Index: librime/include/rime/dict/mapped_file.h
===================================================================
--- librime.orig/include/rime/dict/mapped_file.h
+++ librime/include/rime/dict/mapped_file.h
@@ -133,7 +133,9 @@ template <class T>
 T* MappedFile::Allocate(size_t count) {
   if (!IsOpen())
     return NULL;
-  size_t used_space = size_;
+
+  /* do the alignment computing for mapped file. */
+  size_t used_space = (size_ + __alignof__(T) - 1) & ~(__alignof__(T) - 1);
   size_t required_space = sizeof(T) * count;
   size_t file_size = capacity();
   if (used_space + required_space > file_size) {
@@ -141,13 +143,11 @@ T* MappedFile::Allocate(size_t count) {
     size_t new_size = (std::max)(used_space + required_space, file_size * 2);
     if(!Resize(new_size) || !OpenReadWrite())
       return NULL;
-    // note that size_ has been reset after the file was closed for resizing
-    // now lets restore it to the saved value
-    size_ = used_space;
   }
+
   T* ptr = reinterpret_cast<T*>(address() + used_space);
   std::memset(ptr, 0, required_space);
-  size_ += required_space;
+  size_ = used_space + required_space;
   return ptr;
 }
 
Index: librime/include/rime/dict/table.h
===================================================================
--- librime.orig/include/rime/dict/table.h
+++ librime/include/rime/dict/table.h
@@ -29,7 +29,7 @@ using Code = List<SyllableId>;
 
 struct Entry {
   String text;
-  float weight;
+  double weight;
 };
 
 struct HeadIndexNode {
Index: librime/src/dict/table.cc
===================================================================
--- librime.orig/src/dict/table.cc
+++ librime/src/dict/table.cc
@@ -410,7 +410,7 @@ bool Table::BuildEntry(const DictEntry&
                << "'; file size: " << file_size();
     return false;
   }
-  entry->weight = static_cast<float>(dict_entry.weight);
+  entry->weight = static_cast<double>(dict_entry.weight);
   return true;
 }