diff --git a/gcc/config/riscv/autovec.md b/gcc/config/riscv/autovec.md
index 00947207f3f..af55ef7b68f 100644
--- a/gcc/config/riscv/autovec.md
+++ b/gcc/config/riscv/autovec.md
@@ -1687,3 +1687,42 @@
   riscv_vector::expand_reduction (SMIN, operands, f);
   DONE;
 })
+
+;; -------------------------------------------------------------------------
+;; ---- [FP] Left-to-right reductions
+;; -------------------------------------------------------------------------
+;; Includes:
+;; - vfredosum.vs
+;; -------------------------------------------------------------------------
+
+;; Unpredicated in-order FP reductions.
+(define_expand "fold_left_plus_<mode>"
+  [(match_operand:<VEL> 0 "register_operand")
+   (match_operand:<VEL> 1 "register_operand")
+   (match_operand:VF 2 "register_operand")]
+  "TARGET_VECTOR"
+{
+  riscv_vector::expand_reduction (PLUS, operands,
+				  operands[1],
+				  riscv_vector::FOLD_LEFT_REDUDUCTION);
+  DONE;
+})
+
+;; Predicated in-order FP reductions.
+(define_expand "mask_len_fold_left_plus_<mode>"
+  [(match_operand:<VEL> 0 "register_operand")
+   (match_operand:<VEL> 1 "register_operand")
+   (match_operand:VF 2 "register_operand")
+   (match_operand:<VM> 3 "vector_mask_operand")
+   (match_operand 4 "autovec_length_operand")
+   (match_operand 5 "const_0_operand")]
+  "TARGET_VECTOR"
+{
+  if (rtx_equal_p (operands[4], const0_rtx))
+    emit_move_insn (operands[0], operands[1]);
+  else
+    riscv_vector::expand_reduction (PLUS, operands,
+				    operands[1],
+				    riscv_vector::MASK_LEN_FOLD_LEFT_REDUDUCTION);
+  DONE;
+})
diff --git a/gcc/config/riscv/riscv-protos.h b/gcc/config/riscv/riscv-protos.h
index 16fb8dabca0..aa313b56a32 100644
--- a/gcc/config/riscv/riscv-protos.h
+++ b/gcc/config/riscv/riscv-protos.h
@@ -199,6 +199,7 @@ enum insn_type
   RVV_GATHER_M_OP = 5,
   RVV_SCATTER_M_OP = 4,
   RVV_REDUCTION_OP = 3,
+  RVV_REDUCTION_TU_OP = RVV_REDUCTION_OP + 2,
 };
 enum vlmul_type
 {
@@ -270,6 +271,13 @@ enum mask_policy
   MASK_AGNOSTIC = 1,
   MASK_ANY = 2,
 };
+
+enum reduction_type
+{
+  UNORDERED_REDUDUCTION,
+  FOLD_LEFT_REDUDUCTION,
+  MASK_LEN_FOLD_LEFT_REDUDUCTION,
+};
 enum tail_policy get_prefer_tail_policy ();
 enum mask_policy get_prefer_mask_policy ();
 rtx get_avl_type_rtx (enum avl_type);
@@ -282,7 +290,8 @@ bool has_vi_variant_p (rtx_code, rtx);
 void expand_vec_cmp (rtx, rtx_code, rtx, rtx);
 bool expand_vec_cmp_float (rtx, rtx_code, rtx, rtx, bool);
 void expand_cond_len_binop (rtx_code, rtx *);
-void expand_reduction (rtx_code, rtx *, rtx);
+void expand_reduction (rtx_code, rtx *, rtx,
+		       reduction_type = UNORDERED_REDUDUCTION);
 #endif
 bool sew64_scalar_helper (rtx *, rtx *, rtx, machine_mode,
 			  bool, void (*)(rtx *, rtx));
diff --git a/gcc/config/riscv/riscv-v.cc b/gcc/config/riscv/riscv-v.cc
index 53088edf909..16321f1b116 100644
--- a/gcc/config/riscv/riscv-v.cc
+++ b/gcc/config/riscv/riscv-v.cc
@@ -1196,6 +1196,26 @@ emit_vlmax_fp_reduction_insn (unsigned icode, int op_num, rtx *ops)
   e.emit_insn ((enum insn_code) icode, ops);
 }
 
+/* Emit reduction instruction.  */
+static void
+emit_nonvlmax_fp_reduction_insn (unsigned icode, int op_num, rtx *ops, rtx vl)
+{
+  machine_mode dest_mode = GET_MODE (ops[0]);
+  machine_mode mask_mode = get_mask_mode (GET_MODE (ops[1])).require ();
+  insn_expander<RVV_INSN_OPERANDS_MAX> e (op_num,
+					  /* HAS_DEST_P */ true,
+					  /* FULLY_UNMASKED_P */ false,
+					  /* USE_REAL_MERGE_P */ true,
+					  /* HAS_AVL_P */ true,
+					  /* VLMAX_P */ false, dest_mode,
+					  mask_mode);
+
+  e.set_policy (TAIL_ANY);
+  e.set_rounding_mode (FRM_DYN);
+  e.set_vl (vl);
+  e.emit_insn ((enum insn_code) icode, ops);
+}
+
 /* Emit merge instruction.  */
 
 static machine_mode
@@ -3343,9 +3363,10 @@ expand_cond_len_ternop (unsigned icode, rtx *ops)
 
 /* Expand reduction operations.  */
 void
-expand_reduction (rtx_code code, rtx *ops, rtx init)
+expand_reduction (rtx_code code, rtx *ops, rtx init, reduction_type type)
 {
-  machine_mode vmode = GET_MODE (ops[1]);
+  rtx vector = type == UNORDERED_REDUDUCTION ? ops[1] : ops[2];
+  machine_mode vmode = GET_MODE (vector);
   machine_mode m1_mode = get_m1_mode (vmode).require ();
   machine_mode m1_mmode = get_mask_mode (m1_mode).require ();
 
@@ -3356,13 +3377,25 @@ expand_reduction (rtx_code code, rtx *ops, rtx init)
   emit_scalar_move_insn (code_for_pred_broadcast (m1_mode), scalar_move_ops);
 
   rtx m1_tmp2 = gen_reg_rtx (m1_mode);
-  rtx reduc_ops[] = {m1_tmp2, ops[1], m1_tmp};
+  rtx reduc_ops[] = {m1_tmp2, vector, m1_tmp};
 
   if (FLOAT_MODE_P (vmode) && code == PLUS)
     {
-      insn_code icode
-	= code_for_pred_reduc_plus (UNSPEC_UNORDERED, vmode, m1_mode);
-      emit_vlmax_fp_reduction_insn (icode, RVV_REDUCTION_OP, reduc_ops);
+      insn_code icode = code_for_pred_reduc_plus (type == UNORDERED_REDUDUCTION
+						    ? UNSPEC_UNORDERED
+						    : UNSPEC_ORDERED,
+						  vmode, m1_mode);
+      if (type == MASK_LEN_FOLD_LEFT_REDUDUCTION)
+	{
+	  rtx mask = ops[3];
+	  rtx len = ops[4];
+	  rtx mask_len_reduc_ops[]
+	    = {m1_tmp2, mask, RVV_VUNDEF (m1_mode), vector, m1_tmp};
+	  emit_nonvlmax_fp_reduction_insn (icode, RVV_REDUCTION_TU_OP,
+					   mask_len_reduc_ops, len);
+	}
+      else
+	emit_vlmax_fp_reduction_insn (icode, RVV_REDUCTION_OP, reduc_ops);
     }
   else
     {
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-1.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-1.c
new file mode 100644
index 00000000000..c293e9ae746
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-1.c
@@ -0,0 +1,28 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-march=rv32gcv_zvfh -mabi=ilp32d --param=riscv-autovec-preference=scalable -fno-vect-cost-model" } */
+
+#include <stdint-gcc.h>
+
+#define NUM_ELEMS(TYPE) ((int)(5 * (256 / sizeof (TYPE)) + 3))
+
+#define DEF_REDUC_PLUS(TYPE)			\
+  TYPE __attribute__ ((noinline, noclone))	\
+  reduc_plus_##TYPE (TYPE *a, TYPE *b)		\
+  {						\
+    TYPE r = 0, q = 3;				\
+    for (int i = 0; i < NUM_ELEMS (TYPE); i++)	\
+      {						\
+	r += a[i];				\
+	q -= b[i];				\
+      }						\
+    return r * q;				\
+  }
+
+#define TEST_ALL(T) \
+  T (_Float16) \
+  T (float) \
+  T (double)
+
+TEST_ALL (DEF_REDUC_PLUS)
+
+/* { dg-final { scan-assembler-times {vfredosum\.vs\s+v[0-9]+,\s*v[0-9]+,\s*v[0-9]+} 6 } } */
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-2.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-2.c
new file mode 100644
index 00000000000..2e1e7ab674d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-2.c
@@ -0,0 +1,26 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-march=rv32gcv_zvfh -mabi=ilp32d --param=riscv-autovec-preference=scalable -fno-vect-cost-model" } */
+
+#define NUM_ELEMS(TYPE) ((int) (5 * (256 / sizeof (TYPE)) + 3))
+
+#define DEF_REDUC_PLUS(TYPE)					\
+void __attribute__ ((noinline, noclone))			\
+reduc_plus_##TYPE (TYPE (*restrict a)[NUM_ELEMS (TYPE)],	\
+		   TYPE *restrict r, int n)			\
+{								\
+  for (int i = 0; i < n; i++)					\
+    {								\
+      r[i] = 0;							\
+      for (int j = 0; j < NUM_ELEMS (TYPE); j++)		\
+        r[i] += a[i][j];					\
+    }								\
+}
+
+#define TEST_ALL(T) \
+  T (_Float16) \
+  T (float) \
+  T (double)
+
+TEST_ALL (DEF_REDUC_PLUS)
+
+/* { dg-final { scan-assembler-times {vfredosum\.vs\s+v[0-9]+,\s*v[0-9]+,\s*v[0-9]+} 3 } } */
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-3.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-3.c
new file mode 100644
index 00000000000..f559d40e60f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-3.c
@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-march=rv32gcv_zvfh -mabi=ilp32d --param=riscv-autovec-preference=scalable -fno-vect-cost-model" } */
+
+double mat[100][2];
+
+double
+slp_reduc_plus (int n)
+{
+  double tmp = 0.0;
+  for (int i = 0; i < n; i++)
+    {
+      tmp = tmp + mat[i][0];
+      tmp = tmp + mat[i][1];
+    }
+  return tmp;
+}
+
+/* { dg-final { scan-assembler-times {vfredosum\.vs\s+v[0-9]+,\s*v[0-9]+,\s*v[0-9]+} 1 } } */
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-4.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-4.c
new file mode 100644
index 00000000000..428d371d9cf
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-4.c
@@ -0,0 +1,24 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-march=rv32gcv_zvfh -mabi=ilp32d --param=riscv-autovec-preference=scalable -fno-vect-cost-model" } */
+
+double mat[100][8];
+
+double
+slp_reduc_plus (int n)
+{
+  double tmp = 0.0;
+  for (int i = 0; i < n; i++)
+    {
+      tmp = tmp + mat[i][0];
+      tmp = tmp + mat[i][1];
+      tmp = tmp + mat[i][2];
+      tmp = tmp + mat[i][3];
+      tmp = tmp + mat[i][4];
+      tmp = tmp + mat[i][5];
+      tmp = tmp + mat[i][6];
+      tmp = tmp + mat[i][7];
+    }
+  return tmp;
+}
+
+/* { dg-final { scan-assembler {vfredosum\.vs\s+v[0-9]+,\s*v[0-9]+,\s*v[0-9]+} } } */
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-5.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-5.c
new file mode 100644
index 00000000000..24add2291f1
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-5.c
@@ -0,0 +1,28 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-march=rv32gcv_zvfh -mabi=ilp32d --param=riscv-autovec-preference=scalable -fno-vect-cost-model" } */
+
+double mat[100][12];
+
+double
+slp_reduc_plus (int n)
+{
+  double tmp = 0.0;
+  for (int i = 0; i < n; i++)
+    {
+      tmp = tmp + mat[i][0];
+      tmp = tmp + mat[i][1];
+      tmp = tmp + mat[i][2];
+      tmp = tmp + mat[i][3];
+      tmp = tmp + mat[i][4];
+      tmp = tmp + mat[i][5];
+      tmp = tmp + mat[i][6];
+      tmp = tmp + mat[i][7];
+      tmp = tmp + mat[i][8];
+      tmp = tmp + mat[i][9];
+      tmp = tmp + mat[i][10];
+      tmp = tmp + mat[i][11];
+    }
+  return tmp;
+}
+
+/* { dg-final { scan-assembler {vfredosum\.vs\s+v[0-9]+,\s*v[0-9]+,\s*v[0-9]+} } } */
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-6.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-6.c
new file mode 100644
index 00000000000..c1567b067ba
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-6.c
@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-march=rv32gcv_zvfh -mabi=ilp32d --param=riscv-autovec-preference=scalable -fno-vect-cost-model -fdump-tree-vect-details" } */
+
+float
+double_reduc (float (*i)[16])
+{
+  float l = 0;
+
+#pragma GCC unroll 0
+  for (int a = 0; a < 8; a++)
+    for (int b = 0; b < 100; b++)
+      l += i[b][a];
+  return l;
+}
+
+/* { dg-final { scan-assembler-times {vfredosum\.vs\s+v[0-9]+,\s*v[0-9]+,\s*v[0-9]+} 1 } } */
+/* { dg-final { scan-tree-dump "Detected double reduction" "vect" } } */
+/* { dg-final { scan-tree-dump-not "OUTER LOOP VECTORIZED" "vect" } } */
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-7.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-7.c
new file mode 100644
index 00000000000..f742a824bb2
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict-7.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-march=rv32gcv_zvfh -mabi=ilp32d --param=riscv-autovec-preference=scalable -fno-vect-cost-model -fdump-tree-vect-details" } */
+
+float
+double_reduc (float *i, float *j)
+{
+  float k = 0, l = 0;
+
+  for (int a = 0; a < 8; a++)
+    for (int b = 0; b < 100; b++)
+      {
+        k += i[b];
+        l += j[b];
+      }
+  return l * k;
+}
+
+/* { dg-final { scan-assembler-times {vle32\.v} 2 } } */
+/* { dg-final { scan-assembler-times {vfredosum\.vs\s+v[0-9]+,\s*v[0-9]+,\s*v[0-9]+} 2 } } */
+/* { dg-final { scan-tree-dump "Detected double reduction" "vect" } } */
+/* { dg-final { scan-tree-dump-not "OUTER LOOP VECTORIZED" "vect" } } */
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict_run-1.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict_run-1.c
new file mode 100644
index 00000000000..516be97e9eb
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict_run-1.c
@@ -0,0 +1,29 @@
+/* { dg-do run { target { riscv_vector } } } */
+/* { dg-additional-options "--param=riscv-autovec-preference=scalable -fno-vect-cost-model" } */
+
+#include "reduc_strict-1.c"
+
+#define TEST_REDUC_PLUS(TYPE)			\
+  {						\
+    TYPE a[NUM_ELEMS (TYPE)];			\
+    TYPE b[NUM_ELEMS (TYPE)];			\
+    TYPE r = 0, q = 3;				\
+    for (int i = 0; i < NUM_ELEMS (TYPE); i++)	\
+      {						\
+	a[i] = (i * 0.1) * (i & 1 ? 1 : -1);	\
+	b[i] = (i * 0.3) * (i & 1 ? 1 : -1);	\
+	r += a[i];				\
+	q -= b[i];				\
+	asm volatile ("" ::: "memory");		\
+      }						\
+    TYPE res = reduc_plus_##TYPE (a, b);	\
+    if (res != r * q)				\
+      __builtin_abort ();			\
+  }
+
+int __attribute__ ((optimize (1)))
+main ()
+{
+  TEST_ALL (TEST_REDUC_PLUS);
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict_run-2.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict_run-2.c
new file mode 100644
index 00000000000..0a4238d96f3
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/reduc/reduc_strict_run-2.c
@@ -0,0 +1,31 @@
+/* { dg-do run { target { riscv_vector } } } */
+/* { dg-additional-options "--param=riscv-autovec-preference=scalable -fno-vect-cost-model" } */
+
+#include "reduc_strict-2.c"
+
+#define NROWS 5
+
+#define TEST_REDUC_PLUS(TYPE)					\
+  {								\
+    TYPE a[NROWS][NUM_ELEMS (TYPE)];				\
+    TYPE r[NROWS];						\
+    TYPE expected[NROWS] = {};					\
+    for (int i = 0; i < NROWS; ++i)				\
+      for (int j = 0; j < NUM_ELEMS (TYPE); ++j)		\
+	{							\
+	  a[i][j] = (i * 0.1 + j * 0.6) * (j & 1 ? 1 : -1);	\
+	  expected[i] += a[i][j];				\
+	  asm volatile ("" ::: "memory");			\
+	}							\
+    reduc_plus_##TYPE (a, r, NROWS);				\
+    for (int i = 0; i < NROWS; ++i)				\
+      if (r[i] != expected[i])					\
+	__builtin_abort ();					\
+  }
+
+int __attribute__ ((optimize (1)))
+main ()
+{
+  TEST_ALL (TEST_REDUC_PLUS);
+  return 0;
+}
