This backport contains 1 patch from gcc main stream tree.
The commit id of these patchs list as following in the order of time.

0001-re-PR-tree-optimization-92345-ICE-in-vec-_stmt_vec_i.patch
a6ba623777513e31721030092e4d786f461a0f06

diff -Nurp a/gcc/testsuite/gcc.dg/torture/pr92345.c b/gcc/testsuite/gcc.dg/torture/pr92345.c
--- a/gcc/testsuite/gcc.dg/torture/pr92345.c	1970-01-01 08:00:00.000000000 +0800
+++ b/gcc/testsuite/gcc.dg/torture/pr92345.c	2020-08-10 15:08:19.992000000 +0800
@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-ftree-vectorize" } */
+
+long int x1;
+int fr;
+
+int
+us (int sk, int jx)
+{
+  while (sk < 1)
+    {
+      jx *= 2;
+      fr += x1 + 1;
+      ++sk;
+    }
+
+  return jx;
+}
diff -Nurp a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
--- a/gcc/tree-vect-loop.c	2020-08-10 15:07:44.456000000 +0800
+++ b/gcc/tree-vect-loop.c	2020-08-10 15:08:19.992000000 +0800
@@ -155,7 +155,7 @@ along with GCC; see the file COPYING3.
 
 static void vect_estimate_min_profitable_iters (loop_vec_info, int *, int *);
 static stmt_vec_info vect_is_simple_reduction (loop_vec_info, stmt_vec_info,
-					       bool *);
+					       bool *, bool *);
 
 /* Subroutine of vect_determine_vf_for_stmt that handles only one
    statement.  VECTYPE_MAYBE_SET_P is true if STMT_VINFO_VECTYPE
@@ -489,7 +489,7 @@ vect_analyze_scalar_cycles_1 (loop_vec_i
   tree init, step;
   auto_vec<stmt_vec_info, 64> worklist;
   gphi_iterator gsi;
-  bool double_reduc;
+  bool double_reduc, reduc_chain;
 
   DUMP_VECT_SCOPE ("vect_analyze_scalar_cycles");
 
@@ -561,7 +561,8 @@ vect_analyze_scalar_cycles_1 (loop_vec_i
 		  && STMT_VINFO_DEF_TYPE (stmt_vinfo) == vect_unknown_def_type);
 
       stmt_vec_info reduc_stmt_info
-	= vect_is_simple_reduction (loop_vinfo, stmt_vinfo, &double_reduc);
+	= vect_is_simple_reduction (loop_vinfo, stmt_vinfo, &double_reduc,
+				    &reduc_chain);
       if (reduc_stmt_info)
         {
 	  STMT_VINFO_REDUC_DEF (stmt_vinfo) = reduc_stmt_info;
@@ -596,7 +597,7 @@ vect_analyze_scalar_cycles_1 (loop_vec_i
                   /* Store the reduction cycles for possible vectorization in
                      loop-aware SLP if it was not detected as reduction
 		     chain.  */
-		  if (! REDUC_GROUP_FIRST_ELEMENT (reduc_stmt_info))
+		  if (! reduc_chain)
 		    LOOP_VINFO_REDUCTIONS (loop_vinfo).safe_push
 		      (reduc_stmt_info);
                 }
@@ -3032,7 +3033,7 @@ check_reduction_path (dump_user_location
 
 static stmt_vec_info
 vect_is_simple_reduction (loop_vec_info loop_info, stmt_vec_info phi_info,
-			  bool *double_reduc)
+			  bool *double_reduc, bool *reduc_chain_p)
 {
   gphi *phi = as_a <gphi *> (phi_info->stmt);
   gimple *phi_use_stmt = NULL;
@@ -3040,6 +3041,7 @@ vect_is_simple_reduction (loop_vec_info
   use_operand_p use_p;
 
   *double_reduc = false;
+  *reduc_chain_p = false;
   STMT_VINFO_REDUC_TYPE (phi_info) = TREE_CODE_REDUCTION;
 
   tree phi_name = PHI_RESULT (phi);
@@ -3214,6 +3216,7 @@ vect_is_simple_reduction (loop_vec_info
 	  LOOP_VINFO_REDUCTION_CHAINS (loop_info).safe_push (reduc_chain[0]);
 	  REDUC_GROUP_SIZE (reduc_chain[0]) = reduc_chain.length ();
 
+	  *reduc_chain_p = true;
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_NOTE, vect_location,
 			    "reduction: detected reduction chain\n");