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  1. #include <iostream>
  2. #include <cstring>
  3. #include <iomanip>
  4.  
  5. // 打印内存内容的工具函数
  6. void hexdump(const void* addr, size_t len) {
  7.     const uint8_t* p = static_cast<const uint8_t*>(addr);
  8.     std::cout << "Address  | 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F\n";
  9.     std::cout << "---------|------------------------------------------------\n";
  10.     for (size_t i = 0; i < len; i += 16) {
  11.         std::cout << reinterpret_cast<const void*>(p + i) << " | ";
  12.         for (int j = 0; j < 16 && (i + j) < len; ++j) {
  13.             std::cout << std::hex << std::setw(2) << std::setfill('0') 
  14.                       << static_cast<int>(p[i + j]) << " ";
  15.         }
  16.         std::cout << "\n";
  17.     }
  18. }
  19.  
  20. int main() {
  21.     // 64字节对齐的缓冲区（避免实验噪声）
  22.     alignas(64) uint8_t buffer[32];
  23.     memset(buffer, 0xAA, sizeof(buffer)); // 填充初始值 0xAA
  24.  
  25.     // 在地址 0x6 处强制放置 int64_t（跨越 0x0~0x7 和 0x8~0xF 两个 8 字节块）
  26.     int64_t* unaligned_ptr = reinterpret_cast<int64_t*>(buffer + 6);
  27.     *unaligned_ptr = 0x1122334455667788; // 写入测试值
  28.  
  29.     // 转储内存，观察写入位置和总线读取行为
  30.     std::cout << "=== 内存转储 (写入地址 0x6~0xD) ===\n";
  31.     hexdump(buffer, 32);
  32.  
  33.     // 验证读取操作是否成功
  34.     volatile int64_t read_value = *unaligned_ptr; // volatile 阻止编译器优化
  35.     std::cout << "\n读取值: 0x" << std::hex << read_value << std::endl;
  36.  
  37.     return 0;
  38. }
Success #stdin #stdout 0.01s 5292KB
comments (?)
stdin 
Standard input is empty
stdout 
=== 内存转储 (写入地址 0x6~0xD) ===
Address  | 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
---------|------------------------------------------------
0x7ffcd9a17500 | aa aa aa aa aa aa 88 77 66 55 44 33 22 11 aa aa 
0x7ffcd9a17510 | aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa 

读取值: 0x1122334455667788
https://ideone.com/KmYMCo
language:
C++14 (gcc 8.3)
created:
5 days ago
visibility:
public

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