From 6c85d03940f87770a7e8b7195ffe45f99afef411 Mon Sep 17 00:00:00 2001
From: Xi Ruoyao <xry111@xry111.site>
Date: Fri, 1 Dec 2023 10:09:33 +0800
Subject: [PATCH 056/188] LoongArch: Switch loongarch-def from C to C++ to make
 it possible.

We'll use HOST_WIDE_INT in LoongArch static properties in following patches.

To keep the same readability as C99 designated initializers, create a
std::array like data structure with position setter function, and add
field setter functions for structs used in loongarch-def.cc.

Remove unneeded guards #if
!defined(IN_LIBGCC2) && !defined(IN_TARGET_LIBS) && !defined(IN_RTS)
in loongarch-def.h and loongarch-opts.h.

gcc/ChangeLog:

	* config/loongarch/loongarch-def.h: Remove extern "C".
	(loongarch_isa_base_strings): Declare as loongarch_def_array
	instead of plain array.
	(loongarch_isa_ext_strings): Likewise.
	(loongarch_abi_base_strings): Likewise.
	(loongarch_abi_ext_strings): Likewise.
	(loongarch_cmodel_strings): Likewise.
	(loongarch_cpu_strings): Likewise.
	(loongarch_cpu_default_isa): Likewise.
	(loongarch_cpu_issue_rate): Likewise.
	(loongarch_cpu_multipass_dfa_lookahead): Likewise.
	(loongarch_cpu_cache): Likewise.
	(loongarch_cpu_align): Likewise.
	(loongarch_cpu_rtx_cost_data): Likewise.
	(loongarch_isa): Add a constructor and field setter functions.
	* config/loongarch/loongarch-opts.h (loongarch-defs.h): Do not
	include for target libraries.
	* config/loongarch/loongarch-opts.cc: Comment code that doesn't
	run and causes compilation errors.
	* config/loongarch/loongarch-tune.h (LOONGARCH_TUNE_H): Likewise.
	(struct loongarch_rtx_cost_data): Likewise.
	(struct loongarch_cache): Likewise.
	(struct loongarch_align): Likewise.
	* config/loongarch/t-loongarch: Compile loongarch-def.cc with the
	C++ compiler.
	* config/loongarch/loongarch-def-array.h: New file for a
	std:array like data structure with position setter function.
	* config/loongarch/loongarch-def.c: Rename to ...
	* config/loongarch/loongarch-def.cc: ... here.
	(loongarch_cpu_strings): Define as loongarch_def_array instead
	of plain array.
	(loongarch_cpu_default_isa): Likewise.
	(loongarch_cpu_cache): Likewise.
	(loongarch_cpu_align): Likewise.
	(loongarch_cpu_rtx_cost_data): Likewise.
	(loongarch_cpu_issue_rate): Likewise.
	(loongarch_cpu_multipass_dfa_lookahead): Likewise.
	(loongarch_isa_base_strings): Likewise.
	(loongarch_isa_ext_strings): Likewise.
	(loongarch_abi_base_strings): Likewise.
	(loongarch_abi_ext_strings): Likewise.
	(loongarch_cmodel_strings): Likewise.
	(abi_minimal_isa): Likewise.
	(loongarch_rtx_cost_optimize_size): Use field setter functions
	instead of designated initializers.
	(loongarch_rtx_cost_data): Implement default constructor.
---
 gcc/config/loongarch/loongarch-def-array.h |  40 ++++
 gcc/config/loongarch/loongarch-def.c       | 227 ---------------------
 gcc/config/loongarch/loongarch-def.cc      | 187 +++++++++++++++++
 gcc/config/loongarch/loongarch-def.h       |  55 ++---
 gcc/config/loongarch/loongarch-opts.cc     |   7 +
 gcc/config/loongarch/loongarch-opts.h      |   5 +-
 gcc/config/loongarch/loongarch-tune.h      | 123 ++++++++++-
 gcc/config/loongarch/t-loongarch           |   4 +-
 8 files changed, 390 insertions(+), 258 deletions(-)
 create mode 100644 gcc/config/loongarch/loongarch-def-array.h
 delete mode 100644 gcc/config/loongarch/loongarch-def.c
 create mode 100644 gcc/config/loongarch/loongarch-def.cc

diff --git a/gcc/config/loongarch/loongarch-def-array.h b/gcc/config/loongarch/loongarch-def-array.h
new file mode 100644
index 000000000..bdb3e9c6a
--- /dev/null
+++ b/gcc/config/loongarch/loongarch-def-array.h
@@ -0,0 +1,40 @@
+/* A std::array like data structure for LoongArch static properties.
+   Copyright (C) 2023 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.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef _LOONGARCH_DEF_ARRAY_H
+#define _LOONGARCH_DEF_ARRAY_H 1
+
+template <class T, int N>
+class loongarch_def_array {
+private:
+  T arr[N];
+public:
+  loongarch_def_array () : arr{} {}
+
+  T &operator[] (int n) { return arr[n]; }
+  const T &operator[] (int n) const { return arr[n]; }
+
+  loongarch_def_array set (int idx, T &&value)
+  {
+    (*this)[idx] = value;
+    return *this;
+  }
+};
+
+#endif
diff --git a/gcc/config/loongarch/loongarch-def.c b/gcc/config/loongarch/loongarch-def.c
deleted file mode 100644
index fe4474e77..000000000
--- a/gcc/config/loongarch/loongarch-def.c
+++ /dev/null
@@ -1,227 +0,0 @@
-/* LoongArch static properties.
-   Copyright (C) 2021-2022 Free Software Foundation, Inc.
-   Contributed by Loongson Ltd.
-
-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.
-
-You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING3.  If not see
-<http://www.gnu.org/licenses/>.  */
-
-#include "loongarch-def.h"
-#include "loongarch-str.h"
-
-/* CPU property tables.  */
-const char*
-loongarch_cpu_strings[N_TUNE_TYPES] = {
-  [CPU_NATIVE]		  = STR_CPU_NATIVE,
-  [CPU_ABI_DEFAULT]	  = STR_CPU_ABI_DEFAULT,
-  [CPU_LOONGARCH64]	  = STR_CPU_LOONGARCH64,
-  [CPU_LA464]		  = STR_CPU_LA464,
-  [CPU_LA664]		  = STR_CPU_LA664,
-};
-
-struct loongarch_isa
-loongarch_cpu_default_isa[N_ARCH_TYPES] = {
-  [CPU_LOONGARCH64] = {
-      .base = ISA_BASE_LA64V100,
-      .fpu = ISA_EXT_FPU64,
-      .simd = 0,
-  },
-  [CPU_LA464] = {
-      .base = ISA_BASE_LA64V100,
-      .fpu = ISA_EXT_FPU64,
-      .simd = ISA_EXT_SIMD_LASX,
-  },
-  [CPU_LA664] = {
-      .base = ISA_BASE_LA64V110,
-      .fpu = ISA_EXT_FPU64,
-      .simd = ISA_EXT_SIMD_LASX,
-  },
-};
-
-struct loongarch_cache
-loongarch_cpu_cache[N_TUNE_TYPES] = {
-  [CPU_LOONGARCH64] = {
-      .l1d_line_size = 64,
-      .l1d_size = 64,
-      .l2d_size = 256,
-      .simultaneous_prefetches = 4,
-  },
-  [CPU_LA464] = {
-      .l1d_line_size = 64,
-      .l1d_size = 64,
-      .l2d_size = 256,
-      .simultaneous_prefetches = 4,
-  },
-  [CPU_LA664] = {
-      .l1d_line_size = 64,
-      .l1d_size = 64,
-      .l2d_size = 256,
-      .simultaneous_prefetches = 4,
-  },
-};
-
-struct loongarch_align
-loongarch_cpu_align[N_TUNE_TYPES] = {
-  [CPU_LOONGARCH64] = {
-    .function = "32",
-    .label = "16",
-  },
-  [CPU_LA464] = {
-    .function = "32",
-    .label = "16",
-  },
-  [CPU_LA664] = {
-    .function = "32",
-    .label = "16",
-  },
-};
-
-
-/* Default RTX cost initializer.  */
-#define COSTS_N_INSNS(N) ((N) * 4)
-#define DEFAULT_COSTS				\
-    .fp_add		= COSTS_N_INSNS (1),	\
-    .fp_mult_sf		= COSTS_N_INSNS (2),	\
-    .fp_mult_df		= COSTS_N_INSNS (4),	\
-    .fp_div_sf		= COSTS_N_INSNS (6),	\
-    .fp_div_df		= COSTS_N_INSNS (8),	\
-    .int_mult_si	= COSTS_N_INSNS (1),	\
-    .int_mult_di	= COSTS_N_INSNS (1),	\
-    .int_div_si		= COSTS_N_INSNS (4),	\
-    .int_div_di		= COSTS_N_INSNS (6),	\
-    .branch_cost	= 6,			\
-    .memory_latency	= 4
-
-/* The following properties cannot be looked up directly using "cpucfg".
- So it is necessary to provide a default value for "unknown native"
- tune targets (i.e. -mtune=native while PRID does not correspond to
- any known "-mtune" type).  */
-
-struct loongarch_rtx_cost_data
-loongarch_cpu_rtx_cost_data[N_TUNE_TYPES] = {
-  [CPU_NATIVE] = {
-      DEFAULT_COSTS
-  },
-  [CPU_LOONGARCH64] = {
-      DEFAULT_COSTS
-  },
-  [CPU_LA464] = {
-      DEFAULT_COSTS
-  },
-  [CPU_LA664] = {
-      DEFAULT_COSTS
-  },
-};
-
-/* RTX costs to use when optimizing for size.  */
-const struct loongarch_rtx_cost_data
-loongarch_rtx_cost_optimize_size = {
-    .fp_add	      = 4,
-    .fp_mult_sf	      = 4,
-    .fp_mult_df	      = 4,
-    .fp_div_sf	      = 4,
-    .fp_div_df	      = 4,
-    .int_mult_si      = 4,
-    .int_mult_di      = 4,
-    .int_div_si	      = 4,
-    .int_div_di	      = 4,
-    .branch_cost      = 6,
-    .memory_latency   = 4,
-};
-
-int
-loongarch_cpu_issue_rate[N_TUNE_TYPES] = {
-  [CPU_NATIVE]	      = 4,
-  [CPU_LOONGARCH64]   = 4,
-  [CPU_LA464]	      = 4,
-  [CPU_LA664]	      = 6,
-};
-
-int
-loongarch_cpu_multipass_dfa_lookahead[N_TUNE_TYPES] = {
-  [CPU_NATIVE]	      = 4,
-  [CPU_LOONGARCH64]   = 4,
-  [CPU_LA464]	      = 4,
-  [CPU_LA664]	      = 6,
-};
-
-/* Wiring string definitions from loongarch-str.h to global arrays
-   with standard index values from loongarch-opts.h, so we can
-   print config-related messages and do ABI self-spec filtering
-   from the driver in a self-consistent manner.  */
-
-const char*
-loongarch_isa_base_strings[N_ISA_BASE_TYPES] = {
-  [ISA_BASE_LA64V100] = STR_ISA_BASE_LA64V100,
-  [ISA_BASE_LA64V110] = STR_ISA_BASE_LA64V110,
-};
-
-const char*
-loongarch_isa_ext_strings[N_ISA_EXT_TYPES] = {
-  [ISA_EXT_NONE] = STR_NONE,
-  [ISA_EXT_FPU32] = STR_ISA_EXT_FPU32,
-  [ISA_EXT_FPU64] = STR_ISA_EXT_FPU64,
-  [ISA_EXT_SIMD_LSX] = STR_ISA_EXT_LSX,
-  [ISA_EXT_SIMD_LASX] = STR_ISA_EXT_LASX,
-};
-
-const char*
-loongarch_abi_base_strings[N_ABI_BASE_TYPES] = {
-  [ABI_BASE_LP64D] = STR_ABI_BASE_LP64D,
-  [ABI_BASE_LP64F] = STR_ABI_BASE_LP64F,
-  [ABI_BASE_LP64S] = STR_ABI_BASE_LP64S,
-};
-
-const char*
-loongarch_abi_ext_strings[N_ABI_EXT_TYPES] = {
-  [ABI_EXT_BASE] = STR_ABI_EXT_BASE,
-};
-
-const char*
-loongarch_cmodel_strings[] = {
-  [CMODEL_NORMAL]	  = STR_CMODEL_NORMAL,
-  [CMODEL_TINY]		  = STR_CMODEL_TINY,
-  [CMODEL_TINY_STATIC]	  = STR_CMODEL_TS,
-  [CMODEL_MEDIUM]	  = STR_CMODEL_MEDIUM,
-  [CMODEL_LARGE]	  = STR_CMODEL_LARGE,
-  [CMODEL_EXTREME]	  = STR_CMODEL_EXTREME,
-};
-
-
-/* ABI-related definitions.  */
-const struct loongarch_isa
-abi_minimal_isa[N_ABI_BASE_TYPES][N_ABI_EXT_TYPES] = {
-  [ABI_BASE_LP64D] = {
-      [ABI_EXT_BASE] = {
-	  .base = ISA_BASE_LA64V100,
-	  .fpu = ISA_EXT_FPU64,
-	  .simd = 0
-      },
-  },
-  [ABI_BASE_LP64F] = {
-      [ABI_EXT_BASE] = {
-	  .base = ISA_BASE_LA64V100,
-	  .fpu = ISA_EXT_FPU32,
-	  .simd = 0
-      },
-  },
-  [ABI_BASE_LP64S] = {
-      [ABI_EXT_BASE] = {
-	  .base = ISA_BASE_LA64V100,
-	  .fpu = ISA_EXT_NONE,
-	  .simd = 0
-      },
-  },
-};
diff --git a/gcc/config/loongarch/loongarch-def.cc b/gcc/config/loongarch/loongarch-def.cc
new file mode 100644
index 000000000..6990c86c2
--- /dev/null
+++ b/gcc/config/loongarch/loongarch-def.cc
@@ -0,0 +1,187 @@
+/* LoongArch static properties.
+   Copyright (C) 2021-2023 Free Software Foundation, Inc.
+   Contributed by Loongson Ltd.
+
+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.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "loongarch-def.h"
+#include "loongarch-str.h"
+
+template <class T, int N>
+using array = loongarch_def_array<T, N>;
+
+template <class T>
+using array_tune = array<T, N_TUNE_TYPES>;
+
+template <class T>
+using array_arch = array<T, N_ARCH_TYPES>;
+
+/* CPU property tables.  */
+array_tune<const char *> loongarch_cpu_strings = array_tune<const char *> ()
+  .set (CPU_NATIVE, STR_CPU_NATIVE)
+  .set (CPU_ABI_DEFAULT, STR_CPU_ABI_DEFAULT)
+  .set (CPU_LOONGARCH64, STR_CPU_LOONGARCH64)
+  .set (CPU_LA464, STR_CPU_LA464)
+  .set (CPU_LA664, STR_CPU_LA664);
+
+array_arch<loongarch_isa> loongarch_cpu_default_isa =
+  array_arch<loongarch_isa> ()
+    .set (CPU_LOONGARCH64,
+	  loongarch_isa ()
+	    .base_ (ISA_BASE_LA64V100)
+	    .fpu_ (ISA_EXT_FPU64))
+    .set (CPU_LA464,
+	  loongarch_isa ()
+	    .base_ (ISA_BASE_LA64V100)
+	    .fpu_ (ISA_EXT_FPU64)
+	    .simd_ (ISA_EXT_SIMD_LASX))
+    .set (CPU_LA664,
+	  loongarch_isa ()
+	    .base_ (ISA_BASE_LA64V110)
+	    .fpu_ (ISA_EXT_FPU64)
+	    .simd_ (ISA_EXT_SIMD_LASX));
+
+static inline loongarch_cache la464_cache ()
+{
+  return loongarch_cache ()
+    .l1d_line_size_ (64)
+    .l1d_size_ (64)
+    .l2d_size_ (256)
+    .simultaneous_prefetches_ (4);
+}
+
+array_tune<loongarch_cache> loongarch_cpu_cache =
+  array_tune<loongarch_cache> ()
+    .set (CPU_LOONGARCH64, la464_cache ())
+    .set (CPU_LA464, la464_cache ())
+    .set (CPU_LA664, la464_cache ());
+
+static inline loongarch_align la464_align ()
+{
+  return loongarch_align ().function_ ("32").label_ ("16");
+}
+
+array_tune<loongarch_align> loongarch_cpu_align =
+  array_tune<loongarch_align> ()
+    .set (CPU_LOONGARCH64, la464_align ())
+    .set (CPU_LA464, la464_align ())
+    .set (CPU_LA664, la464_align ());
+
+#define COSTS_N_INSNS(N) ((N) * 4)
+
+/* Default RTX cost initializer.  */
+loongarch_rtx_cost_data::loongarch_rtx_cost_data ()
+  : fp_add (COSTS_N_INSNS (1)),
+    fp_mult_sf (COSTS_N_INSNS (2)),
+    fp_mult_df (COSTS_N_INSNS (4)),
+    fp_div_sf (COSTS_N_INSNS (6)),
+    fp_div_df (COSTS_N_INSNS (8)),
+    int_mult_si (COSTS_N_INSNS (1)),
+    int_mult_di (COSTS_N_INSNS (1)),
+    int_div_si (COSTS_N_INSNS (4)),
+    int_div_di (COSTS_N_INSNS (6)),
+    branch_cost (6),
+    memory_latency (4) {}
+
+/* The following properties cannot be looked up directly using "cpucfg".
+ So it is necessary to provide a default value for "unknown native"
+ tune targets (i.e. -mtune=native while PRID does not correspond to
+ any known "-mtune" type).  Currently all numbers are default.  */
+array_tune<loongarch_rtx_cost_data> loongarch_cpu_rtx_cost_data =
+  array_tune<loongarch_rtx_cost_data> ();
+
+/* RTX costs to use when optimizing for size.  */
+const loongarch_rtx_cost_data loongarch_rtx_cost_optimize_size =
+  loongarch_rtx_cost_data ()
+    .fp_add_ (4)
+    .fp_mult_sf_ (4)
+    .fp_mult_df_ (4)
+    .fp_div_sf_ (4)
+    .fp_div_df_ (4)
+    .int_mult_si_ (4)
+    .int_mult_di_ (4)
+    .int_div_si_ (4)
+    .int_div_di_ (4);
+
+array_tune<int> loongarch_cpu_issue_rate = array_tune<int> ()
+  .set (CPU_NATIVE, 4)
+  .set (CPU_LOONGARCH64, 4)
+  .set (CPU_LA464, 4)
+  .set (CPU_LA664, 6);
+
+array_tune<int> loongarch_cpu_multipass_dfa_lookahead = array_tune<int> ()
+  .set (CPU_NATIVE, 4)
+  .set (CPU_LOONGARCH64, 4)
+  .set (CPU_LA464, 4)
+  .set (CPU_LA664, 6);
+
+/* Wiring string definitions from loongarch-str.h to global arrays
+   with standard index values from loongarch-opts.h, so we can
+   print config-related messages and do ABI self-spec filtering
+   from the driver in a self-consistent manner.  */
+
+array<const char *, N_ISA_BASE_TYPES> loongarch_isa_base_strings =
+  array<const char *, N_ISA_BASE_TYPES> ()
+    .set (ISA_BASE_LA64V100, STR_ISA_BASE_LA64V100)
+    .set (ISA_BASE_LA64V110, STR_ISA_BASE_LA64V110);
+
+array<const char *, N_ISA_EXT_TYPES> loongarch_isa_ext_strings =
+  array<const char *, N_ISA_EXT_TYPES> ()
+    .set (ISA_EXT_NONE, STR_NONE)
+    .set (ISA_EXT_FPU32, STR_ISA_EXT_FPU32)
+    .set (ISA_EXT_FPU64, STR_ISA_EXT_FPU64)
+    .set (ISA_EXT_SIMD_LSX, STR_ISA_EXT_LSX)
+    .set (ISA_EXT_SIMD_LASX, STR_ISA_EXT_LASX);
+
+array<const char *, N_ABI_BASE_TYPES> loongarch_abi_base_strings =
+  array<const char *, N_ABI_BASE_TYPES> ()
+    .set (ABI_BASE_LP64D, STR_ABI_BASE_LP64D)
+    .set (ABI_BASE_LP64F, STR_ABI_BASE_LP64F)
+    .set (ABI_BASE_LP64S, STR_ABI_BASE_LP64S);
+
+array<const char *, N_ABI_EXT_TYPES> loongarch_abi_ext_strings =
+  array<const char *, N_ABI_EXT_TYPES> ()
+    .set (ABI_EXT_BASE, STR_ABI_EXT_BASE);
+
+array<const char *, N_CMODEL_TYPES> loongarch_cmodel_strings =
+  array<const char *, N_CMODEL_TYPES> ()
+    .set (CMODEL_NORMAL,		STR_CMODEL_NORMAL)
+    .set (CMODEL_TINY,		STR_CMODEL_TINY)
+    .set (CMODEL_TINY_STATIC,	STR_CMODEL_TS)
+    .set (CMODEL_MEDIUM,		STR_CMODEL_MEDIUM)
+    .set (CMODEL_LARGE,		STR_CMODEL_LARGE)
+    .set (CMODEL_EXTREME,		STR_CMODEL_EXTREME);
+
+array<array<loongarch_isa, N_ABI_EXT_TYPES>, N_ABI_BASE_TYPES>
+  abi_minimal_isa = array<array<loongarch_isa, N_ABI_EXT_TYPES>,
+			  N_ABI_BASE_TYPES> ()
+    .set (ABI_BASE_LP64D,
+	  array<loongarch_isa, N_ABI_EXT_TYPES> ()
+	    .set (ABI_EXT_BASE,
+		  loongarch_isa ()
+		    .base_ (ISA_BASE_LA64V100)
+		    .fpu_ (ISA_EXT_FPU64)))
+    .set (ABI_BASE_LP64F,
+	  array<loongarch_isa, N_ABI_EXT_TYPES> ()
+	    .set (ABI_EXT_BASE,
+		  loongarch_isa ()
+		    .base_ (ISA_BASE_LA64V100)
+		    .fpu_ (ISA_EXT_FPU32)))
+    .set (ABI_BASE_LP64S,
+	  array<loongarch_isa, N_ABI_EXT_TYPES> ()
+	    .set (ABI_EXT_BASE,
+		  loongarch_isa ().base_ (ISA_BASE_LA64V100)));
diff --git a/gcc/config/loongarch/loongarch-def.h b/gcc/config/loongarch/loongarch-def.h
index ef848f606..5ac70dfdd 100644
--- a/gcc/config/loongarch/loongarch-def.h
+++ b/gcc/config/loongarch/loongarch-def.h
@@ -50,20 +50,18 @@ along with GCC; see the file COPYING3.  If not see
 #include <stdint.h>
 #endif
 
+#include "loongarch-def-array.h"
 #include "loongarch-tune.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 /* enum isa_base */
-extern const char* loongarch_isa_base_strings[];
 
 /* LoongArch V1.00.  */
 #define ISA_BASE_LA64V100     0
 /* LoongArch V1.10.  */
 #define ISA_BASE_LA64V110     1
 #define N_ISA_BASE_TYPES      2
+extern loongarch_def_array<const char *, N_ISA_BASE_TYPES>
+  loongarch_isa_base_strings;
 
 #if !defined(IN_LIBGCC2) && !defined(IN_TARGET_LIBS) && !defined(IN_RTS)
 /* Unlike other arrays, this is defined in loongarch-cpu.cc.  The problem is
@@ -72,7 +70,6 @@ extern int64_t loongarch_isa_base_features[];
 #endif
 
 /* enum isa_ext_* */
-extern const char* loongarch_isa_ext_strings[];
 #define ISA_EXT_NONE	      0
 #define ISA_EXT_FPU32	      1
 #define ISA_EXT_FPU64	      2
@@ -80,13 +77,16 @@ extern const char* loongarch_isa_ext_strings[];
 #define ISA_EXT_SIMD_LSX      3
 #define ISA_EXT_SIMD_LASX     4
 #define N_ISA_EXT_TYPES	      5
+extern loongarch_def_array<const char *, N_ISA_EXT_TYPES>
+  loongarch_isa_ext_strings;
 
 /* enum abi_base */
-extern const char* loongarch_abi_base_strings[];
 #define ABI_BASE_LP64D	      0
 #define ABI_BASE_LP64F	      1
 #define ABI_BASE_LP64S	      2
 #define N_ABI_BASE_TYPES      3
+extern loongarch_def_array<const char *, N_ABI_BASE_TYPES>
+  loongarch_abi_base_strings;
 
 #define TO_LP64_ABI_BASE(C) (C)
 
@@ -99,12 +99,12 @@ extern const char* loongarch_abi_base_strings[];
 
 
 /* enum abi_ext */
-extern const char* loongarch_abi_ext_strings[];
 #define ABI_EXT_BASE	      0
 #define N_ABI_EXT_TYPES	      1
+extern loongarch_def_array<const char *, N_ABI_EXT_TYPES>
+  loongarch_abi_ext_strings;
 
 /* enum cmodel */
-extern const char* loongarch_cmodel_strings[];
 #define CMODEL_NORMAL	      0
 #define CMODEL_TINY	      1
 #define CMODEL_TINY_STATIC    2
@@ -112,6 +112,8 @@ extern const char* loongarch_cmodel_strings[];
 #define CMODEL_LARGE	      4
 #define CMODEL_EXTREME	      5
 #define N_CMODEL_TYPES	      6
+extern loongarch_def_array<const char *, N_CMODEL_TYPES>
+  loongarch_cmodel_strings;
 
 /* enum explicit_relocs */
 #define EXPLICIT_RELOCS_AUTO	0
@@ -126,7 +128,6 @@ extern const char* loongarch_cmodel_strings[];
 #define M_OPT_ABSENT(opt_enum)  ((opt_enum) == M_OPT_UNSET)
 
 
-#if !defined(IN_LIBGCC2) && !defined(IN_TARGET_LIBS) && !defined(IN_RTS)
 /* Internal representation of the target.  */
 struct loongarch_isa
 {
@@ -139,6 +140,13 @@ struct loongarch_isa
 
      Using int64_t instead of HOST_WIDE_INT for C compatibility.  */
   int64_t evolution;
+
+  loongarch_isa () : base (0), fpu (0), simd (0), evolution (0) {}
+  loongarch_isa base_ (int _base) { base = _base; return *this; }
+  loongarch_isa fpu_ (int _fpu) { fpu = _fpu; return *this; }
+  loongarch_isa simd_ (int _simd) { simd = _simd; return *this; }
+  loongarch_isa evolution_ (int64_t _evolution)
+    { evolution = _evolution; return *this; }
 };
 
 struct loongarch_abi
@@ -156,9 +164,6 @@ struct loongarch_target
   int cmodel;	    /* CMODEL_ */
 };
 
-extern struct loongarch_isa loongarch_cpu_default_isa[];
-#endif
-
 /* CPU properties.  */
 /* index */
 #define CPU_NATIVE	  0
@@ -170,15 +175,19 @@ extern struct loongarch_isa loongarch_cpu_default_isa[];
 #define N_TUNE_TYPES	  5
 
 /* parallel tables.  */
-extern const char* loongarch_cpu_strings[];
-extern int loongarch_cpu_issue_rate[];
-extern int loongarch_cpu_multipass_dfa_lookahead[];
+extern loongarch_def_array<const char *, N_ARCH_TYPES>
+  loongarch_cpu_strings;
+extern loongarch_def_array<loongarch_isa, N_ARCH_TYPES>
+  loongarch_cpu_default_isa;
+extern loongarch_def_array<int, N_TUNE_TYPES>
+  loongarch_cpu_issue_rate;
+extern loongarch_def_array<int, N_TUNE_TYPES>
+  loongarch_cpu_multipass_dfa_lookahead;
+extern loongarch_def_array<loongarch_cache, N_TUNE_TYPES>
+  loongarch_cpu_cache;
+extern loongarch_def_array<loongarch_align, N_TUNE_TYPES>
+  loongarch_cpu_align;
+extern loongarch_def_array<loongarch_rtx_cost_data, N_TUNE_TYPES>
+  loongarch_cpu_rtx_cost_data;
 
-extern struct loongarch_cache loongarch_cpu_cache[];
-extern struct loongarch_align loongarch_cpu_align[];
-extern struct loongarch_rtx_cost_data loongarch_cpu_rtx_cost_data[];
-
-#ifdef __cplusplus
-}
-#endif
 #endif /* LOONGARCH_DEF_H */
diff --git a/gcc/config/loongarch/loongarch-opts.cc b/gcc/config/loongarch/loongarch-opts.cc
index 390720479..45fc521e4 100644
--- a/gcc/config/loongarch/loongarch-opts.cc
+++ b/gcc/config/loongarch/loongarch-opts.cc
@@ -163,6 +163,7 @@ loongarch_config_target (struct loongarch_target *target,
 			 int follow_multilib_list_p)
 {
   struct loongarch_target t;
+
   if (!target)
     return;
 
@@ -657,12 +658,18 @@ abi_str (struct loongarch_abi abi)
 		     strlen (loongarch_abi_base_strings[abi.base]));
   else
     {
+      /* This situation has not yet occurred, so in order to avoid the
+	 -Warray-bounds warning during C++ syntax checking, this part
+	 of the code is commented first.  */
+      /*
       APPEND_STRING (loongarch_abi_base_strings[abi.base])
       APPEND1 ('/')
       APPEND_STRING (loongarch_abi_ext_strings[abi.ext])
       APPEND1 ('\0')
 
       return XOBFINISH (&msg_obstack, const char *);
+      */
+      gcc_unreachable ();
     }
 }
 
diff --git a/gcc/config/loongarch/loongarch-opts.h b/gcc/config/loongarch/loongarch-opts.h
index 9b3d023ac..0dabf1551 100644
--- a/gcc/config/loongarch/loongarch-opts.h
+++ b/gcc/config/loongarch/loongarch-opts.h
@@ -21,7 +21,10 @@ along with GCC; see the file COPYING3.  If not see
 #ifndef LOONGARCH_OPTS_H
 #define LOONGARCH_OPTS_H
 
+/* This is a C++ header and it shouldn't be used by target libraries.  */
+#if !defined(IN_LIBGCC2) && !defined(IN_TARGET_LIBS) && !defined(IN_RTS)
 #include "loongarch-def.h"
+#endif
 
 /* Target configuration */
 extern struct loongarch_target la_target;
@@ -33,7 +36,6 @@ struct loongarch_flags {
     int sx[2];
 };
 
-#if !defined(IN_LIBGCC2) && !defined(IN_TARGET_LIBS) && !defined(IN_RTS)
 
 /* Initialize loongarch_target from separate option variables.  */
 void
@@ -54,7 +56,6 @@ void
 loongarch_update_gcc_opt_status (struct loongarch_target *target,
 				 struct gcc_options *opts,
 				 struct gcc_options *opts_set);
-#endif
 
 
 /* Macros for common conditional expressions used in loongarch.{c,h,md} */
diff --git a/gcc/config/loongarch/loongarch-tune.h b/gcc/config/loongarch/loongarch-tune.h
index d961963f0..616b94e87 100644
--- a/gcc/config/loongarch/loongarch-tune.h
+++ b/gcc/config/loongarch/loongarch-tune.h
@@ -21,6 +21,8 @@ along with GCC; see the file COPYING3.  If not see
 #ifndef LOONGARCH_TUNE_H
 #define LOONGARCH_TUNE_H
 
+#include "loongarch-def-array.h"
+
 /* RTX costs of various operations on the different architectures.  */
 struct loongarch_rtx_cost_data
 {
@@ -35,6 +37,76 @@ struct loongarch_rtx_cost_data
   unsigned short int_div_di;
   unsigned short branch_cost;
   unsigned short memory_latency;
+
+  /* Default RTX cost initializer, implemented in loongarch-def.cc.  */
+  loongarch_rtx_cost_data ();
+
+  loongarch_rtx_cost_data fp_add_ (unsigned short _fp_add)
+  {
+    fp_add = _fp_add;
+    return *this;
+  }
+
+  loongarch_rtx_cost_data fp_mult_sf_ (unsigned short _fp_mult_sf)
+  {
+    fp_mult_sf = _fp_mult_sf;
+    return *this;
+  }
+
+  loongarch_rtx_cost_data fp_mult_df_ (unsigned short _fp_mult_df)
+  {
+    fp_mult_df = _fp_mult_df;
+    return *this;
+  }
+
+  loongarch_rtx_cost_data fp_div_sf_ (unsigned short _fp_div_sf)
+  {
+    fp_div_sf = _fp_div_sf;
+    return *this;
+  }
+
+  loongarch_rtx_cost_data fp_div_df_ (unsigned short _fp_div_df)
+  {
+    fp_div_df = _fp_div_df;
+    return *this;
+  }
+
+  loongarch_rtx_cost_data int_mult_si_ (unsigned short _int_mult_si)
+  {
+    int_mult_si = _int_mult_si;
+    return *this;
+  }
+
+  loongarch_rtx_cost_data int_mult_di_ (unsigned short _int_mult_di)
+  {
+    int_mult_di = _int_mult_di;
+    return *this;
+  }
+
+  loongarch_rtx_cost_data int_div_si_ (unsigned short _int_div_si)
+  {
+    int_div_si = _int_div_si;
+    return *this;
+  }
+
+  loongarch_rtx_cost_data int_div_di_ (unsigned short _int_div_di)
+  {
+    int_div_di = _int_div_di;
+    return *this;
+  }
+
+  loongarch_rtx_cost_data branch_cost_ (unsigned short _branch_cost)
+  {
+    branch_cost = _branch_cost;
+    return *this;
+  }
+
+  loongarch_rtx_cost_data memory_latency_ (unsigned short _memory_latency)
+  {
+    memory_latency = _memory_latency;
+    return *this;
+  }
+
 };
 
 /* Costs to use when optimizing for size.  */
@@ -42,10 +114,39 @@ extern const struct loongarch_rtx_cost_data loongarch_rtx_cost_optimize_size;
 
 /* Cache size record of known processor models.  */
 struct loongarch_cache {
-    int l1d_line_size;  /* bytes */
-    int l1d_size;       /* KiB */
-    int l2d_size;       /* kiB */
-    int simultaneous_prefetches; /* number of parallel prefetch */
+  int l1d_line_size;  /* bytes */
+  int l1d_size;       /* KiB */
+  int l2d_size;       /* kiB */
+  int simultaneous_prefetches; /* number of parallel prefetch */
+
+  loongarch_cache () : l1d_line_size (0),
+		       l1d_size (0),
+		       l2d_size (0),
+		       simultaneous_prefetches (0) {}
+
+  loongarch_cache l1d_line_size_ (int _l1d_line_size)
+  {
+    l1d_line_size = _l1d_line_size;
+    return *this;
+  }
+
+  loongarch_cache l1d_size_ (int _l1d_size)
+  {
+    l1d_size = _l1d_size;
+    return *this;
+  }
+
+  loongarch_cache l2d_size_ (int _l2d_size)
+  {
+    l2d_size = _l2d_size;
+    return *this;
+  }
+
+  loongarch_cache simultaneous_prefetches_ (int _simultaneous_prefetches)
+  {
+    simultaneous_prefetches = _simultaneous_prefetches;
+    return *this;
+  }
 };
 
 /* Alignment for functions and labels for best performance.  For new uarchs
@@ -54,6 +155,20 @@ struct loongarch_cache {
 struct loongarch_align {
   const char *function;	/* default value for -falign-functions */
   const char *label;	/* default value for -falign-labels */
+
+  loongarch_align () : function (nullptr), label (nullptr) {}
+
+  loongarch_align function_ (const char *_function)
+  {
+    function = _function;
+    return *this;
+  }
+
+  loongarch_align label_ (const char *_label)
+  {
+    label = _label;
+    return *this;
+  }
 };
 
 #endif /* LOONGARCH_TUNE_H */
diff --git a/gcc/config/loongarch/t-loongarch b/gcc/config/loongarch/t-loongarch
index 57b1176bc..a1a40431f 100644
--- a/gcc/config/loongarch/t-loongarch
+++ b/gcc/config/loongarch/t-loongarch
@@ -64,8 +64,8 @@ loongarch-cpu.o: $(srcdir)/config/loongarch/loongarch-cpu.cc $(LA_STR_H) \
 		 $(srcdir)/config/loongarch/loongarch-cpucfg-map.h
 	$(COMPILER) -c $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) $<
 
-loongarch-def.o: $(srcdir)/config/loongarch/loongarch-def.c $(LA_STR_H)
-	$(CC) -c $(ALL_CFLAGS) $(INCLUDES) $<
+loongarch-def.o: $(srcdir)/config/loongarch/loongarch-def.cc $(LA_STR_H)
+	$(COMPILER) -c $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) $<
 
 $(srcdir)/config/loongarch/loongarch.opt: s-loongarch-opt ; @true
 s-loongarch-opt: $(srcdir)/config/loongarch/genopts/genstr.sh \
-- 
2.43.0