[turbofan] Avoid unnecessary write barriers and improve code generation.

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 5d67f429cbf918cdada4d1d20c60a2a3085482d4..5ca9c203969bada5cfc9dfc6c55d03b06b303830 100644
--- a/src/compiler/ia32/code-generator-ia32.cc
+++ b/src/compiler/ia32/code-generator-ia32.cc
@@ -217,6 +217,46 @@ class OutOfLineTruncateDoubleToI final : public OutOfLineCode {
   XMMRegister const input_;
 };
 
+
+class OutOfLineRecordWrite final : public OutOfLineCode {
+ public:
+  OutOfLineRecordWrite(CodeGenerator* gen, Register object, Operand operand,
+                       Register value, Register scratch0, Register scratch1,
+                       RecordWriteMode mode)
+      : OutOfLineCode(gen),
+        object_(object),
+        operand_(operand),
+        value_(value),
+        scratch0_(scratch0),
+        scratch1_(scratch1),
+        mode_(mode) {}
+
+  void Generate() final {
+    if (mode_ > RecordWriteMode::kValueIsPointer) {
+      __ JumpIfSmi(value_, exit());
+    }
+    if (mode_ > RecordWriteMode::kValueIsMap) {
+      __ CheckPageFlag(value_, scratch0_,
+                       MemoryChunk::kPointersToHereAreInterestingMask, zero,
+                       exit());
+    }
+    SaveFPRegsMode const save_fp_mode =
+        frame()->DidAllocateDoubleRegisters() ? kSaveFPRegs : kDontSaveFPRegs;
+    RecordWriteStub stub(isolate(), object_, scratch0_, scratch1_,
+                         EMIT_REMEMBERED_SET, save_fp_mode);
+    __ lea(scratch1_, operand_);
+    __ CallStub(&stub);
+  }
+
+ private:
+  Register const object_;
+  Operand const operand_;
+  Register const value_;
+  Register const scratch0_;
+  Register const scratch1_;
+  RecordWriteMode const mode_;
+};
+
 }  // namespace
 
 
@@ -407,6 +447,24 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       __ bind(ool->exit());
       break;
     }
+    case kArchStoreWithWriteBarrier: {
+      RecordWriteMode mode =
+          static_cast<RecordWriteMode>(MiscField::decode(instr->opcode()));
+      Register object = i.InputRegister(0);
+      size_t index = 0;
+      Operand operand = i.MemoryOperand(&index);
+      Register value = i.InputRegister(index);
+      Register scratch0 = i.TempRegister(0);
+      Register scratch1 = i.TempRegister(1);
+      auto ool = new (zone()) OutOfLineRecordWrite(this, object, operand, value,
+                                                   scratch0, scratch1, mode);
+      __ mov(operand, value);
+      __ CheckPageFlag(object, scratch0,
+                       MemoryChunk::kPointersFromHereAreInterestingMask,
+                       not_zero, ool->entry());
+      __ bind(ool->exit());
+      break;
+    }
     case kIA32Add:
       if (HasImmediateInput(instr, 1)) {
         __ add(i.InputOperand(0), i.InputImmediate(1));
@@ -920,24 +978,6 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       }
       break;
     }
-    case kIA32StoreWriteBarrier: {
-      Register object = i.InputRegister(0);
-      Register value = i.InputRegister(2);
-      SaveFPRegsMode mode =
-          frame()->DidAllocateDoubleRegisters() ? kSaveFPRegs : kDontSaveFPRegs;
-      if (HasImmediateInput(instr, 1)) {
-        int index = i.InputInt32(1);
-        Register scratch = i.TempRegister(1);
-        __ mov(Operand(object, index), value);
-        __ RecordWriteContextSlot(object, index, value, scratch, mode);
-      } else {
-        Register index = i.InputRegister(1);
-        __ mov(Operand(object, index, times_1, 0), value);
-        __ lea(index, Operand(object, index, times_1, 0));
-        __ RecordWrite(object, index, value, mode);
-      }
-      break;
-    }
     case kCheckedLoadInt8:
       ASSEMBLE_CHECKED_LOAD_INTEGER(movsx_b);
       break;