LoongArch: Enable switchable target

diff --git a/gcc/config/loongarch/loongarch-builtins.cc b/gcc/config/loongarch/loongarch-builtins.cc
index efe7e5e5ebc..fbe46833c9b 100644
--- a/gcc/config/loongarch/loongarch-builtins.cc
+++ b/gcc/config/loongarch/loongarch-builtins.cc
@@ -2512,14 +2512,11 @@  loongarch_init_builtins (void)
   for (i = 0; i < ARRAY_SIZE (loongarch_builtins); i++)
     {
       d = &loongarch_builtins[i];
-      if (d->avail ())
-	{
-	  type = loongarch_build_function_type (d->function_type);
-	  loongarch_builtin_decls[i]
-	    = add_builtin_function (d->name, type, i, BUILT_IN_MD, NULL,
-				    NULL);
-	  loongarch_get_builtin_decl_index[d->icode] = i;
-	}
+      type = loongarch_build_function_type (d->function_type);
+      loongarch_builtin_decls[i]
+	= add_builtin_function (d->name, type, i, BUILT_IN_MD, NULL,
+			  NULL);
+      loongarch_get_builtin_decl_index[d->icode] = i;
     }
 }
 
@@ -3105,15 +3102,21 @@  loongarch_expand_builtin (tree exp, rtx target, rtx subtarget ATTRIBUTE_UNUSED,
 			  int ignore ATTRIBUTE_UNUSED)
 {
   tree fndecl;
-  unsigned int fcode, avail;
+  unsigned int fcode;
   const struct loongarch_builtin_description *d;
 
   fndecl = TREE_OPERAND (CALL_EXPR_FN (exp), 0);
   fcode = DECL_MD_FUNCTION_CODE (fndecl);
   gcc_assert (fcode < ARRAY_SIZE (loongarch_builtins));
   d = &loongarch_builtins[fcode];
-  avail = d->avail ();
-  gcc_assert (avail != 0);
+
+  if (!d->avail ())
+    {
+      error_at (EXPR_LOCATION (exp),
+		"built-in function %qD is not enabled", fndecl);
+      return target;
+    }
+
   switch (d->builtin_type)
     {
     case LARCH_BUILTIN_DIRECT:
diff --git a/gcc/config/loongarch/loongarch.cc b/gcc/config/loongarch/loongarch.cc
index c90b701a533..6b92e7034c5 100644
--- a/gcc/config/loongarch/loongarch.cc
+++ b/gcc/config/loongarch/loongarch.cc
@@ -7570,15 +7570,19 @@  loongarch_global_init (void)
 	loongarch_dwarf_regno[i] = INVALID_REGNUM;
     }
 
+  /* Function to allocate machine-dependent function status.  */
+  init_machine_status = &loongarch_init_machine_status;
+};
+
+static void
+loongarch_reg_init (void)
+{
   /* Set up loongarch_hard_regno_mode_ok.  */
   for (int mode = 0; mode < MAX_MACHINE_MODE; mode++)
     for (int regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
       loongarch_hard_regno_mode_ok_p[mode][regno]
 	= loongarch_hard_regno_mode_ok_uncached (regno, (machine_mode) mode);
-
-  /* Function to allocate machine-dependent function status.  */
-  init_machine_status = &loongarch_init_machine_status;
-};
+}
 
 static void
 loongarch_option_override_internal (struct loongarch_target *target,
@@ -7605,20 +7609,92 @@  loongarch_option_override_internal (struct loongarch_target *target,
 
   /* Override some options according to the resolved target.  */
   loongarch_target_option_override (target, opts, opts_set);
+
+  target_option_default_node = target_option_current_node
+    = build_target_option_node (opts, opts_set);
+
+  loongarch_reg_init ();
+}
+
+/* Remember the last target of loongarch_set_current_function.  */
+
+static GTY(()) tree loongarch_previous_fndecl;
+
+/* Restore or save the TREE_TARGET_GLOBALS from or to new_tree.
+   Used by loongarch_set_current_function to
+   make sure optab availability predicates are recomputed when necessary.  */
+
+static void
+loongarch_save_restore_target_globals (tree new_tree)
+{
+  if (TREE_TARGET_GLOBALS (new_tree))
+    restore_target_globals (TREE_TARGET_GLOBALS (new_tree));
+  else if (new_tree == target_option_default_node)
+    restore_target_globals (&default_target_globals);
+  else
+    TREE_TARGET_GLOBALS (new_tree) = save_target_globals_default_opts ();
+}
+
+/* Implement TARGET_SET_CURRENT_FUNCTION.  */
+
+static void
+loongarch_set_current_function (tree fndecl)
+{
+  if (fndecl == loongarch_previous_fndecl)
+    return;
+
+  tree old_tree;
+  if (loongarch_previous_fndecl == NULL_TREE)
+    old_tree = target_option_current_node;
+  else if (DECL_FUNCTION_SPECIFIC_TARGET (loongarch_previous_fndecl))
+    old_tree = DECL_FUNCTION_SPECIFIC_TARGET (loongarch_previous_fndecl);
+  else
+    old_tree = target_option_default_node;
+
+  if (fndecl == NULL_TREE)
+    {
+      if (old_tree != target_option_current_node)
+	{
+	  loongarch_previous_fndecl = NULL_TREE;
+	  cl_target_option_restore (&global_options, &global_options_set,
+				    TREE_TARGET_OPTION
+				    (target_option_current_node));
+	}
+      return;
+    }
+
+  tree new_tree = DECL_FUNCTION_SPECIFIC_TARGET (fndecl);
+  if (new_tree == NULL_TREE)
+    new_tree = target_option_default_node;
+
+  loongarch_previous_fndecl = fndecl;
+
+  if (new_tree == old_tree)
+    return;
+
+  cl_target_option_restore (&global_options, &global_options_set,
+			    TREE_TARGET_OPTION (new_tree));
+
+  loongarch_reg_init ();
+
+  loongarch_save_restore_target_globals (new_tree);
 }
 
+
+
 /* Implement TARGET_OPTION_OVERRIDE.  */
 
 static void
 loongarch_option_override (void)
 {
+  /* Global initializations.  */
+  loongarch_global_init ();
+
   /* Setting up the target configuration.  */
   loongarch_option_override_internal (&la_target,
 				      &global_options,
 				      &global_options_set);
 
-  /* Global initializations.  */
-  loongarch_global_init ();
 }
 
 /* Implement TARGET_OPTION_SAVE.  */
@@ -10935,6 +11011,9 @@  loongarch_asm_code_end (void)
 #undef TARGET_OPTION_RESTORE
 #define TARGET_OPTION_RESTORE loongarch_option_restore
 
+#undef TARGET_SET_CURRENT_FUNCTION
+#define TARGET_SET_CURRENT_FUNCTION loongarch_set_current_function
+
 #undef TARGET_LEGITIMIZE_ADDRESS
 #define TARGET_LEGITIMIZE_ADDRESS loongarch_legitimize_address
 
diff --git a/gcc/config/loongarch/loongarch.h b/gcc/config/loongarch/loongarch.h
index 23bb3254883..db8a9eb9516 100644
--- a/gcc/config/loongarch/loongarch.h
+++ b/gcc/config/loongarch/loongarch.h
@@ -23,6 +23,8 @@  along with GCC; see the file COPYING3.  If not see
 
 #include "config/loongarch/loongarch-opts.h"
 
+#define SWITCHABLE_TARGET 1
+
 #define TARGET_SUPPORTS_WIDE_INT 1
 
 /* Macros to silence warnings about numbers being signed in traditional
diff --git a/gcc/testsuite/gcc.dg/lto/pr113233_0.c b/gcc/testsuite/gcc.dg/lto/pr113233_0.c
new file mode 100644
index 00000000000..0a045c51966
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/lto/pr113233_0.c
@@ -0,0 +1,14 @@ 
+/* { dg-require-effective-target loongarch_sx_as } */
+/* { dg-lto-do link } */
+/* { dg-skip-if "" { ! { loongarch*-linux-* } } } */
+/* { dg-lto-options { {-mlsx } } } */
+/* { dg-suppress-ld-options { -mlsx } } */
+
+#include <lsxintrin.h>
+
+int main (void)
+{
+  __m128i a, b, c;
+  c = __lsx_vand_v (a, b);
+  return 0;
+} 
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index 45435586de2..0122440e8d9 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -13402,6 +13402,18 @@  proc check_effective_target_loongarch_sx { } {
     } "-mlsx"]
 }
 
+proc check_effective_target_loongarch_sx_as { } {
+    return [check_no_compiler_messages loongarch_sx_as object {
+        #include <lsxintrin.h>
+        int main (void)
+        {
+          __m128i a, b, c;
+          c = __lsx_vand_v (a, b);
+          return 0;
+        }
+    } "-mlsx"]
+}
+
 proc check_effective_target_loongarch_sx_hw { } {
     return [check_runtime loongarch_sx_hw {
 	#include <lsxintrin.h>