RISC-V: Always define MULTILIB_DEFAULTS

 - Define MULTILIB_DEFAULTS can reduce the total number of multilib if
   the default arch and ABI are listed in the multilib config.

 - This also simplify the implementation of --with-multilib-list.

gcc/ChangeLog:

	* config.gcc (riscv*-*-*): Add TARGET_RISCV_DEFAULT_ABI and
	TARGET_RISCV_DEFAULT_ARCH to tm_defines.
	Remove including riscv/withmultilib.h for --with-multilib-list.
	* config/riscv/riscv.h (STRINGIZING): New.
	(__STRINGIZING): Ditto.
	(MULTILIB_DEFAULTS): Ditto.
	* config/riscv/withmultilib.h: Remove.

3 files changed, 12 insertions, 88 deletions

diff --git a/gcc/config.gcc b/gcc/config.gcc
index aacab0d..6f1ee62 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -4612,6 +4612,8 @@ case "${target}" in
 			exit 1
 			;;
 		esac
+		with_arch=`${srcdir}/config/riscv/arch-canonicalize ${with_arch}`
+		tm_defines="${tm_defines} TARGET_RISCV_DEFAULT_ARCH=${with_arch}"
 
 		# Make sure --with-abi is valid.  If it was not specified,
 		# pick a default based on the ISA, preferring soft-float
@@ -4633,6 +4635,7 @@ case "${target}" in
 			exit 1
 			;;
 		esac
+		tm_defines="${tm_defines} TARGET_RISCV_DEFAULT_ABI=${with_abi}"
 
 		# Make sure ABI and ISA are compatible.
 		case "${with_abi},${with_arch}" in
@@ -4675,7 +4678,6 @@ case "${target}" in
 
 		# Handle --with-multilib-list.
 		if test "x${with_multilib_list}" != xdefault; then
-			tm_file="${tm_file} riscv/withmultilib.h"
 			tmake_file="${tmake_file} riscv/t-withmultilib"
 
 			case ${with_multilib_list} in
@@ -4687,42 +4689,6 @@ case "${target}" in
 				echo "--with-multilib-list=${with_multilib_list} not supported."
 				exit 1
 			esac
-
-			# Define macros to select the default multilib.
-			case ${with_arch} in
-			rv32gc)
-				tm_defines="${tm_defines} TARGET_MLIB_ARCH=1"
-				;;
-			rv64gc)
-				tm_defines="${tm_defines} TARGET_MLIB_ARCH=2"
-				;;
-			*)
-				echo "unsupported --with-arch for --with-multilib-list"
-				exit 1
-			esac
-			case ${with_abi} in
-			ilp32)
-				tm_defines="${tm_defines} TARGET_MLIB_ABI=1"
-				;;
-			ilp32f)
-				tm_defines="${tm_defines} TARGET_MLIB_ABI=2"
-				;;
-			ilp32d)
-				tm_defines="${tm_defines} TARGET_MLIB_ABI=3"
-				;;
-			lp64)
-				tm_defines="${tm_defines} TARGET_MLIB_ABI=4"
-				;;
-			lp64f)
-				tm_defines="${tm_defines} TARGET_MLIB_ABI=5"
-				;;
-			lp64d)
-				tm_defines="${tm_defines} TARGET_MLIB_ABI=6"
-				;;
-			*)
-				echo "unsupported --with-abi for --with-multilib"
-				exit 1
-			esac
 		fi
 		;;
 
diff --git a/gcc/config/riscv/riscv.h b/gcc/config/riscv/riscv.h
index e71fbf3..df3003f 100644
--- a/gcc/config/riscv/riscv.h
+++ b/gcc/config/riscv/riscv.h
@@ -76,6 +76,15 @@ extern const char *riscv_default_mtune (int argc, const char **argv);
 #define ASM_MISA_SPEC ""
 #endif
 
+/* Reference:
+     https://gcc.gnu.org/onlinedocs/cpp/Stringizing.html#Stringizing  */
+#define STRINGIZING(s) __STRINGIZING(s)
+#define __STRINGIZING(s) #s
+
+#define MULTILIB_DEFAULTS \
+  {"march=" STRINGIZING (TARGET_RISCV_DEFAULT_ARCH), \
+   "mabi=" STRINGIZING (TARGET_RISCV_DEFAULT_ABI) }
+
 #undef ASM_SPEC
 #define ASM_SPEC "\
 %(subtarget_asm_debugging_spec) \
diff --git a/gcc/config/riscv/withmultilib.h b/gcc/config/riscv/withmultilib.h
deleted file mode 100644
index d022716..0000000
--- a/gcc/config/riscv/withmultilib.h
+++ /dev/null
@@ -1,51 +0,0 @@
-/* MULTILIB_DEFAULTS definitions for --with-multilib-list.
-   Copyright (C) 2018-2020 Free Software Foundation, Inc.
-
-   This file is part of GCC.
-
-   GCC is free software; you can redistribute it and/or modify it
-   under the terms of the GNU General Public License as published
-   by the Free Software Foundation; either version 3, or (at your
-   option) any later version.
-
-   GCC is distributed in the hope that it will be useful, but WITHOUT
-   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
-   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
-   License for more details.
-
-   Under Section 7 of GPL version 3, you are granted additional
-   permissions described in the GCC Runtime Library Exception, version
-   3.1, as published by the Free Software Foundation.
-
-   You should have received a copy of the GNU General Public License and
-   a copy of the GCC Runtime Library Exception along with this program;
-   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#if TARGET_MLIB_ARCH == 1
-
-# if TARGET_MLIB_ABI == 1
-#  define MULTILIB_DEFAULTS {"march=rv32gc", "mabi=ilp32" }
-# elif TARGET_MLIB_ABI == 2
-#  define MULTILIB_DEFAULTS {"march=rv32gc", "mabi=ilp32f" }
-# elif TARGET_MLIB_ABI == 3
-#  define MULTILIB_DEFAULTS {"march=rv32gc", "mabi=ilp32d" }
-# else
-#  error "unsupported TARGET_MLIB_ABI value for rv32gc"
-# endif
-
-#elif TARGET_MLIB_ARCH == 2
-
-# if TARGET_MLIB_ABI == 4
-#  define MULTILIB_DEFAULTS {"march=rv64gc", "mabi=lp64" }
-# elif TARGET_MLIB_ABI == 5
-#  define MULTILIB_DEFAULTS {"march=rv64gc", "mabi=lp64f" }
-# elif TARGET_MLIB_ABI == 6
-#  define MULTILIB_DEFAULTS {"march=rv64gc", "mabi=lp64d" }
-# else
-#  error "unsupported TARGET_MLIB_ABI value for rv64gc"
-# endif
-
-#else
-# error "unsupported TARGET_MLIB_ARCH value"
-#endif