diff options
Diffstat (limited to 'libatomic/gcas.c')
| -rw-r--r-- | libatomic/gcas.c | 120 |
1 files changed, 0 insertions, 120 deletions
diff --git a/libatomic/gcas.c b/libatomic/gcas.c deleted file mode 100644 index 63a06c3def..0000000000 --- a/libatomic/gcas.c +++ /dev/null @@ -1,120 +0,0 @@ -/* Copyright (C) 2012-2017 Free Software Foundation, Inc. - Contributed by Richard Henderson <rth@redhat.com>. - - This file is part of the GNU Atomic Library (libatomic). - - Libatomic is free software; you can redistribute it and/or modify it - under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 3 of the License, or - (at your option) any later version. - - Libatomic is distributed in the hope that it will be useful, but WITHOUT ANY - WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS - FOR A PARTICULAR PURPOSE. See the GNU General Public License for - more details. - - Under Section 7 of GPL version 3, you are granted additional - permissions described in the GCC Runtime Library Exception, version - 3.1, as published by the Free Software Foundation. - - You should have received a copy of the GNU General Public License and - a copy of the GCC Runtime Library Exception along with this program; - see the files COPYING3 and COPYING.RUNTIME respectively. If not, see - <http://www.gnu.org/licenses/>. */ - -#include "libatomic_i.h" - - -/* If we natively support the cas, and if we're unconcerned with extra - barriers (e.g. fully in-order cpu for which barriers are a nop), then - go ahead and expand the operation inline. */ -#if !defined(WANT_SPECIALCASE_RELAXED) && !defined(__OPTIMIZE_SIZE__) -# define EXACT_INLINE(N) \ - if (C2(HAVE_ATOMIC_CAS_,N)) \ - return __atomic_compare_exchange_n \ - (PTR(N,mptr), PTR(N,eptr), *PTR(N,dptr), false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST) -#else -# define EXACT_INLINE(N) -#endif - -/* ... and if all that fails, invoke the function we generated elsewhere. - Worst case, this will *also* use locks. */ -#define EXACT(N) \ - do { \ - if (!C2(HAVE_INT,N)) break; \ - if ((uintptr_t)mptr & (N - 1)) break; \ - EXACT_INLINE (N); \ - return C3(local_,compare_exchange_,N) \ - (PTR(N,mptr), PTR(N,eptr), *PTR(N,dptr), smodel, fmodel); \ - } while (0) - -#define LARGER(N) \ - do { \ - if (!C2(HAVE_INT,N)) break; \ - if (!C2(HAVE_ATOMIC_LDST_,N)) break; \ - if (!C2(MAYBE_HAVE_ATOMIC_CAS_,N)) break; \ - r = (uintptr_t)mptr & (N - 1); \ - a = (uintptr_t)mptr & -N; \ - if (r + n <= N) \ - { \ - pre_barrier (smodel); \ - u.C2(i,N) = __atomic_load_n (PTR(N,a), __ATOMIC_RELAXED); \ - do { \ - if (memcmp (u.b + r, eptr, n) != 0) goto Lfail; \ - v = u; memcpy (v.b + r, dptr, n); \ - } while (!(C2(HAVE_ATOMIC_CAS_,N) \ - ? __atomic_compare_exchange_n (PTR(N,a), \ - &u.C2(i,N), v.C2(i,N), true, \ - __ATOMIC_RELAXED, __ATOMIC_RELAXED) \ - : C3(local_,compare_exchange_,N) (PTR(N,a), \ - &u.C2(i,N), v.C2(i,N), \ - __ATOMIC_RELAXED, __ATOMIC_RELAXED))); \ - goto Lsucc; \ - } \ - } while (0) - - - -bool -libat_compare_exchange (size_t n, void *mptr, void *eptr, void *dptr, - int smodel, int fmodel) -{ - union max_size_u u, v; - uintptr_t r, a; - bool ret; - - switch (n) - { - case 0: return true; - case 1: EXACT(1); goto L4; - case 2: EXACT(2); goto L4; - case 4: EXACT(4); goto L8; - case 8: EXACT(8); goto L16; - case 16: EXACT(16); break; - - case 3: L4: LARGER(4); /* FALLTHRU */ - case 5 ... 7: L8: LARGER(8); /* FALLTHRU */ - case 9 ... 15: L16: LARGER(16); break; - - Lsucc: - post_barrier (smodel); - return true; - Lfail: - post_barrier (fmodel); - memcpy (eptr, u.b + r, n); - return false; - } - - pre_seq_barrier (smodel); - libat_lock_n (mptr, n); - - ret = memcmp (mptr, eptr, n) == 0; - memcpy ((ret ? mptr : eptr), (ret ? dptr : mptr), n); - - libat_unlock_n (mptr, n); - post_seq_barrier (ret ? smodel : fmodel); - - return ret; -} - -EXPORT_ALIAS (compare_exchange); |