user: 下面的汇编指令对应的C源代码是什么：

```asm
<ns_hexdump>:
  endbr64
  push   %r15
  pxor   %xmm0,%xmm0
  push   %r14
  push   %r13
  push   %r12
  mov    %ecx,%r12d
  push   %rbp
  mov    %rdx,%rbp
  push   %rbx
  sub    $0x48,%rsp
  mov    %esi,0x1c(%rsp)
  mov    %fs:0x28,%rax
  mov    %rax,0x38(%rsp)
  xor    %eax,%eax
  movb   $0x0,0x30(%rsp)
  movaps %xmm0,0x20(%rsp)
  test   %esi,%esi
  jle    L67
  mov    %esi,%eax
  xor    %r14d,%r14d
  mov    %rdi,%r13
  xor    %r8d,%r8d
  mov    %rax,(%rsp)
  lea    0x20(%rsp),%rax
  mov    %r14,%r15
  mov    %rax,0x8(%rsp)
  xchg   %ax,%ax
L5:
  mov    %r15d,%ebx
  mov    %r15d,%r11d
  mov    %r8d,%r14d
  and    $0xf,%ebx
  jne    L37
  test   %r15,%r15
  je     L12
  movslq %r8d,%rdi
  mov    0x8(%rsp),%rcx
  mov    %r12d,%esi
  xor    %eax,%eax
  sub    %r8d,%esi
  add    %rbp,%rdi
  mov    %r8d,0x14(%rsp)
  lea    D5(%rip),%rdx
  mov    %r15d,0x18(%rsp)
  call   <snprintf@plt>
  mov    0x14(%rsp),%r8d
  mov    0x18(%rsp),%r11d
  lea    (%r8,%rax,1),%r14d
  mov    %r14d,%r8d
L12:
  movslq %r8d,%rdi
  mov    %r12d,%esi
  mov    %r11d,%ecx
  xor    %eax,%eax
  sub    %r8d,%esi
  add    %rbp,%rdi
  lea    D25(%rip),%rdx
  call   <snprintf@plt>
  add    %eax,%r14d
  mov    %r14d,%r8d
L37:
  movzbl 0x0(%r13,%r15,1),%ecx
  movslq %r8d,%rdi
  mov    %r12d,%esi
  xor    %eax,%eax
  sub    %r8d,%esi
  add    %rbp,%rdi
  lea    D9(%rip),%rdx
  call   <snprintf@plt>
  mov    $0x2e,%ecx
  lea    (%r14,%rax,1),%r10d
  movzbl 0x0(%r13,%r15,1),%eax
  movslq %r10d,%r8
  lea    -0x20(%rax),%edx
  cmp    $0x5f,%dl
  movslq %ebx,%rdx
  cmovae %ecx,%eax
  add    $0x1,%ebx
  add    $0x1,%r15
  movslq %ebx,%rbx
  mov    %al,0x20(%rsp,%rdx,1)
  movb   $0x0,0x20(%rsp,%rbx,1)
  cmp    (%rsp),%r15
  jne    L5
  mov    %r10d,%r15d
  testb  $0xf,0x1c(%rsp)
  je     L60
  mov    0x1c(%rsp),%r14d
  lea    D17(%rip),%r13
  lea    D47(%rip),%rbx
  add    $0x1,%r14d
L47:
  movslq %r15d,%rdi
  mov    %r12d,%esi
  mov    %r13,%rcx
  mov    %rbx,%rdx
  sub    %r15d,%esi
  add    %rbp,%rdi
  xor    %eax,%eax
  call   <snprintf@plt>
  add    %eax,%r15d
  mov    %r14d,%eax
  add    $0x1,%r14d
  and    $0xf,%eax
  test   %eax,%eax
  jne    L47
  movslq %r15d,%rax
  sub    %r15d,%r12d
  add    %rax,%rbp
L34:
  mov    0x8(%rsp),%rcx
  mov    %r12d,%esi
  mov    %rbp,%rdi
  xor    %eax,%eax
  lea    D2(%rip),%rdx
  call   <snprintf@plt>
  add    %r15d,%eax
  mov    0x38(%rsp),%rdx
  sub    %fs:0x28,%rdx
  jne    L16
  add    $0x48,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  xchg   %ax,%ax
L67:
  lea    0x20(%rsp),%rax
  xor    %r15d,%r15d
  mov    %rax,0x8(%rsp)
  jmp    L34
L60:
  sub    %r8d,%r12d
  add    %r8,%rbp
  jmp    L34
L16:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: unpack_data
arguments: label: D5
type_infered: string
name: unpack_data
arguments: label: D25
type_infered: string
name: unpack_data
arguments: label: D9
type_infered: string
name: unpack_data
arguments: label: D17
type_infered: string
name: unpack_data
arguments: label: D47
type_infered: string
name: unpack_data
arguments: label: D2
type_infered: string

tool: D5:   %s


tool: D25: %04x 

tool: D9:  %02x

tool: D17:    

tool: D47: %s

tool: D2:   %s



assistant: ```c
int ns_hexdump(const void *buf, int len, char *dst, int dst_len) {
  const unsigned char *p = (const unsigned char *)buf;
  char ascii[17] = "";
  int i, idx, n = 0;
  for (i = 0; i < len; i++) {
    idx = i % 16;
    if (idx == 0) {
      if (i > 0)
        n += snprintf(dst + n, dst_len - n, "  %s\n", ascii);
      n += snprintf(dst + n, dst_len - n, "%04x ", i);
    }
    n += snprintf(dst + n, dst_len - n, " %02x", p[i]);
    ascii[idx] = p[i] < 0x20 || p[i] > 0x7e ? '.' : p[i];
    ascii[idx + 1] = '\0';
  }
  while (i++ % 16)
    n += snprintf(dst + n, dst_len - n, "%s", "   ");
  n += snprintf(dst + n, dst_len - n, "  %s\n\n", ascii);
  return n;
}
```