# Labels (ivss)

A **label** names the current byte offset in a section. It lets instructions and data refer to locations without hard-coding the final address:

```asm
.section my_data
first:
    .word 11
second:
    .word 22
```

`first` has section-relative value zero; `second` has value four because one word occupies four bytes. Neither declaration itself emits bytes. Once the linker places the section, a label's address is:

$$
A_{\mathrm{label}}=B_{\mathrm{section}}+V_{\mathrm{label}}
$$

Here $B_{\mathrm{section}}$ is the section's base address and $V_{\mathrm{label}}$ is the recorded offset. Moving the section changes both addresses while preserving their four-byte separation.

A use such as `ld $second, %r1` requests the label's address; `ld second, %r1` requests the value stored there. The assembler can record an unresolved symbol use before encountering its definition, leaving the required relocation for linking.

Labels are local unless exported with [[ivss-symbol-visibility|`.global`]]. Their names provide identity, while their section and value determine location; the eventual address need not appear literally in the source.

Source: [asembler.c](https://github.com/yanevskiv/ivss/blob/main/src/asembler.c).