diff --git a/gcc/config/riscv/riscv-vector-costs.cc b/gcc/config/riscv/riscv-vector-costs.cc
index 21f8a81c89cb451ad79db07ed197c34bbdd1b33b..e4435032035d99ee41bf5f8230382c491b075b03 100644
--- a/gcc/config/riscv/riscv-vector-costs.cc
+++ b/gcc/config/riscv/riscv-vector-costs.cc
@@ -255,6 +255,29 @@ variable_vectorized_p (stmt_vec_info stmt_info, tree var, bool lhs_p)
 	    return false;
 	}
     }
+  else if (is_gimple_assign (stmt))
+    {
+      tree_code tcode = gimple_assign_rhs_code (stmt);
+      /* vi variant doesn't need to allocate such statement.
+	 E.g. tmp_15 = _4 + 1; will be transformed into vadd.vi
+	 so the INTEGER_CST '1' doesn't need a vector register.  */
+      switch (tcode)
+	{
+	case PLUS_EXPR:
+	case BIT_IOR_EXPR:
+	case BIT_XOR_EXPR:
+	case BIT_AND_EXPR:
+	  return TREE_CODE (var) != INTEGER_CST
+		 || !IN_RANGE (tree_to_shwi (var), -16, 15);
+	case MINUS_EXPR:
+	  return TREE_CODE (var) != INTEGER_CST
+		 || !IN_RANGE (tree_to_shwi (var), -16, 15)
+		 || gimple_assign_rhs1 (stmt) != var;
+	default:
+	  break;
+	}
+    }
+
   if (lhs_p)
     return is_gimple_reg (var)
 	   && (!POINTER_TYPE_P (TREE_TYPE (var))
@@ -331,13 +354,6 @@ compute_local_live_ranges (
 	      for (i = 0; i < gimple_num_args (stmt); i++)
 		{
 		  tree var = gimple_arg (stmt, i);
-		  /* Both IMM and REG are included since a VECTOR_CST may be
-		     potentially held in a vector register.  However, it's not
-		     accurate, since a PLUS_EXPR can be vectorized into vadd.vi
-		     if IMM is -16 ~ 15.
-
-		     TODO: We may elide the cases that the unnecessary IMM in
-		     the future.  */
 		  if (variable_vectorized_p (program_point.stmt_info, var,
 					     false))
 		    {
diff --git a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul8-13.c b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul8-13.c
new file mode 100644
index 0000000000000000000000000000000000000000..baef4e390143c372b65dd6c37421d77a4cbd6ee6
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul8-13.c
@@ -0,0 +1,74 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -ftree-vectorize --param riscv-autovec-lmul=dynamic -fdump-tree-vect-details" } */
+
+void
+f (int *restrict a, int *restrict b, int *restrict c, int *restrict d, int n)
+{
+  for (int i = 0; i < n; i++)
+    {
+      int tmp = b[i] + 15;
+      int tmp2 = tmp + b[i];
+      c[i] = tmp2 + b[i];
+      d[i] = tmp + tmp2 + b[i];
+    }
+}
+
+void
+f2 (int *restrict a, int *restrict b, int *restrict c, int *restrict d, int n)
+{
+  for (int i = 0; i < n; i++)
+    {
+      int tmp = 15 - b[i];
+      int tmp2 = tmp * b[i];
+      c[i] = tmp2 * b[i];
+      d[i] = tmp * tmp2 * b[i];
+    }
+}
+
+void
+f3 (int *restrict a, int *restrict b, int *restrict c, int *restrict d, int n)
+{
+  for (int i = 0; i < n; i++)
+    {
+      int tmp = b[i] & 15;
+      int tmp2 = tmp * b[i];
+      c[i] = tmp2 * b[i];
+      d[i] = tmp * tmp2 * b[i];
+    }
+}
+
+void
+f4 (int *restrict a, int *restrict b, int *restrict c, int *restrict d, int n)
+{
+  for (int i = 0; i < n; i++)
+    {
+      int tmp = b[i] | 15;
+      int tmp2 = tmp * b[i];
+      c[i] = tmp2 * b[i];
+      d[i] = tmp * tmp2 * b[i];
+    }
+}
+
+void
+f5 (int *restrict a, int *restrict b, int *restrict c, int *restrict d, int n)
+{
+  for (int i = 0; i < n; i++)
+    {
+      int tmp = b[i] ^ 15;
+      int tmp2 = tmp * b[i];
+      c[i] = tmp2 * b[i];
+      d[i] = tmp * tmp2 * b[i];
+    }
+}
+
+/* { dg-final { scan-assembler-times {e32,m8} 5 } } */
+/* { dg-final { scan-assembler-not {csrr} } } */
+/* { dg-final { scan-assembler-not {jr} } } */
+/* { dg-final { scan-assembler-not {e32,m4} } } */
+/* { dg-final { scan-assembler-not {e32,m2} } } */
+/* { dg-final { scan-assembler-not {e32,m1} } } */
+/* { dg-final { scan-assembler-times {ret} 5 } } */
+/* { dg-final { scan-tree-dump-not "Preferring smaller LMUL loop because it has unexpected spills" "vect" } } */
+/* { dg-final { scan-tree-dump-times "Maximum lmul = 8" 5 "vect" } } */
+/* { dg-final { scan-tree-dump-times "Maximum lmul = 4" 5 "vect" } } */
+/* { dg-final { scan-tree-dump-times "Maximum lmul = 2" 5 "vect" } } */