Parse bytecode to determine minimum arity

* libguile/programs.c (try_parse_arity): New helper, to parse bytecode
  to determine the minimum arity of a function in a cheaper way than
  grovelling through the debug info.  Should speed up all thunk? checks
  and similar.
  (scm_i_program_arity): Simplify.
* libguile/gsubr.h:
* libguile/gsubr.c (scm_i_primitive_arity):
* libguile/foreign.h:
* libguile/foreign.c (scm_i_foreign_arity):

1 files changed, 0 insertions, 31 deletions

diff --git a/libguile/gsubr.c b/libguile/gsubr.c
index d80e5dd42..b456b220a 100644
--- a/libguile/gsubr.c
+++ b/libguile/gsubr.c
@@ -262,37 +262,6 @@ scm_i_primitive_code_p (const scm_t_uint32 *code)
   return 1;
 }
 
-/* Given a program that is a primitive, determine its minimum arity.
-   This is possible because each primitive's code is 4 32-bit words
-   long, and they are laid out contiguously in an ordered pattern.  */
-int
-scm_i_primitive_arity (SCM prim, int *req, int *opt, int *rest)
-{
-  const scm_t_uint32 *code = SCM_PROGRAM_CODE (prim);
-  unsigned idx, nargs, base, next;
-
-  if (!scm_i_primitive_code_p (code))
-    return 0;
-
-  idx = (code - subr_stub_code) / 4;
-
-  nargs = -1;
-  next = 0;
-  do
-    {
-      base = next;
-      nargs++;
-      next = (nargs + 1) * (nargs + 1);
-    }
-  while (idx >= next);
-
-  *rest = (next - idx) < (idx - base);
-  *req = *rest ? (next - 1) - idx : (base + nargs) - idx;
-  *opt = *rest ? idx - (next - nargs) : idx - base;
-
-  return 1;
-}
-
 scm_t_uintptr
 scm_i_primitive_call_ip (SCM subr)
 {