汇编函数调用

sem.s(函数调用计算2^3+5^2)

.section .data

.section .text
.globl _start
_start:
 pushl $3
 pushl $2
 call power
 addl $8, %esp
 pushl %eax
 pushl $2
 pushl $5
 call power
 addl $8, %esp
 popl %ebx
 addl %eax, %ebx
 
 movl $1, %eax
 int $0x80

.type power, @function
power:
 pushl %ebp
 movl %esp, %ebp
 subl $4, %esp

 movl 8(%ebp), %ebx
 movl 12(%ebp), %ecx
 movl %ebx, -4(%ebp)

power_loop_start:
 cmpl $1, %ecx
 je end_power
 movl -4(%ebp), %eax
 imull %ebx, %eax

 movl %eax, -4(%ebp)
 
 decl %ecx
 jmp power_loop_start

end_power:
 movl -4(%ebp), %eax
 movl %ebp, %esp
 popl %ebp
 ret


 

编译：

as sem.s -o sem.o

ld sem.o -o sem