4.4.2 The Special Dot Symbol

The special symbol . refers to the current address being processed by the assembler. Thus, the expression melvin: .long . defines a label melvin and places the address of that label in the output. Assigning a value to . is treated the same as an .org directive. Thus, the expression .=.+4 is the same as saying .space 4.

When used in an executable section, . refers to a Program Counter address. Ensure that any instructions following where the dot symbol has been modified are properly aligned to the instruction width. For example, if a section contains instructions that are 32-bit wide, the address should be aligned to 4 bytes before any instructions are placed, for example:
.=.+20
.align 4
moreCode:
  li   $2, 55