fix the bug of computing the size of a memory piece

source/sample/transformer/T2TTrainer.cpp

@@ -449,7 +449,7 @@ int T2TTrainer::LoadBatch(FILE * file, bool isLM,
                           int devID, XMem * mem)
 {
     if(nextSeq < 0 || nextSeq >= nseqBuf)
-        LoadBuf(file, isSorted);
+        LoadBuf(file, isSorted, step);
 
     int seq = MAX(nextSeq, 0);
     int wc = 0;

source/tensor/XMem.cpp

@@ -1041,9 +1041,11 @@ void XMem::RebuildIndex()
                 /* make a new index node */
                 MPieceNode * newNode = memIndex2 + nodeNumUsed2++;
                 newNode->p = p;
-                newNode->size = node->size;
-                //newNode->size = (char*)p + head->size - 
-                //                ( head->state == 1 ? (char*)GetPitchedAddress((char*)p, MY_PITCH) : (char*)head->indexNode->pReal);
+                if(head->state == 1)
+                    newNode->size = (char*)p + head->size - 
+                                    ( head->state == 1 ? (char*)GetPitchedAddress((char*)p, MY_PITCH) : (char*)head->indexNode->pReal);
+                else
+                    newNode->size = node->size;
                 newNode->pre = NULL;
                 newNode->next = NULL;