diff options
Diffstat (limited to 'erts/include/internal/gcc/ethr_dw_atomic.h')
| -rw-r--r-- | erts/include/internal/gcc/ethr_dw_atomic.h | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/erts/include/internal/gcc/ethr_dw_atomic.h b/erts/include/internal/gcc/ethr_dw_atomic.h new file mode 100644 index 0000000000..6736f9c547 --- /dev/null +++ b/erts/include/internal/gcc/ethr_dw_atomic.h @@ -0,0 +1,115 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson AB 2011. All Rights Reserved. + * + * The contents of this file are subject to the Erlang Public License, + * Version 1.1, (the "License"); you may not use this file except in + * compliance with the License. You should have received a copy of the + * Erlang Public License along with this software. If not, it can be + * retrieved online at http://www.erlang.org/. + * + * Software distributed under the License is distributed on an "AS IS" + * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See + * the License for the specific language governing rights and limitations + * under the License. + * + * %CopyrightEnd% + */ + +/* + * Description: Native double word atomics using gcc's builtins + * Author: Rickard Green + */ + +#undef ETHR_INCLUDE_DW_ATOMIC_IMPL__ +#ifndef ETHR_GCC_DW_ATOMIC_H__ +# define ETHR_GCC_DW_ATOMIC_H__ +# if ((ETHR_SIZEOF_PTR == 4 \ + && defined(ETHR_HAVE___SYNC_VAL_COMPARE_AND_SWAP64)) \ + || (ETHR_SIZEOF_PTR == 8 \ + && defined(ETHR_HAVE___SYNC_VAL_COMPARE_AND_SWAP128) \ + && defined(ETHR_HAVE_INT128_T))) +# define ETHR_INCLUDE_DW_ATOMIC_IMPL__ +# endif +#endif + +#ifdef ETHR_INCLUDE_DW_ATOMIC_IMPL__ +# define ETHR_HAVE_NATIVE_SU_DW_ATOMIC +# define ETHR_NATIVE_DW_ATOMIC_IMPL "gcc" + +# if defined(__i386__) || defined(__x86_64__) +/* + * If ETHR_RTCHK_USE_NATIVE_DW_ATOMIC_IMPL__ is defined, it will be used + * at runtime in order to determine if native or fallback implementation + * should be used. + */ +# define ETHR_RTCHK_USE_NATIVE_DW_ATOMIC_IMPL__ \ + ETHR_X86_RUNTIME_CONF_HAVE_DW_CMPXCHG__ +# endif + +# if ETHR_SIZEOF_PTR == 4 +# define ETHR_DW_NATMC_ALIGN_MASK__ 0x7 +# define ETHR_NATIVE_SU_DW_SINT_T ethr_sint64_t +# elif ETHR_SIZEOF_PTR == 8 +# define ETHR_DW_NATMC_ALIGN_MASK__ 0xf +# define ETHR_NATIVE_SU_DW_SINT_T ethr_sint128_t +# endif + +typedef volatile ETHR_NATIVE_SU_DW_SINT_T * ethr_native_dw_ptr_t; + +/* + * We need 16 byte aligned memory in 64-bit mode, and 8 byte aligned + * memory in 32-bit mode. 16 byte aligned malloc in 64-bit mode is + * not common, and at least some glibc malloc implementations + * only 4 byte align in 32-bit mode. + * + * This code assumes 8 byte aligned memory in 64-bit mode, and 4 byte + * aligned memory in 32-bit mode. A malloc implementation that does + * not adhere to these alignment requirements is seriously broken, + * and we wont bother trying to work around it. + * + * Since memory alignment may be off by one word we need to align at + * runtime. We, therefore, need an extra word allocated. + */ +#define ETHR_DW_NATMC_MEM__(VAR) \ + (&var->c[(int) ((ethr_uint_t) &(VAR)->c[0]) & ETHR_DW_NATMC_ALIGN_MASK__]) +typedef union { + volatile ETHR_NATIVE_SU_DW_SINT_T dw_sint; + volatile ethr_sint_t sint[3]; + volatile char c[ETHR_SIZEOF_PTR*3]; +} ethr_native_dw_atomic_t; + +#if defined(ETHR_TRY_INLINE_FUNCS) || defined(ETHR_ATOMIC_IMPL__) + +# ifdef ETHR_DEBUG +# define ETHR_DW_DBG_ALIGNED__(PTR) \ + ETHR_ASSERT((((ethr_uint_t) (PTR)) & ETHR_DW_NATMC_ALIGN_MASK__) == 0); +# else +# define ETHR_DW_DBG_ALIGNED__(PTR) +# endif + +#define ETHR_HAVE_ETHR_NATIVE_DW_ATOMIC_ADDR +static ETHR_INLINE ethr_sint_t * +ethr_native_dw_atomic_addr(ethr_native_dw_atomic_t *var) +{ + return (ethr_sint_t *) ETHR_DW_NATMC_MEM__(var); +} + + +#define ETHR_HAVE_ETHR_NATIVE_SU_DW_ATOMIC_CMPXCHG_MB + +static ETHR_INLINE ETHR_NATIVE_SU_DW_SINT_T +ethr_native_su_dw_atomic_cmpxchg_mb(ethr_native_dw_atomic_t *var, + ETHR_NATIVE_SU_DW_SINT_T new, + ETHR_NATIVE_SU_DW_SINT_T old) +{ + ethr_native_dw_ptr_t p = (ethr_native_dw_ptr_t) ETHR_DW_NATMC_MEM__(var); + ETHR_DW_DBG_ALIGNED__(p); + return __sync_val_compare_and_swap(p, old, new); +} + +#endif /* ETHR_TRY_INLINE_FUNCS */ + +#endif /* ETHR_GCC_DW_ATOMIC_H__ */ + |