Adding atomic ops for MIPS64.

base/atomicops_internals_mips_gcc.h

Index: base/atomicops_internals_mips_gcc.h
diff --git a/base/atomicops_internals_mips_gcc.h b/base/atomicops_internals_mips_gcc.h
index 29947b37afa61bd48e9ee13f2a47c04ab9d1a5de..9111a535b26f8fc0f173b91d7f59b40b5f3922fa 100644
--- a/base/atomicops_internals_mips_gcc.h
+++ b/base/atomicops_internals_mips_gcc.h
@@ -51,7 +51,7 @@ inline Atomic32 NoBarrier_AtomicExchange(volatile Atomic32* ptr,
   __asm__ __volatile__(".set push\n"
                        ".set noreorder\n"
                        "1:\n"
-                       "ll %1, %2\n"  // old = *ptr
+                       "ll %1, %4\n"  // old = *ptr
                        "move %0, %3\n"  // temp = new_value
                        "sc %0, %2\n"  // *ptr = temp (with atomic check)
                        "beqz %0, 1b\n"  // start again on atomic error
@@ -73,7 +73,7 @@ inline Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32* ptr,
   __asm__ __volatile__(".set push\n"
                        ".set noreorder\n"
                        "1:\n"
-                       "ll %0, %2\n"  // temp = *ptr
+                       "ll %0, %4\n"  // temp = *ptr
                        "addu %1, %0, %3\n"  // temp2 = temp + increment
                        "sc %1, %2\n"  // *ptr = temp2 (with atomic check)
                        "beqz %1, 1b\n"  // start again on atomic error
@@ -148,6 +148,132 @@ inline Atomic32 Release_Load(volatile const Atomic32* ptr) {
   return *ptr;
 }
 
+#if defined(__LP64__)
+// 64-bit versions of the atomic ops.
+
+inline Atomic64 NoBarrier_CompareAndSwap(volatile Atomic64* ptr,
+                                         Atomic64 old_value,
+                                         Atomic64 new_value) {
+  Atomic64 prev, tmp;
+  __asm__ __volatile__(".set push\n"
+                       ".set noreorder\n"
+                       "1:\n"
+                       "lld %0, %5\n"  // prev = *ptr
+                       "bne %0, %3, 2f\n"  // if (prev != old_value) goto 2
+                       "move %2, %4\n"  // tmp = new_value
+                       "scd %2, %1\n"  // *ptr = tmp (with atomic check)
+                       "beqz %2, 1b\n"  // start again on atomic error
+                       "nop\n"  // delay slot nop
+                       "2:\n"
+                       ".set pop\n"
+                       : "=&r" (prev), "=m" (*ptr), "=&r" (tmp)
+                       : "Ir" (old_value), "r" (new_value), "m" (*ptr)
+                       : "memory");
+  return prev;
+}
+
+// Atomically store new_value into *ptr, returning the previous value held in
+// *ptr.  This routine implies no memory barriers.
+inline Atomic64 NoBarrier_AtomicExchange(volatile Atomic64* ptr,
+                                         Atomic64 new_value) {
+  Atomic64 temp, old;
+  __asm__ __volatile__(".set push\n"
+                       ".set noreorder\n"
+                       "1:\n"
+                       "lld %1, %4\n"  // old = *ptr
+                       "move %0, %3\n"  // temp = new_value
+                       "scd %0, %2\n"  // *ptr = temp (with atomic check)
+                       "beqz %0, 1b\n"  // start again on atomic error
+                       "nop\n"  // delay slot nop
+                       ".set pop\n"
+                       : "=&r" (temp), "=&r" (old), "=m" (*ptr)
+                       : "r" (new_value), "m" (*ptr)
+                       : "memory");
+
+  return old;
+}
+
+// Atomically increment *ptr by "increment".  Returns the new value of
+// *ptr with the increment applied.  This routine implies no memory barriers.
+inline Atomic64 NoBarrier_AtomicIncrement(volatile Atomic64* ptr,
+                                          Atomic64 increment) {
+  Atomic64 temp, temp2;
+
+  __asm__ __volatile__(".set push\n"
+                       ".set noreorder\n"
+                       "1:\n"
+                       "lld %0, %4\n"  // temp = *ptr
+                       "daddu %1, %0, %3\n"  // temp2 = temp + increment
+                       "scd %1, %2\n"  // *ptr = temp2 (with atomic check)
+                       "beqz %1, 1b\n"  // start again on atomic error
+                       "daddu %1, %0, %3\n"  // temp2 = temp + increment
+                       ".set pop\n"
+                       : "=&r" (temp), "=&r" (temp2), "=m" (*ptr)
+                       : "Ir" (increment), "m" (*ptr)
+                       : "memory");
+  // temp2 now holds the final value.
+  return temp2;
+}
+
+inline Atomic64 Barrier_AtomicIncrement(volatile Atomic64* ptr,
+                                        Atomic64 increment) {
+  MemoryBarrier();
+  Atomic64 res = NoBarrier_AtomicIncrement(ptr, increment);
+  MemoryBarrier();
+  return res;
+}
+
+// "Acquire" operations
+// ensure that no later memory access can be reordered ahead of the operation.
+// "Release" operations ensure that no previous memory access can be reordered
+// after the operation.  "Barrier" operations have both "Acquire" and "Release"
+// semantics.   A MemoryBarrier() has "Barrier" semantics, but does no memory
+// access.
+inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr,
+                                       Atomic64 old_value,
+                                       Atomic64 new_value) {
+  Atomic64 res = NoBarrier_CompareAndSwap(ptr, old_value, new_value);
+  MemoryBarrier();
+  return res;
+}
+
+inline Atomic64 Release_CompareAndSwap(volatile Atomic64* ptr,
+                                       Atomic64 old_value,
+                                       Atomic64 new_value) {
+  MemoryBarrier();
+  return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
+}
+
+inline void NoBarrier_Store(volatile Atomic64* ptr, Atomic64 value) {
+  *ptr = value;
+}
+
+inline void Acquire_Store(volatile Atomic64* ptr, Atomic64 value) {
+  *ptr = value;
+  MemoryBarrier();
+}
+
+inline void Release_Store(volatile Atomic64* ptr, Atomic64 value) {
+  MemoryBarrier();
+  *ptr = value;
+}
+
+inline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) {
+  return *ptr;
+}
+
+inline Atomic64 Acquire_Load(volatile const Atomic64* ptr) {
+  Atomic64 value = *ptr;
+  MemoryBarrier();
+  return value;
+}
+
+inline Atomic64 Release_Load(volatile const Atomic64* ptr) {
+  MemoryBarrier();
+  return *ptr;
+}
+#endif
+
 } // namespace base::subtle
 } // namespace base