MIPS directives

Declares a section for storing initialized data, such as variables.

Declares a section for storing executable instructions. This is where program logic is written.

Declares a section for storing kernel-mode initialized data.

Declares a section for storing kernel-mode executable instructions.

Allocates one or more 32-bit (4-byte) words in memory.

Example:

values: .word 1, 2, 3, 4

Allocates one or more 16-bit (2-byte) halfwords in memory.

Example:

values: .half 1234, 5678

Allocates one or more 8-bit (1-byte) values in memory.

Example:

flags: .byte 0, 1, 1, 0

Allocates a single-precision floating-point (32-bit) number in memory.

Allocates a double-precision floating-point (64-bit) number in memory.

Stores a null-terminated string (C-style string).

Example:

message: .asciiz "Hello, world!"

Stores a string without a null terminator. Useful when manually handling string length.

Reserves a specified number of bytes in memory without initializing them.

Example:

buffer: .space 100   # Reserves 100 bytes

Aligns the next data to a 2^n-byte boundary.

Example:

.align 2   # Aligns to a 4-byte boundary

Marks a symbol as global, making it accessible from other files.

Example:

.globl main   # Makes 'main' visible to the linker

Declares a symbol that is defined in another file, specifying its size.

Defines a macro, which allows writing reusable code blocks.

Ends a macro definition.

Includes an external assembly file.

Example:

.include "myfile.s"

Defines a symbolic constant, similar to #define in C.

Example:

.eqv SIZE 10

Configures assembler settings, such as allowing modifications to the $at register.

Example:

.set noat  # Allows use of register $at

Declares an uninitialized data section, typically used for reserving large blocks of memory.

Describes a function's stack frame for the debugger: base register, stack size and return register. MARS accepts it and does nothing with it, so that compiler output assembles unchanged.

Marks the start of a function for the debugger. MARS accepts it and does nothing with it, so that compiler output assembles unchanged.

Marks the end of a function for the debugger. MARS accepts it and does nothing with it, so that compiler output assembles unchanged.

Marks a symbol as local to this file for the linker. MARS accepts it and does nothing with it, so that compiler output assembles unchanged.

Switches to the named section. A read-only or zeroed section becomes part of the data segment here.

Example:

.section .rodata

Declares a section for read-only initialized data, such as string literals. Read-only data is not stored separately in this simulator, so it joins the data segment.

Alias for .rdata.

Alias for .bss.

Reserves bytes for an uninitialized global variable, the way a C compiler declares one. Takes a symbol, a size in bytes and an optional alignment, and leaves the current section unchanged.

Example:

.comm total, 4, 4

Like .comm, but for a symbol local to this file, as a C compiler declares an uninitialized static variable.

Reserves the given number of bytes, which read as zero. Alias for .space.

Alias for .align: aligns the next item on a 2^n byte boundary.

Aligns the next item on the given byte boundary, written directly rather than as a power of two.

Example:

.balign 8

Alias for .half.

Alias for .word.

Alias for .asciiz: stores a null-terminated string.

Alias for .asciiz: stores a null-terminated string.

Alias for .globl.