[WIP][turbofan] Instruction scheduler for Turbofan.

src/compiler/arm64/instruction-scheduler-arm64.cc

Index: src/compiler/arm64/instruction-scheduler-arm64.cc
diff --git a/src/compiler/arm64/instruction-scheduler-arm64.cc b/src/compiler/arm64/instruction-scheduler-arm64.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e50074e925e93a210fb41a4d1003e9a023850979
--- /dev/null
+++ b/src/compiler/arm64/instruction-scheduler-arm64.cc
@@ -0,0 +1,68 @@
+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/compiler/instruction-scheduler.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+int InstructionScheduler::GetInstructionLatency(const Instruction* instr) {
+  // Basic latency modeling for arm64 instructions. They have been determined
+  // in an empirical way.
+  switch (instr->arch_opcode()) {
+    case kArm64Float32ToFloat64:
+    case kArm64Float64ToFloat32:
+    case kArm64Float64ToInt32:
+    case kArm64Float64ToUint32:
+    case kArm64Int32ToFloat64:
+    case kArm64Uint32ToFloat64:
+      return 3;
+
+    case kArm64Float64Add:
+    case kArm64Float64Sub:
+      return 2;
+
+    case kArm64Float64Mul:
+      return 3;
+
+    case kArm64Float64Div:
+      return 6;
+
+    case kArm64Lsl:
+    case kArm64Lsl32:
+    case kArm64Lsr:
+    case kArm64Lsr32:
+    case kArm64Asr:
+    case kArm64Asr32:
+    case kArm64Ror:
+    case kArm64Ror32:
+      return 3;
+
+    case kCheckedLoadInt8:
+    case kCheckedLoadUint8:
+    case kCheckedLoadInt16:
+    case kCheckedLoadUint16:
+    case kCheckedLoadWord32:
+    case kCheckedLoadWord64:
+    case kCheckedLoadFloat32:
+    case kCheckedLoadFloat64:
+    case kArm64LdrS:
+    case kArm64LdrD:
+    case kArm64Ldrb:
+    case kArm64Ldrsb:
+    case kArm64Ldrh:
+    case kArm64Ldrsh:
+    case kArm64LdrW:
+    case kArm64Ldr:
+      return 5;
+
+    default:
+      return 1;
+  }
+}
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8