user: What is the c source code of the assembly code below?

```asm
<airBesselIn>:
  endbr64
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x18,%rsp
  mov    %edi,%ebx
  movq   %xmm0,%r12
  pxor   %xmm0,%xmm0
  cvtsi2ss %edi,%xmm0
  mov    %edi,%eax
  neg    %eax
  ucomiss D81(%rip),%xmm0
  cmovbe %eax,%ebx
  test   %ebx,%ebx
  je     L17
  cmp    $0x1,%ebx
  je     L94
  movq   %r12,%xmm5
  ucomisd D100(%rip),%xmm5
  jp     L106
  pxor   %xmm0,%xmm0
  je     L123
L106:
  movq   %r12,%xmm0
  comisd D100(%rip),%xmm0
  jbe    L177
L158:
  movsd  D104(%rip),%xmm1
  divsd  %xmm0,%xmm1
  movsd  %xmm1,0x8(%rsp)
  pxor   %xmm0,%xmm0
  cvtsi2sd %ebx,%xmm0
  mulsd  D63(%rip),%xmm0
  call   <sqrt@plt>
  add    %ebx,%eax
  add    %eax,%eax
  test   %eax,%eax
  jle    L23
  pxor   %xmm0,%xmm0
  mov    D21(%rip),%rbp
  movq   %xmm0,%r13
  movapd %xmm0,%xmm3
  movsd  D67(%rip),%xmm2
  movsd  D15(%rip),%xmm5
  movsd  D119(%rip),%xmm4
  jmp    L44
L17:
  movq   %r12,%xmm0
  call   <airBesselI0@plt>
  jmp    L123
L94:
  movq   %r12,%xmm0
  call   <airBesselI1@plt>
  jmp    L123
L177:
  xorpd  D81(%rip),%xmm0
  jmp    L158
L62:
  comisd %xmm1,%xmm5
  jbe    L35
L73:
  movq   %r13,%xmm6
  mulsd  %xmm2,%xmm6
  movq   %xmm6,%r13
  movq   %rbp,%xmm0
  mulsd  %xmm2,%xmm0
  mulsd  %xmm2,%xmm1
  movq   %xmm1,%rbp
L64:
  cmp    %eax,%ebx
  je     L25
L170:
  sub    $0x1,%eax
  je     L97
L44:
  pxor   %xmm1,%xmm1
  cvtsi2sd %eax,%xmm1
  mulsd  0x8(%rsp),%xmm1
  movq   %rbp,%xmm7
  mulsd  %xmm7,%xmm1
  addsd  %xmm0,%xmm1
  comisd %xmm3,%xmm1
  jbe    L62
  comisd %xmm4,%xmm1
  ja     L73
  movq   %rbp,%xmm0
  movq   %xmm1,%rbp
  jmp    L64
L35:
  movq   %rbp,%xmm0
  movq   %xmm1,%rbp
  jmp    L64
L25:
  movq   %xmm0,%r13
  jmp    L170
L23:
  mov    D21(%rip),%rbp
  mov    D100(%rip),%r13
L97:
  movq   %r12,%xmm0
  call   <airBesselI0@plt>
  movq   %rbp,%xmm4
  divsd  %xmm4,%xmm0
  movq   %r13,%xmm3
  mulsd  %xmm3,%xmm0
  pxor   %xmm1,%xmm1
  movq   %r12,%xmm5
  comisd %xmm5,%xmm1
  ja     L42
L123:
  add    $0x18,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
L42:
  xorpd  D81(%rip),%xmm0
  jmp    L123
```

tool_calls: name: unpack_data
arguments: label: D81
datatype: f32[4]
name: unpack_data
arguments: label: D100
datatype: f32
name: unpack_data
arguments: label: D104
datatype: f64
name: unpack_data
arguments: label: D63
datatype: f64
name: unpack_data
arguments: label: D21
datatype: f64
name: unpack_data
arguments: label: D67
datatype: byte[8]
name: unpack_data
arguments: label: D15
datatype: byte[8]
name: unpack_data
arguments: label: D119
datatype: f64

tool: {"D81": [0.0,-0.0,0.0,0.0]}

tool: D100: 0

tool: D104: 2

tool: D63: 40

tool: D21: 1

tool: {"D67": [0xbb,0xbd,0xd7,0xd9,0xdf,0x7c,0xdb,0x3d]}

tool: {"D15": [0x00,0x00,0x00,0x20,0x5f,0xa0,0x02,0xc2]}

tool: D119: 10000000000

assistant: ```c
double airBesselIn(int nn, double xx) {
  double tax, bb, bi, bim, bip;
  int ii, an, top;
  an = ((nn) > 0.0f ? (nn) : -(nn));
  if (0 == an) {
    return airBesselI0(xx);
  } else if (1 == an) {
    return airBesselI1(xx);
  }
  if (0.0 == xx) {
    return 0.0;
  }
  tax = 2.0 / ((xx) > 0.0f ? (xx) : -(xx));
  bip = bb = 0.0;
  bi = 1.0;
  top = 2 * (an + ((int)(sqrt(40.0 * an))));
  for (ii = top; ii > 0; ii--) {
    bim = bip + ii * tax * bi;
    bip = bi;
    bi = bim;
    if (((bi) > 0.0f ? (bi) : -(bi)) > 1.0e10) {
      bb *= 1.0e-10;
      bi *= 1.0e-10;
      bip *= 1.0e-10;
    }
    if (ii == an) {
      bb = bip;
    }
  }
  bb *= airBesselI0(xx) / bi;
  return (xx < 0.0 ? -bb : bb);
}
```