user: 提供的汇编代码用C语言表示会是什么样子：

```asm
<decode_dxt1_block>:
  endbr64
  push   %r13
  push   %r12
  push   %rbp
  mov    %rdi,%rbp
  push   %rbx
  mov    %rsi,%rbx
  sub    $0x48,%rsp
  mov    (%rdi),%r13d
  mov    0x8(%rdi),%r12d
  mov    %fs:0x28,%rax
  mov    %rax,0x38(%rsp)
  xor    %eax,%eax
  lea    0x10(%rsp),%rcx
  lea    0xc(%rsp),%rdx
  lea    0x8(%rsp),%rsi
  mov    %r13d,%edi
  call   <rgb565_le@plt>
  lea    0x1c(%rsp),%rcx
  lea    0x18(%rsp),%rdx
  mov    %r12d,%edi
  lea    0x14(%rsp),%rsi
  call   <rgb565_le@plt>
  mov    0x10(%rsp),%edx
  mov    0xc(%rsp),%esi
  mov    $0xff,%ecx
  movq   $0x0,0x28(%rsp)
  mov    0x8(%rsp),%edi
  call   <color@plt>
  mov    0x1c(%rsp),%edx
  mov    0x18(%rsp),%esi
  mov    $0xff,%ecx
  mov    0x14(%rsp),%edi
  mov    %eax,0x20(%rsp)
  call   <color@plt>
  mov    %eax,0x24(%rsp)
  cmp    %r12d,%r13d
  jle    L14
  mov    0x10(%rsp),%edx
  mov    0x1c(%rsp),%eax
  mov    0xc(%rsp),%ecx
  lea    (%rax,%rdx,2),%eax
  movslq %eax,%rdx
  sar    $0x1f,%eax
  imul   $0x55555556,%rdx,%rdx
  shr    $0x20,%rdx
  sub    %eax,%edx
  mov    0x18(%rsp),%eax
  lea    (%rax,%rcx,2),%eax
  mov    0x8(%rsp),%ecx
  movslq %eax,%rsi
  sar    $0x1f,%eax
  imul   $0x55555556,%rsi,%rsi
  shr    $0x20,%rsi
  sub    %eax,%esi
  mov    0x14(%rsp),%eax
  lea    (%rax,%rcx,2),%eax
  mov    $0xff,%ecx
  movslq %eax,%rdi
  sar    $0x1f,%eax
  imul   $0x55555556,%rdi,%rdi
  shr    $0x20,%rdi
  sub    %eax,%edi
  call   <color@plt>
  mov    0x1c(%rsp),%edx
  mov    0x18(%rsp),%ecx
  mov    %eax,0x28(%rsp)
  mov    0x10(%rsp),%eax
  lea    (%rax,%rdx,2),%eax
  movslq %eax,%rdx
  sar    $0x1f,%eax
  imul   $0x55555556,%rdx,%rdx
  shr    $0x20,%rdx
  sub    %eax,%edx
  mov    0xc(%rsp),%eax
  lea    (%rax,%rcx,2),%eax
  mov    0x14(%rsp),%ecx
  movslq %eax,%rsi
  sar    $0x1f,%eax
  imul   $0x55555556,%rsi,%rsi
  shr    $0x20,%rsi
  sub    %eax,%esi
  mov    0x8(%rsp),%eax
  lea    (%rax,%rcx,2),%eax
  mov    $0xff,%ecx
  movslq %eax,%rdi
  sar    $0x1f,%eax
  imul   $0x55555556,%rdi,%rdi
  shr    $0x20,%rdi
  sub    %eax,%edi
  call   <color@plt>
L22:
  mov    %eax,0x2c(%rsp)
  mov    0x10(%rbp),%eax
  mov    %eax,%ecx
  mov    %eax,%edi
  mov    %eax,%esi
  mov    %eax,%edx
  sar    $0xa,%ecx
  sar    $0xe,%edi
  sar    $0xc,%esi
  and    $0x3,%ecx
  and    $0x3,%edi
  sar    $0x8,%edx
  mov    0x20(%rsp,%rcx,4),%ecx
  mov    0x20(%rsp,%rdi,4),%edi
  and    $0x3,%esi
  and    $0x3,%edx
  movd   0x20(%rsp,%rsi,4),%xmm0
  movd   0x20(%rsp,%rdx,4),%xmm2
  mov    %eax,%esi
  mov    %eax,%edx
  sar    $0x10,%edx
  movd   %ecx,%xmm6
  mov    %eax,%ecx
  sar    $0x14,%esi
  sar    $0x12,%ecx
  movd   %edi,%xmm5
  mov    %eax,%edi
  and    $0x3,%edx
  and    $0x3,%ecx
  sar    $0x16,%edi
  punpckldq %xmm5,%xmm0
  punpckldq %xmm6,%xmm2
  mov    0x20(%rsp,%rcx,4),%ecx
  and    $0x3,%edi
  and    $0x3,%esi
  movd   0x20(%rsp,%rdx,4),%xmm1
  mov    0x20(%rsp,%rdi,4),%edi
  punpcklqdq %xmm0,%xmm2
  mov    %eax,%edx
  movd   0x20(%rsp,%rsi,4),%xmm0
  movd   %ecx,%xmm5
  mov    %eax,%ecx
  mov    %eax,%esi
  sar    $0x18,%edx
  sar    $0x1a,%ecx
  movd   %edi,%xmm7
  sar    $0x1c,%esi
  punpckldq %xmm5,%xmm1
  and    $0x3,%ecx
  punpckldq %xmm7,%xmm0
  and    $0x3,%edx
  and    $0x3,%esi
  mov    0x20(%rsp,%rcx,4),%ecx
  mov    %eax,%edi
  movd   0x20(%rsp,%rsi,4),%xmm3
  punpcklqdq %xmm0,%xmm1
  mov    %eax,%esi
  movd   0x20(%rsp,%rdx,4),%xmm0
  shr    $0x1e,%edi
  mov    %eax,%edx
  movd   %ecx,%xmm7
  mov    %eax,%ecx
  sar    $0x6,%eax
  mov    0x20(%rsp,%rdi,4),%edi
  and    $0x3,%eax
  sar    $0x2,%edx
  punpckldq %xmm7,%xmm0
  and    $0x3,%esi
  mov    0x20(%rsp,%rax,4),%eax
  movd   %edi,%xmm6
  and    $0x3,%edx
  sar    $0x4,%ecx
  punpckldq %xmm6,%xmm3
  and    $0x3,%ecx
  movups %xmm2,0x10(%rbx)
  movd   %eax,%xmm5
  mov    0x20(%rsp,%rdx,4),%eax
  punpcklqdq %xmm3,%xmm0
  movups %xmm1,0x20(%rbx)
  movd   0x20(%rsp,%rcx,4),%xmm4
  movd   0x20(%rsp,%rsi,4),%xmm3
  movups %xmm0,0x30(%rbx)
  movd   %eax,%xmm6
  punpckldq %xmm5,%xmm4
  punpckldq %xmm6,%xmm3
  punpcklqdq %xmm4,%xmm3
  movups %xmm3,(%rbx)
  mov    0x38(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L6
  add    $0x48,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
  nopl   0x0(%rax)
L14:
  mov    0x1c(%rsp),%eax
  add    0x10(%rsp),%eax
  mov    $0xff,%ecx
  mov    %eax,%edx
  shr    $0x1f,%edx
  add    %eax,%edx
  mov    0x18(%rsp),%eax
  add    0xc(%rsp),%eax
  mov    %eax,%esi
  sar    %edx
  shr    $0x1f,%esi
  add    %eax,%esi
  mov    0x14(%rsp),%eax
  add    0x8(%rsp),%eax
  mov    %eax,%edi
  sar    %esi
  shr    $0x1f,%edi
  add    %eax,%edi
  sar    %edi
  call   <color@plt>
  mov    $0xff,%ecx
  xor    %edx,%edx
  xor    %esi,%esi
  xor    %edi,%edi
  mov    %eax,0x28(%rsp)
  call   <color@plt>
  jmp    L22
L6:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
void decode_dxt1_block(const uint8_t *data, uint32_t *outbuf) {
  uint8_t r0, g0, b0, r1, g1, b1;
  int q0 = *(uint16_t *)(data);
  int q1 = *(uint16_t *)(data + 2);
  rgb565_le(q0, &r0, &g0, &b0);
  rgb565_le(q1, &r1, &g1, &b1);
  uint_fast32_t c[4] = {color(r0, g0, b0, 255), color(r1, g1, b1, 255)};
  if (q0 > q1) {
    c[2] = color((r0 * 2 + r1) / 3, (g0 * 2 + g1) / 3, (b0 * 2 + b1) / 3, 255);
    c[3] = color((r0 + r1 * 2) / 3, (g0 + g1 * 2) / 3, (b0 + b1 * 2) / 3, 255);
  } else {
    c[2] = color((r0 + r1) / 2, (g0 + g1) / 2, (b0 + b1) / 2, 255);
    c[3] = color(0, 0, 0, 255);
  }
  uint_fast32_t d = (*(uint32_t *)(data + 4));
  for (int i = 0; i < 16; i++, d >>= 2)
    outbuf[i] = c[d & 3];
}
```