user: 请将这段汇编代码片段转换成等效的C代码：

```asm
<rftbsub>:
  endbr64
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x30,%rsp
  mov    %edi,%r13d
  mov    %rsi,%rbp
  pxor   %xmm0,%xmm0
  cvtsi2sd %edi,%xmm0
  movsd  D45(%rip),%xmm1
  divsd  %xmm0,%xmm1
  movsd  %xmm1,0x8(%rsp)
  lea    0x28(%rsp),%rdi
  lea    0x20(%rsp),%rsi
  movapd %xmm1,%xmm0
  call   <sincos@plt>
  movsd  0x28(%rsp),%xmm4
  movapd %xmm4,%xmm2
  mulsd  0x20(%rsp),%xmm2
  mulsd  %xmm4,%xmm4
  movapd %xmm4,%xmm0
  addsd  %xmm4,%xmm0
  movsd  D81(%rip),%xmm1
  subsd  %xmm0,%xmm1
  movsd  %xmm1,0x10(%rsp)
  movapd %xmm2,%xmm3
  addsd  %xmm2,%xmm3
  movsd  %xmm3,0x18(%rsp)
  addsd  %xmm3,%xmm3
  movsd  %xmm3,(%rsp)
  mov    %r13d,%esi
  sar    %esi
  lea    0x1(%rsi),%eax
  cltq
  lea    0x0(%rbp,%rax,8),%rax
  movsd  (%rax),%xmm0
  xorpd  D39(%rip),%xmm0
  movsd  %xmm0,(%rax)
  pxor   %xmm3,%xmm3
  movapd %xmm3,%xmm5
  movslq %r13d,%r12
  lea    0x40(%rbp),%r14
L26:
  lea    -0x100(%rsi),%ebx
  mov    $0x4,%eax
  cmp    %eax,%ebx
  cmovl  %eax,%ebx
  lea    -0x4(%rsi),%eax
  cmp    %eax,%ebx
  jg     L23
  cltq
  lea    0x0(%rbp,%rax,8),%rdx
  mov    %r12,%rcx
  sub    %rax,%rcx
  lea    0x0(%rbp,%rcx,8),%rax
  lea    -0x4(%rsi),%ecx
  sub    %ebx,%ecx
  shr    $0x2,%ecx
  mov    %ecx,%ecx
  movslq %esi,%r8
  mov    %r12,%rdi
  sub    %r8,%rdi
  lea    (%rdi,%rcx,4),%rcx
  lea    (%r14,%rcx,8),%rcx
L38:
  movsd  0x10(%rdx),%xmm6
  movapd %xmm6,%xmm7
  subsd  -0x10(%rax),%xmm7
  movsd  0x18(%rdx),%xmm8
  movapd %xmm8,%xmm0
  addsd  -0x8(%rax),%xmm0
  movapd %xmm7,%xmm1
  mulsd  %xmm4,%xmm1
  movapd %xmm0,%xmm9
  mulsd  %xmm2,%xmm9
  addsd  %xmm9,%xmm1
  mulsd  %xmm4,%xmm0
  mulsd  %xmm2,%xmm7
  subsd  %xmm7,%xmm0
  subsd  %xmm1,%xmm6
  movsd  %xmm6,0x10(%rdx)
  movapd %xmm0,%xmm6
  subsd  %xmm8,%xmm6
  movsd  %xmm6,0x18(%rdx)
  addsd  -0x10(%rax),%xmm1
  movsd  %xmm1,-0x10(%rax)
  subsd  -0x8(%rax),%xmm0
  movsd  %xmm0,-0x8(%rax)
  movsd  (%rsp),%xmm10
  movapd %xmm10,%xmm0
  mulsd  %xmm2,%xmm0
  addsd  %xmm0,%xmm5
  movsd  D48(%rip),%xmm0
  subsd  %xmm4,%xmm0
  mulsd  %xmm10,%xmm0
  addsd  %xmm0,%xmm3
  movsd  (%rdx),%xmm6
  movapd %xmm6,%xmm7
  subsd  (%rax),%xmm7
  movsd  0x8(%rdx),%xmm8
  movapd %xmm8,%xmm0
  addsd  0x8(%rax),%xmm0
  movapd %xmm5,%xmm1
  mulsd  %xmm7,%xmm1
  movapd %xmm3,%xmm9
  mulsd  %xmm0,%xmm9
  addsd  %xmm9,%xmm1
  mulsd  %xmm5,%xmm0
  mulsd  %xmm3,%xmm7
  subsd  %xmm7,%xmm0
  subsd  %xmm1,%xmm6
  movsd  %xmm6,(%rdx)
  movapd %xmm0,%xmm6
  subsd  %xmm8,%xmm6
  movsd  %xmm6,0x8(%rdx)
  addsd  (%rax),%xmm1
  movsd  %xmm1,(%rax)
  subsd  0x8(%rax),%xmm0
  movsd  %xmm0,0x8(%rax)
  movapd %xmm10,%xmm0
  mulsd  %xmm3,%xmm0
  addsd  %xmm0,%xmm4
  movsd  D48(%rip),%xmm0
  subsd  %xmm5,%xmm0
  mulsd  %xmm10,%xmm0
  addsd  %xmm0,%xmm2
  sub    $0x20,%rdx
  add    $0x20,%rax
  cmp    %rcx,%rax
  jne    L38
L23:
  cmp    $0x104,%esi
  jle    L29
  lea    0x28(%rsp),%rdi
  lea    0x20(%rsp),%rsi
  pxor   %xmm0,%xmm0
  cvtsi2sd %ebx,%xmm0
  mulsd  0x8(%rsp),%xmm0
  call   <sincos@plt>
  movsd  0x28(%rsp),%xmm0
  mulsd  D48(%rip),%xmm0
  movsd  0x20(%rsp),%xmm3
  mulsd  D48(%rip),%xmm3
  movsd  0x10(%rsp),%xmm5
  movapd %xmm5,%xmm1
  mulsd  %xmm0,%xmm1
  movsd  0x18(%rsp),%xmm7
  movapd %xmm7,%xmm2
  mulsd  %xmm3,%xmm2
  subsd  %xmm2,%xmm1
  movsd  D48(%rip),%xmm4
  subsd  %xmm1,%xmm4
  movapd %xmm7,%xmm2
  mulsd  %xmm0,%xmm2
  mulsd  %xmm3,%xmm5
  addsd  %xmm5,%xmm2
  movsd  D48(%rip),%xmm5
  subsd  %xmm0,%xmm5
  mov    %ebx,%esi
  jmp    L26
L29:
  movsd  0x10(%rbp),%xmm3
  movslq %r13d,%rax
  shl    $0x3,%rax
  lea    -0x10(%rbp,%rax,1),%rdx
  movapd %xmm3,%xmm5
  subsd  (%rdx),%xmm5
  movsd  0x18(%rbp),%xmm6
  lea    -0x8(%rbp,%rax,1),%rax
  movapd %xmm6,%xmm0
  addsd  (%rax),%xmm0
  movapd %xmm5,%xmm1
  mulsd  %xmm4,%xmm1
  movapd %xmm0,%xmm7
  mulsd  %xmm2,%xmm7
  addsd  %xmm7,%xmm1
  mulsd  %xmm4,%xmm0
  mulsd  %xmm2,%xmm5
  subsd  %xmm5,%xmm0
  subsd  %xmm1,%xmm3
  movsd  %xmm3,0x10(%rbp)
  movapd %xmm0,%xmm2
  subsd  %xmm6,%xmm2
  movsd  %xmm2,0x18(%rbp)
  addsd  (%rdx),%xmm1
  movsd  %xmm1,(%rdx)
  subsd  (%rax),%xmm0
  movsd  %xmm0,(%rax)
  movsd  0x8(%rbp),%xmm0
  xorpd  D39(%rip),%xmm0
  movsd  %xmm0,0x8(%rbp)
  add    $0x30,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  ret
```

tool_calls: name: extract_symbolic_data
arguments: tag: D45
type: byte[8]
name: extract_symbolic_data
arguments: tag: D81
type: byte[8]
name: extract_symbolic_data
arguments: tag: D39
type: byte[16]
name: extract_symbolic_data
arguments: tag: D48
type: f64

tool: {"D45": [0x18,0x2d,0x44,0x54,0xfb,0x21,0x09,0x40]}

tool: {"D81": [0x00,0x00,0x00,0x00,0x00,0x00,0xf0,0x3f]}

tool: {"D39": [0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00]}

tool: D48: 0.5

assistant: ```c
void rftbsub(int n, double *a) {
  int i, i0, j, k;
  double ec, w1r, w1i, wkr, wki, wdr, wdi, ss, xr, xi, yr, yi;
  ec = 2 * 1.570796326794896619231321691639751442098584699687 / 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;
  a[i + 1] = -a[i + 1];
  for (;;) {
    i0 = i - 4 * 64;
    if (i0 < 4) {
      i0 = 4;
    }
    for (j = i - 4; j >= i0; j -= 4) {
      k = n - j;
      xr = a[j + 2] - a[k - 2];
      xi = a[j + 3] + a[k - 1];
      yr = wdr * xr + wdi * xi;
      yi = wdr * xi - wdi * xr;
      a[j + 2] -= yr;
      a[j + 3] = yi - a[j + 3];
      a[k - 2] += yr;
      a[k - 1] = yi - a[k - 1];
      wkr += ss * wdi;
      wki += ss * (0.5 - wdr);
      xr = a[j] - a[k];
      xi = a[j + 1] + a[k + 1];
      yr = wkr * xr + wki * xi;
      yi = wkr * xi - wki * xr;
      a[j] -= yr;
      a[j + 1] = yi - a[j + 1];
      a[k] += yr;
      a[k + 1] = yi - a[k + 1];
      wdr += ss * wki;
      wdi += ss * (0.5 - wkr);
    }
    if (i0 == 4) {
      break;
    }
    wkr = 0.5 * sin(ec * i0);
    wki = 0.5 * cos(ec * i0);
    wdr = 0.5 - (wkr * w1r - wki * w1i);
    wdi = wkr * w1i + wki * w1r;
    wkr = 0.5 - wkr;
    i = i0;
  }
  xr = a[2] - a[n - 2];
  xi = a[3] + a[n - 1];
  yr = wdr * xr + wdi * xi;
  yi = wdr * xi - wdi * xr;
  a[2] -= yr;
  a[3] = yi - a[3];
  a[n - 2] += yr;
  a[n - 1] = yi - a[n - 1];
  a[1] = -a[1];
}
```