使用N个汇编指令将N unsigned int []复制到char []中

时间：2015-10-08 06:23:45

标签： c++ assembly

我正在开始一个数独计划，正在尝试有效地将unsigned int[]复制到char[]，同时查看生成的AT＆amp; T x86-64程序集 objdump -d 结果。我正在做的是为了学习目的产生这样的输出（我的代码当前所做的）：

 ------- ------- ------- 
|       | 2   7 |       |
|   1 5 |       | 7 8   |
|   6   | 4   1 |   3   |
 ------- ------- ------- 
|     4 |       | 9     |
| 1 9   |   3   |   2 5 |
|       |       |       |
 ------- ------- ------- 
|   8   |   9   |   1   |
|     2 | 6   8 | 3     |
| 6     |       |     4 |
 ------- ------- -------

我使用unsigned int[]代表董事会，并在static char[]函数中设置printBoard，以便在我致电printBoard(const unsigned int* ac_board)时显示董事会。我希望的是static char[]初始化所需的格式，每次拨打unsigned int[]

时，static char[]都有printBoard 81份副本

目前我无法实现这一目标，我的代码中出现了81 * 2个副本（我编译为g++ -std=c++14 -O3 "$1" -o "$2"）：

...
   100000adc:   88 05 ba 05 00 00       mov    %al,0x5ba(%rip)        # 10000109c <__ZZ10printBoardPKjE10s_printBuf+0x1c>
   100000ae2:   8b 47 04                mov    0x4(%rdi),%eax
   100000ae5:   88 05 b3 05 00 00       mov    %al,0x5b3(%rip)        # 10000109e <__ZZ10printBoardPKjE10s_printBuf+0x1e>
   100000aeb:   8b 47 08                mov    0x8(%rdi),%eax
   100000aee:   88 05 ac 05 00 00       mov    %al,0x5ac(%rip)        # 1000010a0 <__ZZ10printBoardPKjE10s_printBuf+0x20>
   100000af4:   8b 47 0c                mov    0xc(%rdi),%eax
   100000af7:   88 05 a7 05 00 00       mov    %al,0x5a7(%rip)        # 1000010a4 <__ZZ10printBoardPKjE10s_printBuf+0x24>
   100000afd:   8b 47 10                mov    0x10(%rdi),%eax
   100000b00:   88 05 a0 05 00 00       mov    %al,0x5a0(%rip)        # 1000010a6 <__ZZ10printBoardPKjE10s_printBuf+0x26>
   100000b06:   8b 47 14                mov    0x14(%rdi),%eax
...

有没有办法真正实现81 mov 指令而不是81 * 2？

以下是我的main.cpp ：

#include <ctime>

#include "print.hpp"


// -----------------------------------------------------------------------------
unsigned int g_board[81] = {
    0x20, 0x20, 0x20, 0x32, 0x20, 0x37, 0x20, 0x20, 0x20,
    0x20, 0x31, 0x35, 0x20, 0x20, 0x20, 0x37, 0x38, 0x20,
    0x20, 0x36, 0x20, 0x34, 0x20, 0x31, 0x20, 0x33, 0x20,
    0x20, 0x20, 0x34, 0x20, 0x20, 0x20, 0x39, 0x20, 0x20,
    0x31, 0x39, 0x20, 0x20, 0x33, 0x20, 0x20, 0x32, 0x35,
    0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
    0x20, 0x38, 0x20, 0x20, 0x39, 0x20, 0x20, 0x31, 0x20,
    0x20, 0x20, 0x32, 0x36, 0x20, 0x38, 0x33, 0x20, 0x20,
    0x36, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x34
};

// -----------------------------------------------------------------------------
int main() {
    ::std::clock_t begin = clock();
    printBoard(g_board);
    ::std::clock_t end = clock();
    ::std::cout << (end - begin) << ::std::endl;

    return 0;
}

这是我目前最好的print.hpp实现：

#include <iostream>


// -----------------------------------------------------------------------------
void printBoard(const unsigned int* ac_board) {
    static char s_printBuf[] = {
        ' ', '-', '-', '-', '-', '-', '-', '-', ' ', '-', '-', '-', '-',
        '-', '-', '-', ' ', '-', '-', '-', '-', '-', '-', '-', ' ', '\n',
        '|', ' ', 'x', ' ', 'x', ' ', 'x', ' ', '|', ' ', 'x', ' ', 'x',
        ' ', 'x', ' ', '|', ' ', 'x', ' ', 'x', ' ', 'x', ' ', '|', '\n',
        '|', ' ', 'x', ' ', 'x', ' ', 'x', ' ', '|', ' ', 'x', ' ', 'x',
        ' ', 'x', ' ', '|', ' ', 'x', ' ', 'x', ' ', 'x', ' ', '|', '\n',
        '|', ' ', 'x', ' ', 'x', ' ', 'x', ' ', '|', ' ', 'x', ' ', 'x',
        ' ', 'x', ' ', '|', ' ', 'x', ' ', 'x', ' ', 'x', ' ', '|', '\n',
        ' ', '-', '-', '-', '-', '-', '-', '-', ' ', '-', '-', '-', '-',
        '-', '-', '-', ' ', '-', '-', '-', '-', '-', '-', '-', ' ', '\n',
        '|', ' ', 'x', ' ', 'x', ' ', 'x', ' ', '|', ' ', 'x', ' ', 'x',
        ' ', 'x', ' ', '|', ' ', 'x', ' ', 'x', ' ', 'x', ' ', '|', '\n',
        '|', ' ', 'x', ' ', 'x', ' ', 'x', ' ', '|', ' ', 'x', ' ', 'x',
        ' ', 'x', ' ', '|', ' ', 'x', ' ', 'x', ' ', 'x', ' ', '|', '\n',
        '|', ' ', 'x', ' ', 'x', ' ', 'x', ' ', '|', ' ', 'x', ' ', 'x',
        ' ', 'x', ' ', '|', ' ', 'x', ' ', 'x', ' ', 'x', ' ', '|', '\n',
        ' ', '-', '-', '-', '-', '-', '-', '-', ' ', '-', '-', '-', '-',
        '-', '-', '-', ' ', '-', '-', '-', '-', '-', '-', '-', ' ', '\n',
        '|', ' ', 'x', ' ', 'x', ' ', 'x', ' ', '|', ' ', 'x', ' ', 'x',
        ' ', 'x', ' ', '|', ' ', 'x', ' ', 'x', ' ', 'x', ' ', '|', '\n',
        '|', ' ', 'x', ' ', 'x', ' ', 'x', ' ', '|', ' ', 'x', ' ', 'x',
        ' ', 'x', ' ', '|', ' ', 'x', ' ', 'x', ' ', 'x', ' ', '|', '\n',
        '|', ' ', 'x', ' ', 'x', ' ', 'x', ' ', '|', ' ', 'x', ' ', 'x',
        ' ', 'x', ' ', '|', ' ', 'x', ' ', 'x', ' ', 'x', ' ', '|', '\n',
        ' ', '-', '-', '-', '-', '-', '-', '-', ' ', '-', '-', '-', '-',
        '-', '-', '-', ' ', '-', '-', '-', '-', '-', '-', '-', ' ', '\n',
        0
    };

    s_printBuf[28]  = ac_board[0];
    s_printBuf[30]  = ac_board[1];
    s_printBuf[32]  = ac_board[2];
    s_printBuf[36]  = ac_board[3];
    s_printBuf[38]  = ac_board[4];
    s_printBuf[40]  = ac_board[5];
    s_printBuf[44]  = ac_board[6];
    s_printBuf[46]  = ac_board[7];
    s_printBuf[48]  = ac_board[8];

    s_printBuf[54]  = ac_board[9];
    s_printBuf[56]  = ac_board[10];
    s_printBuf[58]  = ac_board[11];
    s_printBuf[62]  = ac_board[12];
    s_printBuf[64]  = ac_board[13];
    s_printBuf[66]  = ac_board[14];
    s_printBuf[70]  = ac_board[15];
    s_printBuf[72]  = ac_board[16];
    s_printBuf[74]  = ac_board[17];

    s_printBuf[80]  = ac_board[18];
    s_printBuf[82]  = ac_board[19];
    s_printBuf[84]  = ac_board[20];
    s_printBuf[88]  = ac_board[21];
    s_printBuf[90]  = ac_board[22];
    s_printBuf[92]  = ac_board[23];
    s_printBuf[96]  = ac_board[24];
    s_printBuf[98]  = ac_board[25];
    s_printBuf[100] = ac_board[26];

    s_printBuf[132] = ac_board[27];
    s_printBuf[134] = ac_board[28];
    s_printBuf[136] = ac_board[29];
    s_printBuf[140] = ac_board[30];
    s_printBuf[142] = ac_board[31];
    s_printBuf[144] = ac_board[32];
    s_printBuf[148] = ac_board[33];
    s_printBuf[150] = ac_board[34];
    s_printBuf[152] = ac_board[35];

    s_printBuf[158] = ac_board[36];
    s_printBuf[160] = ac_board[37];
    s_printBuf[162] = ac_board[38];
    s_printBuf[166] = ac_board[39];
    s_printBuf[168] = ac_board[40];
    s_printBuf[170] = ac_board[41];
    s_printBuf[174] = ac_board[42];
    s_printBuf[176] = ac_board[43];
    s_printBuf[178] = ac_board[44];

    s_printBuf[184] = ac_board[45];
    s_printBuf[186] = ac_board[46];
    s_printBuf[188] = ac_board[47];
    s_printBuf[192] = ac_board[48];
    s_printBuf[194] = ac_board[49];
    s_printBuf[196] = ac_board[50];
    s_printBuf[200] = ac_board[51];
    s_printBuf[202] = ac_board[52];
    s_printBuf[204] = ac_board[53];

    s_printBuf[236] = ac_board[54];
    s_printBuf[238] = ac_board[55];
    s_printBuf[240] = ac_board[56];
    s_printBuf[244] = ac_board[57];
    s_printBuf[246] = ac_board[58];
    s_printBuf[248] = ac_board[59];
    s_printBuf[252] = ac_board[60];
    s_printBuf[254] = ac_board[61];
    s_printBuf[256] = ac_board[62];

    s_printBuf[262] = ac_board[63];
    s_printBuf[264] = ac_board[64];
    s_printBuf[266] = ac_board[65];
    s_printBuf[270] = ac_board[66];
    s_printBuf[272] = ac_board[67];
    s_printBuf[274] = ac_board[68];
    s_printBuf[278] = ac_board[69];
    s_printBuf[280] = ac_board[70];
    s_printBuf[282] = ac_board[71];

    s_printBuf[288] = ac_board[72];
    s_printBuf[290] = ac_board[73];
    s_printBuf[292] = ac_board[74];
    s_printBuf[296] = ac_board[75];
    s_printBuf[298] = ac_board[76];
    s_printBuf[300] = ac_board[77];
    s_printBuf[304] = ac_board[78];
    s_printBuf[306] = ac_board[79];
    s_printBuf[308] = ac_board[80];

    ::std::cout << s_printBuf;
}

0 个答案:

没有答案
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