6 /* Copyright (C) 2001, 2002, 2003, 2004, 2006, 2008 Free Software Foundation, Inc.
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 /* This file is for inline functions. On platforms that don't support
24 inlining functions, they are turned into ordinary functions. See
28 #include "libguile/__scm.h"
30 #if (SCM_DEBUG_CELL_ACCESSES == 1)
34 #include "libguile/pairs.h"
35 #include "libguile/gc.h"
36 #include "libguile/threads.h"
37 #include "libguile/unif.h"
38 #include "libguile/pairs.h"
41 #ifndef SCM_INLINE_C_INCLUDING_INLINE_H
43 /* GCC has `__inline__' in all modes, including strict ansi. GCC 4.3 and
44 above with `-std=c99' or `-std=gnu99' implements ISO C99 inline semantics,
45 unless `-fgnu89-inline' is used. Here we want GNU "extern inline"
46 semantics, hence the `__gnu_inline__' attribute, in accordance with:
47 http://gcc.gnu.org/gcc-4.3/porting_to.html .
49 With GCC 4.2, `__GNUC_STDC_INLINE__' is never defined (because C99 inline
50 semantics are not supported), but a warning is issued in C99 mode if
51 `__gnu_inline__' is not used.
53 Apple's GCC build >5400 (since Xcode 3.0) doesn't support GNU inline in
54 C99 mode and doesn't define `__GNUC_STDC_INLINE__'. Fall back to "static
55 inline" in that case. */
57 # if (defined __GNUC__) && (!(__APPLE_CC__ > 5400 && __STDC_VERSION__ >= 199901L))
58 # if (defined __GNUC_STDC_INLINE__) || (__GNUC__ == 4 && __GNUC_MINOR__ == 2)
59 # define SCM_C_EXTERN_INLINE \
60 extern __inline__ __attribute__ ((__gnu_inline__))
62 # define SCM_C_EXTERN_INLINE extern __inline__
64 # elif (defined SCM_C_INLINE)
65 # define SCM_C_EXTERN_INLINE static SCM_C_INLINE
68 #endif /* SCM_INLINE_C_INCLUDING_INLINE_H */
71 #if ((!defined SCM_C_INLINE) && (!defined SCM_INLINE_C_INCLUDING_INLINE_H)) \
74 /* The `extern' declarations. They should only appear when used from
75 "inline.c", when `inline' is not supported at all or when GCC's "extern
78 SCM_API SCM scm_cell (scm_t_bits car, scm_t_bits cdr);
79 SCM_API SCM scm_double_cell (scm_t_bits car, scm_t_bits cbr,
80 scm_t_bits ccr, scm_t_bits cdr);
82 SCM_API SCM scm_array_handle_ref (scm_t_array_handle *h, ssize_t pos);
83 SCM_API void scm_array_handle_set (scm_t_array_handle *h, ssize_t pos, SCM val);
85 SCM_API int scm_is_pair (SCM x);
90 #if defined SCM_C_INLINE || defined SCM_INLINE_C_INCLUDING_INLINE_H
91 /* either inlining, or being included from inline.c. We use (and
92 repeat) this long #if test here and below so that we don't have to
93 introduce any extraneous symbols into the public namespace. We
94 only need SCM_C_INLINE to be seen publically . */
96 extern unsigned scm_newcell2_count;
97 extern unsigned scm_newcell_count;
100 #if defined SCM_C_EXTERN_INLINE && ! defined SCM_INLINE_C_INCLUDING_INLINE_H
104 scm_cell (scm_t_bits car, scm_t_bits cdr)
107 SCM *freelist = SCM_FREELIST_LOC (scm_i_freelist);
109 if (scm_is_null (*freelist))
110 z = scm_gc_for_newcell (&scm_i_master_freelist, freelist);
114 *freelist = SCM_FREE_CELL_CDR (*freelist);
118 We update scm_cells_allocated from this function. If we don't
119 update this explicitly, we will have to walk a freelist somewhere
120 later on, which seems a lot more expensive.
122 scm_cells_allocated += 1;
124 #if (SCM_DEBUG_CELL_ACCESSES == 1)
125 if (scm_debug_cell_accesses_p)
127 if (SCM_GC_MARK_P (z))
129 fprintf(stderr, "scm_cell tried to allocate a marked cell.\n");
132 else if (SCM_GC_CELL_WORD(z, 0) != scm_tc_free_cell)
134 fprintf(stderr, "cell from freelist is not a free cell.\n");
140 Always set mark. Otherwise cells that are alloced before
141 scm_debug_cell_accesses_p is toggled seem invalid.
146 TODO: figure out if this use of mark bits is valid with
147 threading. What if another thread is doing GC at this point
154 /* Initialize the type slot last so that the cell is ignored by the
155 GC until it is completely initialized. This is only relevant
156 when the GC can actually run during this code, which it can't
157 since the GC only runs when all other threads are stopped.
159 SCM_GC_SET_CELL_WORD (z, 1, cdr);
160 SCM_GC_SET_CELL_WORD (z, 0, car);
162 #if (SCM_DEBUG_CELL_ACCESSES == 1)
163 if (scm_expensive_debug_cell_accesses_p )
164 scm_i_expensive_validation_check (z);
170 #if defined SCM_C_EXTERN_INLINE && ! defined SCM_INLINE_C_INCLUDING_INLINE_H
174 scm_double_cell (scm_t_bits car, scm_t_bits cbr,
175 scm_t_bits ccr, scm_t_bits cdr)
178 SCM *freelist = SCM_FREELIST_LOC (scm_i_freelist2);
180 if (scm_is_null (*freelist))
181 z = scm_gc_for_newcell (&scm_i_master_freelist2, freelist);
185 *freelist = SCM_FREE_CELL_CDR (*freelist);
188 scm_cells_allocated += 2;
190 /* Initialize the type slot last so that the cell is ignored by the
191 GC until it is completely initialized. This is only relevant
192 when the GC can actually run during this code, which it can't
193 since the GC only runs when all other threads are stopped.
195 SCM_GC_SET_CELL_WORD (z, 1, cbr);
196 SCM_GC_SET_CELL_WORD (z, 2, ccr);
197 SCM_GC_SET_CELL_WORD (z, 3, cdr);
198 SCM_GC_SET_CELL_WORD (z, 0, car);
200 #if (SCM_DEBUG_CELL_ACCESSES == 1)
201 if (scm_debug_cell_accesses_p)
203 if (SCM_GC_MARK_P (z))
206 "scm_double_cell tried to allocate a marked cell.\n");
216 /* When this function is inlined, it's possible that the last
217 SCM_GC_SET_CELL_WORD above will be adjacent to a following
218 initialization of z. E.g., it occurred in scm_make_real. GCC
219 from around version 3 (e.g., certainly 3.2) began taking
220 advantage of strict C aliasing rules which say that it's OK to
221 interchange the initialization above and the one below when the
222 pointer types appear to differ sufficiently. We don't want that,
223 of course. GCC allows this behaviour to be disabled with the
224 -fno-strict-aliasing option, but would also need to be supplied
225 by Guile users. Instead, the following statements prevent the
229 __asm__ volatile ("" : : : "memory");
231 /* portable version, just in case any other compiler does the same
233 scm_remember_upto_here_1 (z);
239 #if defined SCM_C_EXTERN_INLINE && ! defined SCM_INLINE_C_INCLUDING_INLINE_H
243 scm_array_handle_ref (scm_t_array_handle *h, ssize_t p)
245 return h->ref (h, p);
248 #if defined SCM_C_EXTERN_INLINE && ! defined SCM_INLINE_C_INCLUDING_INLINE_H
252 scm_array_handle_set (scm_t_array_handle *h, ssize_t p, SCM v)
257 #if defined SCM_C_EXTERN_INLINE && ! defined SCM_INLINE_C_INCLUDING_INLINE_H
263 /* The following "workaround_for_gcc_295" avoids bad code generated by
264 i386 gcc 2.95.4 (the Debian packaged 2.95.4-24 at least).
266 Under the default -O2 the inlined SCM_I_CONSP test gets "optimized" so
267 the fetch of the tag word from x is done before confirming it's a
268 non-immediate (SCM_NIMP). Needless to say that bombs badly if x is a
269 immediate. This was seen to afflict scm_srfi1_split_at and something
270 deep in the bowels of ceval(). In both cases segvs resulted from
271 deferencing a random immediate value. srfi-1.test exposes the problem
272 through a short list, the immediate being SCM_EOL in that case.
273 Something in syntax.test exposed the ceval() problem.
275 Just "volatile SCM workaround_for_gcc_295 = lst" is enough to avoid the
276 problem, without even using that variable. The "w=w" is just to
277 prevent a warning about it being unused.
279 #if defined (__GNUC__) && __GNUC__ == 2 && __GNUC_MINOR__ == 95
280 volatile SCM workaround_for_gcc_295 = x;
281 workaround_for_gcc_295 = workaround_for_gcc_295;
284 return SCM_I_CONSP (x);