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-92537-ICE-in-vect_slp_analyz.patch
2439d584d5def75d705f33218bb3b97fca4c11a1

diff -Nurp a/gcc/testsuite/gfortran.dg/pr92537.f90 b/gcc/testsuite/gfortran.dg/pr92537.f90
--- a/gcc/testsuite/gfortran.dg/pr92537.f90	1970-01-01 08:00:00.000000000 +0800
+++ b/gcc/testsuite/gfortran.dg/pr92537.f90	2020-09-03 16:53:43.024000000 +0800
@@ -0,0 +1,32 @@
+! { dg-do compile }
+! { dg-options "-O2 -ftree-vectorize -fno-inline" }
+! { dg-additional-options "-march=skylake" { target x86_64-*-* i?86-*-* } }
+MODULE pr93527
+  implicit none
+  integer, parameter :: wp = kind (1.d0)
+  interface p_min
+     module procedure p_min_wp
+  end interface
+contains
+  subroutine foo (pr)
+    real(wp), pointer     :: pr(:)
+    integer  ::  nzd
+    real(wp) ::  pmin
+    real(wp) ::  pmin_diag
+    integer  ::  i
+    nzd  = 15
+    allocate (pr(nzd))
+    pmin_diag = 4000._wp
+    pmin = p_min(pmin_diag)
+    pmin = min (pmin,pmin_diag)
+    pr(1) = log(pmin)
+    do i=1,nzd-1
+       pr(i+1) = log(pmin) + i
+    end do
+  end subroutine foo
+  function p_min_wp (x) result (p_min)
+    real(wp), intent(in) :: x
+    real(wp)             :: p_min
+    p_min = x
+  end function p_min_wp
+end module pr93527
diff -Nurp a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
--- a/gcc/tree-vect-slp.c	2020-09-03 16:53:22.668000000 +0800
+++ b/gcc/tree-vect-slp.c	2020-09-03 16:53:43.024000000 +0800
@@ -2176,18 +2176,6 @@ vect_analyze_slp_instance (vec_info *vin
 	  matches[group_size / const_max_nunits * const_max_nunits] = false;
 	  vect_free_slp_tree (node, false);
 	}
-      else if (constructor
-	       && SLP_TREE_DEF_TYPE (node) != vect_internal_def)
-	{
-	  /* CONSTRUCTOR vectorization relies on a vector stmt being
-	     generated, that doesn't work for fully external ones.  */
-	  if (dump_enabled_p ())
-	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
-			     "Build SLP failed: CONSTRUCTOR of external "
-			     "or constant elements\n");
-	  vect_free_slp_tree (node, false);
-	  return false;
-	}
       else
 	{
 	  /* Create a new SLP instance.  */
@@ -2872,7 +2860,12 @@ vect_slp_analyze_operations (vec_info *v
       if (!vect_slp_analyze_node_operations (vinfo,
 					     SLP_INSTANCE_TREE (instance),
 					     instance, visited, lvisited,
-					     &cost_vec))
+					     &cost_vec)
+	  /* Instances with a root stmt require vectorized defs for the
+	     SLP tree root.  */
+	  || (SLP_INSTANCE_ROOT_STMT (instance)
+	      && (SLP_TREE_DEF_TYPE (SLP_INSTANCE_TREE (instance))
+		  != vect_internal_def)))
         {
 	  slp_tree node = SLP_INSTANCE_TREE (instance);
 	  stmt_vec_info stmt_info = SLP_TREE_SCALAR_STMTS (node)[0];