[Atomics] Make Atomics.exchange a builtin using TF

src/compiler/ia32/code-generator-ia32.cc

Index: src/compiler/ia32/code-generator-ia32.cc
diff --git a/src/compiler/ia32/code-generator-ia32.cc b/src/compiler/ia32/code-generator-ia32.cc
index 369699067e2b8b9d8dc65ad5e9b322be0dfc9ff3..0f6d1c3a4a8ff7db2ed2a07436e3a96e542bbe16 100644
--- a/src/compiler/ia32/code-generator-ia32.cc
+++ b/src/compiler/ia32/code-generator-ia32.cc
@@ -1888,24 +1888,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       }
       break;
     }
-    case kIA32Xchgb: {
-      size_t index = 0;
-      Operand operand = i.MemoryOperand(&index);
-      __ xchg_b(i.InputRegister(index), operand);
-      break;
-    }
-    case kIA32Xchgw: {
-      size_t index = 0;
-      Operand operand = i.MemoryOperand(&index);
-      __ xchg_w(i.InputRegister(index), operand);
-      break;
-    }
-    case kIA32Xchgl: {
-      size_t index = 0;
-      Operand operand = i.MemoryOperand(&index);
-      __ xchg(i.InputRegister(index), operand);
-      break;
-    }
     case kCheckedLoadInt8:
       ASSEMBLE_CHECKED_LOAD_INTEGER(movsx_b);
       break;
@@ -1952,6 +1934,30 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kCheckedStoreWord64:
       UNREACHABLE();  // currently unsupported checked int64 load/store.
       break;
+    case kAtomicExchangeInt8: {
+      __ xchg_b(i.InputRegister(0), i.MemoryOperand(1));
+      __ movsx_b(i.InputRegister(0), i.InputRegister(0));
+      break;
+    }
+    case kAtomicExchangeUint8: {
+      __ xchg_b(i.InputRegister(0), i.MemoryOperand(1));
+      __ movzx_b(i.InputRegister(0), i.InputRegister(0));
+      break;
+    }
+    case kAtomicExchangeInt16: {
+      __ xchg_w(i.InputRegister(0), i.MemoryOperand(1));
+      __ movsx_w(i.InputRegister(0), i.InputRegister(0));
+      break;
+    }
+    case kAtomicExchangeUint16: {
+      __ xchg_w(i.InputRegister(0), i.MemoryOperand(1));
+      __ movzx_w(i.InputRegister(0), i.InputRegister(0));
+      break;
+    }
+    case kAtomicExchangeWord32: {
+      __ xchg(i.InputRegister(0), i.MemoryOperand(1));
+      break;
+    }
     case kAtomicLoadInt8:
     case kAtomicLoadUint8:
     case kAtomicLoadInt16: