[wasm] I added comparison operators to the Int64Lowering.

src/compiler/int64-lowering.cc

Index: src/compiler/int64-lowering.cc
diff --git a/src/compiler/int64-lowering.cc b/src/compiler/int64-lowering.cc
index 2c32b962c3fc00d4af846adf6c9ae13f4137b8e2..94c7b3b15bf6d6759cb095b1ab0d901387ec7400 100644
--- a/src/compiler/int64-lowering.cc
+++ b/src/compiler/int64-lowering.cc
@@ -294,13 +294,30 @@ void Int64Lowering::LowerNode(Node* node) {
     // kExprI64Eq:
     // kExprI64Ne:
     // kExprI64LtS:
+    case IrOpcode::kInt64LessThan: {
+      LowerComparisonToLexicographicComparison(node, machine()->Int32LessThan(),
+                                               machine()->Uint32LessThan());
+      break;
+    }
     // kExprI64LeS:
+    case IrOpcode::kInt64LessThanOrEqual: {
+      LowerComparisonToLexicographicComparison(
+          node, machine()->Int32LessThan(), machine()->Uint32LessThanOrEqual());
+      break;
+    }
     // kExprI64LtU:
+    case IrOpcode::kUint64LessThan: {
+      LowerComparisonToLexicographicComparison(
+          node, machine()->Uint32LessThan(), machine()->Uint32LessThan());
+      break;
+    }
     // kExprI64LeU:
-    // kExprI64GtS:
-    // kExprI64GeS:
-    // kExprI64GtU:
-    // kExprI64GeU:
+    case IrOpcode::kUint64LessThanOrEqual: {
+      LowerComparisonToLexicographicComparison(
+          node, machine()->Uint32LessThan(),
+          machine()->Uint32LessThanOrEqual());
+      break;
+    }
 
     // kExprI64SConvertI32:
     // kExprI64UConvertI32:
@@ -324,6 +341,25 @@ void Int64Lowering::LowerNode(Node* node) {
   }
 }
 
+void Int64Lowering::LowerComparisonToLexicographicComparison(
+    Node* node, const Operator* high_word_op, const Operator* low_word_op) {
+  DCHECK(node->InputCount() == 2);
+  Node* left = node->InputAt(0);
+  Node* right = node->InputAt(1);
+  Node* replacement = graph()->NewNode(
+      machine()->Word32Or(),
+      graph()->NewNode(high_word_op, GetReplacementHigh(left),
+                       GetReplacementHigh(right)),
+      graph()->NewNode(
+          machine()->Word32And(),
+          graph()->NewNode(machine()->Word32Equal(), GetReplacementHigh(left),
+                           GetReplacementHigh(right)),
+          graph()->NewNode(low_word_op, GetReplacementLow(left),
+                           GetReplacementLow(right))));
+
+  ReplaceNode(node, replacement, nullptr);
+}
+
 bool Int64Lowering::DefaultLowering(Node* node) {
   bool something_changed = false;
   for (int i = NodeProperties::PastValueIndex(node) - 1; i >= 0; i--) {