diff options
Diffstat (limited to 'erts/include/internal/gcc/ethread.h')
| -rw-r--r-- | erts/include/internal/gcc/ethread.h | 329 |
1 files changed, 320 insertions, 9 deletions
diff --git a/erts/include/internal/gcc/ethread.h b/erts/include/internal/gcc/ethread.h index 365a3535cf..be3e1da90e 100644 --- a/erts/include/internal/gcc/ethread.h +++ b/erts/include/internal/gcc/ethread.h @@ -1,7 +1,7 @@ /* * %CopyrightBegin% * - * Copyright Ericsson AB 2010-2011. All Rights Reserved. + * Copyright Ericsson AB 2010-2015. 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 @@ -18,20 +18,292 @@ */ /* - * Description: Native atomic ethread support when using gcc + * Description: Native atomic ethread support when using gcc's __atomic + * and __sync builtins * Author: Rickard Green */ -#ifndef ETHREAD_GCC_H__ -#define ETHREAD_GCC_H__ - -#if defined(ETHR_HAVE___SYNC_VAL_COMPARE_AND_SWAP32) \ - || defined(ETHR_HAVE___SYNC_VAL_COMPARE_AND_SWAP64) +#if !defined(ETHREAD_GCC_NATIVE_H__) && ETHR_GCC_COMPILER +#define ETHREAD_GCC_NATIVE_H__ #ifndef ETHR_MEMBAR # include "ethr_membar.h" #endif +#define ETHR_GCC_VERSIONS_MASK__ 28 + +#undef ETHR_GCC_VOLATILE_STORE_IS_ATOMIC_STORE__ +#undef ETHR_GCC_VOLATILE_STORE_IS_ATOMIC_STORE_RELB__ +#undef ETHR_GCC_VOLATILE_LOAD_IS_ATOMIC_LOAD__ +#undef ETHR_GCC_VOLATILE_LOAD_IS_ATOMIC_LOAD_ACQB__ +#undef ETHR_GCC_RELAXED_VERSIONS__ +#undef ETHR_GCC_RELAXED_MOD_VERSIONS__ +#undef ETHR_GCC_ACQB_VERSIONS__ +#undef ETHR_GCC_ACQB_MOD_VERSIONS__ +#undef ETHR_GCC_RELB_VERSIONS__ +#undef ETHR_GCC_RELB_MOD_VERSIONS__ +#undef ETHR_GCC_MB_MOD_VERSIONS__ + +/* + * True GNU GCCs before version 4.8 do not emit a memory barrier + * after the load in the __atomic_load_n(_, __ATOMIC_ACQUIRE) + * case (which is needed on most architectures). + */ +#undef ETHR___atomic_load_ACQUIRE_barrier_bug +#if ETHR_GCC_COMPILER != ETHR_GCC_COMPILER_TRUE +/* + * A gcc compatible compiler. We have no information + * about the existence of this bug, but we assume + * that it is not impossible that it could have + * been "inherited". Therefore, until we are certain + * that the bug does not exist, we assume that it + * does. + */ +# define ETHR___atomic_load_ACQUIRE_barrier_bug ETHR_GCC_VERSIONS_MASK__ +#elif !ETHR_AT_LEAST_GCC_VSN__(4, 8, 0) +/* True gcc of version < 4.8, i.e., bug exist... */ +# define ETHR___atomic_load_ACQUIRE_barrier_bug ETHR_GCC_VERSIONS_MASK__ +#else /* True gcc of version >= 4.8 */ +/* + * Sizes less than or equal to word size have been fixed, + * but double word size has not been fixed. + */ +# if ETHR_SIZEOF_PTR == 8 +# define ETHR___atomic_load_ACQUIRE_barrier_bug \ + (~(8|4) & ETHR_GCC_VERSIONS_MASK__) +# elif ETHR_SIZEOF_PTR == 4 +# define ETHR___atomic_load_ACQUIRE_barrier_bug \ + (~4 & ETHR_GCC_VERSIONS_MASK__) +# else +# error word size not supported +# endif +#endif + +#define ETHR_GCC_VOLATILE_STORE_IS_ATOMIC_STORE__ 0 +#define ETHR_GCC_VOLATILE_STORE_IS_ATOMIC_STORE_RELB__ 0 +#define ETHR_GCC_VOLATILE_LOAD_IS_ATOMIC_LOAD__ 0 +#define ETHR_GCC_VOLATILE_LOAD_IS_ATOMIC_LOAD_ACQB__ 0 +#define ETHR_GCC_RELAXED_VERSIONS__ ETHR_GCC_VERSIONS_MASK__ +#define ETHR_GCC_RELAXED_MOD_VERSIONS__ ETHR_GCC_VERSIONS_MASK__ + +#if ETHR_TRUST_GCC_ATOMIC_BUILTINS_MEMORY_BARRIERS +# define ETHR_GCC_ACQB_VERSIONS__ ETHR_GCC_VERSIONS_MASK__ +# define ETHR_GCC_ACQB_MOD_VERSIONS__ ETHR_GCC_VERSIONS_MASK__ +# define ETHR_GCC_RELB_VERSIONS__ ETHR_GCC_VERSIONS_MASK__ +# define ETHR_GCC_RELB_MOD_VERSIONS__ ETHR_GCC_VERSIONS_MASK__ +#else +/* + * This is currently the default (on most platforms) since + * we've seen too many memory barrier bugs produced by gcc... + */ +# define ETHR_GCC_ACQB_VERSIONS__ 0 +# define ETHR_GCC_ACQB_MOD_VERSIONS__ 0 +# define ETHR_GCC_RELB_VERSIONS__ 0 +# define ETHR_GCC_RELB_MOD_VERSIONS__ 0 +#endif +/* + * In the general case we do not want any full barrier versions + * if we can implement more relaxed ones (using __atomic_* builtins). + * This since the implementations normally need extra memory barrier + * instructions to implement these. The x86/x86_64 implementations + * are an exception see below. + */ +#define ETHR_GCC_MB_MOD_VERSIONS__ \ + (ETHR_GCC_VERSIONS_MASK__ & ~ETHR_HAVE___atomic_compare_exchange_n) + +#if ETHR_SIZEOF_PTR == 8 +# define ETHR_GCC_VOLATILE_BIT_MASK__ 12 +#elif ETHR_SIZEOF_PTR == 4 +# define ETHR_GCC_VOLATILE_BIT_MASK__ 4 +#endif + +#if defined(__i386__) || defined(__x86_64__) || defined(__sparc__) \ + || defined(__powerpc__) || defined(__ppc__) || defined(__mips__) \ + || defined(__alpha__) || defined(__ia64__) + +/* + * Aligned volatile stores and loads of data smaller + * than or equal to word size are atomic... + */ +# undef ETHR_GCC_VOLATILE_STORE_IS_ATOMIC_STORE__ +# define ETHR_GCC_VOLATILE_STORE_IS_ATOMIC_STORE__ ETHR_GCC_VOLATILE_BIT_MASK__ +# undef ETHR_GCC_VOLATILE_LOAD_IS_ATOMIC_LOAD__ +# define ETHR_GCC_VOLATILE_LOAD_IS_ATOMIC_LOAD__ ETHR_GCC_VOLATILE_BIT_MASK__ + +#elif defined(__arm__) + +/* volatile stores are problematic on some machines... */ +# undef ETHR_GCC_VOLATILE_LOAD_IS_ATOMIC_LOAD__ +# define ETHR_GCC_VOLATILE_LOAD_IS_ATOMIC_LOAD__ ETHR_GCC_VOLATILE_BIT_MASK__ + +#endif + +#if defined(__ia64__) + +/* Volatile stores produce stores with release barriers. */ +# undef ETHR_GCC_VOLATILE_STORE_IS_ATOMIC_STORE_RELB__ +# define ETHR_GCC_VOLATILE_STORE_IS_ATOMIC_STORE_RELB__ ETHR_GCC_VOLATILE_BIT_MASK__ + +/* Volatile loads produce loads with acquire barrier. */ +# undef ETHR_GCC_VOLATILE_LOAD_IS_ATOMIC_LOAD_ACQB__ +# define ETHR_GCC_VOLATILE_LOAD_IS_ATOMIC_LOAD_ACQB__ ETHR_GCC_VOLATILE_BIT_MASK__ + +/* + * We trust gcc to produce acquire/release barriers on itanium. + * Since all atomic ops also have at least acquire or release + * barriers (also when passed the relaxed memory model) it + * would be very inefficient not to use these as native + * barriers on Itanium. + */ +# undef ETHR_GCC_ACQB_VERSIONS__ +# define ETHR_GCC_ACQB_VERSIONS__ ETHR_GCC_VERSIONS_MASK__ +# undef ETHR_GCC_ACQB_MOD_VERSIONS__ +# define ETHR_GCC_ACQB_MOD_VERSIONS__ ETHR_GCC_VERSIONS_MASK__ +# undef ETHR_GCC_RELB_VERSIONS__ +# define ETHR_GCC_RELB_VERSIONS__ ETHR_GCC_VERSIONS_MASK__ +# undef ETHR_GCC_RELB_MOD_VERSIONS__ +# define ETHR_GCC_RELB_MOD_VERSIONS__ ETHR_GCC_VERSIONS_MASK__ + +/* + * Itanium is not effected by the load acquire + * bug since the barrier is part of the instruction + * on Itanium (ld.acq), and not a separate instruction + * as on most platforms. + */ +# undef ETHR___atomic_load_ACQUIRE_barrier_bug +# define ETHR___atomic_load_ACQUIRE_barrier_bug 0 + +/* + * No point exposing relaxed versions since they are + * implemended using either acquire or release + * barriers. + */ +# undef ETHR_GCC_RELAXED_VERSIONS__ +# define ETHR_GCC_RELAXED_VERSIONS__ 0 + +/* #endif defined(__ia64__) */ +#elif defined(__i386__) || defined(__x86_64__) + +/* + * Want full barrier versions of all modification + * operations since all of these are implemented + * using locked instructions implying full memory + * barriers. + */ +# undef ETHR_GCC_MB_MOD_VERSIONS__ +# define ETHR_GCC_MB_MOD_VERSIONS__ ETHR_HAVE___sync_val_compare_and_swap + +/* + * No point exposing acquire/release versions + * when we got full memory barrier versions + * of modification operations since all of these + * are implemented using locked instructions + * implying full memory barriers. + */ +# if ETHR_GCC_ACQB_MOD_VERSIONS__ +# undef ETHR_GCC_ACQB_MOD_VERSIONS__ +# define ETHR_GCC_ACQB_MOD_VERSIONS__ \ + (ETHR_GCC_VERSIONS_MASK__ & ~ETHR_HAVE___sync_val_compare_and_swap) +# endif +# if ETHR_GCC_RELB_MOD_VERSIONS__ +# undef ETHR_GCC_RELB_MOD_VERSIONS__ +# define ETHR_GCC_RELB_MOD_VERSIONS__ \ + (ETHR_GCC_VERSIONS_MASK__ & ~ETHR_HAVE___sync_val_compare_and_swap) +# endif + +# ifdef ETHR_X86_OUT_OF_ORDER + +/* See above... */ +# undef ETHR_GCC_RELAXED_MOD_VERSIONS__ +# define ETHR_GCC_RELAXED_MOD_VERSIONS__ 0 + +# else /* !ETHR_X86_OUT_OF_ORDER, i.e., we don't use any x86-OOO instructions... */ + +/* + * Not effected by the load acquire barrier bug, + * since no barrier at all is needed for a load + * acquire... + */ +# undef ETHR___atomic_load_ACQUIRE_barrier_bug +# define ETHR___atomic_load_ACQUIRE_barrier_bug 0 + +/* Stores imply release barriers semantics. */ +# undef ETHR_GCC_VOLATILE_STORE_IS_ATOMIC_STORE_RELB__ +# define ETHR_GCC_VOLATILE_STORE_IS_ATOMIC_STORE_RELB__ ETHR_GCC_VOLATILE_BIT_MASK__ + +/* Loads imply acquire barrier semantics. */ +# undef ETHR_GCC_VOLATILE_LOAD_IS_ATOMIC_LOAD_ACQB__ +# define ETHR_GCC_VOLATILE_LOAD_IS_ATOMIC_LOAD_ACQB__ ETHR_GCC_VOLATILE_BIT_MASK__ + +/* + * Trust load acquire and store release for sizes + * where volatile operation implies these barrier + * semantics since no barriers are needed. + */ +# if !ETHR_GCC_ACQB_VERSIONS__ +# undef ETHR_GCC_ACQB_VERSIONS__ +# define ETHR_GCC_ACQB_VERSIONS__ ETHR_GCC_VOLATILE_BIT_MASK__ +# endif +# if !ETHR_GCC_RELB_VERSIONS__ +# undef ETHR_GCC_RELB_VERSIONS__ +# define ETHR_GCC_RELB_VERSIONS__ ETHR_GCC_VOLATILE_BIT_MASK__ +# endif + +/* + * No point exposing relaxed versions at all since + * all mod operations are implemented with locked + * instructions implying full memory barriers and + * volatile store and load imply release and + * acquire barrier semantics. + */ +# undef ETHR_GCC_RELAXED_VERSIONS__ +# define ETHR_GCC_RELAXED_VERSIONS__ 0 + +# endif /* !ETHR_X86_OUT_OF_ORDER */ + +/* #endif defined(__i386__) || defined(__x86_64__) */ +#elif defined(__powerpc__) || defined(__ppc__) + +# if !defined(ETHR_PPC_HAVE_LWSYNC) +/* + * Release barriers are typically implemented using + * the lwsync instruction. We want our runtime + * configure test to determine if the lwsync + * instruction is available on the system or not + * before we use it. Therefore, do not implement any + * native ops using the __ATOMIC_RELEASE model. + */ +# undef ETHR_GCC_RELB_VERSIONS__ +# define ETHR_GCC_RELB_VERSIONS__ 0 +# if defined(ETHR_GCC_IMPLEMENT_ACQB_USING_LWSYNC) +/* + * Acquire barriers are usually implemented by other means + * than lwsync, but can be implemented using lwsync. Define + * ETHR_GCC_IMPLEMENT_ACQB_USING_LWSYNC if acquire barriers + * are implemented using lwsync. + */ +# undef ETHR_GCC_ACQB_VERSIONS__ +# define ETHR_GCC_ACQB_VERSIONS__ 0 +# endif +# endif + +#endif /* defined(__powerpc__) || defined(__ppc__) */ + +#if !ETHR_GCC_RELAXED_VERSIONS__ +# undef ETHR_GCC_RELAXED_MOD_VERSIONS__ +# define ETHR_GCC_RELAXED_MOD_VERSIONS__ 0 +#endif + +#if !ETHR_GCC_ACQB_VERSIONS__ +# undef ETHR_GCC_ACQB_MOD_VERSIONS__ +# define ETHR_GCC_ACQB_MOD_VERSIONS__ 0 +#endif + +#if !ETHR_GCC_RELB_VERSIONS__ +# undef ETHR_GCC_RELB_MOD_VERSIONS__ +# define ETHR_GCC_RELB_MOD_VERSIONS__ 0 +#endif + #if !defined(ETHR_HAVE_NATIVE_ATOMIC32) # define ETHR_ATOMIC_WANT_32BIT_IMPL__ # include "ethr_atomic.h" @@ -42,12 +314,51 @@ # include "ethr_atomic.h" #endif +#if defined(__x86_64__) +/* + * No instructions available for native implementation + * of these for dw-atomics... + */ +# undef ETHR_GCC_RELAXED_VERSIONS__ +# define ETHR_GCC_RELAXED_VERSIONS__ 0 +# undef ETHR_GCC_ACQB_VERSIONS__ +# define ETHR_GCC_ACQB_VERSIONS__ 0 +# undef ETHR_GCC_RELB_VERSIONS__ +# define ETHR_GCC_RELB_VERSIONS__ 0 +#endif + +#if !ETHR_GCC_RELAXED_VERSIONS__ +# undef ETHR_GCC_RELAXED_MOD_VERSIONS__ +# define ETHR_GCC_RELAXED_MOD_VERSIONS__ 0 +#endif + +#if !ETHR_GCC_ACQB_VERSIONS__ +# undef ETHR_GCC_ACQB_MOD_VERSIONS__ +# define ETHR_GCC_ACQB_MOD_VERSIONS__ 0 +#endif + +#if !ETHR_GCC_RELB_VERSIONS__ +# undef ETHR_GCC_RELB_MOD_VERSIONS__ +# define ETHR_GCC_RELB_MOD_VERSIONS__ 0 +#endif + #if (!defined(ETHR_HAVE_NATIVE_DW_ATOMIC) \ && !(ETHR_SIZEOF_PTR == 4 && defined(ETHR_HAVE_NATIVE_ATOMIC64)) \ && !(ETHR_SIZEOF_PTR == 8 && defined(ETHR_HAVE_NATIVE_ATOMIC128))) # include "ethr_dw_atomic.h" #endif -#endif +#undef ETHR___atomic_load_ACQUIRE_barrier_bug +#undef ETHR_GCC_VOLATILE_STORE_IS_ATOMIC_STORE__ +#undef ETHR_GCC_VOLATILE_STORE_IS_ATOMIC_STORE_RELB__ +#undef ETHR_GCC_VOLATILE_LOAD_IS_ATOMIC_LOAD__ +#undef ETHR_GCC_VOLATILE_LOAD_IS_ATOMIC_LOAD_ACQB__ +#undef ETHR_GCC_RELAXED_VERSIONS__ +#undef ETHR_GCC_RELB_VERSIONS__ +#undef ETHR_GCC_RELB_VERSIONS__ +#undef ETHR_GCC_RELAXED_MOD_VERSIONS__ +#undef ETHR_GCC_ACQB_MOD_VERSIONS__ +#undef ETHR_GCC_RELB_MOD_VERSIONS__ +#undef ETHR_GCC_MB_MOD_VERSIONS__ -#endif +#endif /* ETHREAD_GCC_NATIVE_H__ */ |