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-92161-ICE-in-vect_get_vec_de.patch
ae7f3143a3876378d051e64c8e68718f27c41075

diff -Nurp a/gcc/testsuite/gfortran.dg/pr92161.f b/gcc/testsuite/gfortran.dg/pr92161.f
--- a/gcc/testsuite/gfortran.dg/pr92161.f	1970-01-01 08:00:00.000000000 +0800
+++ b/gcc/testsuite/gfortran.dg/pr92161.f	2020-08-17 10:18:05.996000000 +0800
@@ -0,0 +1,23 @@
+! { dg-do compile }
+! { dg-options "-O1 -ftree-loop-vectorize -fno-signed-zeros -fno-trapping-math" }
+! { dg-additional-options "-mvsx" { target { powerpc*-*-* } } }
+      COMPLEX FUNCTION R1 (ZR, CC, EA, U6)
+
+      INTEGER ZR, U6, FZ, J2
+      COMPLEX EA(*), CC
+      DOUBLE PRECISION OS, GA, YU, XT
+
+      OS = DBLE(REAL(CC))
+      GA = DBLE(AIMAG(CC))
+      J2 = 1
+
+      DO 5 FZ = 1, ZR
+        YU = DBLE(REAL(EA(J2)))
+        XT = DBLE(AIMAG(EA(J2)))
+        OS = OS + (YU * 2) - (XT * 2)
+        GA = GA + (YU * 3) + (XT * 3)
+        J2 = J2 + U6
+    5 CONTINUE
+      R1 = CMPLX(REAL(OS), REAL(GA))
+      RETURN
+      END
diff -Nurp a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
--- a/gcc/tree-vect-loop.c	2020-08-17 10:17:08.288000000 +0800
+++ b/gcc/tree-vect-loop.c	2020-08-17 10:18:05.996000000 +0800
@@ -2339,6 +2339,17 @@ again:
 	{
 	  stmt_vec_info stmt_info = loop_vinfo->lookup_stmt (gsi_stmt (si));
 	  STMT_SLP_TYPE (stmt_info) = loop_vect;
+	  if (STMT_VINFO_DEF_TYPE (stmt_info) == vect_reduction_def
+	      || STMT_VINFO_DEF_TYPE (stmt_info) == vect_double_reduction_def)
+	    {
+	      /* vectorizable_reduction adjusts reduction stmt def-types,
+		 restore them to that of the PHI.  */
+	      STMT_VINFO_DEF_TYPE (STMT_VINFO_REDUC_DEF (stmt_info))
+		= STMT_VINFO_DEF_TYPE (stmt_info);
+	      STMT_VINFO_DEF_TYPE (vect_stmt_to_vectorize
+					(STMT_VINFO_REDUC_DEF (stmt_info)))
+		= STMT_VINFO_DEF_TYPE (stmt_info);
+	    }
 	}
       for (gimple_stmt_iterator si = gsi_start_bb (bb);
 	   !gsi_end_p (si); gsi_next (&si))