user: 这段汇编代码用C语言表示是什么样的？

```asm
<cftfsub>:
  endbr64
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  mov    %rsi,%rbx
  sub    $0x8,%rsp
  cmp    $0x8,%edi
  jg     L84
  lea    0x10(%rsi),%rax
  mov    $0x2,%ebp
  je     L65
L57:
  xor    %edx,%edx
  nopw   0x0(%rax,%rax,1)
L144:
  movupd (%rbx),%xmm0
  movupd (%rax),%xmm2
  add    $0x2,%edx
  add    $0x10,%rbx
  add    $0x10,%rax
  movapd %xmm0,%xmm1
  subpd  %xmm2,%xmm0
  addsd  %xmm2,%xmm1
  movsd  %xmm1,-0x10(%rbx)
  movsd  -0x8(%rax),%xmm1
  addsd  -0x8(%rbx),%xmm1
  movsd  %xmm1,-0x8(%rbx)
  movups %xmm0,-0x10(%rax)
  cmp    %edx,%ebp
  jg     L144
L34:
  add    $0x8,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
  cs nopw 0x0(%rax,%rax,1)
L65:
  mov    $0x2,%ebp
L27:
  movslq %ebp,%rdx
  lea    -0x1(%rbp),%edi
  mov    $0x1,%eax
  shl    $0x3,%rdx
  shr    %edi
  lea    (%rbx,%rdx,1),%rsi
  add    $0x1,%edi
  lea    (%rsi,%rdx,1),%rcx
  add    %rcx,%rdx
  test   %ebp,%ebp
  cmovle %rax,%rdi
  xor    %eax,%eax
  shl    $0x4,%rdi
L127:
  movupd (%rbx,%rax,1),%xmm7
  movupd (%rsi,%rax,1),%xmm5
  movupd (%rdx,%rax,1),%xmm6
  movupd (%rcx,%rax,1),%xmm0
  movapd %xmm7,%xmm1
  movupd (%rsi,%rax,1),%xmm2
  subpd  %xmm5,%xmm1
  subpd  %xmm6,%xmm0
  addpd  %xmm7,%xmm2
  movupd (%rcx,%rax,1),%xmm7
  movapd %xmm1,%xmm3
  shufpd $0x1,%xmm0,%xmm0
  subpd  %xmm0,%xmm3
  addpd  %xmm1,%xmm0
  movapd %xmm6,%xmm1
  addpd  %xmm7,%xmm1
  movapd %xmm0,%xmm7
  movapd %xmm1,%xmm4
  movsd  %xmm3,%xmm7
  movsd  %xmm0,%xmm3
  addpd  %xmm2,%xmm4
  subpd  %xmm1,%xmm2
  movups %xmm4,(%rbx,%rax,1)
  movups %xmm2,(%rcx,%rax,1)
  movups %xmm7,(%rsi,%rax,1)
  movups %xmm3,(%rdx,%rax,1)
  add    $0x10,%rax
  cmp    %rdi,%rax
  jne    L127
  add    $0x8,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
  nopl   0x0(%rax,%rax,1)
L84:
  mov    %edi,%r12d
  mov    %rdx,%r13
  call   <cft1st@plt>
  cmp    $0x20,%r12d
  jle    L136
  mov    $0x8,%esi
  mov    $0x20,%ebp
  jmp    L8
  nopl   0x0(%rax)
L30:
  mov    %eax,%ebp
L8:
  mov    %r13,%rcx
  mov    %rbx,%rdx
  mov    %r12d,%edi
  call   <cftmdl@plt>
  lea    0x0(,%rbp,4),%eax
  mov    %ebp,%esi
  cmp    %r12d,%eax
  jl     L30
  je     L41
  test   %ebp,%ebp
  jle    L34
L92:
  movslq %ebp,%rax
  lea    0x20(%rbx),%rdx
  lea    0x20(,%rax,8),%rcx
  lea    (%rbx,%rax,8),%rax
  cmp    %rdx,%rax
  jb     L57
  cmp    $0x4,%ebp
  jle    L57
  lea    -0x1(%rbp),%edx
  xor    %edi,%edi
  lea    -0x18(%rbx,%rcx,1),%rcx
  shr    %edx
  test   %ebp,%ebp
  setg   %dil
  imul   %edx,%edi
  mov    %rbx,%rdx
  mov    %edi,%esi
  shr    %esi
  sub    $0x1,%esi
  shl    $0x5,%rsi
  lea    0x20(%rax,%rsi,1),%rsi
  nopl   0x0(%rax)
L7:
  movupd (%rdx),%xmm3
  movupd (%rax),%xmm6
  add    $0x20,%rax
  add    $0x20,%rdx
  movupd -0x10(%rdx),%xmm2
  movupd -0x10(%rax),%xmm5
  add    $0x20,%rcx
  movapd %xmm3,%xmm1
  movapd %xmm6,%xmm0
  movupd -0x20(%rcx),%xmm4
  subpd  %xmm6,%xmm3
  unpcklpd %xmm2,%xmm1
  unpcklpd %xmm5,%xmm0
  subpd  %xmm5,%xmm2
  addpd  %xmm1,%xmm0
  movupd -0x18(%rdx),%xmm1
  movhpd -0x10(%rcx),%xmm4
  movhpd -0x8(%rdx),%xmm1
  addpd  %xmm4,%xmm1
  movapd %xmm0,%xmm4
  unpcklpd %xmm1,%xmm4
  unpckhpd %xmm1,%xmm0
  movups %xmm4,-0x20(%rdx)
  movups %xmm0,-0x10(%rdx)
  movups %xmm3,-0x20(%rax)
  movups %xmm2,-0x10(%rax)
  cmp    %rax,%rsi
  jne    L7
  and    $0xfffffffe,%edi
  lea    (%rdi,%rdi,1),%eax
  movslq %eax,%rsi
  lea    0x0(%rbp,%rax,1),%edx
  lea    0x0(,%rsi,8),%r8
  movslq %edx,%rdx
  lea    0x8(%rbx,%rsi,8),%rsi
  shl    $0x3,%rdx
  lea    (%rbx,%r8,1),%rdi
  movupd (%rdi),%xmm0
  lea    (%rbx,%rdx,1),%rcx
  movupd (%rcx),%xmm2
  movapd %xmm0,%xmm1
  addsd  %xmm2,%xmm1
  subpd  %xmm2,%xmm0
  movsd  %xmm1,(%rdi)
  movsd  (%rsi),%xmm1
  addsd  0x8(%rbx,%rdx,1),%xmm1
  lea    0x2(%rax),%edx
  movsd  %xmm1,(%rsi)
  movups %xmm0,(%rcx)
  cmp    %ebp,%edx
  jge    L34
  add    %ebp,%edx
  lea    0x10(%rbx,%r8,1),%rsi
  add    $0x3,%eax
  movslq %edx,%rdx
  movupd (%rsi),%xmm0
  cltq
  shl    $0x3,%rdx
  lea    (%rbx,%rax,8),%rax
  lea    (%rbx,%rdx,1),%rcx
  movapd %xmm0,%xmm1
  movupd (%rcx),%xmm2
  addsd  %xmm2,%xmm1
  subpd  %xmm2,%xmm0
  movsd  %xmm1,(%rsi)
  movsd  (%rax),%xmm1
  addsd  0x8(%rbx,%rdx,1),%xmm1
  movsd  %xmm1,(%rax)
  movups %xmm0,(%rcx)
  add    $0x8,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
  nop
L41:
  test   %ebp,%ebp
  jg     L27
  jmp    L34
L136:
  mov    $0x8,%ebp
  jne    L92
  jmp    L27
```

assistant: ```c
void cftfsub(int n, double *a, double *w) {
  int j, j1, j2, j3, l;
  double x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i;
  l = 2;
  if (n > 8) {
    cft1st(n, a, w);
    l = 8;
    while ((l << 2) < n) {
      cftmdl(n, l, a, w);
      l <<= 2;
    }
  }
  if ((l << 2) == n) {
    for (j = 0; j < l; j += 2) {
      j1 = j + l;
      j2 = j1 + l;
      j3 = j2 + l;
      x0r = a[j] + a[j1];
      x0i = a[j + 1] + a[j1 + 1];
      x1r = a[j] - a[j1];
      x1i = a[j + 1] - a[j1 + 1];
      x2r = a[j2] + a[j3];
      x2i = a[j2 + 1] + a[j3 + 1];
      x3r = a[j2] - a[j3];
      x3i = a[j2 + 1] - a[j3 + 1];
      a[j] = x0r + x2r;
      a[j + 1] = x0i + x2i;
      a[j2] = x0r - x2r;
      a[j2 + 1] = x0i - x2i;
      a[j1] = x1r - x3i;
      a[j1 + 1] = x1i + x3r;
      a[j3] = x1r + x3i;
      a[j3 + 1] = x1i - x3r;
    }
  } else {
    for (j = 0; j < l; j += 2) {
      j1 = j + l;
      x0r = a[j] - a[j1];
      x0i = a[j + 1] - a[j1 + 1];
      a[j] += a[j1];
      a[j + 1] += a[j1 + 1];
      a[j1] = x0r;
      a[j1 + 1] = x0i;
    }
  }
}
```