CSC448: Code Generation: Simplified Example [64/133]

GCC's output can be simplified:

.global _main

.text
        .align 4

_main:
        pushl   %ebp
        movl    %esp, %ebp
        subl    $8, %esp

        movl    $3, -4(%ebp)
        jmp     lab2
lab1:
        pushl   -4(%ebp)
        pushl   $somenameforthestring
        call    _printf
        addl    $8, %esp
        leal    -4(%ebp), %eax
        decl    (%eax)
lab2:
        cmpl    $0, -4(%ebp)
        jns     lab1

        movl    $0, %eax
        leave
        ret


.section .rodata

somenameforthestring:
        .string "%d\n"
        

$ gcc -o loop simplified-loop.s
$ ./loop 
3
2
1
0
        

For Linux (note underscore changes):

.global main

.text
        .align 4

main:
        pushl   %ebp
        movl    %esp, %ebp
        subl    $8, %esp

        movl    $3, -4(%ebp)
        jmp     lab2
lab1:
        pushl   -4(%ebp)
        pushl   $somenameforthestring
        call    printf
        addl    $8, %esp
        leal    -4(%ebp), %eax
        decl    (%eax)
lab2:
        cmpl    $0, -4(%ebp)
        jns     lab1

        movl    $0, %eax
        leave
        ret


.section .rodata

somenameforthestring:
        .string "%d\n"