[turbofan] Revive the useful parts of the SimplifiedOperatorReducer.

src/compiler/simplified-operator-reducer.cc

Index: src/compiler/simplified-operator-reducer.cc
diff --git a/src/compiler/simplified-operator-reducer.cc b/src/compiler/simplified-operator-reducer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2e87f362e7c67b2cf3fd56693885fee5d9cb92b9
--- /dev/null
+++ b/src/compiler/simplified-operator-reducer.cc
@@ -0,0 +1,138 @@
+// 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/simplified-operator-reducer.h"
+
+#include "src/compiler/js-graph.h"
+#include "src/compiler/machine-operator.h"
+#include "src/compiler/node-matchers.h"
+#include "src/compiler/operator-properties.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+SimplifiedOperatorReducer::SimplifiedOperatorReducer(JSGraph* jsgraph)
+    : jsgraph_(jsgraph), simplified_(jsgraph->zone()) {}
+
+
+SimplifiedOperatorReducer::~SimplifiedOperatorReducer() {}
+
+
+Reduction SimplifiedOperatorReducer::Reduce(Node* node) {
+  switch (node->opcode()) {
+    case IrOpcode::kBooleanNot: {
+      HeapObjectMatcher m(node->InputAt(0));
+      if (m.HasValue()) {
+        return Replace(
+            jsgraph()->BooleanConstant(!m.Value().handle()->BooleanValue()));
+      }
+      if (m.IsBooleanNot()) return Replace(m.InputAt(0));
+      break;
+    }
+    case IrOpcode::kChangeBitToBool: {
+      Int32Matcher m(node->InputAt(0));
+      if (m.Is(0)) return Replace(jsgraph()->FalseConstant());
+      if (m.Is(1)) return Replace(jsgraph()->TrueConstant());
+      if (m.IsChangeBoolToBit()) return Replace(m.InputAt(0));
+      break;
+    }
+    case IrOpcode::kChangeBoolToBit: {
+      HeapObjectMatcher m(node->InputAt(0));
+      if (m.HasValue()) return ReplaceInt32(m.Value().handle()->BooleanValue());
+      if (m.IsChangeBitToBool()) return Replace(m.InputAt(0));
+      break;
+    }
+    case IrOpcode::kChangeFloat64ToTagged: {
+      Float64Matcher m(node->InputAt(0));
+      if (m.HasValue()) return ReplaceNumber(m.Value());
+      break;
+    }
+    case IrOpcode::kChangeInt32ToTagged: {
+      Int32Matcher m(node->InputAt(0));
+      if (m.HasValue()) return ReplaceNumber(m.Value());
+      break;
+    }
+    case IrOpcode::kChangeTaggedToFloat64: {
+      NumberMatcher m(node->InputAt(0));
+      if (m.HasValue()) return ReplaceFloat64(m.Value());
+      if (m.IsChangeFloat64ToTagged()) return Replace(m.node()->InputAt(0));
+      if (m.IsChangeInt32ToTagged()) {
+        return Change(node, machine()->ChangeInt32ToFloat64(), m.InputAt(0));
+      }
+      if (m.IsChangeUint32ToTagged()) {
+        return Change(node, machine()->ChangeUint32ToFloat64(), m.InputAt(0));
+      }
+      break;
+    }
+    case IrOpcode::kChangeTaggedToInt32: {
+      NumberMatcher m(node->InputAt(0));
+      if (m.HasValue()) return ReplaceInt32(DoubleToInt32(m.Value()));
+      if (m.IsChangeFloat64ToTagged()) {
+        return Change(node, machine()->ChangeFloat64ToInt32(), m.InputAt(0));
+      }
+      if (m.IsChangeInt32ToTagged()) return Replace(m.InputAt(0));
+      break;
+    }
+    case IrOpcode::kChangeTaggedToUint32: {
+      NumberMatcher m(node->InputAt(0));
+      if (m.HasValue()) return ReplaceUint32(DoubleToUint32(m.Value()));
+      if (m.IsChangeFloat64ToTagged()) {
+        return Change(node, machine()->ChangeFloat64ToUint32(), m.InputAt(0));
+      }
+      if (m.IsChangeUint32ToTagged()) return Replace(m.InputAt(0));
+      break;
+    }
+    case IrOpcode::kChangeUint32ToTagged: {
+      Uint32Matcher m(node->InputAt(0));
+      if (m.HasValue()) return ReplaceNumber(FastUI2D(m.Value()));
+      break;
+    }
+    default:
+      break;
+  }
+  return NoChange();
+}
+
+
+Reduction SimplifiedOperatorReducer::Change(Node* node, const Operator* op,
+                                            Node* a) {
+  DCHECK_EQ(node->InputCount(), OperatorProperties::GetTotalInputCount(op));
+  DCHECK_LE(1, node->InputCount());
+  node->set_op(op);
+  node->ReplaceInput(0, a);
+  return Changed(node);
+}
+
+
+Reduction SimplifiedOperatorReducer::ReplaceFloat64(double value) {
+  return Replace(jsgraph()->Float64Constant(value));
+}
+
+
+Reduction SimplifiedOperatorReducer::ReplaceInt32(int32_t value) {
+  return Replace(jsgraph()->Int32Constant(value));
+}
+
+
+Reduction SimplifiedOperatorReducer::ReplaceNumber(double value) {
+  return Replace(jsgraph()->Constant(value));
+}
+
+
+Reduction SimplifiedOperatorReducer::ReplaceNumber(int32_t value) {
+  return Replace(jsgraph()->Constant(value));
+}
+
+
+Graph* SimplifiedOperatorReducer::graph() const { return jsgraph()->graph(); }
+
+
+MachineOperatorBuilder* SimplifiedOperatorReducer::machine() const {
+  return jsgraph()->machine();
+}
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8