asm

MIPS ASM

Calling convention

Top of stack
+----------------+ <- old $sp
| $ra            |
| old $fp        |
| ...            |
+----------------+ <- $16($fp)
| reserved       |
+----------------+ <- 0($fp)
| dynamic area   |
+----------------+ <- 0($sp)

The stack size is at least 24.

• Example:

    .globl  func
    .ent    func
func:
    .frame  $fp,24,$ra  # this is necessary to allow backtracing
    addi   $sp,$sp,-24
    sw      $ra,20($sp)
    sw      $fp,16($sp)
    move    $fp,$sp

    move    $sp,$fp
    lw  $ra,20($sp)
    lw  $fp,16($sp)
    addi   $sp,$sp,24
    .end    func

See inc.s

Macros

GNU AS:

.macro (name)
...
.endm

MARS:

.macro (name)
...
.end_macro

References

• 1
• 2