user: Translate the below assembly code into C programming language:

```asm
<double_to_ieee_80>:
  endbr64
  push   %r13
  movapd %xmm0,%xmm2
  pxor   %xmm0,%xmm0
  xor    %r13d,%r13d
  push   %r12
  push   %rbp
  push   %rbx
  mov    %rdi,%rbx
  sub    $0x18,%rsp
  comisd %xmm2,%xmm0
  jbe    L29
  xorpd  D5(%rip),%xmm2
  mov    $0xffffff80,%r13d
L29:
  ucomisd %xmm0,%xmm2
  jp     L17
  jne    L17
  xor    %edx,%edx
  xor    %r8d,%r8d
  xor    %esi,%esi
  xor    %r9d,%r9d
  xor    %eax,%eax
  xor    %r10d,%r10d
  xor    %edi,%edi
  xor    %r11d,%r11d
  xor    %ecx,%ecx
L11:
  mov    %r13b,(%rbx)
  mov    %cl,0x1(%rbx)
  mov    %r11b,0x2(%rbx)
  mov    %dil,0x3(%rbx)
  mov    %r10b,0x4(%rbx)
  mov    %al,0x5(%rbx)
  mov    %r9b,0x6(%rbx)
  mov    %sil,0x7(%rbx)
  mov    %r8b,0x8(%rbx)
  mov    %dl,0x9(%rbx)
  add    $0x18,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
  nopl   (%rax)
L17:
  movapd %xmm2,%xmm0
  movsd  %xmm2,0x8(%rsp)
  call   <log@plt>
  divsd  D46(%rip),%xmm0
  addsd  D20(%rip),%xmm0
  movsd  D13(%rip),%xmm1
  cvttsd2si %xmm0,%ebp
  pxor   %xmm0,%xmm0
  movswl %bp,%eax
  cvtsi2sd %eax,%xmm0
  subsd  %xmm0,%xmm1
  movsd  D0(%rip),%xmm0
  call   <pow@plt>
  movsd  0x8(%rsp),%xmm2
  mulsd  %xmm0,%xmm2
  movapd %xmm2,%xmm0
  movsd  %xmm2,0x8(%rsp)
  call   <myDoubleToUlong@plt>
  mov    %eax,%edi
  mov    %eax,%r12d
  call   <myUlongToDouble@plt>
  pxor   %xmm0,%xmm0
  movsd  0x8(%rsp),%xmm2
  cvtsi2sd %rax,%xmm0
  subsd  %xmm0,%xmm2
  mulsd  D23(%rip),%xmm2
  movapd %xmm2,%xmm0
  call   <myDoubleToUlong@plt>
  mov    %ebp,%ecx
  mov    %r12d,%edi
  mov    %eax,%edx
  mov    %ebp,%eax
  shr    $0x10,%edi
  sar    $0x8,%ax
  mov    %edx,%esi
  movzbl %dh,%ebp
  or     %eax,%r13d
  mov    %r12d,%eax
  shr    $0x18,%esi
  mov    %ebp,%r8d
  shr    $0x18,%eax
  mov    %esi,%r9d
  mov    %edx,%esi
  mov    %eax,%r11d
  mov    %r12d,%eax
  shr    $0x10,%esi
  movzbl %ah,%eax
  mov    %eax,%r10d
  mov    %r12d,%eax
  jmp    L11
```

tool_calls: name: unpack_data
arguments: data_label: D5
data_type: f32[4]
name: unpack_data
arguments: data_label: D46
data_type: byte[8]
name: unpack_data
arguments: data_label: D20
data_type: f64
name: unpack_data
arguments: data_label: D13
data_type: f32[2]
name: unpack_data
arguments: data_label: D0
data_type: f64
name: unpack_data
arguments: data_label: D23
data_type: f32[2]

tool: {"D5": [0.0,-0.0,0.0,0.0]}

tool: {"D46": [0xef,0x39,0xfa,0xfe,0x42,0x2e,0xe6,0x3f]}

tool: D20: 16383

tool: {"D13": [0.0,6.50091552734375]}

tool: D0: 2

tool: {"D23": [0.0,30.0]}

assistant: ```c
void double_to_ieee_80(double val, unsigned char *p) {
  short lexp = 0;
  unsigned char sign = 0;
  unsigned int mant1 = 0;
  unsigned int mant0 = 0;
  if (val < 0.0) {
    sign = 1;
    val = -val;
  }
  if (val != 0.0) {
    lexp = (short)(log(val) / log(2.0) + 16383.0);
    val *= pow(2.0, 31.0 + 16383.0 - (double)lexp);
    mant1 = myDoubleToUlong(val);
    val -= myUlongToDouble(mant1);
    val *= pow(2.0, 32.0);
    mant0 = myDoubleToUlong(val);
  }
  *p++ = ((sign << 7) | (lexp >> 8));
  *p++ = 0xFF & lexp;
  *p++ = 0xFF & (mant1 >> 24);
  *p++ = 0xFF & (mant1 >> 16);
  *p++ = 0xFF & (mant1 >> 8);
  *p++ = 0xFF & (mant1);
  *p++ = 0xFF & (mant0 >> 24);
  *p++ = 0xFF & (mant0 >> 16);
  *p++ = 0xFF & (mant0 >> 8);
  *p++ = 0xFF & (mant0);
}
```