Add unpack-values-object intrinsic

* libguile/intrinsics.h (SCM_FOR_ALL_VM_INTRINSICS): Add
  unpack-values-object.
* libguile/vm-engine.c (subr-call): If the object is a values object,
  call out to unpack-values-object.  This is to avoid reifying
  allocate-frame code in each jitted subr.
* libguile/vm.c (unpack_values_object, scm_bootstrap_vm): Define new
  intrinsic.

1 files changed, 12 insertions, 0 deletions

diff --git a/libguile/vm.c b/libguile/vm.c
index 8ad8cfe3f..9dc94f8d3 100644
--- a/libguile/vm.c
+++ b/libguile/vm.c
@@ -1183,6 +1183,17 @@ rest_arg_length (SCM x)
   return len;
 }
 
+/* This is here to avoid putting the code for "alloc-frame" in subr
+   calls. */
+static void
+unpack_values_object (scm_thread *thread, SCM obj)
+{
+  size_t n, nvals = scm_i_nvalues (obj);
+  alloc_frame (thread, nvals);
+  for (n = 0; n < nvals; n++)
+    SCM_FRAME_LOCAL (thread->vm.fp, n) = scm_i_value_ref (obj, n);
+}
+
 static SCM
 capture_delimited_continuation (struct scm_vm *vp,
                                 union scm_vm_stack_element *saved_fp,
@@ -1685,6 +1696,7 @@ scm_bootstrap_vm (void)
   scm_vm_intrinsics.rest_arg_length = rest_arg_length;
   scm_vm_intrinsics.abort_to_prompt = abort_to_prompt;
   scm_vm_intrinsics.get_callee_vcode = get_callee_vcode;
+  scm_vm_intrinsics.unpack_values_object = unpack_values_object;
 
   sym_keyword_argument_error = scm_from_latin1_symbol ("keyword-argument-error");
   sym_regular = scm_from_latin1_symbol ("regular");