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-fortran-92094-ice-in-vect_transform_stmt-at-tr.patch
c30587c0200f52f8845a5aea21bd7bef6cbe0bf4

diff -Nurp a/gcc/testsuite/gfortran.dg/pr92094.f90 b/gcc/testsuite/gfortran.dg/pr92094.f90
--- a/gcc/testsuite/gfortran.dg/pr92094.f90	1970-01-01 08:00:00.000000000 +0800
+++ b/gcc/testsuite/gfortran.dg/pr92094.f90	2020-08-18 14:25:12.392000000 +0800
@@ -0,0 +1,28 @@
+! { dg-do compile }
+! { dg-options "-O3" }
+      subroutine hesfcn(n, x, h, ldh)
+      integer n,ldh
+      double precision x(n), h(ldh)
+
+      integer i,j,k,kj
+      double precision th,u1,u2,v2
+ 
+      kj = 0
+      do 770 j = 1, n
+         kj = kj - j
+         do 760 k = 1, j
+            kj = kj + 1
+            v2 = 2 * x(k) - 1
+            u1 = 0
+            u2 = 2
+            do 750 i = 1, n
+               h(kj) = h(kj) + u2
+               th = 4 * v2 + u2 - u1
+               u1 = u2
+               u2 = th
+               th = v2 - 1
+  750       continue
+  760    continue
+  770 continue
+
+      end
diff -Nurp a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
--- a/gcc/tree-vect-loop.c	2020-08-18 14:19:43.784000000 +0800
+++ b/gcc/tree-vect-loop.c	2020-08-18 14:25:12.396000000 +0800
@@ -5891,20 +5891,9 @@ vectorizable_reduction (stmt_vec_info st
   if (STMT_VINFO_DEF_TYPE (stmt_info) == vect_nested_cycle)
     {
       if (is_a <gphi *> (stmt_info->stmt))
-	{
-	  /* Analysis for double-reduction is done on the outer
-	     loop PHI, nested cycles have no further restrictions.  */
-	  STMT_VINFO_TYPE (stmt_info) = cycle_phi_info_type;
-	  /* For nested cycles we want to let regular vectorizable_*
-	     routines handle code-generation.  */
-	  if (STMT_VINFO_DEF_TYPE (reduc_info) != vect_double_reduction_def)
-	    {
-	      stmt_info = STMT_VINFO_REDUC_DEF (stmt_info);
-	      STMT_VINFO_DEF_TYPE (stmt_info) = vect_internal_def;
-	      STMT_VINFO_DEF_TYPE (vect_stmt_to_vectorize (stmt_info))
-		= vect_internal_def;
-	    }
-	}
+	/* Analysis for double-reduction is done on the outer
+	   loop PHI, nested cycles have no further restrictions.  */
+	STMT_VINFO_TYPE (stmt_info) = cycle_phi_info_type;
       else
 	STMT_VINFO_TYPE (stmt_info) = reduc_vec_info_type;
       return true;
diff -Nurp a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
--- a/gcc/tree-vect-stmts.c	2020-08-18 14:19:45.556000000 +0800
+++ b/gcc/tree-vect-stmts.c	2020-08-18 14:25:12.396000000 +0800
@@ -10224,13 +10224,16 @@ vect_transform_stmt (stmt_vec_info stmt_
       && STMT_VINFO_REDUC_TYPE (reduc_info) != EXTRACT_LAST_REDUCTION)
     {
       gphi *phi;
+      edge e;
       if (!slp_node
 	  && (phi = dyn_cast <gphi *>
 		      (STMT_VINFO_REDUC_DEF (orig_stmt_info)->stmt))
 	  && dominated_by_p (CDI_DOMINATORS,
-			     gimple_bb (orig_stmt_info->stmt), gimple_bb (phi)))
+			     gimple_bb (orig_stmt_info->stmt), gimple_bb (phi))
+	  && (e = loop_latch_edge (gimple_bb (phi)->loop_father))
+	  && (PHI_ARG_DEF_FROM_EDGE (phi, e)
+	      == gimple_get_lhs (orig_stmt_info->stmt)))
 	{
-	  edge e = loop_latch_edge (gimple_bb (phi)->loop_father);
 	  stmt_vec_info phi_info
 	    = STMT_VINFO_VEC_STMT (STMT_VINFO_REDUC_DEF (orig_stmt_info));
 	  stmt_vec_info vec_stmt = STMT_VINFO_VEC_STMT (stmt_info);
@@ -10250,7 +10253,7 @@ vect_transform_stmt (stmt_vec_info stmt_
 	{
 	  slp_tree phi_node = slp_node_instance->reduc_phis;
 	  gphi *phi = as_a <gphi *> (SLP_TREE_SCALAR_STMTS (phi_node)[0]->stmt);
-	  edge e = loop_latch_edge (gimple_bb (phi)->loop_father);
+	  e = loop_latch_edge (gimple_bb (phi)->loop_father);
 	  gcc_assert (SLP_TREE_VEC_STMTS (phi_node).length ()
 		      == SLP_TREE_VEC_STMTS (slp_node).length ());
 	  for (unsigned i = 0; i < SLP_TREE_VEC_STMTS (phi_node).length (); ++i)