//x86平台 x86指令集，intel风格test.c
#include <stdio.h>
int add(void) {
long eax=4;
long ebx=2;
__asm__ __volatile__ ("addl %1, %0"
: "=b"((long)ebx)
: "a"((long)eax), "b"((long)ebx)
: "1"
);
printf("ebx=%d/n", ebx);
return 0;
}
int main(){
int a=12;
char *hello="hello,world/n";
__asm__(
".intel_syntax noprefix/n"
"mov eax,4/n"
"mov ebx,1/n"
"mov ecx,%0/n"
"mov edx,%1/n"
"int 0x80/n"
".att_syntax/n"
:
:"r"(hello),"r"(a)
:"eax","ebx","ecx","edx"
);
add();
exit(0);
}
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//x86平台 x86指令集 ，at&t风格test.c
#include<stdio.h>
int sum(int a, int b)
{
int r;
__asm__(
"sub $0x4, %%esp/n"
"movl 0xc(%%ebp), %%eax/n"
"addl 0x8(%%ebp),%%eax/n"
" movl %%eax, 0xfffffffc(%%ebp)/n"
" movl 0xfffffffc(%%ebp), %%eax/n"
" movl %%eax, %%eax/n"
: "=a"(r)
);
return r;
}
int main()
{
int x = sum(10,2);
printf("x = %d/n", x);
return 0;
}
gcc -o test test.c
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//arm 平台，用arm平台的指令集 ，test.c
int main()
{
//printf("starting.../n");
//直接内嵌
汇编 __asm__(
"ldr r0, =0x30000000/n"//别忘记加个等号
"mov r1,#1/n"
"str r1,[r0]/n"
);
}
arm-linux-gcc -o test test.c
