8372528: Unify atomic exchange and compare exchange

Reviewed-by: kbarrett, stefank

Author: xmas92

src/hotspot/cpu/ppc/atomicAccess_ppc.hpp

@@ -157,6 +157,9 @@ inline D AtomicAccess::PlatformAdd<8>::add_then_fetch(D volatile* dest, I add_va
   return result;
 }
 
+template<>
+struct AtomicAccess::PlatformXchg<1> : AtomicAccess::XchgUsingCmpxchg<1> {};
+
 template<>
 template<typename T>
 inline T AtomicAccess::PlatformXchg<4>::operator()(T volatile* dest,

src/hotspot/os_cpu/bsd_aarch64/atomicAccess_bsd_aarch64.hpp

@@ -52,12 +52,16 @@ struct AtomicAccess::PlatformAdd {
   }
 };
 
+template<>
+struct AtomicAccess::PlatformXchg<1> : AtomicAccess::XchgUsingCmpxchg<1> {};
+
 template<size_t byte_size>
 template<typename T>
 inline T AtomicAccess::PlatformXchg<byte_size>::operator()(T volatile* dest,
                                                            T exchange_value,
                                                            atomic_memory_order order) const {
   STATIC_ASSERT(byte_size == sizeof(T));
+  STATIC_ASSERT(byte_size == 4 || byte_size == 8);
   T res = __atomic_exchange_n(dest, exchange_value, __ATOMIC_RELEASE);
   FULL_MEM_BARRIER;
   return res;

src/hotspot/os_cpu/bsd_x86/atomicAccess_bsd_x86.hpp

@@ -52,6 +52,9 @@ inline D AtomicAccess::PlatformAdd<4>::fetch_then_add(D volatile* dest, I add_va
   return old_value;
 }
 
+template<>
+struct AtomicAccess::PlatformXchg<1> : AtomicAccess::XchgUsingCmpxchg<1> {};
+
 template<>
 template<typename T>
 inline T AtomicAccess::PlatformXchg<4>::operator()(T volatile* dest,

src/hotspot/os_cpu/bsd_zero/atomicAccess_bsd_zero.hpp

@@ -66,6 +66,9 @@ inline D AtomicAccess::PlatformAdd<8>::add_then_fetch(D volatile* dest, I add_va
   return res;
 }
 
+template<>
+struct AtomicAccess::PlatformXchg<1> : AtomicAccess::XchgUsingCmpxchg<1> {};
+
 template<>
 template<typename T>
 inline T AtomicAccess::PlatformXchg<4>::operator()(T volatile* dest,

src/hotspot/os_cpu/linux_aarch64/atomicAccess_linux_aarch64.hpp

@@ -113,6 +113,9 @@ inline D AtomicAccess::PlatformAdd<8>::fetch_then_add(D volatile* dest, I add_va
   return atomic_fastcall(stub, dest, add_value);
 }
 
+template<>
+struct AtomicAccess::PlatformXchg<1> : AtomicAccess::XchgUsingCmpxchg<1> {};
+
 template<>
 template<typename T>
 inline T AtomicAccess::PlatformXchg<4>::operator()(T volatile* dest,

src/hotspot/os_cpu/linux_arm/atomicAccess_linux_arm.hpp

@@ -118,6 +118,8 @@ inline D AtomicAccess::PlatformAdd<4>::add_then_fetch(D volatile* dest, I add_va
   return add_using_helper<int32_t>(ARMAtomicFuncs::_add_func, dest, add_value);
 }
 
+template<>
+struct AtomicAccess::PlatformXchg<1> : AtomicAccess::XchgUsingCmpxchg<1> {};
 
 template<>
 template<typename T>

src/hotspot/os_cpu/linux_riscv/atomicAccess_linux_riscv.hpp

@@ -152,6 +152,9 @@ inline T AtomicAccess::PlatformCmpxchg<4>::operator()(T volatile* dest __attribu
 }
 #endif
 
+template<>
+struct AtomicAccess::PlatformXchg<1> : AtomicAccess::XchgUsingCmpxchg<1> {};
+
 template<size_t byte_size>
 template<typename T>
 inline T AtomicAccess::PlatformXchg<byte_size>::operator()(T volatile* dest,
@@ -164,6 +167,7 @@ inline T AtomicAccess::PlatformXchg<byte_size>::operator()(T volatile* dest,
 #endif
 
   STATIC_ASSERT(byte_size == sizeof(T));
+  STATIC_ASSERT(byte_size == 4 || byte_size == 8);
 
   if (order != memory_order_relaxed) {
     FULL_MEM_BARRIER;

src/hotspot/os_cpu/linux_s390/atomicAccess_linux_s390.hpp

@@ -209,6 +209,9 @@ inline D AtomicAccess::PlatformAdd<8>::add_then_fetch(D volatile* dest, I inc,
 //
 // The return value is the (unchanged) value from memory as it was when the
 // replacement succeeded.
+template<>
+struct AtomicAccess::PlatformXchg<1> : AtomicAccess::XchgUsingCmpxchg<1> {};
+
 template<>
 template<typename T>
 inline T AtomicAccess::PlatformXchg<4>::operator()(T volatile* dest,

src/hotspot/os_cpu/linux_x86/atomicAccess_linux_x86.hpp

@@ -52,6 +52,9 @@ inline D AtomicAccess::PlatformAdd<4>::fetch_then_add(D volatile* dest, I add_va
   return old_value;
 }
 
+template<>
+struct AtomicAccess::PlatformXchg<1> : AtomicAccess::XchgUsingCmpxchg<1> {};
+
 template<>
 template<typename T>
 inline T AtomicAccess::PlatformXchg<4>::operator()(T volatile* dest,

src/hotspot/os_cpu/linux_zero/atomicAccess_linux_zero.hpp

@@ -65,6 +65,9 @@ inline D AtomicAccess::PlatformAdd<8>::add_then_fetch(D volatile* dest, I add_va
   return res;
 }
 
+template<>
+struct AtomicAccess::PlatformXchg<1> : AtomicAccess::XchgUsingCmpxchg<1> {};
+
 template<>
 template<typename T>
 inline T AtomicAccess::PlatformXchg<4>::operator()(T volatile* dest,