--- a/gcc/tree-outof-ssa.c	Thu Oct 25 07:37:49 2018 +0900
+++ b/gcc/tree-outof-ssa.c	Thu Feb 13 11:34:05 2020 +0900
@@ -1,5 +1,5 @@
 /* Convert a program in SSA form into Normal form.
-   Copyright (C) 2004-2018 Free Software Foundation, Inc.
+   Copyright (C) 2004-2020 Free Software Foundation, Inc.
    Contributed by Andrew Macleod <amacleod@redhat.com>
 
 This file is part of GCC.
@@ -129,8 +129,9 @@
    rarely more than 6, and in the bootstrap of gcc, the maximum number
    of nodes encountered was 12.  */
 
-struct elim_graph
+class elim_graph
 {
+public:
   elim_graph (var_map map);
 
   /* Size of the elimination vectors.  */
@@ -143,7 +144,7 @@
   auto_vec<int> edge_list;
 
   /* Source locus on each edge */
-  auto_vec<source_location> edge_locus;
+  auto_vec<location_t> edge_locus;
 
   /* Visited vector.  */
   auto_sbitmap visited;
@@ -162,7 +163,7 @@
   auto_vec<tree> const_copies;
 
   /* Source locations for any constant copies.  */
-  auto_vec<source_location> copy_locus;
+  auto_vec<location_t> copy_locus;
 };
 
 
@@ -171,14 +172,43 @@
    use its location.  Otherwise search instructions in predecessors
    of E for a location, and use that one.  That makes sense because
    we insert on edges for PHI nodes, and effects of PHIs happen on
-   the end of the predecessor conceptually.  */
+   the end of the predecessor conceptually.  An exception is made
+   for EH edges because we don't want to drag the source location
+   of unrelated statements at the beginning of handlers; they would
+   be further reused for various EH constructs, which would damage
+   the coverage information.  */
 
 static void
 set_location_for_edge (edge e)
 {
   if (e->goto_locus)
+    set_curr_insn_location (e->goto_locus);
+  else if (e->flags & EDGE_EH)
     {
-      set_curr_insn_location (e->goto_locus);
+      basic_block bb = e->dest;
+      gimple_stmt_iterator gsi;
+
+      do
+	{
+	  for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+	    {
+	      gimple *stmt = gsi_stmt (gsi);
+	      if (is_gimple_debug (stmt))
+		continue;
+	      if (gimple_has_location (stmt) || gimple_block (stmt))
+		{
+		  set_curr_insn_location (gimple_location (stmt));
+		  return;
+		}
+	    }
+	  /* Nothing found in this basic block.  Make a half-assed attempt
+	     to continue with another block.  */
+	  if (single_succ_p (bb))
+	    bb = single_succ (bb);
+	  else
+	    bb = e->dest;
+	}
+      while (bb != e->dest);
     }
   else
     {
@@ -238,7 +268,7 @@
 /* Insert a copy instruction from partition SRC to DEST onto edge E.  */
 
 static void
-insert_partition_copy_on_edge (edge e, int dest, int src, source_location locus)
+insert_partition_copy_on_edge (edge e, int dest, int src, location_t locus)
 {
   tree var;
   if (dump_file && (dump_flags & TDF_DETAILS))
@@ -272,7 +302,7 @@
    onto edge E.  */
 
 static void
-insert_value_copy_on_edge (edge e, int dest, tree src, source_location locus)
+insert_value_copy_on_edge (edge e, int dest, tree src, location_t locus)
 {
   rtx dest_rtx, seq, x;
   machine_mode dest_mode, src_mode;
@@ -333,7 +363,7 @@
 
 static void
 insert_rtx_to_part_on_edge (edge e, int dest, rtx src, int unsignedsrcp,
-			    source_location locus)
+			    location_t locus)
 {
   if (dump_file && (dump_flags & TDF_DETAILS))
     {
@@ -367,7 +397,7 @@
    onto edge E.  */
 
 static void
-insert_part_to_rtx_on_edge (edge e, rtx dest, int src, source_location locus)
+insert_part_to_rtx_on_edge (edge e, rtx dest, int src, location_t locus)
 {
   tree var;
   if (dump_file && (dump_flags & TDF_DETAILS))
@@ -444,7 +474,7 @@
 /* Add the edge PRED->SUCC to graph G.  */
 
 static inline void
-elim_graph_add_edge (elim_graph *g, int pred, int succ, source_location locus)
+elim_graph_add_edge (elim_graph *g, int pred, int succ, location_t locus)
 {
   g->edge_list.safe_push (pred);
   g->edge_list.safe_push (succ);
@@ -456,7 +486,7 @@
    return the successor node.  -1 is returned if there is no such edge.  */
 
 static inline int
-elim_graph_remove_succ_edge (elim_graph *g, int node, source_location *locus)
+elim_graph_remove_succ_edge (elim_graph *g, int node, location_t *locus)
 {
   int y;
   unsigned x;
@@ -556,7 +586,7 @@
   for (gsi = gsi_start_phis (g->e->dest); !gsi_end_p (gsi); gsi_next (&gsi))
     {
       gphi *phi = gsi.phi ();
-      source_location locus;
+      location_t locus;
 
       p0 = var_to_partition (g->map, gimple_phi_result (phi));
       /* Ignore results which are not in partitions.  */
@@ -564,7 +594,11 @@
 	continue;
 
       Ti = PHI_ARG_DEF (phi, g->e->dest_idx);
-      locus = gimple_phi_arg_location_from_edge (phi, g->e);
+      /* See set_location_for_edge for the rationale.  */
+      if (g->e->flags & EDGE_EH)
+	locus = UNKNOWN_LOCATION;
+      else
+	locus = gimple_phi_arg_location_from_edge (phi, g->e);
 
       /* If this argument is a constant, or a SSA_NAME which is being
 	 left in SSA form, just queue a copy to be emitted on this
@@ -597,7 +631,7 @@
 elim_forward (elim_graph *g, int T)
 {
   int S;
-  source_location locus;
+  location_t locus;
 
   bitmap_set_bit (g->visited, T);
   FOR_EACH_ELIM_GRAPH_SUCC (g, T, S, locus,
@@ -615,7 +649,7 @@
 elim_unvisited_predecessor (elim_graph *g, int T)
 {
   int P;
-  source_location locus;
+  location_t locus;
 
   FOR_EACH_ELIM_GRAPH_PRED (g, T, P, locus,
     {
@@ -631,7 +665,7 @@
 elim_backward (elim_graph *g, int T)
 {
   int P;
-  source_location locus;
+  location_t locus;
 
   bitmap_set_bit (g->visited, T);
   FOR_EACH_ELIM_GRAPH_PRED (g, T, P, locus,
@@ -653,6 +687,8 @@
   tree type = TREE_TYPE (name);
   int unsignedp;
   machine_mode reg_mode = promote_ssa_mode (name, &unsignedp);
+  if (reg_mode == BLKmode)
+    return assign_temp (type, 0, 0);
   rtx x = gen_reg_rtx (reg_mode);
   if (POINTER_TYPE_P (type))
     mark_reg_pointer (x, TYPE_ALIGN (TREE_TYPE (type)));
@@ -666,7 +702,7 @@
 elim_create (elim_graph *g, int T)
 {
   int P, S;
-  source_location locus;
+  location_t locus;
 
   if (elim_unvisited_predecessor (g, T))
     {
@@ -741,7 +777,7 @@
     {
       int dest;
       tree src;
-      source_location locus;
+      location_t locus;
 
       src = g->const_copies.pop ();
       dest = g->const_dests.pop ();
@@ -809,26 +845,7 @@
 	  gphi *phi = gsi.phi ();
 	  result = gimple_phi_result (phi);
 	  if (virtual_operand_p (result))
-	    {
-	      /* There should be no arguments which are not virtual, or the
-	         results will be incorrect.  */
-	      if (flag_checking)
-		for (size_t i = 0; i < gimple_phi_num_args (phi); i++)
-		  {
-		    tree arg = PHI_ARG_DEF (phi, i);
-		    if (TREE_CODE (arg) == SSA_NAME
-			&& !virtual_operand_p (arg))
-		      {
-			fprintf (stderr, "Argument of PHI is not virtual (");
-			print_generic_expr (stderr, arg, TDF_SLIM);
-			fprintf (stderr, "), but the result is :");
-			print_gimple_stmt (stderr, phi, 0, TDF_SLIM);
-			internal_error ("SSA corruption");
-		      }
-		  }
-
-	      remove_phi_node (&gsi, true);
-	    }
+	    remove_phi_node (&gsi, true);
           else
 	    {
 	      /* Also remove real PHIs with no uses.  */
@@ -1171,15 +1188,19 @@
 	    {
 	      tree arg = gimple_phi_arg_def (phi, i);
 	      edge e = gimple_phi_arg_edge (phi, i);
+	      /* We are only interested in copies emitted on critical
+                 backedges.  */
+	      if (!(e->flags & EDGE_DFS_BACK)
+		  || !EDGE_CRITICAL_P (e))
+		continue;
 
 	      /* If the argument is not an SSA_NAME, then we will need a
-		 constant initialization.  If the argument is an SSA_NAME with
-		 a different underlying variable then a copy statement will be
-		 needed.  */
-	      if ((e->flags & EDGE_DFS_BACK)
-		  && (TREE_CODE (arg) != SSA_NAME
-		      || SSA_NAME_VAR (arg) != SSA_NAME_VAR (result)
-		      || trivially_conflicts_p (bb, result, arg)))
+		 constant initialization.  If the argument is an SSA_NAME then
+		 a copy statement may be needed.  First handle the case
+		 where we cannot insert before the argument definition.  */
+	      if (TREE_CODE (arg) != SSA_NAME
+		  || (gimple_code (SSA_NAME_DEF_STMT (arg)) == GIMPLE_PHI
+		      && trivially_conflicts_p (bb, result, arg)))
 		{
 		  tree name;
 		  gassign *stmt;
@@ -1226,6 +1247,34 @@
 		    gsi_insert_after (&gsi2, stmt, GSI_NEW_STMT);
 		  SET_PHI_ARG_DEF (phi, i, name);
 		}
+	      /* Insert a copy before the definition of the backedge value
+		 and adjust all conflicting uses.  */
+	      else if (trivially_conflicts_p (bb, result, arg))
+		{
+		  gimple *def = SSA_NAME_DEF_STMT (arg);
+		  if (gimple_nop_p (def)
+		      || gimple_code (def) == GIMPLE_PHI)
+		    continue;
+		  tree name = copy_ssa_name (result);
+		  gimple *stmt = gimple_build_assign (name, result);
+		  imm_use_iterator imm_iter;
+		  gimple *use_stmt;
+		  /* The following matches trivially_conflicts_p.  */
+		  FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, result)
+		    {
+		      if (gimple_bb (use_stmt) != bb
+			  || (gimple_code (use_stmt) != GIMPLE_PHI
+			      && (maybe_renumber_stmts_bb (bb), true)
+			      && gimple_uid (use_stmt) > gimple_uid (def)))
+			{
+			  use_operand_p use;
+			  FOR_EACH_IMM_USE_ON_STMT (use, imm_iter)
+			    SET_USE (use, name);
+			}
+		    }
+		  gimple_stmt_iterator gsi = gsi_for_stmt (def);
+		  gsi_insert_before (&gsi, stmt, GSI_SAME_STMT);
+		}
 	    }
 	}