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Diffstat (limited to 'src/third_party/mozjs-60/extract/js/src/jit/none/AtomicOperations-feeling-lucky.h')
| -rw-r--r-- | src/third_party/mozjs-60/extract/js/src/jit/none/AtomicOperations-feeling-lucky.h | 463 |
1 files changed, 463 insertions, 0 deletions
diff --git a/src/third_party/mozjs-60/extract/js/src/jit/none/AtomicOperations-feeling-lucky.h b/src/third_party/mozjs-60/extract/js/src/jit/none/AtomicOperations-feeling-lucky.h new file mode 100644 index 00000000000..da5722843bf --- /dev/null +++ b/src/third_party/mozjs-60/extract/js/src/jit/none/AtomicOperations-feeling-lucky.h @@ -0,0 +1,463 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- + * vim: set ts=8 sts=4 et sw=4 tw=99: + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/* For documentation, see jit/AtomicOperations.h, both the comment block at the + * beginning and the #ifdef nest near the end. + * + * This is a common file for tier-3 platforms that are not providing + * hardware-specific implementations of the atomic operations. Please keep it + * reasonably platform-independent by adding #ifdefs at the beginning as much as + * possible, not throughout the file. + * + * + * !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + * !!!! NOTE !!!! + * !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + * + * The implementations in this file are NOT SAFE and cannot be safe even in + * principle because they rely on C++ undefined behavior. However, they are + * frequently good enough for tier-3 platforms. + */ + +#ifndef jit_none_AtomicOperations_feeling_lucky_h +#define jit_none_AtomicOperations_feeling_lucky_h + +#include "mozilla/Assertions.h" +#include "mozilla/Types.h" + +// 64-bit atomics are not required by the JS spec, and you can compile +// SpiderMonkey without them. +// +// 64-bit lock-free atomics are however required for WebAssembly, and +// WebAssembly will be disabled if you do not define both HAS_64BIT_ATOMICS and +// HAS_64BIT_LOCKFREE. +// +// If you are only able to provide 64-bit non-lock-free atomics and you really +// want WebAssembly support you can always just lie about the lock-freedom. +// After all, you're already feeling lucky. + +#if defined(__ppc__) || defined(__PPC__) +# define GNUC_COMPATIBLE +#endif + +#if defined(__ppc64__) || defined (__PPC64__) || defined(__ppc64le__) || defined (__PPC64LE__) +# define HAS_64BIT_ATOMICS +# define HAS_64BIT_LOCKFREE +# define GNUC_COMPATIBLE +#endif + +#ifdef __sparc__ +# define GNUC_COMPATIBLE +# ifdef __LP64__ +# define HAS_64BIT_ATOMICS +# define HAS_64BIT_LOCKFREE +# endif +#endif + +#ifdef __alpha__ +# define GNUC_COMPATIBLE +#endif + +#ifdef __hppa__ +# define GNUC_COMPATIBLE +#endif + +#ifdef __sh__ +# define GNUC_COMPATIBLE +#endif + +#ifdef __s390__ +# define GNUC_COMPATIBLE +#endif + +#ifdef __s390x__ +# define HAS_64BIT_ATOMICS +# define HAS_64BIT_LOCKFREE +# define GNUC_COMPATIBLE +#endif + +// The default implementation tactic for gcc/clang is to use the newer +// __atomic intrinsics added for use in C++11 <atomic>. Where that +// isn't available, we use GCC's older __sync functions instead. +// +// ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS is kept as a backward +// compatible option for older compilers: enable this to use GCC's old +// __sync functions instead of the newer __atomic functions. This +// will be required for GCC 4.6.x and earlier, and probably for Clang +// 3.1, should we need to use those versions. + +//#define ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS + +// Sanity check. + +#if defined(HAS_64BIT_LOCKFREE) && !defined(HAS_64BIT_ATOMICS) +# error "This combination of features is senseless, please fix" +#endif + +// Try to avoid platform #ifdefs below this point. + +#ifdef GNUC_COMPATIBLE + +inline bool +js::jit::AtomicOperations::hasAtomic8() +{ +#if defined(HAS_64BIT_ATOMICS) + return true; +#else + return false; +#endif +} + +inline bool +js::jit::AtomicOperations::isLockfree8() +{ +#if defined(HAS_64BIT_LOCKFREE) + return true; +#else + return false; +#endif +} + +inline void +js::jit::AtomicOperations::fenceSeqCst() +{ +# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS + __sync_synchronize(); +# else + __atomic_thread_fence(__ATOMIC_SEQ_CST); +# endif +} + +template<typename T> +inline T +js::jit::AtomicOperations::loadSeqCst(T* addr) +{ + static_assert(sizeof(T) <= 8, "atomics supported up to 8 bytes only"); +# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS + __sync_synchronize(); + T v = *addr; + __sync_synchronize(); +# else + T v; + __atomic_load(addr, &v, __ATOMIC_SEQ_CST); +# endif + return v; +} + +#ifndef HAS_64BIT_ATOMICS +namespace js { namespace jit { + +template<> +inline int64_t +AtomicOperations::loadSeqCst(int64_t* addr) { + MOZ_CRASH("No 64-bit atomics"); +} + +template<> +inline uint64_t +AtomicOperations::loadSeqCst(uint64_t* addr) { + MOZ_CRASH("No 64-bit atomics"); +} + +} } +#endif + +template<typename T> +inline void +js::jit::AtomicOperations::storeSeqCst(T* addr, T val) +{ + static_assert(sizeof(T) <= 8, "atomics supported up to 8 bytes only"); +# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS + __sync_synchronize(); + *addr = val; + __sync_synchronize(); +# else + __atomic_store(addr, &val, __ATOMIC_SEQ_CST); +# endif +} + +#ifndef HAS_64BIT_ATOMICS +namespace js { namespace jit { + +template<> +inline void +AtomicOperations::storeSeqCst(int64_t* addr, int64_t val) { + MOZ_CRASH("No 64-bit atomics"); +} + +template<> +inline void +AtomicOperations::storeSeqCst(uint64_t* addr, uint64_t val) { + MOZ_CRASH("No 64-bit atomics"); +} + +} } +#endif + +template<typename T> +inline T +js::jit::AtomicOperations::compareExchangeSeqCst(T* addr, T oldval, T newval) +{ + static_assert(sizeof(T) <= 8, "atomics supported up to 8 bytes only"); +# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS + return __sync_val_compare_and_swap(addr, oldval, newval); +# else + __atomic_compare_exchange(addr, &oldval, &newval, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST); + return oldval; +# endif +} + +#ifndef HAS_64BIT_ATOMICS +namespace js { namespace jit { + +template<> +inline int64_t +AtomicOperations::compareExchangeSeqCst(int64_t* addr, int64_t oldval, int64_t newval) { + MOZ_CRASH("No 64-bit atomics"); +} + +template<> +inline uint64_t +AtomicOperations::compareExchangeSeqCst(uint64_t* addr, uint64_t oldval, uint64_t newval) { + MOZ_CRASH("No 64-bit atomics"); +} + +} } +#endif + +template<typename T> +inline T +js::jit::AtomicOperations::fetchAddSeqCst(T* addr, T val) +{ + static_assert(sizeof(T) <= 8, "atomics supported up to 8 bytes only"); +# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS + return __sync_fetch_and_add(addr, val); +# else + return __atomic_fetch_add(addr, val, __ATOMIC_SEQ_CST); +# endif +} + +#ifndef HAS_64BIT_ATOMICS +namespace js { namespace jit { + +template<> +inline int64_t +AtomicOperations::fetchAddSeqCst(int64_t* addr, int64_t val) { + MOZ_CRASH("No 64-bit atomics"); +} + +template<> +inline uint64_t +AtomicOperations::fetchAddSeqCst(uint64_t* addr, uint64_t val) { + MOZ_CRASH("No 64-bit atomics"); +} + +} } +#endif + +template<typename T> +inline T +js::jit::AtomicOperations::fetchSubSeqCst(T* addr, T val) +{ + static_assert(sizeof(T) <= 8, "atomics supported up to 8 bytes only"); +# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS + return __sync_fetch_and_sub(addr, val); +# else + return __atomic_fetch_sub(addr, val, __ATOMIC_SEQ_CST); +# endif +} + +#ifndef HAS_64BIT_ATOMICS +namespace js { namespace jit { + +template<> +inline int64_t +AtomicOperations::fetchSubSeqCst(int64_t* addr, int64_t val) { + MOZ_CRASH("No 64-bit atomics"); +} + +template<> +inline uint64_t +AtomicOperations::fetchSubSeqCst(uint64_t* addr, uint64_t val) { + MOZ_CRASH("No 64-bit atomics"); +} + +} } +#endif + +template<typename T> +inline T +js::jit::AtomicOperations::fetchAndSeqCst(T* addr, T val) +{ + static_assert(sizeof(T) <= 8, "atomics supported up to 8 bytes only"); +# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS + return __sync_fetch_and_and(addr, val); +# else + return __atomic_fetch_and(addr, val, __ATOMIC_SEQ_CST); +# endif +} + +#ifndef HAS_64BIT_ATOMICS +namespace js { namespace jit { + +template<> +inline int64_t +AtomicOperations::fetchAndSeqCst(int64_t* addr, int64_t val) { + MOZ_CRASH("No 64-bit atomics"); +} + +template<> +inline uint64_t +AtomicOperations::fetchAndSeqCst(uint64_t* addr, uint64_t val) { + MOZ_CRASH("No 64-bit atomics"); +} + +} } +#endif + +template<typename T> +inline T +js::jit::AtomicOperations::fetchOrSeqCst(T* addr, T val) +{ + static_assert(sizeof(T) <= 8, "atomics supported up to 8 bytes only"); +# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS + return __sync_fetch_and_or(addr, val); +# else + return __atomic_fetch_or(addr, val, __ATOMIC_SEQ_CST); +# endif +} + +#ifndef HAS_64BIT_ATOMICS +namespace js { namespace jit { + +template<> +inline int64_t +AtomicOperations::fetchOrSeqCst(int64_t* addr, int64_t val) { + MOZ_CRASH("No 64-bit atomics"); +} + +template<> +inline uint64_t +AtomicOperations::fetchOrSeqCst(uint64_t* addr, uint64_t val) { + MOZ_CRASH("No 64-bit atomics"); +} + +} } +#endif + +template<typename T> +inline T +js::jit::AtomicOperations::fetchXorSeqCst(T* addr, T val) +{ + static_assert(sizeof(T) <= 8, "atomics supported up to 8 bytes only"); +# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS + return __sync_fetch_and_xor(addr, val); +# else + return __atomic_fetch_xor(addr, val, __ATOMIC_SEQ_CST); +# endif +} + +#ifndef HAS_64BIT_ATOMICS +namespace js { namespace jit { + +template<> +inline int64_t +AtomicOperations::fetchXorSeqCst(int64_t* addr, int64_t val) { + MOZ_CRASH("No 64-bit atomics"); +} + +template<> +inline uint64_t +AtomicOperations::fetchXorSeqCst(uint64_t* addr, uint64_t val) { + MOZ_CRASH("No 64-bit atomics"); +} + +} } +#endif + +template<typename T> +inline T +js::jit::AtomicOperations::loadSafeWhenRacy(T* addr) +{ + static_assert(sizeof(T) <= 8, "atomics supported up to 8 bytes only"); + // This is actually roughly right even on 32-bit platforms since in that + // case, double, int64, and uint64 loads need not be access-atomic. + return *addr; +} + +template<typename T> +inline void +js::jit::AtomicOperations::storeSafeWhenRacy(T* addr, T val) +{ + static_assert(sizeof(T) <= 8, "atomics supported up to 8 bytes only"); + // This is actually roughly right even on 32-bit platforms since in that + // case, double, int64, and uint64 loads need not be access-atomic. + *addr = val; +} + +inline void +js::jit::AtomicOperations::memcpySafeWhenRacy(void* dest, const void* src, size_t nbytes) +{ + MOZ_ASSERT(!((char*)dest <= (char*)src && (char*)src < (char*)dest+nbytes)); + MOZ_ASSERT(!((char*)src <= (char*)dest && (char*)dest < (char*)src+nbytes)); + ::memcpy(dest, src, nbytes); +} + +inline void +js::jit::AtomicOperations::memmoveSafeWhenRacy(void* dest, const void* src, size_t nbytes) +{ + ::memmove(dest, src, nbytes); +} + +template<typename T> +inline T +js::jit::AtomicOperations::exchangeSeqCst(T* addr, T val) +{ + static_assert(sizeof(T) <= 8, "atomics supported up to 8 bytes only"); +# ifdef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS + T v; + __sync_synchronize(); + do { + v = *addr; + } while (__sync_val_compare_and_swap(addr, v, val) != v); + return v; +# else + T v; + __atomic_exchange(addr, &val, &v, __ATOMIC_SEQ_CST); + return v; +# endif +} + +#ifndef HAS_64BIT_ATOMICS +namespace js { namespace jit { + +template<> +inline int64_t +AtomicOperations::exchangeSeqCst(int64_t* addr, int64_t val) { + MOZ_CRASH("No 64-bit atomics"); +} + +template<> +inline uint64_t +AtomicOperations::exchangeSeqCst(uint64_t* addr, uint64_t val) { + MOZ_CRASH("No 64-bit atomics"); +} + +} } +#endif + +#elif defined(ENABLE_SHARED_ARRAY_BUFFER) + +# error "Either disable JS shared memory, use GCC or Clang, or add code here" + +#endif + +#undef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS +#undef GNUC_COMPATIBLE +#undef HAS_64BIT_ATOMICS +#undef HAS_64BIT_LOCKFREE + +#endif // jit_none_AtomicOperations_feeling_lucky_h |