[SAB] Move Atomics builtins to C++

src/builtins/builtins-sharedarraybuffer.cc

Index: src/builtins/builtins-sharedarraybuffer.cc
diff --git a/src/builtins/builtins-sharedarraybuffer.cc b/src/builtins/builtins-sharedarraybuffer.cc
index 7ee144901e1a074818704e50886065439ee1234f..85d08bbcee1c4e6be013bcdbaa31abbe964b000c 100644
--- a/src/builtins/builtins-sharedarraybuffer.cc
+++ b/src/builtins/builtins-sharedarraybuffer.cc
@@ -638,61 +638,6 @@ inline Object* DoExchange(Isolate* isolate, void* buffer, size_t index,
   return ToObject(isolate, result);
 }
 
-// Uint8Clamped functions
-
-uint8_t ClampToUint8(int32_t value) {
-  if (value < 0) return 0;
-  if (value > 255) return 255;
-  return value;
-}
-
-inline Object* DoCompareExchangeUint8Clamped(Isolate* isolate, void* buffer,
-                                             size_t index,
-                                             Handle<Object> oldobj,
-                                             Handle<Object> newobj) {
-  typedef int32_t convert_type;
-  uint8_t oldval = ClampToUint8(FromObject<convert_type>(oldobj));
-  uint8_t newval = ClampToUint8(FromObject<convert_type>(newobj));
-  uint8_t result = CompareExchangeSeqCst(static_cast<uint8_t*>(buffer) + index,
-                                         oldval, newval);
-  return ToObject(isolate, result);
-}
-
-#define DO_UINT8_CLAMPED_OP(name, op)                                        \
-  inline Object* Do##name##Uint8Clamped(Isolate* isolate, void* buffer,      \
-                                        size_t index, Handle<Object> obj) {  \
-    typedef int32_t convert_type;                                            \
-    uint8_t* p = static_cast<uint8_t*>(buffer) + index;                      \
-    convert_type operand = FromObject<convert_type>(obj);                    \
-    uint8_t expected;                                                        \
-    uint8_t result;                                                          \
-    do {                                                                     \
-      expected = *p;                                                         \
-      result = ClampToUint8(static_cast<convert_type>(expected) op operand); \
-    } while (CompareExchangeSeqCst(p, expected, result) != expected);        \
-    return ToObject(isolate, expected);                                      \
-  }
-
-DO_UINT8_CLAMPED_OP(Add, +)
-DO_UINT8_CLAMPED_OP(Sub, -)
-DO_UINT8_CLAMPED_OP(And, &)
-DO_UINT8_CLAMPED_OP(Or, |)
-DO_UINT8_CLAMPED_OP(Xor, ^)
-
-#undef DO_UINT8_CLAMPED_OP
-
-inline Object* DoExchangeUint8Clamped(Isolate* isolate, void* buffer,
-                                      size_t index, Handle<Object> obj) {
-  typedef int32_t convert_type;
-  uint8_t* p = static_cast<uint8_t*>(buffer) + index;
-  uint8_t result = ClampToUint8(FromObject<convert_type>(obj));
-  uint8_t expected;
-  do {
-    expected = *p;
-  } while (CompareExchangeSeqCst(p, expected, result) != expected);
-  return ToObject(isolate, expected);
-}
-
 }  // anonymous namespace
 
 // Duplicated from objects.h
@@ -741,8 +686,7 @@ BUILTIN(AtomicsCompareExchange) {
 #undef TYPED_ARRAY_CASE
 
     case kExternalUint8ClampedArray:
-      return DoCompareExchangeUint8Clamped(isolate, source, i, expectedValue,
-                                           replacementValue);
+      UNREACHABLE();
 
     default:
       break;
@@ -783,7 +727,7 @@ BUILTIN(AtomicsAdd) {
 #undef TYPED_ARRAY_CASE
 
     case kExternalUint8ClampedArray:
-      return DoAddUint8Clamped(isolate, source, i, value);
+      UNREACHABLE();
 
     default:
       break;
@@ -824,7 +768,7 @@ BUILTIN(AtomicsSub) {
 #undef TYPED_ARRAY_CASE
 
     case kExternalUint8ClampedArray:
-      return DoSubUint8Clamped(isolate, source, i, value);
+      UNREACHABLE();
 
     default:
       break;
@@ -865,7 +809,7 @@ BUILTIN(AtomicsAnd) {
 #undef TYPED_ARRAY_CASE
 
     case kExternalUint8ClampedArray:
-      return DoAndUint8Clamped(isolate, source, i, value);
+      UNREACHABLE();
 
     default:
       break;
@@ -906,7 +850,7 @@ BUILTIN(AtomicsOr) {
 #undef TYPED_ARRAY_CASE
 
     case kExternalUint8ClampedArray:
-      return DoOrUint8Clamped(isolate, source, i, value);
+      UNREACHABLE();
 
     default:
       break;
@@ -947,7 +891,7 @@ BUILTIN(AtomicsXor) {
 #undef TYPED_ARRAY_CASE
 
     case kExternalUint8ClampedArray:
-      return DoXorUint8Clamped(isolate, source, i, value);
+      UNREACHABLE();
 
     default:
       break;
@@ -988,7 +932,7 @@ BUILTIN(AtomicsExchange) {
 #undef TYPED_ARRAY_CASE
 
     case kExternalUint8ClampedArray:
-      return DoExchangeUint8Clamped(isolate, source, i, value);
+      UNREACHABLE();
 
     default:
       break;