-			 const vector_insn_info &info2)
-{
-  return info1.get_ta () != info2.get_ta ();
-}
-
-static bool
-different_mask_policy_p (const vector_insn_info &info1,
-			 const vector_insn_info &info2)
-{
-  return info1.get_ma () != info2.get_ma ();
-}
-
-static bool
-possible_zero_avl_p (const vector_insn_info &info1,
-		     const vector_insn_info &info2)
-{
-  return !info1.has_non_zero_avl () || !info2.has_non_zero_avl ();
-}
-
-static bool
-second_ratio_invalid_for_first_sew_p (const vector_insn_info &info1,
-				      const vector_insn_info &info2)
-{
-  return calculate_vlmul (info1.get_sew (), info2.get_ratio ())
-	 == LMUL_RESERVED;
-}
-
-static bool
-second_ratio_invalid_for_first_lmul_p (const vector_insn_info &info1,
-				       const vector_insn_info &info2)
-{
-  return calculate_sew (info1.get_vlmul (), info2.get_ratio ()) == 0;
-}
-
-static bool
-float_insn_valid_sew_p (const vector_insn_info &info, unsigned int sew)
-{
-  if (info.get_insn () && info.get_insn ()->is_real ()
-      && get_attr_type (info.get_insn ()->rtl ()) == TYPE_VFMOVFV)
-    {
-      if (sew == 16)
-	return TARGET_VECTOR_ELEN_FP_16;
-      else if (sew == 32)
-	return TARGET_VECTOR_ELEN_FP_32;
-      else if (sew == 64)
-	return TARGET_VECTOR_ELEN_FP_64;
-    }
-  return true;
-}
-
-static bool
-second_sew_less_than_first_sew_p (const vector_insn_info &info1,
-				  const vector_insn_info &info2)
-{
-  return info2.get_sew () < info1.get_sew ()
-	 || !float_insn_valid_sew_p (info1, info2.get_sew ());
-}
-
-static bool
-first_sew_less_than_second_sew_p (const vector_insn_info &info1,
-				  const vector_insn_info &info2)
-{
-  return info1.get_sew () < info2.get_sew ()
-	 || !float_insn_valid_sew_p (info2, info1.get_sew ());
-}
-
-/* return 0 if LMUL1 == LMUL2.
-   return -1 if LMUL1 < LMUL2.
-   return 1 if LMUL1 > LMUL2.  */
-static int
-compare_lmul (vlmul_type vlmul1, vlmul_type vlmul2)
-{
-  if (vlmul1 == vlmul2)
-    return 0;
-
-  switch (vlmul1)
-    {
-    case LMUL_1:
-      if (vlmul2 == LMUL_2 || vlmul2 == LMUL_4 || vlmul2 == LMUL_8)
-	return 1;
-      else
-	return -1;
-    case LMUL_2:
-      if (vlmul2 == LMUL_4 || vlmul2 == LMUL_8)
-	return 1;
-      else
-	return -1;
-    case LMUL_4:
-      if (vlmul2 == LMUL_8)
-	return 1;
-      else
-	return -1;
-    case LMUL_8:
-      return -1;
-    case LMUL_F2:
-      if (vlmul2 == LMUL_1 || vlmul2 == LMUL_2 || vlmul2 == LMUL_4
-	  || vlmul2 == LMUL_8)
-	return 1;
-      else
-	return -1;
-    case LMUL_F4:
-      if (vlmul2 == LMUL_F2 || vlmul2 == LMUL_1 || vlmul2 == LMUL_2
-	  || vlmul2 == LMUL_4 || vlmul2 == LMUL_8)
-	return 1;
-      else
-	return -1;
-    case LMUL_F8:
-      return 0;
-    default:
-      gcc_unreachable ();
-    }
-}
-
-static bool
-second_lmul_less_than_first_lmul_p (const vector_insn_info &info1,
-				    const vector_insn_info &info2)
-{
-  return compare_lmul (info2.get_vlmul (), info1.get_vlmul ()) == -1;
-}
-
-static bool
-second_ratio_less_than_first_ratio_p (const vector_insn_info &info1,
-				      const vector_insn_info &info2)
-{
-  return info2.get_ratio () < info1.get_ratio ();
-}
-
-static CONSTEXPR const demands_cond incompatible_conds[] = {
-#define DEF_INCOMPATIBLE_COND(AVL1, SEW1, LMUL1, RATIO1, NONZERO_AVL1,         \
-			      GE_SEW1, TAIL_POLICTY1, MASK_POLICY1, AVL2,      \
-			      SEW2, LMUL2, RATIO2, NONZERO_AVL2, GE_SEW2,      \
-			      TAIL_POLICTY2, MASK_POLICY2, COND)               \
-  {{{AVL1, SEW1, LMUL1, RATIO1, NONZERO_AVL1, GE_SEW1, TAIL_POLICTY1,          \
-     MASK_POLICY1},                                                            \
-    {AVL2, SEW2, LMUL2, RATIO2, NONZERO_AVL2, GE_SEW2, TAIL_POLICTY2,          \
-     MASK_POLICY2}},                                                           \
-   COND},
-#include "riscv-vsetvl.def"
-};
-
-static unsigned
-greatest_sew (const vector_insn_info &info1, const vector_insn_info &info2)
-{
-  return std::max (info1.get_sew (), info2.get_sew ());
-}
-
-static unsigned
-first_sew (const vector_insn_info &info1, const vector_insn_info &)
-{
-  return info1.get_sew ();
-}
-
-static unsigned
-second_sew (const vector_insn_info &, const vector_insn_info &info2)
-{
-  return info2.get_sew ();
-}
-
-static vlmul_type
-first_vlmul (const vector_insn_info &info1, const vector_insn_info &)
-{
-  return info1.get_vlmul ();
-}
-
-static vlmul_type
-second_vlmul (const vector_insn_info &, const vector_insn_info &info2)
-{
-  return info2.get_vlmul ();
-}
-
-static unsigned
-first_ratio (const vector_insn_info &info1, const vector_insn_info &)
-{
-  return info1.get_ratio ();
-}
-
-static unsigned
-second_ratio (const vector_insn_info &, const vector_insn_info &info2)
-{
-  return info2.get_ratio ();
-}
-
-static vlmul_type
-vlmul_for_first_sew_second_ratio (const vector_insn_info &info1,
-				  const vector_insn_info &info2)
-{
-  return calculate_vlmul (info1.get_sew (), info2.get_ratio ());
-}
-
-static vlmul_type
-vlmul_for_greatest_sew_second_ratio (const vector_insn_info &info1,
-				     const vector_insn_info &info2)
-{
-  return calculate_vlmul (MAX (info1.get_sew (), info2.get_sew ()),
-			  info2.get_ratio ());
-}
-
-static unsigned
-ratio_for_second_sew_first_vlmul (const vector_insn_info &info1,
-				  const vector_insn_info &info2)
-{
-  return calculate_ratio (info2.get_sew (), info1.get_vlmul ());
-}
-
-static CONSTEXPR const demands_fuse_rule fuse_rules[] = {
-#define DEF_SEW_LMUL_FUSE_RULE(DEMAND_SEW1, DEMAND_LMUL1, DEMAND_RATIO1,       \
-			       DEMAND_GE_SEW1, DEMAND_SEW2, DEMAND_LMUL2,      \
-			       DEMAND_RATIO2, DEMAND_GE_SEW2, NEW_DEMAND_SEW,  \
-			       NEW_DEMAND_LMUL, NEW_DEMAND_RATIO,              \
-			       NEW_DEMAND_GE_SEW, NEW_SEW, NEW_VLMUL,          \
-			       NEW_RATIO)                                      \
-  {{{DEMAND_ANY, DEMAND_SEW1, DEMAND_LMUL1, DEMAND_RATIO1, DEMAND_ANY,         \
-     DEMAND_GE_SEW1, DEMAND_ANY, DEMAND_ANY},                                  \
-    {DEMAND_ANY, DEMAND_SEW2, DEMAND_LMUL2, DEMAND_RATIO2, DEMAND_ANY,         \
-     DEMAND_GE_SEW2, DEMAND_ANY, DEMAND_ANY}},                                 \
-   NEW_DEMAND_SEW,                                                             \
-   NEW_DEMAND_LMUL,                                                            \
-   NEW_DEMAND_RATIO,                                                           \
-   NEW_DEMAND_GE_SEW,                                                          \
-   NEW_SEW,                                                                    \
-   NEW_VLMUL,                                                                  \
-   NEW_RATIO},
-#include "riscv-vsetvl.def"
-};
-
-static bool
-always_unavailable (const vector_insn_info &, const vector_insn_info &)
-{
-  return true;
-}
-
-static bool
-avl_unavailable_p (const vector_insn_info &info1, const vector_insn_info &info2)
-{
-  return !info2.compatible_avl_p (info1.get_avl_info ());
-}
-
-static bool
-sew_unavailable_p (const vector_insn_info &info1, const vector_insn_info &info2)
-{
-  if (!info2.demand_p (DEMAND_LMUL) && !info2.demand_p (DEMAND_RATIO))
-    {
-      if (info2.demand_p (DEMAND_GE_SEW))
-	return info1.get_sew () < info2.get_sew ();
-      return info1.get_sew () != info2.get_sew ();
-    }
-  return true;
-}
-
-static bool
-lmul_unavailable_p (const vector_insn_info &info1,
-		    const vector_insn_info &info2)
-{
-  if (info1.get_vlmul () == info2.get_vlmul () && !info2.demand_p (DEMAND_SEW)
-      && !info2.demand_p (DEMAND_RATIO))
-    return false;
-  return true;
-}
-
-static bool
-ge_sew_unavailable_p (const vector_insn_info &info1,
-		      const vector_insn_info &info2)
-{
-  if (!info2.demand_p (DEMAND_LMUL) && !info2.demand_p (DEMAND_RATIO)
-      && info2.demand_p (DEMAND_GE_SEW))
-    return info1.get_sew () < info2.get_sew ();
-  return true;
-}
-
-static bool
-ge_sew_lmul_unavailable_p (const vector_insn_info &info1,
-			   const vector_insn_info &info2)
-{
-  if (!info2.demand_p (DEMAND_RATIO) && info2.demand_p (DEMAND_GE_SEW))
-    return info1.get_sew () < info2.get_sew ();
-  return true;
-}
-
-static bool
-ge_sew_ratio_unavailable_p (const vector_insn_info &info1,
-			    const vector_insn_info &info2)
-{
-  if (!info2.demand_p (DEMAND_LMUL))
-    {
-      if (info2.demand_p (DEMAND_GE_SEW))
-	return info1.get_sew () < info2.get_sew ();
-      /* Demand GE_SEW should be available for non-demand SEW.  */
-      else if (!info2.demand_p (DEMAND_SEW))
-	return false;
-    }
-  return true;
-}
-
-static CONSTEXPR const demands_cond unavailable_conds[] = {
-#define DEF_UNAVAILABLE_COND(AVL1, SEW1, LMUL1, RATIO1, NONZERO_AVL1, GE_SEW1, \
-			     TAIL_POLICTY1, MASK_POLICY1, AVL2, SEW2, LMUL2,   \
-			     RATIO2, NONZERO_AVL2, GE_SEW2, TAIL_POLICTY2,     \
-			     MASK_POLICY2, COND)                               \
-  {{{AVL1, SEW1, LMUL1, RATIO1, NONZERO_AVL1, GE_SEW1, TAIL_POLICTY1,          \
-     MASK_POLICY1},                                                            \
-    {AVL2, SEW2, LMUL2, RATIO2, NONZERO_AVL2, GE_SEW2, TAIL_POLICTY2,          \
-     MASK_POLICY2}},                                                           \
-   COND},
-#include "riscv-vsetvl.def"
-};
-
-static bool
-same_sew_lmul_demand_p (const bool *dems1, const bool *dems2)
-{
-  return dems1[DEMAND_SEW] == dems2[DEMAND_SEW]
-	 && dems1[DEMAND_LMUL] == dems2[DEMAND_LMUL]
-	 && dems1[DEMAND_RATIO] == dems2[DEMAND_RATIO] && !dems1[DEMAND_GE_SEW]
-	 && !dems2[DEMAND_GE_SEW];
-}
-
-static bool
-propagate_avl_across_demands_p (const vector_insn_info &info1,
-				const vector_insn_info &info2)
-{
-  if (info2.demand_p (DEMAND_AVL))
-    {
-      if (info2.demand_p (DEMAND_NONZERO_AVL))
-	return info1.demand_p (DEMAND_AVL)
-	       && !info1.demand_p (DEMAND_NONZERO_AVL) && info1.has_avl_reg ();
-    }
-  else
-    return info1.demand_p (DEMAND_AVL) && info1.has_avl_reg ();
-  return false;
-}
-
-static bool
-reg_available_p (const insn_info *insn, const vector_insn_info &info)
-{
-  if (info.has_avl_reg () && !info.get_avl_source ())
-    return false;
-  insn_info *def_insn = info.get_avl_source ()->insn ();
-  if (def_insn->bb () == insn->bb ())
-    return before_p (def_insn, insn);
-  else
-    return dominated_by_p (CDI_DOMINATORS, insn->bb ()->cfg_bb (),
-			   def_insn->bb ()->cfg_bb ());
-}
-
-/* Return true if the instruction support relaxed compatible check.  */
-static bool
-support_relaxed_compatible_p (const vector_insn_info &info1,
-			      const vector_insn_info &info2)
-{
-  if (fault_first_load_p (info1.get_insn ()->rtl ())
-      && info2.demand_p (DEMAND_AVL) && info2.has_avl_reg ()
-      && info2.get_avl_source () && info2.get_avl_source ()->insn ()->is_phi ())
-    {
-      hash_set<set_info *> sets
-	= get_all_sets (info2.get_avl_source (), true, false, false);
-      for (set_info *set : sets)
-	{
-	  if (read_vl_insn_p (set->insn ()->rtl ()))
-	    {
-	      const insn_info *insn
-		= get_backward_fault_first_load_insn (set->insn ());
-	      if (insn == info1.get_insn ())
-		return info2.compatible_vtype_p (info1);
-	    }
-	}
-    }
-  return false;
-}
-
-/* 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;
-}
-
-/* Return TRUE if the demands can be fused.  */
-static bool
-demands_can_be_fused_p (const vector_insn_info &be_fused,
-			const vector_insn_info &to_fuse)
-{
-  return be_fused.compatible_p (to_fuse) && !be_fused.available_p (to_fuse);
-}
-
-/* Return true if we can fuse VSETVL demand info into predecessor of earliest
- * edge.  */
-static bool
-earliest_pred_can_be_fused_p (const bb_info *earliest_pred,
-			      const vector_insn_info &earliest_info,
-			      const vector_insn_info &expr, rtx *vlmax_vl)
-{
-  /* Backward VLMAX VL:
-       bb 3:
-	 vsetivli zero, 1 ... -> vsetvli t1, zero
-	 vmv.s.x
-       bb 5:
-	 vsetvli t1, zero ... -> to be elided.
-	 vlse16.v
-
-       We should forward "t1".  */
-  if (!earliest_info.has_avl_reg () && expr.has_avl_reg ())
-    {
-      rtx avl_or_vl_reg = expr.get_avl_or_vl_reg ();
-      gcc_assert (avl_or_vl_reg);
-      const insn_info *last_insn = earliest_info.get_insn ();
-      /* To fuse demand on earlest edge, we make sure AVL/VL
-	 didn't change from the consume insn to the predecessor
-	 of the edge.  */
-      for (insn_info *i = earliest_pred->end_insn ()->prev_nondebug_insn ();
-	   real_insn_and_same_bb_p (i, earliest_pred)
-	   && after_or_same_p (i, last_insn);
-	   i = i->prev_nondebug_insn ())
-	{
-	  if (find_access (i->defs (), REGNO (avl_or_vl_reg)))
-	    return false;
-	  if (find_access (i->uses (), REGNO (avl_or_vl_reg)))
-	    return false;
-	}
-      if (vlmax_vl && vlmax_avl_p (expr.get_avl ()))
-	*vlmax_vl = avl_or_vl_reg;
-    }
-
-  return true;
-}
-
-/* Return true if the current VSETVL 1 is dominated by preceding VSETVL 2.
-
-   VSETVL 2 dominates VSETVL 1 should satisfy this following check:
-
-     - VSETVL 2 should have the RATIO (SEW/LMUL) with VSETVL 1.
-     - VSETVL 2 is user vsetvl (vsetvl VL, AVL)
-     - VSETVL 2 "VL" result is the "AVL" of VSETL1.  */
-static bool
-vsetvl_dominated_by_p (const basic_block cfg_bb,
-		       const vector_insn_info &vsetvl1,
-		       const vector_insn_info &vsetvl2, bool fuse_p)
-{
-  if (!vsetvl1.valid_or_dirty_p () || !vsetvl2.valid_or_dirty_p ())
-    return false;
-  if (!has_vl_op (vsetvl1.get_insn ()->rtl ())
-      || !vsetvl_insn_p (vsetvl2.get_insn ()->rtl ()))
-    return false;
-
-  hash_set<set_info *> sets
-    = get_all_sets (vsetvl1.get_avl_source (), true, false, false);
-  set_info *set = get_same_bb_set (sets, cfg_bb);
-
-  if (!vsetvl1.has_avl_reg () || vlmax_avl_p (vsetvl1.get_avl ())
-      || !vsetvl2.same_vlmax_p (vsetvl1) || !set
-      || set->insn () != vsetvl2.get_insn ())
-    return false;
-
-  if (fuse_p && vsetvl2.same_vtype_p (vsetvl1))
-    return false;
-  else if (!fuse_p && !vsetvl2.same_vtype_p (vsetvl1))
-    return false;
-  return true;
-}
-
 /* 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
@@ -2206,6 +1716,674 @@  public:
   void set_empty_info () { m_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));
+  }
+};
+
 vector_infos_manager::vector_infos_manager ()
 {
   vector_edge_list = nullptr;