user: Converte this assembly snippet into its equivalent C code:

```asm
<mp_mul_rcmul>:
  endbr64
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x38,%rsp
  mov    %edi,%r12d
  mov    %rsi,%rbp
  mov    %rdx,%rbx
  pxor   %xmm0,%xmm0
  cvtsi2sd %edi,%xmm0
  movsd  D60(%rip),%xmm1
  divsd  %xmm0,%xmm1
  movsd  %xmm1,(%rsp)
  lea    0x28(%rsp),%rdi
  lea    0x20(%rsp),%rsi
  movapd %xmm1,%xmm0
  call   <sincos@plt>
  movsd  0x28(%rsp),%xmm8
  movapd %xmm8,%xmm6
  mulsd  0x20(%rsp),%xmm6
  mulsd  %xmm8,%xmm8
  movapd %xmm8,%xmm0
  addsd  %xmm8,%xmm0
  movsd  D19(%rip),%xmm1
  subsd  %xmm0,%xmm1
  movsd  %xmm1,0x8(%rsp)
  movapd %xmm6,%xmm5
  addsd  %xmm6,%xmm5
  movsd  %xmm5,0x10(%rsp)
  addsd  %xmm5,%xmm5
  movsd  %xmm5,0x18(%rsp)
  mov    %r12d,%esi
  sar    %esi
  movslq %esi,%rdx
  lea    0x0(,%rdx,8),%rax
  movsd  0x0(%rbp,%rdx,8),%xmm0
  movsd  0x8(%rbp,%rax,1),%xmm1
  lea    (%rbx,%rax,1),%rdx
  movsd  (%rdx),%xmm3
  lea    0x8(%rbx,%rax,1),%rax
  movsd  (%rax),%xmm4
  movapd %xmm0,%xmm2
  mulsd  %xmm3,%xmm2
  movapd %xmm1,%xmm5
  mulsd  %xmm4,%xmm5
  subsd  %xmm5,%xmm2
  movsd  %xmm2,(%rdx)
  mulsd  %xmm4,%xmm0
  mulsd  %xmm3,%xmm1
  addsd  %xmm1,%xmm0
  movsd  %xmm0,(%rax)
  pxor   %xmm0,%xmm0
  movapd %xmm0,%xmm1
  movslq %r12d,%r12
  lea    0x1(%r12),%r13
L39:
  lea    -0x100(%rsi),%r12d
  mov    $0x2,%eax
  cmp    %eax,%r12d
  cmovl  %eax,%r12d
  lea    -0x2(%rsi),%eax
  cmp    %eax,%r12d
  jg     L10
  cltq
  mov    %r13,%rdx
  sub    %rax,%rdx
  shl    $0x3,%rdx
  lea    0x0(%rbp,%rdx,1),%rcx
  add    %rbx,%rdx
  movsd  0x18(%rsp),%xmm11
L17:
  movapd %xmm8,%xmm4
  movapd %xmm11,%xmm8
  mulsd  %xmm6,%xmm8
  addsd  %xmm1,%xmm8
  movapd %xmm6,%xmm5
  movsd  D68(%rip),%xmm6
  subsd  %xmm4,%xmm6
  mulsd  %xmm11,%xmm6
  addsd  %xmm0,%xmm6
  movsd  0x0(%rbp,%rax,8),%xmm10
  movsd  -0x8(%rcx),%xmm1
  movapd %xmm10,%xmm3
  subsd  %xmm1,%xmm3
  movsd  0x8(%rbp,%rax,8),%xmm2
  movsd  (%rcx),%xmm0
  movapd %xmm2,%xmm9
  addsd  %xmm0,%xmm9
  movapd %xmm3,%xmm7
  mulsd  %xmm4,%xmm7
  movapd %xmm9,%xmm12
  mulsd  %xmm5,%xmm12
  subsd  %xmm12,%xmm7
  mulsd  %xmm4,%xmm9
  mulsd  %xmm5,%xmm3
  addsd  %xmm3,%xmm9
  subsd  %xmm7,%xmm10
  subsd  %xmm9,%xmm2
  addsd  %xmm7,%xmm1
  subsd  %xmm9,%xmm0
  movsd  %xmm10,0x0(%rbp,%rax,8)
  movsd  %xmm2,0x8(%rbp,%rax,8)
  movsd  %xmm1,-0x8(%rcx)
  movsd  %xmm0,(%rcx)
  movsd  (%rbx,%rax,8),%xmm3
  movapd %xmm3,%xmm14
  subsd  -0x8(%rdx),%xmm14
  movsd  0x8(%rbx,%rax,8),%xmm12
  movsd  (%rdx),%xmm9
  movapd %xmm12,%xmm7
  addsd  %xmm9,%xmm7
  movapd %xmm14,%xmm13
  mulsd  %xmm4,%xmm13
  movapd %xmm7,%xmm15
  mulsd  %xmm5,%xmm15
  subsd  %xmm15,%xmm13
  mulsd  %xmm4,%xmm7
  mulsd  %xmm5,%xmm14
  addsd  %xmm14,%xmm7
  subsd  %xmm13,%xmm3
  subsd  %xmm7,%xmm12
  addsd  -0x8(%rdx),%xmm13
  movapd %xmm9,%xmm14
  subsd  %xmm7,%xmm14
  movapd %xmm10,%xmm9
  mulsd  %xmm3,%xmm9
  movapd %xmm2,%xmm7
  mulsd  %xmm12,%xmm7
  subsd  %xmm7,%xmm9
  mulsd  %xmm12,%xmm10
  mulsd  %xmm3,%xmm2
  movapd %xmm10,%xmm3
  addsd  %xmm2,%xmm3
  movapd %xmm1,%xmm2
  mulsd  %xmm13,%xmm2
  movapd %xmm0,%xmm7
  mulsd  %xmm14,%xmm7
  subsd  %xmm7,%xmm2
  mulsd  %xmm14,%xmm1
  mulsd  %xmm13,%xmm0
  addsd  %xmm0,%xmm1
  movapd %xmm9,%xmm10
  subsd  %xmm2,%xmm10
  movapd %xmm3,%xmm0
  addsd  %xmm1,%xmm0
  movapd %xmm10,%xmm7
  mulsd  %xmm4,%xmm7
  movapd %xmm0,%xmm12
  mulsd  %xmm5,%xmm12
  addsd  %xmm12,%xmm7
  mulsd  %xmm4,%xmm0
  mulsd  %xmm5,%xmm10
  subsd  %xmm10,%xmm0
  subsd  %xmm7,%xmm9
  movsd  %xmm9,(%rbx,%rax,8)
  subsd  %xmm0,%xmm3
  movsd  %xmm3,0x8(%rbx,%rax,8)
  addsd  %xmm7,%xmm2
  movsd  %xmm2,-0x8(%rdx)
  subsd  %xmm0,%xmm1
  movsd  %xmm1,(%rdx)
  sub    $0x2,%rax
  add    $0x10,%rcx
  add    $0x10,%rdx
  movapd %xmm4,%xmm1
  movapd %xmm5,%xmm0
  cmp    %eax,%r12d
  jle    L17
L10:
  cmp    $0x102,%esi
  jle    L28
  lea    0x28(%rsp),%rdi
  lea    0x20(%rsp),%rsi
  pxor   %xmm0,%xmm0
  cvtsi2sd %r12d,%xmm0
  mulsd  (%rsp),%xmm0
  call   <sincos@plt>
  movsd  0x28(%rsp),%xmm2
  mulsd  D68(%rip),%xmm2
  movsd  0x20(%rsp),%xmm0
  mulsd  D68(%rip),%xmm0
  movsd  0x8(%rsp),%xmm5
  movapd %xmm5,%xmm1
  mulsd  %xmm2,%xmm1
  movsd  0x10(%rsp),%xmm4
  movapd %xmm4,%xmm3
  mulsd  %xmm0,%xmm3
  subsd  %xmm3,%xmm1
  movsd  D68(%rip),%xmm8
  subsd  %xmm1,%xmm8
  mulsd  %xmm2,%xmm4
  movapd %xmm4,%xmm6
  mulsd  %xmm0,%xmm5
  addsd  %xmm5,%xmm6
  movsd  D68(%rip),%xmm1
  subsd  %xmm2,%xmm1
  mov    %r12d,%esi
  jmp    L39
L28:
  add    $0x38,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
```

tool_calls: name: disassemble_data
arguments: tag: D60
type: byte[8]
name: disassemble_data
arguments: tag: D19
type: byte[8]
name: disassemble_data
arguments: tag: D68
type: f64

tool: {"D60": [0x18,0x2d,0x44,0x54,0xfb,0x21,0x09,0x40]}

tool: {"D19": [0x00,0x00,0x00,0x00,0x00,0x00,0xf0,0x3f]}

tool: D68: 0.5

assistant: ```c
void mp_mul_rcmul(int n, double *a, double *b) {
  int i, i0, j, k;
  double ec, w1r, w1i, wkr, wki, wdr, wdi, ss;
  double xr, xi, yr, yi, ajr, aji, akr, aki, bjr, bji, bkr, bki;
  ec = 2 * ((double)1.570796326794896619231321691639751442098584) / n;
  wkr = 0;
  wki = 0;
  wdi = cos(ec);
  wdr = sin(ec);
  wdi *= wdr;
  wdr *= wdr;
  w1r = 1 - 2 * wdr;
  w1i = 2 * wdi;
  ss = 2 * w1i;
  i = n >> 1;
  xr = a[i];
  xi = a[i + 1];
  yr = b[i];
  yi = b[i + 1];
  b[i] = xr * yr - xi * yi;
  b[i + 1] = xr * yi + xi * yr;
  for (;;) {
    i0 = i - 4 * 64;
    if (i0 < 2) {
      i0 = 2;
    }
    for (j = i - 2; j >= i0; j -= 2) {
      k = n - j;
      xr = wkr + ss * wdi;
      xi = wki + ss * (((double)0.5) - wdr);
      wkr = wdr;
      wki = wdi;
      wdr = xr;
      wdi = xi;
      xr = a[j] - a[k];
      xi = a[j + 1] + a[k + 1];
      yr = wkr * xr - wki * xi;
      yi = wkr * xi + wki * xr;
      ajr = a[j] - yr;
      aji = a[j + 1] - yi;
      akr = a[k] + yr;
      aki = a[k + 1] - yi;
      a[j] = ajr;
      a[j + 1] = aji;
      a[k] = akr;
      a[k + 1] = aki;
      xr = b[j] - b[k];
      xi = b[j + 1] + b[k + 1];
      yr = wkr * xr - wki * xi;
      yi = wkr * xi + wki * xr;
      xr = b[j] - yr;
      xi = b[j + 1] - yi;
      yr = b[k] + yr;
      yi = b[k + 1] - yi;
      bjr = ajr * xr - aji * xi;
      bji = ajr * xi + aji * xr;
      bkr = akr * yr - aki * yi;
      bki = akr * yi + aki * yr;
      xr = bjr - bkr;
      xi = bji + bki;
      yr = wkr * xr + wki * xi;
      yi = wkr * xi - wki * xr;
      b[j] = bjr - yr;
      b[j + 1] = bji - yi;
      b[k] = bkr + yr;
      b[k + 1] = bki - yi;
    }
    if (i0 == 2) {
      break;
    }
    wkr = ((double)0.5) * sin(ec * i0);
    wki = ((double)0.5) * cos(ec * i0);
    wdr = ((double)0.5) - (wkr * w1r - wki * w1i);
    wdi = wkr * w1i + wki * w1r;
    wkr = ((double)0.5) - wkr;
    i = i0;
  }
}
```