[Atomics] Make Atomics.exchange a builtin using TF

src/compiler/x64/code-generator-x64.cc

Index: src/compiler/x64/code-generator-x64.cc
diff --git a/src/compiler/x64/code-generator-x64.cc b/src/compiler/x64/code-generator-x64.cc
index 8f9b69d2c8b033f7654bbc6f53bd4b5d23934667..1a96a3a4c7950bdc9abbace94c806af4e1fdd954 100644
--- a/src/compiler/x64/code-generator-x64.cc
+++ b/src/compiler/x64/code-generator-x64.cc
@@ -2136,24 +2136,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       }
       break;
     }
-    case kX64Xchgb: {
-      size_t index = 0;
-      Operand operand = i.MemoryOperand(&index);
-      __ xchgb(i.InputRegister(index), operand);
-      break;
-    }
-    case kX64Xchgw: {
-      size_t index = 0;
-      Operand operand = i.MemoryOperand(&index);
-      __ xchgw(i.InputRegister(index), operand);
-      break;
-    }
-    case kX64Xchgl: {
-      size_t index = 0;
-      Operand operand = i.MemoryOperand(&index);
-      __ xchgl(i.InputRegister(index), operand);
-      break;
-    }
     case kX64Int32x4Splat: {
       CpuFeatureScope sse_scope(masm(), SSE4_1);
       XMMRegister dst = i.OutputSimd128Register();
@@ -2237,6 +2219,30 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kX64StackCheck:
       __ CompareRoot(rsp, Heap::kStackLimitRootIndex);
       break;
+    case kAtomicExchangeInt8: {
+      __ xchgb(i.InputRegister(0), i.MemoryOperand(1));
+      __ movsxbl(i.InputRegister(0), i.InputRegister(0));
+      break;
+    }
+    case kAtomicExchangeUint8: {
+      __ xchgb(i.InputRegister(0), i.MemoryOperand(1));
+      __ movzxbl(i.InputRegister(0), i.InputRegister(0));
+      break;
+    }
+    case kAtomicExchangeInt16: {
+      __ xchgw(i.InputRegister(0), i.MemoryOperand(1));
+      __ movsxwl(i.InputRegister(0), i.InputRegister(0));
+      break;
+    }
+    case kAtomicExchangeUint16: {
+      __ xchgw(i.InputRegister(0), i.MemoryOperand(1));
+      __ movzxwl(i.InputRegister(0), i.InputRegister(0));
+      break;
+    }
+    case kAtomicExchangeWord32: {
+      __ xchgl(i.InputRegister(0), i.MemoryOperand(1));
+      break;
+    }
     case kAtomicLoadInt8:
     case kAtomicLoadUint8:
     case kAtomicLoadInt16: