--- a/gcc/gimple-ssa-backprop.c	Fri Oct 27 22:46:09 2017 +0900
+++ b/gcc/gimple-ssa-backprop.c	Thu Oct 25 07:37:49 2018 +0900
@@ -1,5 +1,5 @@
 /* Back-propagation of usage information to definitions.
-   Copyright (C) 2015-2017 Free Software Foundation, Inc.
+   Copyright (C) 2015-2018 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -260,6 +260,11 @@
      post-order walk.  */
   auto_sbitmap m_visited_blocks;
 
+  /* A bitmap of phis that we have finished processing in the initial
+     post-order walk, excluding those from blocks mentioned in
+     M_VISITED_BLOCKS.  */
+  auto_bitmap m_visited_phis;
+
   /* A worklist of SSA names whose definitions need to be reconsidered.  */
   auto_vec <tree, 64> m_worklist;
 
@@ -354,6 +359,7 @@
       break;
 
     CASE_CFN_COPYSIGN:
+    CASE_CFN_COPYSIGN_FN:
       /* The sign of the first input is ignored.  */
       if (rhs != gimple_call_arg (call, 1))
 	info->flags.ignore_sign = true;
@@ -373,6 +379,10 @@
       }
 
     CASE_CFN_FMA:
+    CASE_CFN_FMA_FN:
+    case CFN_FMS:
+    case CFN_FNMA:
+    case CFN_FNMS:
       /* In X * X + Y, where Y is distinct from X, the sign of X doesn't
 	 matter.  */
       if (gimple_call_arg (call, 0) == rhs
@@ -403,6 +413,7 @@
   switch (gimple_assign_rhs_code (assign))
     {
     case ABS_EXPR:
+    case ABSU_EXPR:
       /* The sign of the input doesn't matter.  */
       info->flags.ignore_sign = true;
       break;
@@ -418,15 +429,6 @@
 	}
       break;
 
-    case FMA_EXPR:
-      /* In X * X + Y, where Y is distinct from X, the sign of X doesn't
-	 matter.  */
-      if (gimple_assign_rhs1 (assign) == rhs
-	  && gimple_assign_rhs2 (assign) == rhs
-	  && gimple_assign_rhs3 (assign) != rhs)
-	info->flags.ignore_sign = true;
-      break;
-
     case MULT_EXPR:
       /* In X * X, the sign of X doesn't matter.  */
       if (gimple_assign_rhs1 (assign) == rhs
@@ -494,14 +496,18 @@
 backprop::intersect_uses (tree var, usage_info *info)
 {
   imm_use_iterator iter;
-  gimple *stmt;
+  use_operand_p use_p;
   *info = usage_info::intersection_identity ();
-  FOR_EACH_IMM_USE_STMT (stmt, iter, var)
+  FOR_EACH_IMM_USE_FAST (use_p, iter, var)
     {
+      gimple *stmt = USE_STMT (use_p);
       if (is_gimple_debug (stmt))
 	continue;
-      if (is_a <gphi *> (stmt)
-	  && !bitmap_bit_p (m_visited_blocks, gimple_bb (stmt)->index))
+      gphi *phi = dyn_cast <gphi *> (stmt);
+      if (phi
+	  && !bitmap_bit_p (m_visited_blocks, gimple_bb (phi)->index)
+	  && !bitmap_bit_p (m_visited_phis,
+			    SSA_NAME_VERSION (gimple_phi_result (phi))))
 	{
 	  /* Skip unprocessed phis.  */
 	  if (dump_file && (dump_flags & TDF_DETAILS))
@@ -509,7 +515,7 @@
 	      fprintf (dump_file, "[BACKEDGE] ");
 	      print_generic_expr (dump_file, var);
 	      fprintf (dump_file, " in ");
-	      print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
+	      print_gimple_stmt (dump_file, phi, 0, TDF_SLIM);
 	    }
 	}
       else
@@ -518,10 +524,7 @@
 	  process_use (stmt, var, &subinfo);
 	  *info &= subinfo;
 	  if (!info->is_useful ())
-	    {
-	      BREAK_FROM_IMM_USE_STMT (iter);
-	      return false;
-	    }
+	    return false;
 	}
     }
   return true;
@@ -633,7 +636,12 @@
     }
   for (gphi_iterator gpi = gsi_start_phis (bb); !gsi_end_p (gpi);
        gsi_next (&gpi))
-    process_var (gimple_phi_result (gpi.phi ()));
+    {
+      tree result = gimple_phi_result (gpi.phi ());
+      process_var (result);
+      bitmap_set_bit (m_visited_phis, SSA_NAME_VERSION (result));
+    }
+  bitmap_clear (m_visited_phis);
 }
 
 /* Delete the definition of VAR, which has no uses.  */
@@ -679,6 +687,7 @@
     switch (gimple_assign_rhs_code (assign))
       {
       case ABS_EXPR:
+      case ABSU_EXPR:
       case NEGATE_EXPR:
 	return gimple_assign_rhs1 (assign);
 
@@ -689,6 +698,7 @@
     switch (gimple_call_combined_fn (call))
       {
       CASE_CFN_COPYSIGN:
+      CASE_CFN_COPYSIGN_FN:
 	return gimple_call_arg (call, 0);
 
       default:
@@ -726,7 +736,7 @@
 void
 backprop::prepare_change (tree var)
 {
-  if (MAY_HAVE_DEBUG_STMTS)
+  if (MAY_HAVE_DEBUG_BIND_STMTS)
     insert_debug_temp_for_var_def (NULL, var);
   reset_flow_sensitive_info (var);
 }