+static gboolean gsharedvt_supported;
+
+void
+mono_set_generic_sharing_vt_supported (gboolean supported)
+{
+ gsharedvt_supported = supported;
+}
+
+#ifdef MONO_ARCH_GSHAREDVT_SUPPORTED
+
+/*
+ * mini_is_gsharedvt_type:
+ *
+ * Return whenever T references type arguments instantiated with gshared vtypes.
+ */
+gboolean
+mini_is_gsharedvt_type (MonoType *t)
+{
+ int i;
+
+ if (t->byref)
+ return FALSE;
+ if ((t->type == MONO_TYPE_VAR || t->type == MONO_TYPE_MVAR) && t->data.generic_param->gshared_constraint && t->data.generic_param->gshared_constraint->type == MONO_TYPE_VALUETYPE)
+ return TRUE;
+ else if (t->type == MONO_TYPE_GENERICINST) {
+ MonoGenericClass *gclass = t->data.generic_class;
+ MonoGenericContext *context = &gclass->context;
+ MonoGenericInst *inst;
+
+ inst = context->class_inst;
+ if (inst) {
+ for (i = 0; i < inst->type_argc; ++i)
+ if (mini_is_gsharedvt_type (inst->type_argv [i]))
+ return TRUE;
+ }
+ inst = context->method_inst;
+ if (inst) {
+ for (i = 0; i < inst->type_argc; ++i)
+ if (mini_is_gsharedvt_type (inst->type_argv [i]))
+ return TRUE;
+ }
+
+ return FALSE;
+ } else {
+ return FALSE;
+ }
+}
+
+gboolean
+mini_is_gsharedvt_klass (MonoClass *klass)
+{
+ return mini_is_gsharedvt_type (&klass->byval_arg);
+}
+
+gboolean
+mini_is_gsharedvt_signature (MonoMethodSignature *sig)
+{
+ int i;
+
+ if (sig->ret && mini_is_gsharedvt_type (sig->ret))
+ return TRUE;
+ for (i = 0; i < sig->param_count; ++i) {
+ if (mini_is_gsharedvt_type (sig->params [i]))
+ return TRUE;
+ }
+ return FALSE;
+}
+
+/*
+ * mini_is_gsharedvt_variable_type:
+ *
+ * Return whenever T refers to a GSHAREDVT type whose size differs depending on the values of type parameters.
+ */
+gboolean
+mini_is_gsharedvt_variable_type (MonoType *t)
+{
+ if (!mini_is_gsharedvt_type (t))
+ return FALSE;
+ if (t->type == MONO_TYPE_GENERICINST) {
+ MonoGenericClass *gclass = t->data.generic_class;
+ MonoGenericContext *context = &gclass->context;
+ MonoGenericInst *inst;
+ int i;
+
+ if (t->data.generic_class->container_class->byval_arg.type != MONO_TYPE_VALUETYPE || t->data.generic_class->container_class->enumtype)
+ return FALSE;
+
+ inst = context->class_inst;
+ if (inst) {
+ for (i = 0; i < inst->type_argc; ++i)
+ if (mini_is_gsharedvt_variable_type (inst->type_argv [i]))
+ return TRUE;
+ }
+ inst = context->method_inst;
+ if (inst) {
+ for (i = 0; i < inst->type_argc; ++i)
+ if (mini_is_gsharedvt_variable_type (inst->type_argv [i]))
+ return TRUE;
+ }
+
+ return FALSE;
+ }
+ return TRUE;
+}
+
+static gboolean
+is_variable_size (MonoType *t)
+{
+ int i;
+
+ if (t->byref)
+ return FALSE;
+
+ if (t->type == MONO_TYPE_VAR || t->type == MONO_TYPE_MVAR) {
+ MonoGenericParam *param = t->data.generic_param;
+
+ if (param->gshared_constraint && param->gshared_constraint->type != MONO_TYPE_VALUETYPE && param->gshared_constraint->type != MONO_TYPE_GENERICINST)
+ return FALSE;
+ if (param->gshared_constraint && param->gshared_constraint->type == MONO_TYPE_GENERICINST)
+ return is_variable_size (param->gshared_constraint);
+ return TRUE;
+ }
+ if (t->type == MONO_TYPE_GENERICINST && t->data.generic_class->container_class->byval_arg.type == MONO_TYPE_VALUETYPE) {
+ MonoGenericClass *gclass = t->data.generic_class;
+ MonoGenericContext *context = &gclass->context;
+ MonoGenericInst *inst;
+
+ inst = context->class_inst;
+ if (inst) {
+ for (i = 0; i < inst->type_argc; ++i)
+ if (is_variable_size (inst->type_argv [i]))
+ return TRUE;
+ }
+ inst = context->method_inst;
+ if (inst) {
+ for (i = 0; i < inst->type_argc; ++i)
+ if (is_variable_size (inst->type_argv [i]))
+ return TRUE;
+ }
+ }
+
+ return FALSE;
+}
+
+gboolean
+mini_is_gsharedvt_sharable_inst (MonoGenericInst *inst)
+{
+ int i;
+ gboolean has_vt = FALSE;
+
+ for (i = 0; i < inst->type_argc; ++i) {
+ MonoType *type = inst->type_argv [i];
+
+ if ((MONO_TYPE_IS_REFERENCE (type) || type->type == MONO_TYPE_VAR || type->type == MONO_TYPE_MVAR) && !mini_is_gsharedvt_type (type)) {
+ } else {
+ has_vt = TRUE;
+ }
+ }
+
+ return has_vt;
+}
+
+gboolean
+mini_is_gsharedvt_sharable_method (MonoMethod *method)
+{
+ MonoMethodSignature *sig;
+
+ /*
+ * A method is gsharedvt if:
+ * - it has type parameters instantiated with vtypes
+ */
+ if (!gsharedvt_supported)
+ return FALSE;
+ if (method->is_inflated) {
+ MonoMethodInflated *inflated = (MonoMethodInflated*)method;
+ MonoGenericContext *context = &inflated->context;
+ MonoGenericInst *inst;
+
+ if (context->class_inst && context->method_inst) {
+ /* At least one inst has to be gsharedvt sharable, and the other normal or gsharedvt sharable */
+ gboolean vt1 = mini_is_gsharedvt_sharable_inst (context->class_inst);
+ gboolean vt2 = mini_is_gsharedvt_sharable_inst (context->method_inst);
+
+ if ((vt1 && vt2) ||
+ (vt1 && mini_generic_inst_is_sharable (context->method_inst, TRUE, FALSE)) ||
+ (vt2 && mini_generic_inst_is_sharable (context->class_inst, TRUE, FALSE)))
+ ;
+ else
+ return FALSE;
+ } else {
+ inst = context->class_inst;
+ if (inst && !mini_is_gsharedvt_sharable_inst (inst))
+ return FALSE;
+ inst = context->method_inst;
+ if (inst && !mini_is_gsharedvt_sharable_inst (inst))
+ return FALSE;
+ }
+ } else {
+ return FALSE;
+ }