MIPSの引数4つ以上の関数呼出し規約どうなってる？

goodbye.s

goodbye:
        .set    nomips16
        .frame  $fp,8,$31               # vars= 0, regs= 1/0, args= 0, gp= 0
        .mask   0x40000000,-4
        .fmask  0x00000000,0
        .set    noreorder
        .set    nomacro

        addiu   $sp,$sp,-8
        sw      $fp,4($sp)
        move    $fp,$sp
        sw      $4,8($fp)
        sw      $5,12($fp)
        sw      $6,16($fp)
        sw      $7,20($fp)
        lw      $3,8($fp)
        lw      $2,12($fp)
        nop
        addu    $3,$3,$2
        lw      $2,16($fp)
        nop
        addu    $3,$3,$2
        lw      $2,20($fp)
        nop
        addu    $3,$3,$2
        lw      $2,24($fp)
        nop
        addu    $3,$3,$2
        lw      $2,28($fp)
        nop
        addu    $2,$3,$2
        move    $sp,$fp
        lw      $fp,4($sp)
        addiu   $sp,$sp,8
        j       $31
        nop

main.s

main:
        lw      $28,24($fp)
        li      $2,5                    # 0x5
        sw      $2,16($sp)
        li      $2,6                    # 0x6
        sw      $2,20($sp)
        li      $4,1                    # 0x1
        li      $5,2                    # 0x2
        li      $6,3                    # 0x3
        li      $7,4                    # 0x4
        lw      $25,%call16(goodbye)($28)
        nop
        jalr    $25
        nop

        lw      $28,24($fp)
        move    $2,$0
        move    $sp,$fp
        lw      $31,36($sp)
        lw      $fp,32($sp)
        addiu   $sp,$sp,40
        j       $31
        nop