user: 请将这段汇编代码片段转换成等效的C代码:

```asm
<RGB444toRGB444_ROW2X_STRETCH2X>:
  endbr64
  test   %r9d,%r9d
  je     L15
  push   %r15
  mov    %rsi,%r11
  lea    0x2(%r8),%r15
  push   %r14
  push   %r13
  push   %r12
  lea    0x2(%rsi),%r12
  push   %rbp
  mov    %rdi,%rbp
  movzwl (%r8),%edi
  push   %rbx
  movzwl 0x0(%rbp),%eax
  mov    %rdx,%rbx
  lea    0x4(%rbp),%r14
  movzwl 0x0(%rbp),%edx
  mov    %edi,%r10d
  mov    %di,(%rbx)
  lea    0x2(%rbx),%r13
  xor    %edi,%eax
  shr    %eax
  and    %edi,%edx
  movzwl %dx,%edx
  and    $0x777,%eax
  add    %edx,%eax
  lea    -0x1(%r9),%edx
  mov    %ax,(%rsi)
  mov    %eax,%ecx
  cmp    $0x1,%edx
  jle    L16
  lea    -0x3(%r9),%edx
  mov    %edx,-0x4(%rsp)
  shr    %edx
  mov    %edx,-0x8(%rsp)
  add    $0x1,%edx
  mov    %rdx,-0x10(%rsp)
  lea    0x0(,%rdx,4),%r9
  xor    %edx,%edx
  nopl   0x0(%rax)
L13:
  movzwl 0x2(%r8,%rdx,1),%r10d
  mov    %r10d,%ecx
  mov    %r10d,%esi
  and    %edi,%r10d
  xor    %edi,%ecx
  mov    %si,0x4(%rbx,%rdx,2)
  shr    %ecx
  and    $0x777,%ecx
  add    %r10d,%ecx
  mov    %cx,0x2(%rbx,%rdx,2)
  movzwl 0x4(%rbp,%rdx,2),%ecx
  movzwl 0x4(%rbp,%rdx,2),%edi
  xor    %esi,%ecx
  and    %esi,%edi
  shr    %ecx
  movzwl %di,%edi
  and    $0x777,%ecx
  add    %edi,%ecx
  mov    %ecx,%edi
  mov    %cx,0x4(%r11,%rdx,2)
  xor    %eax,%edi
  and    %ecx,%eax
  shr    %edi
  and    $0x777,%edi
  add    %edi,%eax
  mov    %ax,0x2(%r11,%rdx,2)
  movzwl 0x4(%r8,%rdx,1),%edi
  mov    %esi,%eax
  xor    %edi,%eax
  and    %edi,%esi
  mov    %di,0x8(%rbx,%rdx,2)
  mov    %edi,%r10d
  shr    %eax
  movzwl %si,%esi
  and    $0x777,%eax
  add    %esi,%eax
  mov    %ax,0x6(%rbx,%rdx,2)
  movzwl 0x8(%rbp,%rdx,2),%eax
  movzwl 0x8(%rbp,%rdx,2),%esi
  xor    %edi,%eax
  shr    %eax
  and    %edi,%esi
  movzwl %si,%esi
  and    $0x777,%eax
  add    %esi,%eax
  mov    %ecx,%esi
  xor    %eax,%esi
  and    %eax,%ecx
  mov    %ax,0x8(%r11,%rdx,2)
  shr    %esi
  and    $0x777,%esi
  add    %ecx,%esi
  mov    %eax,%ecx
  mov    %si,0x6(%r11,%rdx,2)
  add    $0x4,%rdx
  cmp    %rdx,%r9
  jne    L13
  mov    -0x10(%rsp),%rdx
  mov    -0x4(%rsp),%ebx
  add    %r9,%r15
  shl    $0x3,%rdx
  add    %rdx,%r14
  add    %rdx,%r13
  add    %rdx,%r12
  mov    -0x8(%rsp),%edx
  neg    %edx
  lea    (%rbx,%rdx,2),%edx
L16:
  test   %edx,%edx
  jne    L33
  mov    %r10w,0x0(%r13)
  mov    %cx,(%r12)
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopw   0x0(%rax,%rax,1)
L15:
  ret
  nopl   0x0(%rax)
L33:
  movzwl (%r15),%esi
  mov    %esi,%edx
  mov    %esi,%ecx
  and    %edi,%esi
  xor    %edi,%edx
  mov    %cx,0x2(%r13)
  shr    %edx
  mov    %cx,0x4(%r13)
  and    $0x777,%edx
  add    %esi,%edx
  mov    %dx,0x0(%r13)
  movzwl (%r14),%esi
  mov    %ecx,%edx
  xor    %esi,%edx
  and    %esi,%ecx
  shr    %edx
  movzwl %cx,%ecx
  and    $0x777,%edx
  add    %ecx,%edx
  mov    %edx,%ecx
  mov    %dx,0x2(%r12)
  xor    %eax,%ecx
  and    %edx,%eax
  mov    %dx,0x4(%r12)
  shr    %ecx
  and    $0x777,%ecx
  add    %ecx,%eax
  mov    %ax,(%r12)
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void RGB444toRGB444_ROW2X_STRETCH2X(unsigned char *dest_ptr_1, unsigned char *dest_ptr_12, unsigned char *dest_ptr_2, int dest_dx, unsigned char *src_ptr, int src_dx) {
  register unsigned char *d1 = dest_ptr_1;
  register unsigned char *d12 = dest_ptr_12;
  register unsigned char *d2 = dest_ptr_2;
  register unsigned char *s = src_ptr;
  register int count = src_dx;
  if (count) {
    register unsigned int da_rgb;
    register unsigned int dc_rgb;
    register unsigned int sa_rgb;
    sa_rgb = *(unsigned short *)(s);
    da_rgb = sa_rgb;
    s += 2;
    register unsigned int sb_rgb;
    sb_rgb = *(unsigned short *)(d1);
    dc_rgb = (((da_rgb ^ sb_rgb) >> 1) & (((1U << (8 + 4 - 1)) - (1U << 8)) | ((1U << (4 + 4 - 1)) - (1U << 4)) | ((1U << (0 + 4 - 1)) - (1U << 0)))) + (da_rgb & sb_rgb);
    d1 += 2 * 2;
    count--;
    *(unsigned short *)(d2) = da_rgb;
    d2 += 2;
    *(unsigned short *)(d12) = dc_rgb;
    d12 += 2;
    while (count >= 2) {
      register unsigned int db_rgb;
      register unsigned int dd_rgb;
      register unsigned int sa_rgb;
      sa_rgb = *(unsigned short *)(s);
      db_rgb = sa_rgb;
      da_rgb = (((da_rgb ^ db_rgb) >> 1) & (((1U << (8 + 4 - 1)) - (1U << 8)) | ((1U << (4 + 4 - 1)) - (1U << 4)) | ((1U << (0 + 4 - 1)) - (1U << 0)))) + (da_rgb & db_rgb);
      *(unsigned short *)(d2) = da_rgb;
      *(unsigned short *)(d2 + 2) = db_rgb;
      register unsigned int sb_rgb;
      sb_rgb = *(unsigned short *)(d1);
      dd_rgb = (((db_rgb ^ sb_rgb) >> 1) & (((1U << (8 + 4 - 1)) - (1U << 8)) | ((1U << (4 + 4 - 1)) - (1U << 4)) | ((1U << (0 + 4 - 1)) - (1U << 0)))) + (db_rgb & sb_rgb);
      dc_rgb = (((dc_rgb ^ dd_rgb) >> 1) & (((1U << (8 + 4 - 1)) - (1U << 8)) | ((1U << (4 + 4 - 1)) - (1U << 4)) | ((1U << (0 + 4 - 1)) - (1U << 0)))) + (dc_rgb & dd_rgb);
      *(unsigned short *)(d12) = dc_rgb;
      *(unsigned short *)(d12 + 2) = dd_rgb;
      sa_rgb = *(unsigned short *)(s + 2);
      da_rgb = sa_rgb;
      db_rgb = (((db_rgb ^ da_rgb) >> 1) & (((1U << (8 + 4 - 1)) - (1U << 8)) | ((1U << (4 + 4 - 1)) - (1U << 4)) | ((1U << (0 + 4 - 1)) - (1U << 0)))) + (db_rgb & da_rgb);
      *(unsigned short *)(d2 + 2 * 2) = db_rgb;
      *(unsigned short *)(d2 + 3 * 2) = da_rgb;
      sb_rgb = *(unsigned short *)(d1 + 2 * 2);
      dc_rgb = (((da_rgb ^ sb_rgb) >> 1) & (((1U << (8 + 4 - 1)) - (1U << 8)) | ((1U << (4 + 4 - 1)) - (1U << 4)) | ((1U << (0 + 4 - 1)) - (1U << 0)))) + (da_rgb & sb_rgb);
      dd_rgb = (((dd_rgb ^ dc_rgb) >> 1) & (((1U << (8 + 4 - 1)) - (1U << 8)) | ((1U << (4 + 4 - 1)) - (1U << 4)) | ((1U << (0 + 4 - 1)) - (1U << 0)))) + (dd_rgb & dc_rgb);
      *(unsigned short *)(d12 + 2 * 2) = dd_rgb;
      *(unsigned short *)(d12 + 3 * 2) = dc_rgb;
      s += 4;
      d1 += 4 * 2;
      d2 += 4 * 2;
      d12 += 4 * 2;
      count -= 2;
    }
    if (count) {
      register unsigned int db_rgb;
      register unsigned int dd_rgb;
      register unsigned int sa_rgb;
      sa_rgb = *(unsigned short *)(s);
      db_rgb = sa_rgb;
      da_rgb = (((da_rgb ^ db_rgb) >> 1) & (((1U << (8 + 4 - 1)) - (1U << 8)) | ((1U << (4 + 4 - 1)) - (1U << 4)) | ((1U << (0 + 4 - 1)) - (1U << 0)))) + (da_rgb & db_rgb);
      *(unsigned short *)(d2) = da_rgb;
      *(unsigned short *)(d2 + 2) = db_rgb;
      *(unsigned short *)(d2 + 2 * 2) = db_rgb;
      register unsigned int sb_rgb;
      sb_rgb = *(unsigned short *)(d1);
      dd_rgb = (((db_rgb ^ sb_rgb) >> 1) & (((1U << (8 + 4 - 1)) - (1U << 8)) | ((1U << (4 + 4 - 1)) - (1U << 4)) | ((1U << (0 + 4 - 1)) - (1U << 0)))) + (db_rgb & sb_rgb);
      dc_rgb = (((dc_rgb ^ dd_rgb) >> 1) & (((1U << (8 + 4 - 1)) - (1U << 8)) | ((1U << (4 + 4 - 1)) - (1U << 4)) | ((1U << (0 + 4 - 1)) - (1U << 0)))) + (dc_rgb & dd_rgb);
      *(unsigned short *)(d12) = dc_rgb;
      *(unsigned short *)(d12 + 2) = dd_rgb;
      *(unsigned short *)(d12 + 2 * 2) = dd_rgb;
    } else {
      *(unsigned short *)(d2) = da_rgb;
      *(unsigned short *)(d12) = dc_rgb;
    }
  }
}
```