user: 请显示与下面列出的汇编代码相匹配的C语言实现：

```asm
<cftbsub>:
  endbr64
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  mov    %rsi,%rbx
  sub    $0x8,%rsp
  cmp    $0x8,%rdi
  ja     L110
  mov    $0x2,%ebp
  je     L52
L39:
  lea    0x4(%rbx,%rbp,4),%rdx
  xor    %eax,%eax
  movss  D13(%rip),%xmm5
  nopl   (%rax)
L83:
  movss  (%rbx,%rax,4),%xmm1
  movss  -0x4(%rdx),%xmm3
  add    $0x8,%rdx
  movss  0x4(%rbx,%rax,4),%xmm0
  movss  -0x8(%rdx),%xmm2
  movaps %xmm1,%xmm4
  subss  %xmm3,%xmm1
  addss  %xmm3,%xmm4
  subss  %xmm0,%xmm2
  xorps  %xmm5,%xmm0
  movss  %xmm4,(%rbx,%rax,4)
  subss  -0x8(%rdx),%xmm0
  movss  %xmm0,0x4(%rbx,%rax,4)
  add    $0x2,%rax
  movss  %xmm1,-0xc(%rdx)
  movss  %xmm2,-0x8(%rdx)
  cmp    %rbp,%rax
  jb     L83
L62:
  add    $0x8,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
  nopl   0x0(%rax)
L110:
  mov    %rdi,%r12
  mov    %rdx,%r13
  call   <cft1st@plt>
  cmp    $0x20,%r12
  jbe    L9
  mov    $0x8,%esi
  mov    $0x20,%ebp
  jmp    L113
  nopl   0x0(%rax)
L122:
  mov    %rax,%rbp
L113:
  mov    %r13,%rcx
  mov    %rbx,%rdx
  mov    %r12,%rdi
  call   <cftmdl@plt>
  lea    0x0(,%rbp,4),%rax
  mov    %rbp,%rsi
  cmp    %r12,%rax
  jb     L122
  jne    L53
  test   %rbp,%rbp
  je     L62
L52:
  lea    0x0(,%rbp,4),%rdx
  xor    %eax,%eax
  movss  D13(%rip),%xmm5
  lea    (%rbx,%rdx,1),%rsi
  lea    (%rsi,%rdx,1),%rcx
  add    %rcx,%rdx
  nopl   0x0(%rax)
L106:
  movss  0x4(%rbx,%rax,4),%xmm3
  movss  (%rsi),%xmm4
  add    $0x8,%rcx
  add    $0x8,%rsi
  movss  -0x4(%rsi),%xmm0
  movss  (%rbx,%rax,4),%xmm1
  add    $0x8,%rdx
  movaps %xmm3,%xmm2
  movss  -0x8(%rdx),%xmm10
  movss  -0x4(%rdx),%xmm9
  xorps  %xmm5,%xmm2
  movaps %xmm1,%xmm6
  subss  %xmm4,%xmm1
  subss  %xmm0,%xmm2
  subss  %xmm3,%xmm0
  movss  -0x8(%rcx),%xmm3
  addss  %xmm4,%xmm6
  movss  -0x4(%rcx),%xmm4
  movaps %xmm3,%xmm8
  subss  %xmm10,%xmm3
  addss  %xmm10,%xmm8
  movaps %xmm4,%xmm7
  subss  %xmm9,%xmm4
  addss  %xmm9,%xmm7
  movaps %xmm6,%xmm9
  addss  %xmm8,%xmm9
  subss  %xmm8,%xmm6
  movss  %xmm9,(%rbx,%rax,4)
  movaps %xmm2,%xmm9
  addss  %xmm7,%xmm2
  subss  %xmm7,%xmm9
  movss  %xmm9,0x4(%rbx,%rax,4)
  add    $0x2,%rax
  movss  %xmm2,-0x4(%rcx)
  movaps %xmm1,%xmm2
  addss  %xmm4,%xmm1
  subss  %xmm4,%xmm2
  movss  %xmm6,-0x8(%rcx)
  movss  %xmm2,-0x8(%rsi)
  movaps %xmm0,%xmm2
  addss  %xmm3,%xmm0
  subss  %xmm3,%xmm2
  movss  %xmm2,-0x4(%rsi)
  movss  %xmm1,-0x8(%rdx)
  movss  %xmm0,-0x4(%rdx)
  cmp    %rbp,%rax
  jb     L106
  add    $0x8,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
  xchg   %ax,%ax
L53:
  test   %rbp,%rbp
  jne    L39
  jmp    L62
L9:
  mov    $0x8,%ebp
  jne    L39
  jmp    L52
```

tool_calls: name: disassemble_data
arguments: data_label: D13
type_infered: byte[4]

tool: {"D13": [0x00,0x00,0x00,0x80]}

assistant: ```c
void cftbsub(size_t n, float *a, float *w) {
  size_t j, j1, j2, j3, l;
  float 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[j + 1] - a[j1 + 1];
      a[j1] = x0r;
      a[j1 + 1] = x0i;
    }
  }
}
```