SCM_API SCM scm_cell (scm_t_bits car, scm_t_bits cdr);
-SCM_API SCM scm_immutable_cell (scm_t_bits car, scm_t_bits cdr);
SCM_API SCM scm_double_cell (scm_t_bits car, scm_t_bits cbr,
scm_t_bits ccr, scm_t_bits cdr);
-SCM_API SCM scm_immutable_double_cell (scm_t_bits car, scm_t_bits cbr,
- scm_t_bits ccr, scm_t_bits cdr);
SCM_API SCM scm_words (scm_t_bits car, scm_t_uint16 n_words);
-/* no immutable words for now, would require initialization at the same time as
- allocation */
SCM_API SCM scm_array_handle_ref (scm_t_array_handle *h, ssize_t pos);
SCM_API void scm_array_handle_set (scm_t_array_handle *h, ssize_t pos, SCM val);
return cell;
}
-#ifndef SCM_INLINE_C_INCLUDING_INLINE_H
-SCM_C_EXTERN_INLINE
-#endif
-SCM
-scm_immutable_cell (scm_t_bits car, scm_t_bits cdr)
-{
- SCM cell = PTR2SCM (GC_MALLOC_STUBBORN (sizeof (scm_t_cell)));
-
- /* Initialize the type slot last so that the cell is ignored by the GC
- until it is completely initialized. This is only relevant when the GC
- can actually run during this code, which it can't since the GC only runs
- when all other threads are stopped. */
- SCM_GC_SET_CELL_WORD (cell, 1, cdr);
- SCM_GC_SET_CELL_WORD (cell, 0, car);
-
- GC_END_STUBBORN_CHANGE (SCM2PTR (cell));
-
- return cell;
-}
-
#ifndef SCM_INLINE_C_INCLUDING_INLINE_H
SCM_C_EXTERN_INLINE
#endif
return z;
}
-#ifndef SCM_INLINE_C_INCLUDING_INLINE_H
-SCM_C_EXTERN_INLINE
-#endif
-SCM
-scm_immutable_double_cell (scm_t_bits car, scm_t_bits cbr,
- scm_t_bits ccr, scm_t_bits cdr)
-{
- SCM z;
-
- z = PTR2SCM (GC_MALLOC_STUBBORN (2 * sizeof (scm_t_cell)));
- /* Initialize the type slot last so that the cell is ignored by the
- GC until it is completely initialized. This is only relevant
- when the GC can actually run during this code, which it can't
- since the GC only runs when all other threads are stopped.
- */
- SCM_GC_SET_CELL_WORD (z, 1, cbr);
- SCM_GC_SET_CELL_WORD (z, 2, ccr);
- SCM_GC_SET_CELL_WORD (z, 3, cdr);
- SCM_GC_SET_CELL_WORD (z, 0, car);
-
- GC_END_STUBBORN_CHANGE (SCM2PTR (z));
-
- /* When this function is inlined, it's possible that the last
- SCM_GC_SET_CELL_WORD above will be adjacent to a following
- initialization of z. E.g., it occurred in scm_make_real. GCC
- from around version 3 (e.g., certainly 3.2) began taking
- advantage of strict C aliasing rules which say that it's OK to
- interchange the initialization above and the one below when the
- pointer types appear to differ sufficiently. We don't want that,
- of course. GCC allows this behaviour to be disabled with the
- -fno-strict-aliasing option, but would also need to be supplied
- by Guile users. Instead, the following statements prevent the
- reordering.
- */
-#ifdef __GNUC__
- __asm__ volatile ("" : : : "memory");
-#else
- /* portable version, just in case any other compiler does the same
- thing. */
- scm_remember_upto_here_1 (z);
-#endif
-
- return z;
-}
-
#ifndef SCM_INLINE_C_INCLUDING_INLINE_H
SCM_C_EXTERN_INLINE
#endif