user: 下面的汇编指令对应的C源代码是什么:

```asm
<byte_reverse>:
  endbr64
  push   %rbx
  mov    (%rsi),%esi
  mov    %rdx,%rbx
  test   %esi,%esi
  js     L125
  lea    -0x1(%rsi),%edx
  je     L64
  mov    %rdi,%rcx
  cmp    $0xe,%edx
  jle    L55
  mov    %rdi,%rax
  mov    %esi,%edi
  movdqa D2(%rip),%xmm3
  shr    $0x4,%edi
  sub    $0x1,%edi
  shl    $0x6,%rdi
  lea    0x40(%rcx,%rdi,1),%rdi
  nopl   0x0(%rax,%rax,1)
L82:
  movdqu (%rax),%xmm1
  movdqu 0x10(%rax),%xmm0
  movdqa %xmm3,%xmm6
  add    $0x40,%rax
  movdqu -0x30(%rax),%xmm2
  movdqu -0x20(%rax),%xmm4
  pand   %xmm3,%xmm0
  pand   %xmm3,%xmm1
  movdqu -0x10(%rax),%xmm5
  packuswb %xmm0,%xmm1
  movdqu -0x40(%rax),%xmm0
  psrlw  $0x8,%xmm2
  pand   %xmm3,%xmm4
  psrlw  $0x8,%xmm5
  psrlw  $0x8,%xmm0
  packuswb %xmm2,%xmm0
  movdqu -0x10(%rax),%xmm2
  pand   %xmm3,%xmm2
  packuswb %xmm2,%xmm4
  movdqu -0x20(%rax),%xmm2
  pand   %xmm4,%xmm6
  psrlw  $0x8,%xmm4
  psrlw  $0x8,%xmm2
  packuswb %xmm5,%xmm2
  movdqa %xmm3,%xmm5
  pand   %xmm1,%xmm5
  psrlw  $0x8,%xmm1
  packuswb %xmm6,%xmm5
  packuswb %xmm4,%xmm1
  movdqa %xmm3,%xmm6
  movdqa %xmm3,%xmm4
  pand   %xmm2,%xmm6
  pand   %xmm0,%xmm4
  psrlw  $0x8,%xmm2
  psrlw  $0x8,%xmm0
  packuswb %xmm6,%xmm4
  packuswb %xmm2,%xmm0
  movdqa %xmm0,%xmm2
  punpckhbw %xmm4,%xmm0
  punpcklbw %xmm4,%xmm2
  movdqa %xmm1,%xmm4
  punpckhbw %xmm5,%xmm1
  punpcklbw %xmm5,%xmm4
  movdqa %xmm2,%xmm5
  punpckhbw %xmm4,%xmm2
  punpcklbw %xmm4,%xmm5
  movups %xmm2,-0x30(%rax)
  movdqa %xmm0,%xmm2
  punpckhbw %xmm1,%xmm0
  punpcklbw %xmm1,%xmm2
  movups %xmm5,-0x40(%rax)
  movups %xmm2,-0x20(%rax)
  movups %xmm0,-0x10(%rax)
  cmp    %rdi,%rax
  jne    L82
  mov    %esi,%eax
  and    $0xfffffff0,%eax
  mov    %eax,%edi
  sub    %eax,%edx
  lea    (%rcx,%rdi,4),%rcx
  cmp    %eax,%esi
  je     L64
L55:
  movzbl (%rcx),%eax
  movzbl 0x3(%rcx),%esi
  rolw   $0x8,0x1(%rcx)
  mov    %sil,(%rcx)
  mov    %al,0x3(%rcx)
  test   %edx,%edx
  je     L64
  movzbl 0x4(%rcx),%eax
  movzbl 0x7(%rcx),%esi
  rolw   $0x8,0x5(%rcx)
  mov    %sil,0x4(%rcx)
  mov    %al,0x7(%rcx)
  cmp    $0x1,%edx
  je     L64
  movzbl 0x8(%rcx),%eax
  movzbl 0xb(%rcx),%esi
  rolw   $0x8,0x9(%rcx)
  mov    %sil,0x8(%rcx)
  mov    %al,0xb(%rcx)
  cmp    $0x2,%edx
  je     L64
  movzbl 0xc(%rcx),%eax
  movzbl 0xf(%rcx),%esi
  rolw   $0x8,0xd(%rcx)
  mov    %sil,0xc(%rcx)
  mov    %al,0xf(%rcx)
  cmp    $0x3,%edx
  je     L64
  movzbl 0x10(%rcx),%eax
  movzbl 0x13(%rcx),%esi
  rolw   $0x8,0x11(%rcx)
  mov    %sil,0x10(%rcx)
  mov    %al,0x13(%rcx)
  cmp    $0x4,%edx
  je     L64
  movzbl 0x14(%rcx),%eax
  movzbl 0x17(%rcx),%esi
  rolw   $0x8,0x15(%rcx)
  mov    %sil,0x14(%rcx)
  mov    %al,0x17(%rcx)
  cmp    $0x5,%edx
  je     L64
  movzbl 0x18(%rcx),%eax
  movzbl 0x1b(%rcx),%esi
  rolw   $0x8,0x19(%rcx)
  mov    %sil,0x18(%rcx)
  mov    %al,0x1b(%rcx)
  cmp    $0x6,%edx
  je     L64
  movzbl 0x1c(%rcx),%eax
  movzbl 0x1f(%rcx),%esi
  rolw   $0x8,0x1d(%rcx)
  mov    %sil,0x1c(%rcx)
  mov    %al,0x1f(%rcx)
  cmp    $0x7,%edx
  je     L64
  movzbl 0x20(%rcx),%eax
  movzbl 0x23(%rcx),%esi
  rolw   $0x8,0x21(%rcx)
  mov    %sil,0x20(%rcx)
  mov    %al,0x23(%rcx)
  cmp    $0x8,%edx
  je     L64
  movzbl 0x24(%rcx),%eax
  movzbl 0x27(%rcx),%esi
  rolw   $0x8,0x25(%rcx)
  mov    %sil,0x24(%rcx)
  mov    %al,0x27(%rcx)
  cmp    $0x9,%edx
  je     L64
  movzbl 0x28(%rcx),%eax
  movzbl 0x2b(%rcx),%esi
  rolw   $0x8,0x29(%rcx)
  mov    %sil,0x28(%rcx)
  mov    %al,0x2b(%rcx)
  cmp    $0xa,%edx
  je     L64
  movzbl 0x2c(%rcx),%eax
  movzbl 0x2f(%rcx),%esi
  rolw   $0x8,0x2d(%rcx)
  mov    %sil,0x2c(%rcx)
  mov    %al,0x2f(%rcx)
  cmp    $0xb,%edx
  je     L64
  movzbl 0x30(%rcx),%eax
  movzbl 0x33(%rcx),%esi
  rolw   $0x8,0x31(%rcx)
  mov    %sil,0x30(%rcx)
  mov    %al,0x33(%rcx)
  cmp    $0xc,%edx
  je     L64
  movzbl 0x34(%rcx),%eax
  movzbl 0x37(%rcx),%esi
  rolw   $0x8,0x35(%rcx)
  mov    %sil,0x34(%rcx)
  mov    %al,0x37(%rcx)
  cmp    $0xd,%edx
  je     L64
  movzbl 0x38(%rcx),%eax
  movzbl 0x3b(%rcx),%edx
  rolw   $0x8,0x39(%rcx)
  mov    %dl,0x38(%rcx)
  mov    %al,0x3b(%rcx)
L64:
  xor    %eax,%eax
  mov    %eax,(%rbx)
  pop    %rbx
  ret
  nopl   0x0(%rax)
L125:
  lea    D10(%rip),%rdi
  call   <printf@plt>
  mov    $0x1,%eax
  mov    %eax,(%rbx)
  pop    %rbx
  ret
```

tool_calls: name: unpack_data
arguments: tag: D2
type: byte[16]
name: unpack_data
arguments: tag: D10
type: string

tool: {"D2": [0xff,0x00,0xff,0x00,0xff,0x00,0xff,0x00,0xff,0x00,0xff,0x00,0xff,0x00,0xff,0x00]}

tool: D10: byte_reverse() :: n must be positive


assistant: ```c
void byte_reverse(float *buf, int *nn, int *ierr) {
  int n;
  char temp, *ptr;
  if (*nn < 0) {
    printf("byte_reverse() :: n must be positive\n");
    *ierr = 1;
    return;
  }
  for (ptr = (char *)buf, n = *nn; n--; ptr += 4) {
    temp = (ptr[0]);
    (ptr[0]) = (ptr[3]);
    (ptr[3]) = temp;
    temp = (ptr[1]);
    (ptr[1]) = (ptr[2]);
    (ptr[2]) = temp;
  }
  *ierr = 0;
}
```