X87: [Atomics] Make Atomics.store a builtin using TF.

src/compiler/x87/code-generator-x87.cc

Index: src/compiler/x87/code-generator-x87.cc
diff --git a/src/compiler/x87/code-generator-x87.cc b/src/compiler/x87/code-generator-x87.cc
index 1d22ae9b6be41b86d5e5fe65b76aac727490fdb3..82e575e4843ae9807dbadc6802bd9f65d0091cdf 100644
--- a/src/compiler/x87/code-generator-x87.cc
+++ b/src/compiler/x87/code-generator-x87.cc
@@ -1698,6 +1698,24 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       }
       break;
     }
+    case kX87Xchgb: {
+      size_t index = 0;
+      Operand operand = i.MemoryOperand(&index);
+      __ xchg_b(i.InputRegister(index), operand);
+      break;
+    }
+    case kX87Xchgw: {
+      size_t index = 0;
+      Operand operand = i.MemoryOperand(&index);
+      __ xchg_w(i.InputRegister(index), operand);
+      break;
+    }
+    case kX87Xchgl: {
+      size_t index = 0;
+      Operand operand = i.MemoryOperand(&index);
+      __ xchg(i.InputRegister(index), operand);
+      break;
+    }
     case kX87PushFloat32:
       __ lea(esp, Operand(esp, -kFloatSize));
       if (instr->InputAt(0)->IsDoubleStackSlot()) {
@@ -1771,6 +1789,9 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kAtomicLoadInt16:
     case kAtomicLoadUint16:
     case kAtomicLoadWord32:
+    case kAtomicStoreWord8:
+    case kAtomicStoreWord16:
+    case kAtomicStoreWord32:
       UNREACHABLE();  // Won't be generated by instruction selector.
       break;
   }