Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 453 insertions, 0 deletions

diff --git a/js/src/jit/shared/AtomicOperations-feeling-lucky-gcc.h b/js/src/jit/shared/AtomicOperations-feeling-lucky-gcc.h
new file mode 100644
index 0000000000..d4bf3430ff
--- /dev/null
+++ b/js/src/jit/shared/AtomicOperations-feeling-lucky-gcc.h
@@ -0,0 +1,453 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * 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 (including simulators for our
+ * tier-1 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_shared_AtomicOperations_feeling_lucky_gcc_h
+#define jit_shared_AtomicOperations_feeling_lucky_gcc_h
+
+#include "mozilla/Assertions.h"
+#include "mozilla/Types.h"
+
+// Explicitly exclude tier-1 platforms.
+
+#if (defined(__x86_64__) || defined(_M_X64) || defined(__i386__) || \
+     defined(_M_IX86) || (defined(__arm__) && __ARM_ARCH >= 7) ||   \
+     defined(__aarch64__))
+#  error "Do not use on a tier-1 platform where inline assembly is available"
+#endif
+
+#if !(defined(__clang__) || defined(__GNUC__))
+#  error "This file only for gcc/Clang"
+#endif
+
+// 64-bit atomics are not required by the JS spec, and you can compile
+// SpiderMonkey without them. 64-bit atomics are required for BigInt
+// support.
+//
+// 64-bit lock-free atomics are required for WebAssembly, but gating in the
+// WebAssembly subsystem ensures that no WebAssembly-supporting platforms need
+// code in this file.
+
+#if defined(JS_SIMULATOR_ARM64) || defined(JS_SIMULATOR_ARM) || \
+    defined(JS_SIMULATOR_MIPS64) || defined(JS_SIMULATOR_LOONG64)
+// On some x86 (32-bit) systems this will not work because the compiler does not
+// open-code 64-bit atomics.  If so, try linking with -latomic.  If that doesn't
+// work, you're mostly on your own.
+#  define HAS_64BIT_ATOMICS
+#  define HAS_64BIT_LOCKFREE
+#endif
+
+#if defined(__arm__)
+#  define HAS_64BIT_ATOMICS
+#endif
+
+#if defined(__ppc64__) || defined(__PPC64__) || defined(__ppc64le__) || \
+    defined(__PPC64LE__)
+#  define HAS_64BIT_ATOMICS
+#  define HAS_64BIT_LOCKFREE
+#endif
+
+#if defined(__riscv) && __riscv_xlen == 64
+#  define HAS_64BIT_ATOMICS
+#  define HAS_64BIT_LOCKFREE
+#endif
+
+#if defined(__loongarch64)
+#  define HAS_64BIT_ATOMICS
+#  define HAS_64BIT_LOCKFREE
+#endif
+
+#ifdef __sparc__
+#  ifdef __LP64__
+#    define HAS_64BIT_ATOMICS
+#    define HAS_64BIT_LOCKFREE
+#  endif
+#endif
+
+#ifdef JS_CODEGEN_NONE
+#  ifdef JS_64BIT
+#    define HAS_64BIT_ATOMICS
+#    define HAS_64BIT_LOCKFREE
+#  endif
+#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.  Firefox no longer supports compilers that old.
+
+// #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.
+
+// When compiling with Clang on 32-bit linux it will be necessary to link with
+// -latomic to get the proper 64-bit intrinsics.
+
+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");
+}
+
+}  // namespace jit
+}  // namespace js
+#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");
+}
+
+}  // namespace jit
+}  // namespace js
+#endif
+
+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");
+}
+
+}  // namespace jit
+}  // namespace js
+#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");
+}
+
+}  // namespace jit
+}  // namespace js
+#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");
+}
+
+}  // namespace jit
+}  // namespace js
+#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");
+}
+
+}  // namespace jit
+}  // namespace js
+#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");
+}
+
+}  // namespace jit
+}  // namespace js
+#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");
+}
+
+}  // namespace jit
+}  // namespace js
+#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");
+}
+
+}  // namespace jit
+}  // namespace js
+#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.
+  //
+  // We could use __atomic_load, but it would be needlessly expensive on
+  // 32-bit platforms that could support it and just plain wrong on others.
+  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.
+  //
+  // We could use __atomic_store, but it would be needlessly expensive on
+  // 32-bit platforms that could support it and just plain wrong on others.
+  *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);
+}
+
+#undef ATOMICS_IMPLEMENTED_WITH_SYNC_INTRINSICS
+#undef HAS_64BIT_ATOMICS
+#undef HAS_64BIT_LOCKFREE
+
+#endif  // jit_shared_AtomicOperations_feeling_lucky_gcc_h