user: 这段汇编代码用C语言表示是什么样的：

```asm
<Railgun7a>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x470,%rsp
  mov    %rdi,-0x458(%rbp)
  mov    %esi,-0x45c(%rbp)
  mov    %rdx,-0x468(%rbp)
  mov    %ecx,-0x460(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x8(%rbp)
  xor    %eax,%eax
  mov    -0x458(%rbp),%rax
  mov    %rax,-0x428(%rbp)
  mov    -0x468(%rbp),%rax
  mov    %rax,-0x420(%rbp)
  mov    -0x45c(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x428(%rbp),%rax
  add    %rdx,%rax
  mov    %rax,-0x418(%rbp)
  mov    -0x460(%rbp),%eax
  cmp    -0x45c(%rbp),%eax
  jle    L354
  mov    $0x0,%eax
  jmp    L84
L354:
  cmpl   $0x1,-0x460(%rbp)
  jne    L305
  mov    -0x420(%rbp),%rax
  mov    (%rax),%ecx
  mov    -0x45c(%rbp),%edx
  mov    -0x428(%rbp),%rax
  mov    %ecx,%esi
  mov    %rax,%rdi
  call   <memchr@plt>
  jmp    L84
L305:
  cmpl   $0x2,-0x460(%rbp)
  jne    L132
  addq   $0x8,-0x428(%rbp)
  mov    -0x420(%rbp),%rax
  mov    (%rax),%eax
  shl    $0x8,%eax
  mov    %eax,%edx
  mov    -0x420(%rbp),%rax
  add    $0x4,%rax
  mov    (%rax),%eax
  add    %edx,%eax
  mov    %eax,-0x43c(%rbp)
L394:
  mov    -0x428(%rbp),%rax
  sub    $0x8,%rax
  mov    (%rax),%eax
  shl    $0x8,%eax
  mov    %eax,%edx
  mov    -0x428(%rbp),%rax
  sub    $0x4,%rax
  mov    (%rax),%eax
  add    %edx,%eax
  cmp    %eax,-0x43c(%rbp)
  jne    L287
  mov    -0x428(%rbp),%rax
  sub    $0x2,%rax
  jmp    L84
L287:
  mov    -0x43c(%rbp),%eax
  sar    $0x8,%eax
  mov    %eax,%edx
  mov    -0x428(%rbp),%rax
  sub    $0x4,%rax
  mov    (%rax),%eax
  cmp    %eax,%edx
  jne    L438
  mov    $0x4,%eax
  jmp    L40
L438:
  mov    $0x8,%eax
L40:
  add    %rax,-0x428(%rbp)
  mov    -0x428(%rbp),%rax
  cmp    -0x418(%rbp),%rax
  jbe    L394
  mov    $0x0,%eax
  jmp    L84
L132:
  cmpl   $0x3,-0x460(%rbp)
  jne    L362
  addq   $0xc,-0x428(%rbp)
  mov    -0x420(%rbp),%rax
  mov    (%rax),%eax
  shl    $0x8,%eax
  mov    %eax,%edx
  mov    -0x420(%rbp),%rax
  add    $0x8,%rax
  mov    (%rax),%eax
  add    %edx,%eax
  mov    %eax,-0x43c(%rbp)
L477:
  mov    -0x428(%rbp),%rax
  sub    $0xc,%rax
  mov    (%rax),%eax
  shl    $0x8,%eax
  mov    %eax,%edx
  mov    -0x428(%rbp),%rax
  sub    $0x4,%rax
  mov    (%rax),%eax
  add    %edx,%eax
  cmp    %eax,-0x43c(%rbp)
  jne    L412
  mov    -0x420(%rbp),%rax
  add    $0x4,%rax
  mov    (%rax),%edx
  mov    -0x428(%rbp),%rax
  sub    $0x8,%rax
  mov    (%rax),%eax
  cmp    %eax,%edx
  jne    L412
  mov    -0x428(%rbp),%rax
  sub    $0x3,%rax
  jmp    L84
L412:
  mov    -0x43c(%rbp),%eax
  sar    $0x8,%eax
  mov    %eax,%edx
  mov    -0x428(%rbp),%rax
  sub    $0x8,%rax
  mov    (%rax),%eax
  cmp    %eax,%edx
  jne    L173
  mov    $0x4,%eax
  jmp    L166
L173:
  mov    $0x8,%eax
L166:
  add    %rax,-0x428(%rbp)
  mov    -0x428(%rbp),%rax
  cmp    -0x418(%rbp),%rax
  jbe    L477
  mov    $0x0,%eax
  jmp    L84
L362:
  cmpl   $0x3c0,-0x45c(%rbp)
  jg     L332
  mov    -0x460(%rbp),%eax
  cltq
  shl    $0x2,%rax
  add    %rax,-0x428(%rbp)
  mov    -0x420(%rbp),%rax
  mov    (%rax),%eax
  mov    %eax,-0x43c(%rbp)
  mov    -0x43c(%rbp),%eax
  mov    %eax,-0x438(%rbp)
  mov    -0x438(%rbp),%eax
  shl    $0x8,%eax
  mov    %eax,%edx
  mov    -0x438(%rbp),%eax
  shl    $0x10,%eax
  or     %eax,%edx
  mov    -0x438(%rbp),%eax
  shl    $0x18,%eax
  or     %edx,%eax
  mov    %eax,-0x434(%rbp)
L336:
  mov    -0x460(%rbp),%eax
  cltq
  shl    $0x2,%rax
  neg    %rax
  mov    %rax,%rdx
  mov    -0x428(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%eax
  mov    %eax,-0x430(%rbp)
  mov    -0x43c(%rbp),%eax
  cmp    -0x430(%rbp),%eax
  jne    L44
  movl   $0x1,-0x448(%rbp)
  mov    -0x460(%rbp),%eax
  sub    $0x1,%eax
  mov    %eax,-0x444(%rbp)
  jmp    L221
L376:
  mov    -0x460(%rbp),%eax
  lea    -0x1(%rax),%edx
  mov    -0x448(%rbp),%ecx
  mov    -0x444(%rbp),%eax
  add    %ecx,%eax
  cmp    %eax,%edx
  jne    L310
  mov    -0x444(%rbp),%eax
  neg    %eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x428(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%eax
  cmp    %eax,-0x438(%rbp)
  je     L310
  addl   $0x1,-0x448(%rbp)
L310:
  subl   $0x1,-0x444(%rbp)
L221:
  cmpl   $0x0,-0x444(%rbp)
  je     L6
  mov    -0x460(%rbp),%eax
  sub    -0x444(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x420(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%edx
  mov    -0x444(%rbp),%eax
  neg    %eax
  cltq
  lea    0x0(,%rax,4),%rcx
  mov    -0x428(%rbp),%rax
  add    %rcx,%rax
  mov    (%rax),%eax
  cmp    %eax,%edx
  je     L376
L6:
  cmpl   $0x0,-0x444(%rbp)
  jne    L233
  mov    -0x460(%rbp),%eax
  cltq
  neg    %rax
  mov    %rax,%rdx
  mov    -0x428(%rbp),%rax
  add    %rdx,%rax
  jmp    L84
L44:
  mov    -0x430(%rbp),%eax
  xor    -0x434(%rbp),%eax
  mov    %eax,-0x42c(%rbp)
  mov    -0x42c(%rbp),%eax
  and    $0xff00,%eax
  test   %eax,%eax
  je     L419
  mov    -0x42c(%rbp),%eax
  and    $0xff0000,%eax
  test   %eax,%eax
  je     L396
  mov    -0x42c(%rbp),%eax
  and    $0xff000000,%eax
  test   %eax,%eax
  jne    L71
  mov    $0x3,%eax
  jmp    L210
L71:
  mov    $0x4,%eax
  jmp    L210
L396:
  mov    $0x2,%eax
  jmp    L210
L419:
  mov    $0x1,%eax
L210:
  mov    %eax,-0x448(%rbp)
L233:
  mov    -0x448(%rbp),%eax
  cltq
  shl    $0x2,%rax
  add    %rax,-0x428(%rbp)
  mov    -0x428(%rbp),%rax
  cmp    -0x418(%rbp),%rax
  jbe    L336
  mov    $0x0,%eax
  jmp    L84
L332:
  movl   $0x0,-0x440(%rbp)
  jmp    L259
L425:
  mov    -0x440(%rbp),%eax
  cltq
  mov    -0x460(%rbp),%edx
  mov    %edx,-0x410(%rbp,%rax,4)
  addl   $0x1,-0x440(%rbp)
L259:
  cmpl   $0xff,-0x440(%rbp)
  jle    L425
  movl   $0x0,-0x440(%rbp)
  jmp    L467
L279:
  mov    -0x460(%rbp),%eax
  sub    -0x440(%rbp),%eax
  mov    %eax,%edx
  mov    -0x440(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rcx
  mov    -0x420(%rbp),%rax
  add    %rcx,%rax
  mov    (%rax),%eax
  sub    $0x1,%edx
  cltq
  mov    %edx,-0x410(%rbp,%rax,4)
  addl   $0x1,-0x440(%rbp)
L467:
  mov    -0x460(%rbp),%eax
  sub    $0x1,%eax
  cmp    %eax,-0x440(%rbp)
  jl     L279
  mov    -0x420(%rbp),%rax
  mov    (%rax),%eax
  mov    %eax,-0x43c(%rbp)
  movl   $0x0,-0x440(%rbp)
  jmp    L399
L448:
  mov    -0x440(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x428(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%eax
  cmp    %eax,-0x43c(%rbp)
  jne    L157
  mov    -0x460(%rbp),%eax
  sub    $0x4,%eax
  mov    %eax,-0x444(%rbp)
  jmp    L128
L222:
  subl   $0x1,-0x444(%rbp)
L128:
  cmpl   $0x0,-0x444(%rbp)
  jle    L42
  mov    -0x460(%rbp),%eax
  sub    -0x444(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x420(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%edx
  mov    -0x440(%rbp),%ecx
  mov    -0x460(%rbp),%eax
  add    %ecx,%eax
  sub    -0x444(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rcx
  mov    -0x428(%rbp),%rax
  add    %rcx,%rax
  mov    (%rax),%eax
  cmp    %eax,%edx
  je     L222
L42:
  cmpl   $0x0,-0x444(%rbp)
  jne    L157
  mov    -0x440(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x428(%rbp),%rax
  add    %rdx,%rax
  jmp    L84
L157:
  mov    -0x440(%rbp),%edx
  mov    -0x460(%rbp),%eax
  add    %edx,%eax
  cltq
  shl    $0x2,%rax
  lea    -0x4(%rax),%rdx
  mov    -0x428(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%eax
  cltq
  mov    -0x410(%rbp,%rax,4),%eax
  add    %eax,-0x440(%rbp)
L399:
  mov    -0x45c(%rbp),%eax
  sub    -0x460(%rbp),%eax
  cmp    %eax,-0x440(%rbp)
  jle    L448
  mov    $0x0,%eax
L84:
  mov    -0x8(%rbp),%rdx
  sub    %fs:0x28,%rdx
  je     L75
  call   <__stack_chk_fail@plt>
L75:
  leave
  ret
```

assistant: ```c
char *Railgun7a(char *target, int tgtlen, char *pattern, int patlen) {
  uint8_t *tgt = (uint8_t *)target, *pat = (uint8_t *)pattern;
  uint8_t *tgtMax = tgt + tgtlen;
  uint32_t patwin, tgtwin;
  int skip, count;
  int bm_bc[256];
  if (patlen > tgtlen)
    return NULL;
  if (patlen == 1)
    return memchr(tgt, *pat, tgtlen);
  if (patlen == 2) {
    tgt += 2;
    patwin = (pat[0] << 8) + pat[1];
    while (1) {
      if (patwin == ((uint32_t)tgt[-2] << 8) + tgt[-1])
        return (char *)tgt - 2;
      tgt += (uint8_t)(patwin >> 8) == tgt[-1] ? 1 : 2;
      if (tgt > tgtMax)
        return NULL;
    }
  } else if (patlen == 3) {
    tgt += 3;
    patwin = (pat[0] << 8) + pat[2];
    while (1) {
      if (patwin == ((uint32_t)tgt[-3] << 8) + tgt[-1]) {
        if (pat[1] == tgt[-2])
          return (char *)tgt - 3;
      }
      tgt += (uint8_t)(patwin >> 8) == tgt[-2] ? 1 : 2;
      if (tgt > tgtMax)
        return NULL;
    }
  } else if (tgtlen < 961) {
    tgt = tgt + patlen;
    patwin = *(uint32_t *)pat;
    uint8_t pat0 = (uint8_t)patwin;
    uint32_t ppp0 = (pat0 << 8) | (pat0 << 16) | (pat0 << 24);
    while (1) {
      tgtwin = *(uint32_t *)(tgt - patlen);
      if (patwin == tgtwin) {
        skip = 1;
        for (count = patlen - 1; count && pat[patlen - count] == tgt[-count]; count--) {
          if (patlen - 1 == skip + count && pat0 != tgt[-count])
            skip++;
        }
        if (count == 0)
          return (char *)tgt - patlen;
      } else {
        uint32_t diff = tgtwin ^ ppp0;
        skip = !(diff & 0x0000FF00) ? 1 : !(diff & 0x00FF0000) ? 2 : !(diff & 0xFF000000) ? 3 : 4;
      }
      tgt = tgt + skip;
      if (tgt > tgtMax)
        return NULL;
    }
  } else {
    int i;
    for (i = 0; i < 256; i++)
      bm_bc[i] = patlen;
    for (i = 0; i < patlen - 1; i++)
      bm_bc[pat[i]] = patlen - i - 1;
    patwin = *(uint32_t *)pat;
    for (i = 0; i <= tgtlen - patlen; i = i + bm_bc[tgt[i + patlen - 1]]) {
      if (*(uint32_t *)&tgt[i] == patwin) {
        count = patlen - 4;
        while (count > 0 && pat[patlen - count] == tgt[i + patlen - count])
          count--;
        if (count == 0)
          return (char *)tgt + i;
      }
    }
    return NULL;
  }
}
```