Set long double to 128 bit for RV64

 - Use softfp instead of *PBITS
 - Remove riscv-fp.c.
 - long double and struct {long double} always pass in memory.

gcc/config/riscv/riscv.c

@@ -2554,6 +2554,23 @@ riscv_function_value (const_tree valtype, const_tree func, enum machine_mode mod
 static bool
 riscv_return_in_memory (const_tree type, const_tree fndecl ATTRIBUTE_UNUSED)
 {
+  /* TFmode alwyas pass by reference.  */
+  if (TYPE_MODE (type) == TFmode)
+    {
+      return true;
+    }
+
+  if (TREE_CODE (type) == RECORD_TYPE)
+    {
+      tree field;
+      /* Check if this struc only TFmode, then it's still pass in memory.  */
+      for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
+	if (TREE_CODE (field) == FIELD_DECL
+	    && !error_operand_p (field)
+	    && TYPE_MODE (TREE_TYPE (field)) == TFmode)
+	  return true;
+    }
+
   return !IN_RANGE (int_size_in_bytes (type), 0, 2 * UNITS_PER_WORD);
 }
 
@@ -2564,6 +2581,11 @@ riscv_pass_by_reference (cumulative_args_t cum ATTRIBUTE_UNUSED,
 			 enum machine_mode mode, const_tree type,
 			 bool named ATTRIBUTE_UNUSED)
 {
+  /* TFmode alwyas pass by reference.  */
+  if (mode == TFmode)
+    {
+      return true;
+    }
   if (type && riscv_return_in_memory (type, NULL_TREE))
     return true;
   return targetm.calls.must_pass_in_stack (mode, type);

gcc/config/riscv/riscv.h

@@ -249,8 +249,7 @@ along with GCC; see the file COPYING3.  If not see
 
 #define FLOAT_TYPE_SIZE 32
 #define DOUBLE_TYPE_SIZE 64
-/* XXX The ABI says long doubles are IEEE-754-2008 float128s. */
-#define LONG_DOUBLE_TYPE_SIZE 64
+#define LONG_DOUBLE_TYPE_SIZE (TARGET_64BIT ? 128 : 64)
 
 #ifdef IN_LIBGCC2
 # define LIBGCC2_LONG_DOUBLE_TYPE_SIZE LONG_DOUBLE_TYPE_SIZE

libgcc/config.host

@@ -1097,11 +1097,11 @@ powerpcle-*-eabi*)
 	extra_parts="$extra_parts crtbegin.o crtend.o crtbeginS.o crtendS.o crtbeginT.o ecrti.o ecrtn.o ncrti.o ncrtn.o"
 	;;
 riscv*-*-linux*)
-	tmake_file="${tmake_file} riscv/t-elf riscv/t-elf${host_address}"
+	tmake_file="${tmake_file} t-softfp-sfdf riscv/t-softfp${host_address} t-softfp riscv/t-elf riscv/t-elf${host_address}"
 	extra_parts="$extra_parts crtbegin.o crtend.o crti.o crtn.o crtendS.o crtbeginT.o"
 	;;
 riscv*-*-*)
-	tmake_file="${tmake_file} riscv/t-elf riscv/t-elf${host_address}"
+	tmake_file="${tmake_file} t-softfp-sfdf riscv/t-softfp${host_address} t-softfp riscv/t-elf riscv/t-elf${host_address}"
 	extra_parts="$extra_parts crtbegin.o crtend.o crti.o crtn.o"
 	;;
 rs6000-ibm-aix4.[3456789]* | powerpc-ibm-aix4.[3456789]*)

libgcc/config/riscv/sfp-machine.h

@@ -0,0 +1,100 @@
+
+#ifdef __riscv32
+
+#define _FP_W_TYPE_SIZE		32
+#define _FP_W_TYPE		unsigned long
+#define _FP_WS_TYPE		signed long
+#define _FP_I_TYPE		long
+
+#define _FP_MUL_MEAT_S(R,X,Y)				\
+  _FP_MUL_MEAT_1_wide(_FP_WFRACBITS_S,R,X,Y,umul_ppmm)
+#define _FP_MUL_MEAT_D(R,X,Y)				\
+  _FP_MUL_MEAT_2_wide(_FP_WFRACBITS_D,R,X,Y,umul_ppmm)
+#define _FP_MUL_MEAT_Q(R,X,Y)				\
+  _FP_MUL_MEAT_4_wide(_FP_WFRACBITS_Q,R,X,Y,umul_ppmm)
+
+#define _FP_DIV_MEAT_S(R,X,Y)	_FP_DIV_MEAT_1_udiv_norm(S,R,X,Y)
+#define _FP_DIV_MEAT_D(R,X,Y)	_FP_DIV_MEAT_2_udiv(D,R,X,Y)
+#define _FP_DIV_MEAT_Q(R,X,Y)	_FP_DIV_MEAT_4_udiv(Q,R,X,Y)
+
+#define _FP_NANFRAC_S		((_FP_QNANBIT_S << 1) - 1)
+#define _FP_NANFRAC_D		((_FP_QNANBIT_D << 1) - 1), -1
+#define _FP_NANFRAC_Q		((_FP_QNANBIT_Q << 1) - 1), -1, -1, -1
+
+#else
+
+#define _FP_W_TYPE_SIZE		64
+#define _FP_W_TYPE		unsigned long long
+#define _FP_WS_TYPE		signed long long
+#define _FP_I_TYPE		long long
+
+#define _FP_MUL_MEAT_S(R,X,Y)					\
+  _FP_MUL_MEAT_1_imm(_FP_WFRACBITS_S,R,X,Y)
+#define _FP_MUL_MEAT_D(R,X,Y)					\
+  _FP_MUL_MEAT_1_wide(_FP_WFRACBITS_D,R,X,Y,umul_ppmm)
+#define _FP_MUL_MEAT_Q(R,X,Y)					\
+  _FP_MUL_MEAT_2_wide_3mul(_FP_WFRACBITS_Q,R,X,Y,umul_ppmm)
+
+#define _FP_DIV_MEAT_S(R,X,Y)	_FP_DIV_MEAT_1_imm(S,R,X,Y,_FP_DIV_HELP_imm)
+#define _FP_DIV_MEAT_D(R,X,Y)	_FP_DIV_MEAT_1_udiv_norm(D,R,X,Y)
+#define _FP_DIV_MEAT_Q(R,X,Y)	_FP_DIV_MEAT_2_udiv(Q,R,X,Y)
+
+#define _FP_NANFRAC_S		((_FP_QNANBIT_S << 1) - 1)
+#define _FP_NANFRAC_D		((_FP_QNANBIT_D << 1) - 1)
+#define _FP_NANFRAC_Q		((_FP_QNANBIT_Q << 1) - 1), -1
+
+#endif
+
+#ifdef __riscv64
+typedef int TItype __attribute__ ((mode (TI)));
+typedef unsigned int UTItype __attribute__ ((mode (TI)));
+#define TI_BITS (__CHAR_BIT__ * (int)sizeof(TItype))
+#endif
+
+/* The type of the result of a floating point comparison.  This must
+   match __libgcc_cmp_return__ in GCC for the target.  */
+typedef int __gcc_CMPtype __attribute__ ((mode (__libgcc_cmp_return__)));
+#define CMPtype __gcc_CMPtype
+
+#define _FP_NANSIGN_S		0
+#define _FP_NANSIGN_D		0
+#define _FP_NANSIGN_Q		0
+
+#define _FP_KEEPNANFRACP 1
+#define _FP_QNANNEGATEDP 0
+
+
+/* From my experiments it seems X is chosen unless one of the
+   NaNs is sNaN,  in which case the result is NANSIGN/NANFRAC.  */
+#define _FP_CHOOSENAN(fs, wc, R, X, Y, OP)			\
+  do {								\
+    if ((_FP_FRAC_HIGH_RAW_##fs(X) |				\
+	 _FP_FRAC_HIGH_RAW_##fs(Y)) & _FP_QNANBIT_##fs)		\
+      {								\
+	R##_s = _FP_NANSIGN_##fs;				\
+        _FP_FRAC_SET_##wc(R,_FP_NANFRAC_##fs);			\
+      }								\
+    else							\
+      {								\
+	R##_s = X##_s;						\
+        _FP_FRAC_COPY_##wc(R,X);				\
+      }								\
+    R##_c = FP_CLS_NAN;						\
+  } while (0)
+
+#define _FP_TININESS_AFTER_ROUNDING 0
+
+#define	__LITTLE_ENDIAN	1234
+#define	__BIG_ENDIAN	4321
+
+#if defined __big_endian__
+# define __BYTE_ORDER __BIG_ENDIAN
+#else
+# define __BYTE_ORDER __LITTLE_ENDIAN
+#endif
+
+
+/* Define ALIASNAME as a strong alias for NAME.  */
+# define strong_alias(name, aliasname) _strong_alias(name, aliasname)
+# define _strong_alias(name, aliasname) \
+  extern __typeof (name) aliasname __attribute__ ((alias (#name)));

libgcc/config/riscv/t-elf

@@ -1,16 +1,6 @@
-LIB2ADD += $(srcdir)/config/riscv/riscv-fp.c \
-	   $(srcdir)/config/riscv/save-restore.S \
+LIB2ADD += $(srcdir)/config/riscv/save-restore.S \
 	   $(srcdir)/config/riscv/muldi3.S \
 	   $(srcdir)/config/riscv/multi3.S \
 	   $(srcdir)/config/riscv/div.S \
 	   $(srcdir)/config/riscv/atomic.c \
 
-FPBIT = true
-
-ifeq ($(double_type_size),64)
-DPBIT = true
-endif
-
-ifeq ($(long_double_type_size),128)
-TPBIT = true
-endif

libgcc/config/riscv/t-softfp64

@@ -0,0 +1,4 @@
+softfp_float_modes += tf
+softfp_int_modes += ti
+softfp_extensions += sftf dftf
+softfp_truncations += tfsf tfdf