diff libsanitizer/sanitizer_common/sanitizer_atomic_clang_other.h @ 111:04ced10e8804

gcc 7
author kono
date Fri, 27 Oct 2017 22:46:09 +0900
parents
children 84e7813d76e9
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libsanitizer/sanitizer_common/sanitizer_atomic_clang_other.h	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,159 @@
+//===-- sanitizer_atomic_clang_other.h --------------------------*- C++ -*-===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of ThreadSanitizer/AddressSanitizer runtime.
+// Not intended for direct inclusion. Include sanitizer_atomic.h.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SANITIZER_ATOMIC_CLANG_OTHER_H
+#define SANITIZER_ATOMIC_CLANG_OTHER_H
+
+namespace __sanitizer {
+
+// MIPS32 does not support atomic > 4 bytes. To address this lack of
+// functionality, the sanitizer library provides helper methods which use an
+// internal spin lock mechanism to emulate atomic oprations when the size is
+// 8 bytes.
+#if defined(_MIPS_SIM) && _MIPS_SIM == _ABIO32
+static void __spin_lock(volatile int *lock) {
+  while (__sync_lock_test_and_set(lock, 1))
+    while (*lock) {
+    }
+}
+
+static void __spin_unlock(volatile int *lock) { __sync_lock_release(lock); }
+
+
+// Make sure the lock is on its own cache line to prevent false sharing.
+// Put it inside a struct that is aligned and padded to the typical MIPS
+// cacheline which is 32 bytes.
+static struct {
+  int lock;
+  char pad[32 - sizeof(int)];
+} __attribute__((aligned(32))) lock = {0};
+
+template <class T>
+T __mips_sync_fetch_and_add(volatile T *ptr, T val) {
+  T ret;
+
+  __spin_lock(&lock.lock);
+
+  ret = *ptr;
+  *ptr = ret + val;
+
+  __spin_unlock(&lock.lock);
+
+  return ret;
+}
+
+template <class T>
+T __mips_sync_val_compare_and_swap(volatile T *ptr, T oldval, T newval) {
+  T ret;
+  __spin_lock(&lock.lock);
+
+  ret = *ptr;
+  if (ret == oldval) *ptr = newval;
+
+  __spin_unlock(&lock.lock);
+
+  return ret;
+}
+#endif
+
+INLINE void proc_yield(int cnt) {
+  __asm__ __volatile__("" ::: "memory");
+}
+
+template<typename T>
+INLINE typename T::Type atomic_load(
+    const volatile T *a, memory_order mo) {
+  DCHECK(mo & (memory_order_relaxed | memory_order_consume
+      | memory_order_acquire | memory_order_seq_cst));
+  DCHECK(!((uptr)a % sizeof(*a)));
+  typename T::Type v;
+
+  if (sizeof(*a) < 8 || sizeof(void*) == 8) {
+    // Assume that aligned loads are atomic.
+    if (mo == memory_order_relaxed) {
+      v = a->val_dont_use;
+    } else if (mo == memory_order_consume) {
+      // Assume that processor respects data dependencies
+      // (and that compiler won't break them).
+      __asm__ __volatile__("" ::: "memory");
+      v = a->val_dont_use;
+      __asm__ __volatile__("" ::: "memory");
+    } else if (mo == memory_order_acquire) {
+      __asm__ __volatile__("" ::: "memory");
+      v = a->val_dont_use;
+      __sync_synchronize();
+    } else {  // seq_cst
+      // E.g. on POWER we need a hw fence even before the store.
+      __sync_synchronize();
+      v = a->val_dont_use;
+      __sync_synchronize();
+    }
+  } else {
+    // 64-bit load on 32-bit platform.
+    // Gross, but simple and reliable.
+    // Assume that it is not in read-only memory.
+#if defined(_MIPS_SIM) && _MIPS_SIM == _ABIO32
+    typename T::Type volatile *val_ptr =
+        const_cast<typename T::Type volatile *>(&a->val_dont_use);
+    v = __mips_sync_fetch_and_add<u64>(
+        reinterpret_cast<u64 volatile *>(val_ptr), 0);
+#else
+    v = __sync_fetch_and_add(
+        const_cast<typename T::Type volatile *>(&a->val_dont_use), 0);
+#endif
+  }
+  return v;
+}
+
+template<typename T>
+INLINE void atomic_store(volatile T *a, typename T::Type v, memory_order mo) {
+  DCHECK(mo & (memory_order_relaxed | memory_order_release
+      | memory_order_seq_cst));
+  DCHECK(!((uptr)a % sizeof(*a)));
+
+  if (sizeof(*a) < 8 || sizeof(void*) == 8) {
+    // Assume that aligned loads are atomic.
+    if (mo == memory_order_relaxed) {
+      a->val_dont_use = v;
+    } else if (mo == memory_order_release) {
+      __sync_synchronize();
+      a->val_dont_use = v;
+      __asm__ __volatile__("" ::: "memory");
+    } else {  // seq_cst
+      __sync_synchronize();
+      a->val_dont_use = v;
+      __sync_synchronize();
+    }
+  } else {
+    // 64-bit store on 32-bit platform.
+    // Gross, but simple and reliable.
+    typename T::Type cmp = a->val_dont_use;
+    typename T::Type cur;
+    for (;;) {
+#if defined(_MIPS_SIM) && _MIPS_SIM == _ABIO32
+      typename T::Type volatile *val_ptr =
+          const_cast<typename T::Type volatile *>(&a->val_dont_use);
+      cur = __mips_sync_val_compare_and_swap<u64>(
+          reinterpret_cast<u64 volatile *>(val_ptr), (u64)cmp, (u64)v);
+#else
+      cur = __sync_val_compare_and_swap(&a->val_dont_use, cmp, v);
+#endif
+      if (cmp == v)
+        break;
+      cmp = cur;
+    }
+  }
+}
+
+}  // namespace __sanitizer
+
+#endif  // #ifndef SANITIZER_ATOMIC_CLANG_OTHER_H