user: 请显示与下面列出的汇编代码相匹配的C语言实现：

```asm
<fftixf>:
  endbr64
  push   %r13
  mov    %r8d,%r13d
  push   %r12
  mov    %ecx,%r12d
  push   %rbp
  mov    %rsi,%rbp
  push   %rbx
  mov    %rdi,%rbx
  sub    $0x8,%rsp
  cmp    %edx,%ecx
  jg     L135
L116:
  xor    %esi,%esi
  lea    0x0(,%r12,4),%edx
  mov    %rbx,%rdi
  call   <memset@plt>
  test   %r13d,%r13d
  jne    L85
L114:
  movsd  D8(%rip),%xmm0
  mov    %rbp,%rdx
  mov    %rbx,%rsi
  mov    %r12d,%edi
  call   <fft@plt>
  mov    %r12d,%r8d
  shr    $0x1f,%r8d
  add    %r12d,%r8d
  sar    %r8d
  cmp    $0x1,%r12d
  jle    L27
  movslq %r8d,%rsi
  lea    0x10(%rbx),%r9
  lea    0x4(%rbx),%r10
  lea    0x4(,%rsi,4),%rcx
  lea    0x0(,%rsi,4),%rdi
  lea    0xc(%rbp,%rcx,1),%rax
  lea    0x0(%rbp,%rdi,1),%rdx
  cmp    %rax,%rbx
  setae  %al
  cmp    %r9,%rdx
  setae  %r9b
  or     %r9d,%eax
  mov    %rbp,%r9
  sub    %r10,%r9
  cmp    $0x8,%r9
  seta   %r9b
  cmp    $0x3,%r12d
  setg   %r10b
  and    %r10d,%r9d
  and    %r9d,%eax
  mov    %rcx,%r9
  neg    %r9
  cmp    $0x8,%r9
  seta   %r9b
  test   %r9b,%al
  je     L79
  add    %rbx,%rcx
  mov    %rbp,%rax
  sub    %rcx,%rax
  cmp    $0x8,%rax
  jbe    L79
  cmp    $0x7,%r12d
  jle    L0
  mov    %r8d,%ecx
  add    %rbx,%rdi
  xor    %eax,%eax
  shr    $0x2,%ecx
  shl    $0x4,%rcx
  xchg   %ax,%ax
L136:
  movups (%rdi,%rax,1),%xmm1
  movups %xmm1,(%rbx,%rax,1)
  movups (%rdx,%rax,1),%xmm2
  movups %xmm2,0x0(%rbp,%rax,1)
  add    $0x10,%rax
  cmp    %rcx,%rax
  jne    L136
  mov    %r8d,%edx
  and    $0xfffffffc,%edx
  mov    %edx,%eax
  cmp    %edx,%r8d
  je     L27
L102:
  mov    %r8d,%ecx
  sub    %edx,%ecx
  cmp    $0x1,%ecx
  je     L108
  add    %rdx,%rsi
  mov    (%rbx,%rsi,4),%rdi
  mov    %rdi,(%rbx,%rdx,4)
  mov    0x0(%rbp,%rsi,4),%rsi
  mov    %rsi,0x0(%rbp,%rdx,4)
  mov    %ecx,%edx
  and    $0xfffffffe,%edx
  add    %edx,%eax
  cmp    %edx,%ecx
  je     L27
L108:
  lea    (%r8,%rax,1),%edx
  cltq
  movslq %edx,%rdx
  movss  (%rbx,%rdx,4),%xmm0
  movss  %xmm0,(%rbx,%rax,4)
  movss  0x0(%rbp,%rdx,4),%xmm0
  movss  %xmm0,0x0(%rbp,%rax,4)
L27:
  add    $0x8,%rsp
  mov    %r8d,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
  xchg   %ax,%ax
L135:
  mov    %ecx,%r8d
  sub    %edx,%r8d
  movslq %edx,%rdx
  shl    $0x2,%r8d
  lea    (%rsi,%rdx,4),%rdi
  xor    %esi,%esi
  mov    %r8d,%edx
  call   <memset@plt>
  jmp    L116
L85:
  mov    %r13d,%ecx
  mov    %r12d,%edx
  mov    $0x1,%esi
  mov    %rbp,%rdi
  call   <xxrotate@plt>
  jmp    L114
  nopl   0x0(%rax,%rax,1)
L79:
  add    %rbx,%rdi
  xor    %eax,%eax
  nopl   (%rax)
L18:
  movss  (%rdi,%rax,4),%xmm0
  movss  %xmm0,(%rbx,%rax,4)
  movss  (%rdx,%rax,4),%xmm0
  movss  %xmm0,0x0(%rbp,%rax,4)
  add    $0x1,%rax
  cmp    %eax,%r8d
  jg     L18
  add    $0x8,%rsp
  mov    %r8d,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
L0:
  xor    %edx,%edx
  xor    %eax,%eax
  jmp    L102
```

tool_calls: name: disassemble_data
arguments: label: D8
type: f64

tool: D8: 1

assistant: ```c
int fftixf(float *xrr, float *xri, int isize, int ntot, int rotate) {
  int i;
  if (ntot > isize)
    memset(xri + isize, 0, sizeof(float) * (ntot - isize));
  memset(xrr, 0, sizeof(float) * ntot);
  if (rotate)
    xxrotate(xri, 1, ntot, rotate);
  fft(1.0, ntot, xrr, xri);
  ntot /= 2;
  for (i = 0; i < ntot; i++) {
    xrr[i] = xrr[i + ntot];
    xri[i] = xri[i + ntot];
  }
  return ntot;
}
```