user: 请将这段汇编代码片段转换成等效的C代码：

```asm
<bitrv2>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  mov    %rsi,%r9
  mov    %rdx,%rax
  movl   $0x0,(%rsi)
  cmp    $0x8,%edi
  jle    L7
  mov    $0x1,%r10d
  lea    0x4(%rsi),%r11
  jmp    L184
L93:
  mov    %ebx,%r10d
L184:
  sar    %edi
  test   %r10d,%r10d
  jle    L36
  mov    %r9,%rdx
  lea    -0x1(%r10),%ecx
  lea    (%r11,%rcx,4),%r8
  movslq %r10d,%rsi
L155:
  mov    %edi,%ecx
  add    (%rdx),%ecx
  mov    %ecx,(%rdx,%rsi,4)
  add    $0x4,%rdx
  cmp    %r8,%rdx
  jne    L155
L36:
  lea    (%r10,%r10,1),%ebx
  shl    $0x4,%r10d
  cmp    %edi,%r10d
  jl     L93
  lea    (%rbx,%rbx,1),%esi
  je     L195
L202:
  cmp    $0x1,%ebx
  jle    L119
  lea    0x4(%r9),%r10
  mov    %ebx,%ebx
  mov    $0x1,%r8d
  jmp    L69
L195:
  test   %ebx,%ebx
  jle    L119
L0:
  lea    0x0(,%rbx,4),%r10d
  mov    %r9,%r12
  mov    %esi,-0xc(%rsp)
  mov    %ebx,%ebx
  mov    %rbx,-0x8(%rsp)
  mov    $0x1,%r11d
  jmp    L75
L88:
  mov    $0x1,%ebx
  mov    $0x2,%esi
  jmp    L0
L158:
  lea    (%r11,%r11,1),%ebp
  mov    $0x0,%edi
L72:
  mov    0x4(%rbx),%edx
  lea    (%rdx,%rdi,2),%ecx
  mov    %ebp,%edx
  add    (%r9,%rdi,4),%edx
  movslq %ecx,%r8
  shl    $0x2,%r8
  lea    (%rax,%r8,1),%r14
  movss  (%r14),%xmm1
  lea    0x4(%rax,%r8,1),%r15
  movss  (%r15),%xmm0
  movslq %edx,%r8
  shl    $0x2,%r8
  lea    (%rax,%r8,1),%r13
  movss  0x0(%r13),%xmm3
  lea    0x4(%rax,%r8,1),%r8
  movss  (%r8),%xmm2
  movss  %xmm3,(%r14)
  movss  %xmm2,(%r15)
  movss  %xmm1,0x0(%r13)
  movss  %xmm0,(%r8)
  add    %esi,%ecx
  add    %r10d,%edx
  movslq %ecx,%r8
  shl    $0x2,%r8
  lea    (%rax,%r8,1),%r14
  movss  (%r14),%xmm1
  lea    0x4(%rax,%r8,1),%r15
  movss  (%r15),%xmm0
  movslq %edx,%r8
  shl    $0x2,%r8
  lea    (%rax,%r8,1),%r13
  movss  0x0(%r13),%xmm3
  lea    0x4(%rax,%r8,1),%r8
  movss  (%r8),%xmm2
  movss  %xmm3,(%r14)
  movss  %xmm2,(%r15)
  movss  %xmm1,0x0(%r13)
  movss  %xmm0,(%r8)
  add    %esi,%ecx
  sub    %esi,%edx
  movslq %ecx,%r8
  shl    $0x2,%r8
  lea    (%rax,%r8,1),%r14
  movss  (%r14),%xmm1
  lea    0x4(%rax,%r8,1),%r15
  movss  (%r15),%xmm0
  movslq %edx,%r8
  shl    $0x2,%r8
  lea    (%rax,%r8,1),%r13
  movss  0x0(%r13),%xmm3
  lea    0x4(%rax,%r8,1),%r8
  movss  (%r8),%xmm2
  movss  %xmm3,(%r14)
  movss  %xmm2,(%r15)
  movss  %xmm1,0x0(%r13)
  movss  %xmm0,(%r8)
  add    %esi,%ecx
  movslq %ecx,%rcx
  shl    $0x2,%rcx
  lea    (%rax,%rcx,1),%r8
  movss  (%r8),%xmm1
  lea    0x4(%rax,%rcx,1),%rcx
  movss  (%rcx),%xmm0
  add    %r10d,%edx
  movslq %edx,%rdx
  shl    $0x2,%rdx
  lea    (%rax,%rdx,1),%r13
  movss  0x0(%r13),%xmm3
  lea    0x4(%rax,%rdx,1),%rdx
  movss  (%rdx),%xmm2
  movss  %xmm3,(%r8)
  movss  %xmm2,(%rcx)
  movss  %xmm1,0x0(%r13)
  movss  %xmm0,(%rdx)
  add    $0x1,%rdi
  cmp    %rdi,%r11
  jne    L72
L1:
  add    $0x1,%r11
  add    $0x4,%r12
  addl   $0x2,-0xc(%rsp)
L75:
  mov    %r12,%rbx
  mov    -0xc(%rsp),%edx
  add    (%r12),%edx
  movslq %edx,%rcx
  shl    $0x2,%rcx
  lea    (%rax,%rcx,1),%rdi
  movss  (%rdi),%xmm1
  lea    0x4(%rax,%rcx,1),%rcx
  movss  (%rcx),%xmm0
  add    %esi,%edx
  movslq %edx,%rdx
  shl    $0x2,%rdx
  lea    (%rax,%rdx,1),%r8
  movss  (%r8),%xmm3
  lea    0x4(%rax,%rdx,1),%rdx
  movss  (%rdx),%xmm2
  movss  %xmm3,(%rdi)
  movss  %xmm2,(%rcx)
  movss  %xmm1,(%r8)
  movss  %xmm0,(%rdx)
  cmp    -0x8(%rsp),%r11
  je     L119
  test   %r11d,%r11d
  jg     L158
  jmp    L1
L172:
  mov    (%r10),%edx
  lea    (%rdx,%rdi,2),%ecx
  mov    %r11d,%edx
  add    (%r9,%rdi,4),%edx
  movslq %ecx,%rbp
  shl    $0x2,%rbp
  lea    (%rax,%rbp,1),%r13
  movss  0x0(%r13),%xmm1
  lea    0x4(%rax,%rbp,1),%r14
  movss  (%r14),%xmm0
  movslq %edx,%rbp
  shl    $0x2,%rbp
  lea    (%rax,%rbp,1),%r12
  movss  (%r12),%xmm3
  lea    0x4(%rax,%rbp,1),%rbp
  movss  0x0(%rbp),%xmm2
  movss  %xmm3,0x0(%r13)
  movss  %xmm2,(%r14)
  movss  %xmm1,(%r12)
  movss  %xmm0,0x0(%rbp)
  add    %esi,%ecx
  movslq %ecx,%rcx
  shl    $0x2,%rcx
  lea    (%rax,%rcx,1),%rbp
  movss  0x0(%rbp),%xmm1
  lea    0x4(%rax,%rcx,1),%rcx
  movss  (%rcx),%xmm0
  add    %esi,%edx
  movslq %edx,%rdx
  shl    $0x2,%rdx
  lea    (%rax,%rdx,1),%r12
  movss  (%r12),%xmm3
  lea    0x4(%rax,%rdx,1),%rdx
  movss  (%rdx),%xmm2
  movss  %xmm3,0x0(%rbp)
  movss  %xmm2,(%rcx)
  movss  %xmm1,(%r12)
  movss  %xmm0,(%rdx)
  add    $0x1,%rdi
  cmp    %r8,%rdi
  jne    L172
L196:
  add    $0x1,%r8
  add    $0x4,%r10
  cmp    %rbx,%r8
  je     L119
L69:
  lea    (%r8,%r8,1),%r11d
  mov    $0x0,%edi
  test   %r8d,%r8d
  jg     L172
  jmp    L196
L7:
  je     L88
  mov    $0x1,%ebx
  mov    $0x2,%esi
  jmp    L202
L119:
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void bitrv2(int n, int *ip, float *a) {
  int j, j1, k, k1, l, m, m2;
  float xr, xi, yr, yi;
  ip[0] = 0;
  l = n;
  m = 1;
  while ((m << 3) < l) {
    l >>= 1;
    for (j = 0; j < m; j++) {
      ip[m + j] = ip[j] + l;
    }
    m <<= 1;
  }
  m2 = 2 * m;
  if ((m << 3) == l) {
    for (k = 0; k < m; k++) {
      for (j = 0; j < k; j++) {
        j1 = 2 * j + ip[k];
        k1 = 2 * k + ip[j];
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 += m2;
        k1 += 2 * m2;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 += m2;
        k1 -= m2;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 += m2;
        k1 += 2 * m2;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
      }
      j1 = 2 * k + m2 + ip[k];
      k1 = j1 + m2;
      xr = a[j1];
      xi = a[j1 + 1];
      yr = a[k1];
      yi = a[k1 + 1];
      a[j1] = yr;
      a[j1 + 1] = yi;
      a[k1] = xr;
      a[k1 + 1] = xi;
    }
  } else {
    for (k = 1; k < m; k++) {
      for (j = 0; j < k; j++) {
        j1 = 2 * j + ip[k];
        k1 = 2 * k + ip[j];
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 += m2;
        k1 += m2;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
      }
    }
  }
}
```