[PATCH V2 08/14] RISC-V: P8: Unified insert and delete of vsetvl insn into Phase 4

[Lehua Ding <lehua.ding@rivai.ai>]

This sub-patch move the modification of rtl codes from pass_vsetvl
into pre_vsetvl class.

gcc/ChangeLog:

	* config/riscv/riscv-vsetvl.cc (pre_vsetvl::emit_vsetvl): New.
	(pass_vsetvl::can_refine_vsetvl_p): Removed.
	(pass_vsetvl::refine_vsetvls): Removed.
	(pass_vsetvl::cleanup_vsetvls): Removed.
	(pass_vsetvl::commit_vsetvls): Removed.

---
 gcc/config/riscv/riscv-vsetvl.cc | 389 +++++++++++--------------------
 1 file changed, 134 insertions(+), 255 deletions(-)

diff --git a/gcc/config/riscv/riscv-vsetvl.cc b/gcc/config/riscv/riscv-vsetvl.cc
index a112895a283..5d84d290e9e 100644
--- a/gcc/config/riscv/riscv-vsetvl.cc
+++ b/gcc/config/riscv/riscv-vsetvl.cc
@@ -3658,6 +3658,140 @@ pre_vsetvl::pre_global_vsetvl_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).infos)
+	{
+	  insn_info *insn = curr_info.get_insn ();
+	  if (curr_info.ignore_p ())
+	    {
+	      if (vsetvl_insn_p (insn->rtl ()))
+		eliminate_insn (insn->rtl ());
+	      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 (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 (EMIT_BEFORE, insn->rtl (), curr_info);
+		}
+	    }
+	}
+    }
+
+  for (const vsetvl_info &item : delete_list)
+    {
+      gcc_assert (vsetvl_insn_p (item.get_insn ()->rtl ()));
+      eliminate_insn (item.get_insn ()->rtl ());
+    }
+
+  /* Insert vsetvl as LCM suggest. */
+  for (int ed = 0; ed < NUM_EDGES (edges); ed++)
+    {
+      edge eg = INDEX_EDGE (edges, ed);
+      sbitmap i = 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 = *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 ();
+
+      insn_info *insn = info.get_insn ();
+      insert_vsetvl (EMIT_DIRECT, insn->rtl (), 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_footer_info ();
+      insn_info *insn = footer_info.get_insn ();
+
+      if (footer_info.ignore_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 (EMIT_DIRECT, insn->rtl (), 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 ();
+}
+
+
 const pass_data pass_data_vsetvl = {
   RTL_PASS,	 /* type */
   "vsetvl",	 /* name */
@@ -3790,261 +3924,6 @@ make_pass_vsetvl (gcc::context *ctxt)
   return new pass_vsetvl (ctxt);
 }

-
-/* Return true if VSETVL in the block can be refined as vsetvl zero,zero.  */
-bool
-pass_vsetvl::can_refine_vsetvl_p (const basic_block cfg_bb,
-				  const vector_insn_info &info) const
-{
-  if (!m_vector_manager->all_same_ratio_p (
-	m_vector_manager->vector_avin[cfg_bb->index]))
-    return false;
-
-  if (!m_vector_manager->all_same_avl_p (
-	cfg_bb, m_vector_manager->vector_avin[cfg_bb->index]))
-    return false;
-
-  size_t expr_id
-    = bitmap_first_set_bit (m_vector_manager->vector_avin[cfg_bb->index]);
-  if (!m_vector_manager->vector_exprs[expr_id]->same_vlmax_p (info))
-    return false;
-  if (!m_vector_manager->vector_exprs[expr_id]->compatible_avl_p (info))
-    return false;
-
-  edge e;
-  edge_iterator ei;
-  bool all_valid_p = true;
-  FOR_EACH_EDGE (e, ei, cfg_bb->preds)
-    {
-      if (bitmap_empty_p (m_vector_manager->vector_avout[e->src->index]))
-	{
-	  all_valid_p = false;
-	  break;
-	}
-    }
-
-  if (!all_valid_p)
-    return false;
-  return true;
-}
-
-/* Optimize athe case like this:
-
-      bb 0:
-	vsetvl 0 a5,zero,e8,mf8
-	insn 0 (demand SEW + LMUL)
-      bb 1:
-	vsetvl 1 a5,zero,e16,mf4
-	insn 1 (demand SEW + LMUL)
-
-   In this case, we should be able to refine
-   vsetvl 1 into vsetvl zero, zero according AVIN.  */
-void
-pass_vsetvl::refine_vsetvls (void) const
-{
-  basic_block cfg_bb;
-  FOR_EACH_BB_FN (cfg_bb, cfun)
-    {
-      auto info = get_block_info (cfg_bb).local_dem;
-      insn_info *insn = info.get_insn ();
-      if (!info.valid_p ())
-	continue;
-
-      rtx_insn *rinsn = insn->rtl ();
-      if (!can_refine_vsetvl_p (cfg_bb, info))
-	continue;
-
-      /* We can't refine user vsetvl into vsetvl zero,zero since the dest
-	 will be used by the following instructions.  */
-      if (vector_config_insn_p (rinsn))
-	{
-	  m_vector_manager->to_refine_vsetvls.add (rinsn);
-	  continue;
-	}
-
-      /* If all incoming edges to a block have a vector state that is compatbile
-	 with the block. In such a case we need not emit a vsetvl in the current
-	 block.  */
-
-      gcc_assert (has_vtype_op (insn->rtl ()));
-      rinsn = PREV_INSN (insn->rtl ());
-      gcc_assert (vector_config_insn_p (PREV_INSN (insn->rtl ())));
-      if (m_vector_manager->all_avail_in_compatible_p (cfg_bb))
-	{
-	  size_t id = m_vector_manager->get_expr_id (info);
-	  if (bitmap_bit_p (m_vector_manager->vector_del[cfg_bb->index], id))
-	    continue;
-	  eliminate_insn (rinsn);
-	}
-      else
-	{
-	  rtx new_pat
-	    = gen_vsetvl_pat (VSETVL_VTYPE_CHANGE_ONLY, info, NULL_RTX);
-	  change_insn (rinsn, new_pat);
-	}
-    }
-}
-
-void
-pass_vsetvl::cleanup_vsetvls ()
-{
-  basic_block cfg_bb;
-  FOR_EACH_BB_FN (cfg_bb, cfun)
-    {
-      auto &info = get_block_info (cfg_bb).reaching_out;
-      gcc_assert (m_vector_manager->expr_set_num (
-		    m_vector_manager->vector_del[cfg_bb->index])
-		  <= 1);
-      for (size_t i = 0; i < m_vector_manager->vector_exprs.length (); i++)
-	{
-	  if (bitmap_bit_p (m_vector_manager->vector_del[cfg_bb->index], i))
-	    {
-	      if (info.dirty_p ())
-		info.set_unknown ();
-	      else
-		{
-		  const auto dem = get_block_info (cfg_bb).local_dem;
-		  gcc_assert (dem == *m_vector_manager->vector_exprs[i]);
-		  insn_info *insn = dem.get_insn ();
-		  gcc_assert (insn && insn->rtl ());
-		  rtx_insn *rinsn;
-		  /* We can't eliminate user vsetvl since the dest will be used
-		   * by the following instructions.  */
-		  if (vector_config_insn_p (insn->rtl ()))
-		    {
-		      m_vector_manager->to_delete_vsetvls.add (insn->rtl ());
-		      continue;
-		    }
-
-		  gcc_assert (has_vtype_op (insn->rtl ()));
-		  rinsn = PREV_INSN (insn->rtl ());
-		  gcc_assert (vector_config_insn_p (PREV_INSN (insn->rtl ())));
-		  eliminate_insn (rinsn);
-		}
-	    }
-	}
-    }
-}
-
-bool
-pass_vsetvl::commit_vsetvls (void)
-{
-  bool need_commit = false;
-
-  for (int ed = 0; ed < NUM_EDGES (m_vector_manager->vector_edge_list); ed++)
-    {
-      for (size_t i = 0; i < m_vector_manager->vector_exprs.length (); i++)
-	{
-	  edge eg = INDEX_EDGE (m_vector_manager->vector_edge_list, ed);
-	  if (bitmap_bit_p (m_vector_manager->vector_insert[ed], i))
-	    {
-	      const vector_insn_info *require
-		= m_vector_manager->vector_exprs[i];
-	      gcc_assert (require->valid_or_dirty_p ());
-	      rtl_profile_for_edge (eg);
-	      start_sequence ();
-
-	      insn_info *insn = require->get_insn ();
-	      vector_insn_info prev_info = vector_insn_info ();
-	      sbitmap bitdata = m_vector_manager->vector_avout[eg->src->index];
-	      if (m_vector_manager->all_same_ratio_p (bitdata)
-		  && m_vector_manager->all_same_avl_p (eg->dest, bitdata))
-		{
-		  size_t first = bitmap_first_set_bit (bitdata);
-		  prev_info = *m_vector_manager->vector_exprs[first];
-		}
-
-	      insert_vsetvl (EMIT_DIRECT, insn->rtl (), *require, prev_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);
-
-	      if (dump_file)
-		{
-		  fprintf (dump_file,
-			   "\nInsert vsetvl insn %d at edge %d from <bb %d> to "
-			   "<bb %d>:\n",
-			   INSN_UID (rinsn), ed, eg->src->index,
-			   eg->dest->index);
-		  print_rtl_single (dump_file, rinsn);
-		}
-	    }
-	}
-    }
-
-  for (const bb_info *bb : crtl->ssa->bbs ())
-    {
-      basic_block cfg_bb = bb->cfg_bb ();
-      const auto reaching_out = get_block_info (cfg_bb).reaching_out;
-      if (!reaching_out.dirty_p ())
-	continue;
-
-      rtx new_pat;
-      if (!reaching_out.demand_p (DEMAND_AVL))
-	{
-	  vl_vtype_info new_info = reaching_out;
-	  new_info.set_avl_info (avl_info (const0_rtx, nullptr));
-	  new_pat = gen_vsetvl_pat (VSETVL_DISCARD_RESULT, new_info, NULL_RTX);
-	}
-      else if (can_refine_vsetvl_p (cfg_bb, reaching_out))
-	new_pat
-	  = gen_vsetvl_pat (VSETVL_VTYPE_CHANGE_ONLY, reaching_out, NULL_RTX);
-      else if (vlmax_avl_p (reaching_out.get_avl ()))
-	{
-	  rtx vl = reaching_out.get_avl_or_vl_reg ();
-	  new_pat = gen_vsetvl_pat (VSETVL_NORMAL, reaching_out, vl);
-	}
-      else
-	new_pat
-	  = gen_vsetvl_pat (VSETVL_DISCARD_RESULT, reaching_out, NULL_RTX);
-
-      edge eg;
-      edge_iterator eg_iterator;
-      FOR_EACH_EDGE (eg, eg_iterator, cfg_bb->succs)
-	{
-	  /* We should not get an abnormal edge here.  */
-	  gcc_assert (!(eg->flags & EDGE_ABNORMAL));
-	  /* We failed to optimize this case in Phase 3 (earliest fusion):
-
-		bb 2: vsetvl a5, a3 ...
-		      goto bb 4
-		bb 3: vsetvl a5, a2 ...
-		      goto bb 4
-		bb 4: vsetvli zero, a5 ---> Redundant, should be elided.
-
-	     Since "a5" value can come from either bb 2 or bb 3, we can't make
-	     it optimized in Phase 3 which will make phase 3 so complicated.
-	     Now, we do post optimization here to elide the redundant VSETVL
-	     insn in bb4.   */
-	  if (m_vector_manager->vsetvl_dominated_by_all_preds_p (cfg_bb,
-								 reaching_out))
-	    continue;
-
-	  start_sequence ();
-	  emit_insn (copy_rtx (new_pat));
-	  rtx_insn *rinsn = get_insns ();
-	  end_sequence ();
-
-	  insert_insn_on_edge (rinsn, eg);
-	  need_commit = true;
-	  if (dump_file)
-	    {
-	      fprintf (dump_file,
-		       "\nInsert vsetvl insn %d from <bb %d> to <bb %d>:\n",
-		       INSN_UID (rinsn), cfg_bb->index, eg->dest->index);
-	      print_rtl_single (dump_file, rinsn);
-	    }
-	}
-    }
-
-  return need_commit;
-}
-
 /* Some instruction can not be accessed in RTL_SSA when we don't re-init
    the new RTL_SSA framework but it is definetely at the END of the block.

--
2.36.3