feat(tvm): update comments and tests

Author: Liulei

actuator/src/main/java/org/tron/core/vm/Op.java

@@ -145,9 +145,9 @@ public class Op {
   // (0x5a) Get the amount of available gas
   public static final int GAS = 0x5a;
   public static final int JUMPDEST = 0x5b;
-  // (0x5c) Load word from transient memory
+  // (0x5c) Load word from transient storage
   public static final int TLOAD = 0x5c;
-  // (0x5d) Save word to transient memory
+  // (0x5d) Save word to transient storage
   public static final int TSTORE = 0x5d;
   // (0x5e) Copy word from memory
   public static final int MCOPY = 0x5e;

actuator/src/main/java/org/tron/core/vm/OperationActions.java

@@ -649,7 +649,7 @@ public static void tLoadAction(Program program) {
 
     byte[] data =
         program.getContractState().getTransientStorageValue(address.getData(), key.getData());
-    DataWord value = data != null ? new DataWord(data) : DataWord.ZERO;
+    DataWord value = data != null ? new DataWord(data) : DataWord.ZERO();
 
     program.stackPush(value);
     program.step();

framework/src/test/java/org/tron/common/runtime/vm/OperationsTest.java

@@ -956,9 +956,17 @@ public void testTransientStorageOperations() throws ContractValidateException {
     program = new Program(op, op, invoke, interTrx);
     testOperations(program);
     Assert.assertEquals(106, program.getResult().getEnergyUsed());
-    Assert.assertEquals("0000000000000000000000000000000000000000000000000000000000000001",
-        Hex.toHexString(program.getContractState().getTransientStorageValue(
-            program.getContractAddress().getData(), new DataWord(0x01).getData())));
+    Assert.assertArrayEquals(new DataWord(0x01).getData(),
+        program.getContractState().getTransientStorageValue(
+            program.getContractAddress().getData(), new DataWord(0x01).getData()));
+
+    // TLOAD = 0x5c;
+    op = new byte[] {0x60, 0x01, 0x5c};
+    program = new Program(op, op, invoke, interTrx);
+    testOperations(program);
+    Assert.assertEquals(103, program.getResult().getEnergyUsed());
+    Assert.assertEquals(new DataWord(0x01), program.getStack().pop());
+
     VMConfig.initAllowTvmCancun(0);
   }
 
@@ -978,6 +986,13 @@ public void testMCOPY() throws ContractValidateException {
     Assert.assertEquals(21, program.getResult().getEnergyUsed());
     Assert.assertEquals(64, program.getMemSize());
 
+    op =
+        new byte[] {
+          0x60, 0x01, 0x60, 0x01, 0x52, 0x60, 0x20, 0x60, 0x01, 0x60, 0x20, 0x5e, 0x60, 0x20, 0x51};
+    program = new Program(op, op, invoke, interTrx);
+    testOperations(program);
+    Assert.assertEquals(new DataWord(0x01), program.getStack().pop());
+
     VMConfig.initAllowTvmCancun(0);
   }