我用objdump出来的东西
000083e8 <main>:
83e8:e92d4800 push{fp, lr}
83ec:e28db004 addfp, sp, #4
83f0:e24dd018 subsp, sp, #24
83f4:e24b3014 subr3, fp, #20
83f8:e1a00003 movr0, r3
83fc:e3a01000 movr1, #0
8400:ebffffd1 bl834c <gettimeofday@plt>
8404:e3a01001 movr1, #1
8408:e3b02001 movsr2, #1
840c:e2822001 addr2, r2, #1
8410:e1520f81 cmpr2, r1, lsl #31
8414:1affdef8 bnefffffffc <*ABS*0xfffffffc>
8418:e24b301c subr3, fp, #28
841c:e1a00003 movr0, r3
8420:e3a01000 movr1, #0
8424:ebffffc8 bl834c <gettimeofday@plt>
8428:e51b201c ldrr2, [fp, #-28]
842c:e51b3014 ldrr3, [fp, #-20]
8430:e0633002 rsbr3, r3, r2
8434:e50b3008 strr3, [fp, #-8]
8438:e51b2018 ldrr2, [fp, #-24]
843c:e51b3010 ldrr3, [fp, #-16]
8440:e0633002 rsbr3, r3, r2
8444:e50b300c strr3, [fp, #-12]
8448:e59f302c ldrr3, [pc, #44]; 847c <main+0x94>
844c:e08f3003 addr3, pc, r3
8450:e1a00003 movr0, r3
8454:e51b1008 ldrr1, [fp, #-8]
8458:ebffffb2 bl8328 <printf@plt>
@yangyianni