libgcc/sync.c

   1 /* Out-of-line libgcc versions of __sync_* builtins.  */
   2 /* Copyright (C) 2008-2023 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 Under Section 7 of GPL version 3, you are granted additional
  17 permissions described in the GCC Runtime Library Exception, version
  18 3.1, as published by the Free Software Foundation.
  19
  20 You should have received a copy of the GNU General Public License and
  21 a copy of the GCC Runtime Library Exception along with this program;
  22 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 <http://www.gnu.org/licenses/>.  */
  24
  25 /* This file is used by targets whose makefiles define SYNC
  26    to "yes".  It is compiled with SYNC_CFLAGS and provides
  27    out-of-line versions of all relevant __sync_* primitives.
  28
  29    These routines are intended for targets like MIPS that have two
  30    ISA encodings (the "normal" ISA and the MIPS16 ISA).  The normal
  31    ISA provides full synchronization capabilities but the MIPS16 ISA
  32    has no encoding for them.  MIPS16 code must therefore call external
  33    non-MIPS16 implementations of the __sync_* routines.
  34
  35    The file is compiled once for each routine.  The following __foo
  36    routines are selected by defining a macro called L<foo>:
  37
  38        __sync_synchronize
  39
  40    The following __foo_N routines are selected by defining FN=foo
  41    and SIZE=N:
  42
  43        __sync_fetch_and_add_N
  44        __sync_fetch_and_sub_N
  45        __sync_fetch_and_or_N
  46        __sync_fetch_and_and_N
  47        __sync_fetch_and_xor_N
  48        __sync_fetch_and_nand_N
  49        __sync_add_and_fetch_N
  50        __sync_sub_and_fetch_N
  51        __sync_or_and_fetch_N
  52        __sync_and_and_fetch_N
  53        __sync_xor_and_fetch_N
  54        __sync_nand_and_fetch_N
  55        __sync_bool_compare_and_swap_N
  56        __sync_val_compare_and_swap_N
  57        __sync_lock_test_and_set_N
  58
  59    SIZE can be 1, 2, 4, 8 or 16.  __foo_N is omitted if the target does
  60    not provide __sync_compare_and_swap_N.
  61
  62    Note that __sync_lock_release does not fall back on external
  63    __sync_lock_release_N functions.  The default implementation
  64    of __sync_lock_release is a call to __sync_synchronize followed
  65    by a store of zero, so we don't need separate library functions
  66    for it.  */
  67
  68 #if defined FN
  69
  70 /* Define functions called __sync_<NAME>_<UNITS>, with one macro per
  71    signature.  TYPE is a type that has UNITS bytes.  */
  72
  73 #define DEFINE_V_PV(NAME, UNITS, TYPE)                                  \
  74   TYPE                                                                  \
  75   __##NAME##_##UNITS (TYPE *ptr, TYPE value)                            \
  76   {                                                                     \
  77     return __##NAME (ptr, value);                                       \
  78   }
  79
  80 #define DEFINE_V_PVV(NAME, UNITS, TYPE)                                 \
  81   TYPE                                                                  \
  82   __##NAME##_##UNITS (TYPE *ptr, TYPE value1, TYPE value2)              \
  83   {                                                                     \
  84     return __##NAME (ptr, value1, value2);                              \
  85   }
  86
  87 #define DEFINE_BOOL_PVV(NAME, UNITS, TYPE)                              \
  88   _Bool                                                                 \
  89   __##NAME##_##UNITS (TYPE *ptr, TYPE value1, TYPE value2)              \
  90   {                                                                     \
  91     return __##NAME (ptr, value1, value2);                              \
  92   }
  93
  94 /* Map function names to the appropriate DEFINE_* macro.  */
  95
  96 #define local_sync_fetch_and_add DEFINE_V_PV
  97 #define local_sync_fetch_and_sub DEFINE_V_PV
  98 #define local_sync_fetch_and_or DEFINE_V_PV
  99 #define local_sync_fetch_and_and DEFINE_V_PV
 100 #define local_sync_fetch_and_xor DEFINE_V_PV
 101 #define local_sync_fetch_and_nand DEFINE_V_PV
 102
 103 #define local_sync_add_and_fetch DEFINE_V_PV
 104 #define local_sync_sub_and_fetch DEFINE_V_PV
 105 #define local_sync_or_and_fetch DEFINE_V_PV
 106 #define local_sync_and_and_fetch DEFINE_V_PV
 107 #define local_sync_xor_and_fetch DEFINE_V_PV
 108 #define local_sync_nand_and_fetch DEFINE_V_PV
 109
 110 #define local_sync_bool_compare_and_swap DEFINE_BOOL_PVV
 111 #define local_sync_val_compare_and_swap DEFINE_V_PVV
 112
 113 #define local_sync_lock_test_and_set DEFINE_V_PV
 114
 115 /* Define the function __<NAME>_<UNITS>, given that TYPE is a type with
 116    UNITS bytes.  */
 117 #define DEFINE1(NAME, UNITS, TYPE) \
 118   static int unused[sizeof (TYPE) == UNITS ? 1 : -1]    \
 119     __attribute__((unused));                            \
 120   local_##NAME (NAME, UNITS, TYPE);
 121
 122 /* As above, but performing macro expansion on the arguments.  */
 123 #define DEFINE(NAME, UNITS, TYPE) DEFINE1 (NAME, UNITS, TYPE)
 124
 125 /* Find an appropriate type TYPE for SIZE and invoke DEFINE (FN, SIZE, TYPE).
 126
 127    The types chosen here may be incorrect for some targets.
 128    For example, targets with 16-byte atomicity support might not
 129    support OImode.  We would need some kind of target-specific
 130    override if that becomes a problem.  */
 131
 132 #if SIZE == 1 && __GCC_HAVE_SYNC_COMPARE_AND_SWAP_1
 133
 134 typedef unsigned int UQItype __attribute__((mode (QI)));
 135 DEFINE (FN, 1, UQItype)
 136
 137 #elif SIZE == 2 && __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2
 138
 139 typedef unsigned int UHItype __attribute__((mode (HI)));
 140 DEFINE (FN, 2, UHItype)
 141
 142 #elif SIZE == 4 && __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4
 143
 144 typedef unsigned int USItype __attribute__((mode (SI)));
 145 DEFINE (FN, 4, USItype)
 146
 147 #elif SIZE == 8 && __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8
 148
 149 typedef unsigned int UDItype __attribute__((mode (DI)));
 150 DEFINE (FN, 8, UDItype)
 151
 152 #elif SIZE == 16 && __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16
 153
 154 typedef unsigned int UOItype __attribute__((mode (OI)));
 155 DEFINE (FN, 8, UOItype)
 156
 157 #endif
 158
 159 #elif __GCC_HAVE_SYNC_COMPARE_AND_SWAP_1 \
 160       || __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 \
 161       || __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 \
 162       || __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 \
 163       || __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16
 164
 165 #if defined Lsync_synchronize
 166
 167 void
 168 __sync_synchronize (void)
 169 {
 170   __sync_synchronize ();
 171 }
 172
 173 #endif
 174
 175 #endif