diff --git a/gcc/config/riscv/riscv.h b/gcc/config/riscv/riscv.h
index 7797e67317a..c7ae6e4da79 100644
--- a/gcc/config/riscv/riscv.h
+++ b/gcc/config/riscv/riscv.h
@@ -190,7 +190,7 @@ ASM_MISA_SPEC
 
 #define FLOAT_TYPE_SIZE 32
 #define DOUBLE_TYPE_SIZE 64
-#define LONG_DOUBLE_TYPE_SIZE 128
+#define LONG_DOUBLE_TYPE_SIZE (TARGET_LONG_DOUBLE_64 ? 64 : 128)
 
 /* Allocation boundary (in *bits*) for storing arguments in argument list.  */
 #define PARM_BOUNDARY BITS_PER_WORD
diff --git a/gcc/config/riscv/riscv.opt b/gcc/config/riscv/riscv.opt
index ec792d382a5..4a8f8f77cdd 100644
--- a/gcc/config/riscv/riscv.opt
+++ b/gcc/config/riscv/riscv.opt
@@ -637,3 +637,11 @@ Enum(arcv_mpy_option) String(10c) Value(ARCV_MPY_OPTION_10C)
 -param=arcv-mpy-option=
 Target RejectNegative Joined Enum(arcv_mpy_option) Var(arcv_mpy_option) Init(ARCV_MPY_OPTION_2C)
 The type of MPY unit used by the RMX-100 core (to be used in combination with -mtune=rmx100) (default: 2c).
+
+mlong-double-64
+Target RejectNegative Negative(mlong-double-128) Mask(LONG_DOUBLE_64)
+Use 64-bit long double.
+
+mlong-double-128
+Target RejectNegative Negative(mlong-double-64) InverseMask(LONG_DOUBLE_64)
+Use 128-bit long double.
diff --git a/gcc/testsuite/gcc.target/riscv/arcv-long-double-64.c b/gcc/testsuite/gcc.target/riscv/arcv-long-double-64.c
new file mode 100644
index 00000000000..d531d3f5756
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/arcv-long-double-64.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target rv32 } */
+/* { dg-options "-march=rv32gc -mabi=ilp32d -mlong-double-64" } */
+
+int __attribute__((noinline))
+g (long double ld)
+{
+  return (int)ld;
+}
+
+int
+f (int x)
+{
+  return (long double) 3.141592;
+}
+
+/* { dg-final { scan-assembler-times "__fixtfsi" 0 } } */