user: Converte this assembly snippet into its equivalent C code:

```asm
<veryfastmemcpy>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x90,%rsp
  mov    %rdi,-0x78(%rbp)
  mov    %rsi,-0x80(%rbp)
  mov    %edx,-0x84(%rbp)
  mov    -0x78(%rbp),%rax
  and    $0x3,%eax
  test   %eax,%eax
  jne    L124
  mov    -0x80(%rbp),%rax
  and    $0x3,%eax
  test   %eax,%eax
  jne    L124
  mov    -0x84(%rbp),%eax
  and    $0x3,%eax
  mov    %eax,-0x58(%rbp)
  mov    -0x58(%rbp),%edx
  mov    -0x84(%rbp),%eax
  sub    %edx,%eax
  mov    %eax,-0x54(%rbp)
  mov    -0x54(%rbp),%eax
  lea    0x3(%rax),%edx
  test   %eax,%eax
  cmovs  %edx,%eax
  sar    $0x2,%eax
  mov    %eax,-0x50(%rbp)
  mov    -0x78(%rbp),%rax
  mov    %rax,-0x40(%rbp)
  mov    -0x80(%rbp),%rax
  mov    %rax,-0x38(%rbp)
  mov    -0x54(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x78(%rbp),%rax
  add    %rdx,%rax
  mov    %rax,-0x30(%rbp)
  mov    -0x54(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x80(%rbp),%rax
  add    %rdx,%rax
  mov    %rax,-0x28(%rbp)
  movl   $0x0,-0x64(%rbp)
  jmp    L92
L27:
  mov    -0x64(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x38(%rbp),%rax
  add    %rdx,%rax
  mov    -0x64(%rbp),%edx
  movslq %edx,%rdx
  lea    0x0(,%rdx,4),%rcx
  mov    -0x40(%rbp),%rdx
  add    %rcx,%rdx
  mov    (%rax),%eax
  mov    %eax,(%rdx)
  addl   $0x1,-0x64(%rbp)
L92:
  mov    -0x64(%rbp),%eax
  cmp    -0x50(%rbp),%eax
  jl     L27
  movl   $0x0,-0x60(%rbp)
  jmp    L0
L72:
  mov    -0x60(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    -0x60(%rbp),%edx
  movslq %edx,%rcx
  mov    -0x30(%rbp),%rdx
  add    %rcx,%rdx
  movzbl (%rax),%eax
  mov    %al,(%rdx)
  addl   $0x1,-0x60(%rbp)
L0:
  mov    -0x60(%rbp),%eax
  cmp    -0x58(%rbp),%eax
  jl     L72
  jmp    L56
L124:
  mov    -0x78(%rbp),%rax
  and    $0x1,%eax
  test   %eax,%eax
  jne    L126
  mov    -0x80(%rbp),%rax
  and    $0x1,%eax
  test   %eax,%eax
  jne    L126
  mov    -0x84(%rbp),%eax
  and    $0x1,%eax
  mov    %eax,-0x4c(%rbp)
  mov    -0x4c(%rbp),%edx
  mov    -0x84(%rbp),%eax
  sub    %edx,%eax
  mov    %eax,-0x48(%rbp)
  mov    -0x48(%rbp),%eax
  mov    %eax,%edx
  shr    $0x1f,%edx
  add    %edx,%eax
  sar    %eax
  mov    %eax,-0x44(%rbp)
  mov    -0x78(%rbp),%rax
  mov    %rax,-0x20(%rbp)
  mov    -0x80(%rbp),%rax
  mov    %rax,-0x18(%rbp)
  mov    -0x48(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x78(%rbp),%rax
  add    %rdx,%rax
  mov    %rax,-0x10(%rbp)
  mov    -0x48(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x80(%rbp),%rax
  add    %rdx,%rax
  mov    %rax,-0x8(%rbp)
  movl   $0x0,-0x5c(%rbp)
  jmp    L3
L115:
  mov    -0x5c(%rbp),%eax
  cltq
  lea    (%rax,%rax,1),%rdx
  mov    -0x18(%rbp),%rax
  add    %rdx,%rax
  mov    -0x5c(%rbp),%edx
  movslq %edx,%rdx
  lea    (%rdx,%rdx,1),%rcx
  mov    -0x20(%rbp),%rdx
  add    %rcx,%rdx
  movzwl (%rax),%eax
  mov    %ax,(%rdx)
  addl   $0x1,-0x5c(%rbp)
L3:
  mov    -0x5c(%rbp),%eax
  cmp    -0x44(%rbp),%eax
  jl     L115
  cmpl   $0x0,-0x4c(%rbp)
  je     L59
  mov    -0x8(%rbp),%rax
  movzbl (%rax),%edx
  mov    -0x10(%rbp),%rax
  mov    %dl,(%rax)
  jmp    L59
L126:
  mov    -0x84(%rbp),%edx
  mov    -0x80(%rbp),%rcx
  mov    -0x78(%rbp),%rax
  mov    %rcx,%rsi
  mov    %rax,%rdi
  call   <pigfx_memcpy@plt>
  jmp    L56
L59:
  nop
L56:
  nop
  leave
  ret
```

assistant: ```c
void veryfastmemcpy(void *dest, void *src, unsigned int n) {
  if ((((unsigned int)dest & 0x3) == 0) && (((unsigned int)src & 0x3) == 0)) {
    int single = n & 0x3;
    int singpos = n - single;
    int quad = singpos / 4;
    unsigned int *qdest = dest;
    unsigned int *qsrc = src;
    unsigned char *sdest = (unsigned char *)dest + singpos;
    unsigned char *ssrc = (unsigned char *)src + singpos;
    for (int q = 0; q < quad; q++) {
      qdest[q] = qsrc[q];
    }
    for (int s = 0; s < single; s++) {
      sdest[s] = ssrc[s];
    }
  } else if ((((unsigned int)dest & 0x1) == 0) && (((unsigned int)src & 0x1) == 0)) {
    int single = n & 0x1;
    int singpos = n - single;
    int dbl = singpos / 2;
    unsigned short int *ddest = dest;
    unsigned short int *dsrc = src;
    unsigned char *sdest = (unsigned char *)dest + singpos;
    unsigned char *ssrc = (unsigned char *)src + singpos;
    for (int d = 0; d < dbl; d++) {
      ddest[d] = dsrc[d];
    }
    if (single)
      *sdest = *ssrc;
  } else {
    pigfx_memcpy(dest, src, n);
  }
}
```