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

  port 81cb8411 (r35993)

  original commit message:

BUG=

Review-Url: https://codereview.chromium.org/1947833002
Cr-Commit-Position: refs/heads/master@{#36049}

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;
   }

src/compiler/x87/instruction-codes-x87.h

@@ -96,7 +96,10 @@ namespace compiler {
   V(X87PushFloat64)                \
   V(X87PushFloat32)                \
   V(X87Poke)                       \
-  V(X87StackCheck)
+  V(X87StackCheck)                 \
+  V(X87Xchgb)                      \
+  V(X87Xchgw)                      \
+  V(X87Xchgl)
 
 // Addressing modes represent the "shape" of inputs to an instruction.
 // Many instructions support multiple addressing modes. Addressing modes

src/compiler/x87/instruction-selector-x87.cc

@@ -1598,6 +1598,44 @@ void InstructionSelector::VisitAtomicLoad(Node* node) {
   VisitLoad(node);
 }
 
+void InstructionSelector::VisitAtomicStore(Node* node) {
+  X87OperandGenerator g(this);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  Node* value = node->InputAt(2);
+
+  MachineRepresentation rep = AtomicStoreRepresentationOf(node->op());
+  ArchOpcode opcode = kArchNop;
+  switch (rep) {
+    case MachineRepresentation::kWord8:
+      opcode = kX87Xchgb;
+      break;
+    case MachineRepresentation::kWord16:
+      opcode = kX87Xchgw;
+      break;
+    case MachineRepresentation::kWord32:
+      opcode = kX87Xchgl;
+      break;
+    default:
+      UNREACHABLE();
+      break;
+  }
+  AddressingMode addressing_mode;
+  InstructionOperand inputs[4];
+  size_t input_count = 0;
+  inputs[input_count++] = g.UseUniqueRegister(base);
+  if (g.CanBeImmediate(index)) {
+    inputs[input_count++] = g.UseImmediate(index);
+    addressing_mode = kMode_MRI;
+  } else {
+    inputs[input_count++] = g.UseUniqueRegister(index);
+    addressing_mode = kMode_MR1;
+  }
+  inputs[input_count++] = g.UseUniqueRegister(value);
+  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
+  Emit(code, 0, nullptr, input_count, inputs);
+}
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {

src/x87/assembler-x87.cc

@@ -552,6 +552,18 @@ void Assembler::xchg(Register dst, const Operand& src) {
   emit_operand(dst, src);
 }
 
+void Assembler::xchg_b(Register reg, const Operand& op) {
+  EnsureSpace ensure_space(this);
+  EMIT(0x86);
+  emit_operand(reg, op);
+}
+
+void Assembler::xchg_w(Register reg, const Operand& op) {
+  EnsureSpace ensure_space(this);
+  EMIT(0x66);
+  EMIT(0x87);
+  emit_operand(reg, op);
+}
 
 void Assembler::adc(Register dst, int32_t imm32) {
   EnsureSpace ensure_space(this);

src/x87/assembler-x87.h

@@ -648,6 +648,8 @@ class Assembler : public AssemblerBase {
   // Exchange
   void xchg(Register dst, Register src);
   void xchg(Register dst, const Operand& src);
+  void xchg_b(Register reg, const Operand& op);
+  void xchg_w(Register reg, const Operand& op);
 
   // Arithmetics
   void adc(Register dst, int32_t imm32);