[turbofan] Some strength reduction on Smi/HeapObject checks.

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
index dda29ef6a8c6e07da3769a0380f831065f43a16c..0b2e85a49db44334487bc5d46c86595bb70a87e1 100644
--- a/src/compiler/simplified-operator-reducer.cc
+++ b/src/compiler/simplified-operator-reducer.cc
@@ -16,8 +16,27 @@ namespace v8 {
 namespace internal {
 namespace compiler {
 
-SimplifiedOperatorReducer::SimplifiedOperatorReducer(JSGraph* jsgraph)
-    : jsgraph_(jsgraph), type_cache_(TypeCache::Get()) {}
+namespace {
+
+Decision DecideObjectIsSmi(Node* const input) {
+  NumberMatcher m(input);
+  if (m.HasValue()) {
+    return IsSmiDouble(m.Value()) ? Decision::kTrue : Decision::kFalse;
+  }
+  if (m.IsAllocate()) return Decision::kFalse;
+  if (m.IsChangeBitToTagged()) return Decision::kFalse;
+  if (m.IsChangeInt31ToTaggedSigned()) return Decision::kTrue;
+  if (m.IsHeapConstant()) return Decision::kFalse;
+  return Decision::kUnknown;
+}
+
+}  // namespace
+
+SimplifiedOperatorReducer::SimplifiedOperatorReducer(Editor* editor,
+                                                     JSGraph* jsgraph)
+    : AdvancedReducer(editor),
+      jsgraph_(jsgraph),
+      type_cache_(TypeCache::Get()) {}
 
 SimplifiedOperatorReducer::~SimplifiedOperatorReducer() {}
 
@@ -110,12 +129,32 @@ Reduction SimplifiedOperatorReducer::Reduce(Node* node) {
       }
       break;
     }
+    case IrOpcode::kCheckTaggedPointer: {
+      Node* const input = node->InputAt(0);
+      if (DecideObjectIsSmi(input) == Decision::kFalse) {
+        ReplaceWithValue(node, input);
+        return Replace(input);
+      }
+      break;
+    }
+    case IrOpcode::kCheckTaggedSigned: {
+      Node* const input = node->InputAt(0);
+      if (DecideObjectIsSmi(input) == Decision::kTrue) {
+        ReplaceWithValue(node, input);
+        return Replace(input);
+      }
+      break;
+    }
     case IrOpcode::kObjectIsSmi: {
-      NumberMatcher m(node->InputAt(0));
-      if (m.HasValue()) return ReplaceBoolean(IsSmiDouble(m.Value()));
-      if (m.IsChangeBitToTagged()) return ReplaceBoolean(false);
-      if (m.IsChangeInt31ToTaggedSigned()) return ReplaceBoolean(true);
-      if (m.IsHeapConstant()) return ReplaceBoolean(false);
+      Node* const input = node->InputAt(0);
+      switch (DecideObjectIsSmi(input)) {
+        case Decision::kTrue:
+          return ReplaceBoolean(true);
+        case Decision::kFalse:
+          return ReplaceBoolean(false);
+        case Decision::kUnknown:
+          break;
+      }
       break;
     }
     case IrOpcode::kNumberCeil: