LoongArch: Add support for D frontend.

gcc/ChangeLog:

	* config.gcc: Add loongarch-d.o to d_target_objs for LoongArch
	architecture.
	* config/loongarch/t-loongarch: Add object target for loongarch-d.cc.
	* config/loongarch/loongarch-d.cc
	(loongarch_d_target_versions): add interface function to define builtin
	D versions for LoongArch architecture.
	(loongarch_d_handle_target_float_abi): add interface function to define
	builtin D traits for LoongArch architecture.
	(loongarch_d_register_target_info): add interface function to register
	loongarch_d_handle_target_float_abi function.
	* config/loongarch/loongarch-d.h
	(loongarch_d_target_versions): add function prototype.
	(loongarch_d_register_target_info): Likewise.

libphobos/ChangeLog:

	* configure.tgt: Enable libphobos for LoongArch architecture.
	* libdruntime/gcc/sections/elf.d: Add TLS_DTV_OFFSET constant for
	LoongArch64.
	* libdruntime/gcc/unwind/generic.d: Add __aligned__ constant for
	LoongArch64.

gcc/config.gcc

@@ -482,6 +482,7 @@ mips*-*-*)
 	;;
 loongarch*-*-*)
 	cpu_type=loongarch
+	d_target_objs="loongarch-d.o"
 	extra_headers="larchintrin.h lsxintrin.h lasxintrin.h"
 	extra_objs="loongarch-c.o loongarch-builtins.o loongarch-cpu.o loongarch-opts.o loongarch-def.o"
 	extra_gcc_objs="loongarch-driver.o loongarch-cpu.o loongarch-opts.o loongarch-def.o"

gcc/config/loongarch/loongarch-d.cc

@@ -0,0 +1,77 @@
+/* Subroutines for the D front end on the LoongArch architecture.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+
+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/>.  */
+
+#define IN_TARGET_CODE 1
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm_d.h"
+#include "d/d-target.h"
+#include "d/d-target-def.h"
+
+/* Implement TARGET_D_CPU_VERSIONS for LoongArch targets.  */
+
+void
+loongarch_d_target_versions (void)
+{
+  if (TARGET_64BIT)
+    d_add_builtin_version ("LoongArch64");
+  else
+    d_add_builtin_version ("LoongArch32");
+
+  if (TARGET_HARD_FLOAT_ABI)
+    {
+      d_add_builtin_version ("LoongArch_HardFloat");
+      d_add_builtin_version ("D_HardFloat");
+    }
+  else if (TARGET_SOFT_FLOAT_ABI)
+    {
+      d_add_builtin_version ("LoongArch_SoftFloat");
+      d_add_builtin_version ("D_SoftFloat");
+    }
+}
+
+/* Handle a call to `__traits(getTargetInfo, "floatAbi")'.  */
+
+static tree
+loongarch_d_handle_target_float_abi (void)
+{
+  const char *abi;
+
+  if (TARGET_HARD_FLOAT_ABI)
+    abi = "hard";
+  else if (TARGET_SOFT_FLOAT_ABI)
+    abi = "soft";
+  else
+    abi = "";
+
+  return build_string_literal (strlen (abi) + 1, abi);
+}
+
+/* Implement TARGET_D_REGISTER_CPU_TARGET_INFO.  */
+
+void
+loongarch_d_register_target_info (void)
+{
+  const struct d_target_info_spec handlers[] = {
+    {"floatAbi", loongarch_d_handle_target_float_abi},
+    {NULL, NULL},
+  };
+
+  d_add_target_info_handlers (handlers);
+}

gcc/config/loongarch/loongarch-d.h

@@ -0,0 +1,26 @@
+/* Definitions for the D front end on the LoongArch architecture.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+
+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/>.  */
+
+/* Defined in loongarch-d.cc  */
+extern void
+loongarch_d_target_versions (void);
+extern void
+loongarch_d_register_target_info (void);
+
+/* Target hooks for D language.  */
+#define TARGET_D_CPU_VERSIONS loongarch_d_target_versions
+#define TARGET_D_REGISTER_CPU_TARGET_INFO loongarch_d_register_target_info

gcc/config/loongarch/t-loongarch

@@ -67,6 +67,10 @@ loongarch-cpu.o: $(srcdir)/config/loongarch/loongarch-cpu.cc $(LA_STR_H) \
 loongarch-def.o: $(srcdir)/config/loongarch/loongarch-def.cc $(LA_STR_H)
 	$(COMPILER) -c $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) $<
 
+loongarch-d.o: $(srcdir)/config/loongarch/loongarch-d.cc
+	$(COMPILE) $<
+	$(POSTCOMPILE)
+
 $(srcdir)/config/loongarch/loongarch.opt: s-loongarch-opt ; @true
 s-loongarch-opt: $(srcdir)/config/loongarch/genopts/genstr.sh \
 	$(srcdir)/config/loongarch/genopts/loongarch.opt.in \

libphobos/configure.tgt

@@ -36,6 +36,9 @@ case "${target}" in
   hppa-*-linux*)
 	LIBPHOBOS_SUPPORTED=yes
 	;;
+  loongarch*-*-linux*)
+	LIBPHOBOS_SUPPORTED=yes
+	;;
   mips*-*-linux*)
 	LIBPHOBOS_SUPPORTED=yes
 	;;

libphobos/libdruntime/gcc/sections/elf.d

@@ -1061,6 +1061,8 @@ else version (MIPS64)
     enum TLS_DTV_OFFSET = 0x8000;
 else version (IBMZ_Any)
     enum TLS_DTV_OFFSET = 0x0;
+else version (LoongArch64)
+    enum TLS_DTV_OFFSET = 0x0;
 else
     static assert( false, "Platform not supported." );
 

libphobos/libdruntime/gcc/unwind/generic.d

@@ -141,6 +141,7 @@ else version (SPARC64)  private enum __aligned__ = 16;
 else version (SystemZ)  private enum __aligned__ = 8;
 else version (X86)      private enum __aligned__ = 16;
 else version (X86_64)   private enum __aligned__ = 16;
+else version (LoongArch64) private enum __aligned__ = 16;
 else static assert( false, "Platform not supported.");
 
 align(__aligned__) struct _Unwind_Exception