小小的发现

   先贴点代码,后面再说明问题.

#include <stdio.h>

void god(int [3][2][2]);

int main(void){
    int i[3][2][2]={{{123,456},{789,101}},{{121,314},{151,617}},{{888,777},{999,333}}};
    int (*p)[2][2]=i;
    god(p);
    return 0;
}

void god(int i[3][2][2]){
    printf("%d\n",i[2][0][1]);
    printf("%d\n",*(*(*(i+2))+1));
    printf("%d\n",*(i+2)[0][1]);
}

.file "test.c"

.text

.globl main

.type main, @function

main:

pushl %ebp

movl %esp, %ebp

andl $-16, %esp

subl $80, %esp

movl $123, 28(%esp)

movl $456, 32(%esp)

movl $789, 36(%esp)

movl $101, 40(%esp)

movl $121, 44(%esp)

movl $314, 48(%esp)

movl $151, 52(%esp)

movl $617, 56(%esp)

movl $888, 60(%esp)

movl $777, 64(%esp)

movl $999, 68(%esp)

movl $333, 72(%esp)

leal 28(%esp), %eax

movl %eax, 76(%esp)

movl 76(%esp), %eax

movl %eax, (%esp)

call god

movl $0, %eax

leave

ret

.size main, .-main

.section .rodata

.LC0:

.string "%d\n"

.text

.globl god

.type god, @function

god:

pushl %ebp

movl %esp, %ebp

subl $24, %esp

movl 8(%ebp), %eax

addl $32, %eax

movl 4(%eax), %edx

movl $.LC0, %eax

movl %edx, 4(%esp)

movl %eax, (%esp)

call printf

movl 8(%ebp), %eax

addl $36, %eax

movl (%eax), %edx

movl $.LC0, %eax

movl %edx, 4(%esp)

movl %eax, (%esp)

call printf

movl 8(%ebp), %eax

addl $40, %eax

movl (%eax), %edx

movl $.LC0, %eax

movl %edx, 4(%esp)

movl %eax, (%esp)

call printf

leave

ret

.size god, .-god

.ident "GCC: (Ubuntu 4.4.3-4ubuntu5) 4.4.3"

.section .note.GNU-stack,"",@progbits

test.s

关键在于对应的3句打印结果的汇编,分别是:

printf("%d\n",i[2][0][1]); 对应着 addl $32, %eax 和 movl 4(%eax), %edx;

printf("%d\n",*(*(*(i+2))+1)); 对应着 addl $36, %eax 和 movl (%eax), %edx;

printf("%d\n",*(i+2)[0][1]); 对应着 movl 8(%ebp), %eax 和 addl $40, %eax;

然后他们打印出来的值顺序为:777 777 999

这说明一个问题,对数组操作,要么就都指针,要么就都下标,尽量避免这种组合型的.