optimize access to arrays of rank 1 or 2

* libguile/array-handle.c (scm_array_handle_pos_1):
  (scm_array_handle_pos_2): New functions.

* libguile/generalized-arrays.c (scm_c_array_ref_1, scm_c_array_ref_2):
  (scm_c_array_set_1_x, scm_c_array_set_2_x): New functions.
  (scm_i_array_ref, scm_i_array_set_x): New subr bindings for array-ref
  and array-set! that avoid consing for arrays of rank 1 or 2.

* test-suite/tests/arrays.test ("array-set!"): Fix expected exception
  for wrong number of indices.

1 files changed, 42 insertions, 1 deletions

diff --git a/libguile/array-handle.c b/libguile/array-handle.c
index ec3127a4a..08778f369 100644
--- a/libguile/array-handle.c
+++ b/libguile/array-handle.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1995,1996,1997,1998,2000,2001,2002,2003,2004, 2005, 2006, 2009 Free Software Foundation, Inc.
+/* Copyright (C) 1995,1996,1997,1998,2000,2001,2002,2003,2004, 2005, 2006, 2009, 2013 Free Software Foundation, Inc.
  * 
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License
@@ -97,6 +97,47 @@ scm_array_handle_pos (scm_t_array_handle *h, SCM indices)
   return pos;
 }
 
+static void
+check_array_index_bounds (scm_t_array_dim *dim, ssize_t idx)
+{
+  if (idx < dim->lbnd || idx > dim->ubnd)
+    scm_error (scm_out_of_range_key, NULL, "Value out of range ~S to ~S: ~S",
+               scm_list_3 (scm_from_ssize_t (dim->lbnd),
+                           scm_from_ssize_t (dim->ubnd),
+                           scm_from_ssize_t (idx)),
+               scm_list_1 (scm_from_ssize_t (idx)));
+}
+
+ssize_t
+scm_array_handle_pos_1 (scm_t_array_handle *h, ssize_t idx0)
+{
+  scm_t_array_dim *dim = scm_array_handle_dims (h);
+
+  if (scm_array_handle_rank (h) != 1)
+    scm_misc_error (NULL, "wrong number of indices, expecting ~A",
+		    scm_list_1 (scm_from_size_t (scm_array_handle_rank (h))));
+
+  check_array_index_bounds (&dim[0], idx0);
+
+  return (idx0 - dim[0].lbnd) * dim[0].inc;
+}
+
+ssize_t
+scm_array_handle_pos_2 (scm_t_array_handle *h, ssize_t idx0, ssize_t idx1)
+{
+  scm_t_array_dim *dim = scm_array_handle_dims (h);
+
+  if (scm_array_handle_rank (h) != 2)
+    scm_misc_error (NULL, "wrong number of indices, expecting ~A",
+		    scm_list_1 (scm_from_size_t (scm_array_handle_rank (h))));
+
+  check_array_index_bounds (&dim[0], idx0);
+  check_array_index_bounds (&dim[1], idx1);
+
+  return ((idx0 - dim[0].lbnd) * dim[0].inc
+          + (idx1 - dim[1].lbnd) * dim[1].inc);
+}
+
 SCM
 scm_array_handle_element_type (scm_t_array_handle *h)
 {