How to change the assembly code %hi and %lo to run

问题:

I used 'compiler explorer' to convert c++ to MIPS but it doesn't work well in the MARS because of %hi and %lo

I know I should change the part, but I don't know how to change...

Please help

$L5:
        lui     $2,%hi($LC1)
        lwc1    $f0,%lo($LC1+4)($2)

        lwc1    $f1,%lo($LC1)($2)
        b       $L3
$LC1:
        .word   1100470148
        .word   0

$L17:
        lw      $2,16($fp)
        addiu   $3,$2,1
        sw      $3,16($fp)
        lui     $4,%hi(savepath)
        sll     $3,$2,2
        addiu   $2,$4,%lo(savepath)
        addu    $2,$3,$2
        li      $3,1                        # 0x1
        sw      $3,0($2)
        move    $sp,$fp
        lw      $fp,36($sp)
        addiu   $sp,$sp,40
        j       $31

回答1:

AFAIK, there is no way in Mars to have something like the gas %lo(label) or %hi(label) feature. A simple workaround is to use the standard macro la that loads a label in a register with a pair or lui/ori instructions.

The first part of your code can be rewritten like that:

$L5:
        la      $2, $LC1
        lwc1    $f0,4($2)
        lwc1    $f1,0($2)
        b       $L3
$LC1:
        .word   1100470148
        .word   0

As the la macro is expanded to two instructions,that is an extra instruction compared to the use of %hi/%lo but it works.