user: 提供的汇编代码用C语言表示会是什么样子：

```asm
<tiff_decode_nibble>:
  endbr64
  push   %r15
  mov    $0x1,%eax
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  mov    %ecx,-0x30(%rsp)
  mov    %r9d,%ecx
  shl    %cl,%eax
  mov    %r8d,-0x14(%rsp)
  sub    $0x1,%eax
  test   %r8d,%r8d
  jle    L85
  mov    %edx,%r12d
  lea    -0x1(%rdx),%ecx
  shr    $0x2,%edx
  movd   %eax,%xmm5
  mov    %r12d,%ebx
  lea    -0x1(%rdx),%r11d
  mov    %ecx,-0x2c(%rsp)
  pshufd $0xe0,%xmm5,%xmm3
  and    $0xfffffffc,%ebx
  add    $0x1,%r11
  pshufd $0x0,%xmm5,%xmm2
  movl   $0x0,-0x18(%rsp)
  lea    0x1(%rbx),%edx
  mov    %ebx,-0x28(%rsp)
  mov    %ebx,%r15d
  shl    $0x4,%r11
  mov    %edx,-0x10(%rsp)
  lea    0x2(%rbx),%edx
  shl    $0x2,%r15
  mov    %edx,-0xc(%rsp)
  mov    %ecx,%edx
  mov    %rdx,-0x20(%rsp)
  lea    0x4(,%rdx,4),%r13
  mov    %r12d,%edx
  sub    %ebx,%edx
  mov    %edx,-0x24(%rsp)
  nopl   0x0(%rax,%rax,1)
L9:
  mov    %rsi,%rcx
  test   %r12d,%r12d
  jle    L151
  lea    0x4(%rdi),%rcx
  mov    %rsi,%rdx
  sub    %rcx,%rdx
  cmp    $0x8,%rdx
  mov    $0x0,%edx
  jbe    L65
  cmpl   $0x2,-0x2c(%rsp)
  jbe    L65
  nopl   0x0(%rax)
L24:
  movdqu (%rdi,%rdx,1),%xmm4
  movups %xmm4,(%rsi,%rdx,1)
  add    $0x10,%rdx
  cmp    %r11,%rdx
  jne    L24
  lea    (%rdi,%r15,1),%rcx
  lea    (%rsi,%r15,1),%rdx
  cmp    -0x28(%rsp),%r12d
  je     L33
  mov    (%rcx),%r8d
  mov    %r8d,(%rdx)
  cmp    -0x10(%rsp),%r12d
  jle    L33
  mov    0x4(%rcx),%r8d
  mov    %r8d,0x4(%rdx)
  cmp    %r12d,-0xc(%rsp)
  jge    L33
  mov    0x8(%rcx),%ecx
  mov    %ecx,0x8(%rdx)
L33:
  add    %r13,%rdi
  lea    (%rsi,%r13,1),%rcx
L151:
  cmpl   $0x1,-0x30(%rsp)
  mov    %rsi,%rdx
  mov    $0x1,%ebx
  mov    %rcx,%rsi
  jle    L171
  nopl   0x0(%rax,%rax,1)
L5:
  test   %r12d,%r12d
  jle    L179
  lea    0x4(%rdx),%r8
  mov    %rsi,%rcx
  lea    0x4(%rdi),%r9
  sub    %r8,%rcx
  mov    %rsi,%r8
  cmp    $0x8,%rcx
  seta   %cl
  sub    %r9,%r8
  cmp    $0x8,%r8
  seta   %r8b
  test   %r8b,%cl
  je     L119
  cmp    $0x1,%r12d
  je     L119
  cmpl   $0x2,-0x2c(%rsp)
  jbe    L225
  xor    %ecx,%ecx
  nopl   0x0(%rax)
L137:
  movdqu (%rdi,%rcx,1),%xmm0
  movdqu (%rdx,%rcx,1),%xmm1
  pand   %xmm2,%xmm0
  pand   %xmm2,%xmm1
  paddd  %xmm1,%xmm0
  pand   %xmm2,%xmm0
  movups %xmm0,(%rsi,%rcx,1)
  add    $0x10,%rcx
  cmp    %r11,%rcx
  jne    L137
  mov    -0x28(%rsp),%r10d
  lea    (%rdi,%r15,1),%r9
  lea    (%rsi,%r15,1),%rcx
  lea    (%rdx,%r15,1),%r8
  cmp    %r10d,%r12d
  je     L41
  mov    -0x24(%rsp),%ebp
  mov    %ebp,%r14d
  cmp    $0x1,%ebp
  je     L187
L181:
  movq   (%rdi,%r10,4),%xmm0
  movq   (%rdx,%r10,4),%xmm1
  mov    %r14d,%ebp
  and    $0xfffffffe,%ebp
  pand   %xmm3,%xmm0
  pand   %xmm3,%xmm1
  paddd  %xmm1,%xmm0
  pand   %xmm3,%xmm0
  movq   %xmm0,(%rsi,%r10,4)
  mov    %ebp,%r10d
  shl    $0x2,%r10
  add    %r10,%r9
  add    %r10,%rcx
  add    %r10,%r8
  cmp    %ebp,%r14d
  je     L41
L187:
  mov    (%r9),%r14d
  and    %eax,%r14d
  mov    %r14d,%r9d
  mov    (%r8),%r14d
  and    %eax,%r14d
  add    %r14d,%r9d
  and    %eax,%r9d
  mov    %r9d,(%rcx)
L41:
  add    %r13,%rdi
  add    %r13,%rsi
  add    %r13,%rdx
L179:
  add    $0x1,%ebx
  cmp    %ebx,-0x30(%rsp)
  jne    L5
L171:
  addl   $0x1,-0x18(%rsp)
  mov    -0x18(%rsp),%ebx
  cmp    %ebx,-0x14(%rsp)
  jne    L9
L85:
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopw   0x0(%rax,%rax,1)
L119:
  mov    -0x20(%rsp),%r9
  xor    %ecx,%ecx
  nop
L93:
  mov    (%rdi,%rcx,4),%r8d
  mov    (%rdx,%rcx,4),%r10d
  and    %eax,%r8d
  and    %eax,%r10d
  add    %r10d,%r8d
  and    %eax,%r8d
  mov    %r8d,(%rsi,%rcx,4)
  mov    %rcx,%r8
  add    $0x1,%rcx
  cmp    %r8,%r9
  jne    L93
  jmp    L41
L225:
  mov    %r12d,%r14d
  mov    %rdx,%r8
  mov    %rsi,%rcx
  mov    %rdi,%r9
  xor    %r10d,%r10d
  jmp    L181
L65:
  mov    -0x20(%rsp),%r8
  nop
L129:
  mov    (%rdi,%rdx,4),%ecx
  mov    %ecx,(%rsi,%rdx,4)
  mov    %rdx,%rcx
  add    $0x1,%rdx
  cmp    %rcx,%r8
  jne    L129
  jmp    L33
```

assistant: ```c
void tiff_decode_nibble(uint8_t *in, uint8_t *out, uint8_t colors, uint16_t columns, uint16_t rows, uint8_t bpc) {
  int i;
  int j;
  int r;
  uint8_t *in_p = in;
  uint8_t *out_p = out;
  uint8_t mask = (1 << bpc) - 1;
  for (r = 0; r < rows; r++) {
    uint8_t *prev = out_p;
    for (j = 0; j < colors; j++) {
      *out_p++ = *in_p++;
    }
    for (i = 1; i < columns; i++) {
      for (j = 0; j < colors; j++) {
        *out_p++ = ((*in_p++ & mask) + (*prev++ & mask)) & mask;
      }
    }
  }
}
```