Sizes and Offsets

The intermediate language aims to be platform independent. In particular, it supports both 32- and 64-bit systems. Since the size of a pointer differs on 32- and 64-bit systems, the sizes of data structures typically differ between the two. For this reason, the intermediate language provides two datatypes, core.asm.Size and core.asm.Offset to make it easier to work with sizes and offsets in a platform-agnostic manner. Both types achieve this by storing both a 32-bit and a 64-bit size and offset respectively.


The core.asm.Size type represents the size of some data in memory. As mentioned above, the Size type contains two versions of the size. One for 32-bit systems, and another for 64-bit systems.

Each size consists of an unsigned integer that represents the size. In addition, each size contains the alignment of the data. The size portion of the data is not aligned internally, but it is automatically aligned when it is retrieved. The 32-bit size is retrieved through the member size32, and the 64-bit size is retrieved through the member size64. In portable code, the member current can be used to retrieve the size for the current platform.

Since the size is not aligned internally, addition and multiplication operates on the unaligned size. It is, however, possible to force alignment of the internal size by calling the aligned member. Similarly, it is possible to remove the internal alignment by calling the unaligned member.

There are a number of pre-defined constants in the package core.asm that create sizes for Storm types:


The core.asm.Offset type represents an offset into a type. An offset is signed and can thereby be negative. Furthermore, the offset does not carry an alignment. It can, however, be manually aligned using the alignAs member. The stored value can be retrieved using v32 or v64 for specific offsets, or using the current member for the current platform.