user: 请从给定的汇编指令推导出C源代码：

```asm
<bitrevR2>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x40,%rsp
  mov    %rdi,-0xa8(%rbp)
  mov    %esi,-0xac(%rbp)
  mov    %rdx,-0xb8(%rbp)
  mov    -0xac(%rbp),%eax
  add    $0x3,%eax
  mov    %eax,%edx
  shr    $0x1f,%edx
  add    %edx,%eax
  sar    %eax
  mov    $0x1,%edx
  mov    %eax,%ecx
  shl    %cl,%rdx
  mov    %rdx,%rax
  mov    %eax,-0x80(%rbp)
  mov    -0xac(%rbp),%eax
  mov    $0x1,%edx
  mov    %eax,%ecx
  shl    %cl,%rdx
  mov    %rdx,%rax
  sub    -0x80(%rbp),%eax
  mov    %eax,-0x7c(%rbp)
  mov    -0xac(%rbp),%eax
  mov    %eax,%edx
  shr    $0x1f,%edx
  add    %edx,%eax
  sar    %eax
  sub    $0x1,%eax
  mov    $0x1,%edx
  mov    %eax,%ecx
  shl    %cl,%rdx
  mov    %rdx,%rax
  sub    $0x1,%eax
  mov    %eax,-0x78(%rbp)
  mov    -0xac(%rbp),%eax
  add    $0x1,%eax
  mov    %eax,%edx
  shr    $0x1f,%edx
  add    %edx,%eax
  sar    %eax
  add    $0x1,%eax
  mov    %eax,-0x74(%rbp)
  mov    -0xac(%rbp),%eax
  mov    $0x1,%edx
  mov    %eax,%ecx
  shl    %cl,%rdx
  mov    %rdx,%rax
  mov    %eax,-0x70(%rbp)
  mov    -0x70(%rbp),%eax
  add    $0x1,%eax
  mov    %eax,-0x6c(%rbp)
  mov    -0x70(%rbp),%eax
  add    $0x2,%eax
  mov    %eax,-0x68(%rbp)
  mov    -0x68(%rbp),%eax
  add    $0x1,%eax
  mov    %eax,-0x64(%rbp)
  mov    -0x80(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0xa8(%rbp),%rax
  add    %rdx,%rax
  mov    %rax,-0x10(%rbp)
  jmp    L10
L31:
  mov    -0x78(%rbp),%eax
  mov    %eax,-0x88(%rbp)
  jmp    L9
L51:
  mov    -0x78(%rbp),%eax
  mov    %eax,-0x84(%rbp)
  mov    -0x7c(%rbp),%edx
  mov    -0x88(%rbp),%eax
  cltq
  lea    (%rax,%rax,1),%rcx
  mov    -0xb8(%rbp),%rax
  add    %rcx,%rax
  movzwl (%rax),%eax
  cwtl
  shl    $0x2,%eax
  cltq
  add    %rdx,%rax
  lea    0x0(,%rax,4),%rdx
  mov    -0xa8(%rbp),%rax
  add    %rdx,%rax
  mov    %rax,-0x20(%rbp)
  mov    -0x74(%rbp),%eax
  mov    -0x88(%rbp),%edx
  mov    %eax,%ecx
  shl    %cl,%edx
  mov    %edx,%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0xa8(%rbp),%rax
  add    %rdx,%rax
  mov    %rax,-0x8(%rbp)
  mov    -0x84(%rbp),%eax
  cltq
  lea    (%rax,%rax,1),%rdx
  mov    -0xb8(%rbp),%rax
  add    %rdx,%rax
  movzwl (%rax),%eax
  cwtl
  shl    $0x2,%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x8(%rbp),%rax
  add    %rdx,%rax
  mov    %rax,-0x18(%rbp)
  mov    -0x20(%rbp),%rax
  movss  (%rax),%xmm0
  movss  %xmm0,-0x98(%rbp)
  mov    -0x20(%rbp),%rax
  movss  0x4(%rax),%xmm0
  movss  %xmm0,-0x94(%rbp)
  mov    -0x70(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movss  (%rax),%xmm0
  movss  %xmm0,-0x90(%rbp)
  mov    -0x6c(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movss  (%rax),%xmm0
  movss  %xmm0,-0x8c(%rbp)
  jmp    L21
L50:
  mov    -0x20(%rbp),%rax
  movss  0x8(%rax),%xmm0
  movss  %xmm0,-0x60(%rbp)
  mov    -0x20(%rbp),%rax
  movss  0xc(%rax),%xmm0
  movss  %xmm0,-0x5c(%rbp)
  mov    -0x68(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movss  (%rax),%xmm0
  movss  %xmm0,-0x58(%rbp)
  mov    -0x64(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movss  (%rax),%xmm0
  movss  %xmm0,-0x54(%rbp)
  mov    -0x18(%rbp),%rax
  movss  (%rax),%xmm0
  movss  %xmm0,-0x40(%rbp)
  mov    -0x18(%rbp),%rax
  movss  0x4(%rax),%xmm0
  movss  %xmm0,-0x3c(%rbp)
  mov    -0x70(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x18(%rbp),%rax
  add    %rdx,%rax
  movss  (%rax),%xmm0
  movss  %xmm0,-0x38(%rbp)
  mov    -0x6c(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x18(%rbp),%rax
  add    %rdx,%rax
  movss  (%rax),%xmm0
  movss  %xmm0,-0x34(%rbp)
  mov    -0x18(%rbp),%rax
  movss  0x8(%rax),%xmm0
  movss  %xmm0,-0x30(%rbp)
  mov    -0x18(%rbp),%rax
  movss  0xc(%rax),%xmm0
  movss  %xmm0,-0x2c(%rbp)
  mov    -0x68(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x18(%rbp),%rax
  add    %rdx,%rax
  movss  (%rax),%xmm0
  movss  %xmm0,-0x28(%rbp)
  mov    -0x64(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x18(%rbp),%rax
  add    %rdx,%rax
  movss  (%rax),%xmm0
  movss  %xmm0,-0x24(%rbp)
  movss  -0x98(%rbp),%xmm0
  addss  -0x90(%rbp),%xmm0
  movss  %xmm0,-0x50(%rbp)
  movss  -0x94(%rbp),%xmm0
  addss  -0x8c(%rbp),%xmm0
  movss  %xmm0,-0x4c(%rbp)
  movss  -0x98(%rbp),%xmm0
  subss  -0x90(%rbp),%xmm0
  movss  %xmm0,-0x90(%rbp)
  movss  -0x94(%rbp),%xmm0
  subss  -0x8c(%rbp),%xmm0
  movss  %xmm0,-0x8c(%rbp)
  movss  -0x60(%rbp),%xmm0
  addss  -0x58(%rbp),%xmm0
  movss  %xmm0,-0x48(%rbp)
  movss  -0x5c(%rbp),%xmm0
  addss  -0x54(%rbp),%xmm0
  movss  %xmm0,-0x44(%rbp)
  movss  -0x60(%rbp),%xmm0
  subss  -0x58(%rbp),%xmm0
  movss  %xmm0,-0x58(%rbp)
  movss  -0x5c(%rbp),%xmm0
  subss  -0x54(%rbp),%xmm0
  movss  %xmm0,-0x54(%rbp)
  movss  -0x40(%rbp),%xmm0
  addss  -0x38(%rbp),%xmm0
  movss  %xmm0,-0x98(%rbp)
  movss  -0x3c(%rbp),%xmm0
  addss  -0x34(%rbp),%xmm0
  movss  %xmm0,-0x94(%rbp)
  movss  -0x40(%rbp),%xmm0
  subss  -0x38(%rbp),%xmm0
  movss  %xmm0,-0x38(%rbp)
  movss  -0x3c(%rbp),%xmm0
  subss  -0x34(%rbp),%xmm0
  movss  %xmm0,-0x34(%rbp)
  movss  -0x30(%rbp),%xmm0
  addss  -0x28(%rbp),%xmm0
  movss  %xmm0,-0x60(%rbp)
  movss  -0x2c(%rbp),%xmm0
  addss  -0x24(%rbp),%xmm0
  movss  %xmm0,-0x5c(%rbp)
  movss  -0x30(%rbp),%xmm0
  subss  -0x28(%rbp),%xmm0
  movss  %xmm0,-0x28(%rbp)
  movss  -0x2c(%rbp),%xmm0
  subss  -0x24(%rbp),%xmm0
  movss  %xmm0,-0x24(%rbp)
  mov    -0x18(%rbp),%rax
  movss  -0x50(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x18(%rbp),%rax
  add    $0x4,%rax
  movss  -0x4c(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x18(%rbp),%rax
  add    $0x8,%rax
  movss  -0x90(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x18(%rbp),%rax
  add    $0xc,%rax
  movss  -0x8c(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x70(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x18(%rbp),%rax
  add    %rdx,%rax
  movss  -0x48(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x6c(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x18(%rbp),%rax
  add    %rdx,%rax
  movss  -0x44(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x68(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x18(%rbp),%rax
  add    %rdx,%rax
  movss  -0x58(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x64(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x18(%rbp),%rax
  add    %rdx,%rax
  movss  -0x54(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x20(%rbp),%rax
  movss  -0x98(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x20(%rbp),%rax
  add    $0x4,%rax
  movss  -0x94(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x20(%rbp),%rax
  add    $0x8,%rax
  movss  -0x38(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x20(%rbp),%rax
  add    $0xc,%rax
  movss  -0x34(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x70(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movss  -0x60(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x6c(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movss  -0x5c(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x68(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movss  -0x28(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x64(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movss  -0x24(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x80(%rbp),%eax
  shl    $0x2,%rax
  neg    %rax
  add    %rax,-0x20(%rbp)
  mov    -0x20(%rbp),%rax
  movss  (%rax),%xmm0
  movss  %xmm0,-0x98(%rbp)
  mov    -0x20(%rbp),%rax
  movss  0x4(%rax),%xmm0
  movss  %xmm0,-0x94(%rbp)
  mov    -0x70(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movss  (%rax),%xmm0
  movss  %xmm0,-0x90(%rbp)
  mov    -0x6c(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movss  (%rax),%xmm0
  movss  %xmm0,-0x8c(%rbp)
  subl   $0x1,-0x84(%rbp)
  mov    -0x84(%rbp),%eax
  cltq
  lea    (%rax,%rax,1),%rdx
  mov    -0xb8(%rbp),%rax
  add    %rdx,%rax
  movzwl (%rax),%eax
  cwtl
  shl    $0x2,%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x8(%rbp),%rax
  add    %rdx,%rax
  mov    %rax,-0x18(%rbp)
L21:
  mov    -0x84(%rbp),%eax
  cmp    -0x88(%rbp),%eax
  jg     L50
  mov    -0x20(%rbp),%rax
  movss  0x8(%rax),%xmm0
  movss  %xmm0,-0x60(%rbp)
  mov    -0x20(%rbp),%rax
  movss  0xc(%rax),%xmm0
  movss  %xmm0,-0x5c(%rbp)
  mov    -0x68(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movss  (%rax),%xmm0
  movss  %xmm0,-0x58(%rbp)
  mov    -0x64(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movss  (%rax),%xmm0
  movss  %xmm0,-0x54(%rbp)
  movss  -0x98(%rbp),%xmm0
  addss  -0x90(%rbp),%xmm0
  movss  %xmm0,-0x50(%rbp)
  movss  -0x94(%rbp),%xmm0
  addss  -0x8c(%rbp),%xmm0
  movss  %xmm0,-0x4c(%rbp)
  movss  -0x98(%rbp),%xmm0
  subss  -0x90(%rbp),%xmm0
  movss  %xmm0,-0x90(%rbp)
  movss  -0x94(%rbp),%xmm0
  subss  -0x8c(%rbp),%xmm0
  movss  %xmm0,-0x8c(%rbp)
  movss  -0x60(%rbp),%xmm0
  addss  -0x58(%rbp),%xmm0
  movss  %xmm0,-0x48(%rbp)
  movss  -0x5c(%rbp),%xmm0
  addss  -0x54(%rbp),%xmm0
  movss  %xmm0,-0x44(%rbp)
  movss  -0x60(%rbp),%xmm0
  subss  -0x58(%rbp),%xmm0
  movss  %xmm0,-0x58(%rbp)
  movss  -0x5c(%rbp),%xmm0
  subss  -0x54(%rbp),%xmm0
  movss  %xmm0,-0x54(%rbp)
  mov    -0x20(%rbp),%rax
  movss  -0x50(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x20(%rbp),%rax
  add    $0x4,%rax
  movss  -0x4c(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x20(%rbp),%rax
  add    $0x8,%rax
  movss  -0x90(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x20(%rbp),%rax
  add    $0xc,%rax
  movss  -0x8c(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x70(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movss  -0x48(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x6c(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movss  -0x44(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x68(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movss  -0x58(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x64(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movss  -0x54(%rbp),%xmm0
  movss  %xmm0,(%rax)
  subl   $0x1,-0x88(%rbp)
L9:
  cmpl   $0x0,-0x88(%rbp)
  jns    L51
  mov    -0xac(%rbp),%eax
  mov    %eax,%edx
  shr    $0x1f,%edx
  add    %edx,%eax
  sar    %eax
  add    $0x1,%eax
  mov    $0x4,%edx
  mov    %eax,%ecx
  shl    %cl,%rdx
  mov    %rdx,%rax
  add    %rax,-0xa8(%rbp)
L10:
  mov    -0xa8(%rbp),%rax
  cmp    -0x10(%rbp),%rax
  jb     L31
  nop
  nop
  leave
  ret
```

assistant: ```c
void bitrevR2(float *ioptr, int M, short *BRLow) {
  float f0r;
  float f0i;
  float f1r;
  float f1i;
  float f2r;
  float f2i;
  float f3r;
  float f3i;
  float f4r;
  float f4i;
  float f5r;
  float f5i;
  float f6r;
  float f6i;
  float f7r;
  float f7i;
  float t0r;
  float t0i;
  float t1r;
  float t1i;
  float *p0r;
  float *p1r;
  float *IOP;
  float *iolimit;
  int Colstart;
  int iCol;
  unsigned int posA;
  unsigned int posAi;
  unsigned int posB;
  unsigned int posBi;
  const unsigned int Nrems2 = ((unsigned long)1 << ((M + 3) / 2));
  const unsigned int Nroot_1_ColInc = ((unsigned long)1 << (M)) - Nrems2;
  const unsigned int Nroot_1 = ((unsigned long)1 << (M / 2 - 1)) - 1;
  const unsigned int ColstartShift = (M + 1) / 2 + 1;
  posA = ((unsigned long)1 << (M));
  posAi = posA + 1;
  posB = posA + 2;
  posBi = posB + 1;
  iolimit = ioptr + Nrems2;
  for (; ioptr < iolimit; ioptr += ((unsigned long)1 << (M / 2 + 1))) {
    for (Colstart = Nroot_1; Colstart >= 0; Colstart--) {
      iCol = Nroot_1;
      p0r = ioptr + Nroot_1_ColInc + BRLow[Colstart] * 4;
      IOP = ioptr + (Colstart << ColstartShift);
      p1r = IOP + BRLow[iCol] * 4;
      f0r = *(p0r);
      f0i = *(p0r + 1);
      f1r = *(p0r + posA);
      f1i = *(p0r + posAi);
      for (; iCol > Colstart;) {
        f2r = *(p0r + 2);
        f2i = *(p0r + (2 + 1));
        f3r = *(p0r + posB);
        f3i = *(p0r + posBi);
        f4r = *(p1r);
        f4i = *(p1r + 1);
        f5r = *(p1r + posA);
        f5i = *(p1r + posAi);
        f6r = *(p1r + 2);
        f6i = *(p1r + (2 + 1));
        f7r = *(p1r + posB);
        f7i = *(p1r + posBi);
        t0r = f0r + f1r;
        t0i = f0i + f1i;
        f1r = f0r - f1r;
        f1i = f0i - f1i;
        t1r = f2r + f3r;
        t1i = f2i + f3i;
        f3r = f2r - f3r;
        f3i = f2i - f3i;
        f0r = f4r + f5r;
        f0i = f4i + f5i;
        f5r = f4r - f5r;
        f5i = f4i - f5i;
        f2r = f6r + f7r;
        f2i = f6i + f7i;
        f7r = f6r - f7r;
        f7i = f6i - f7i;
        *(p1r) = t0r;
        *(p1r + 1) = t0i;
        *(p1r + 2) = f1r;
        *(p1r + (2 + 1)) = f1i;
        *(p1r + posA) = t1r;
        *(p1r + posAi) = t1i;
        *(p1r + posB) = f3r;
        *(p1r + posBi) = f3i;
        *(p0r) = f0r;
        *(p0r + 1) = f0i;
        *(p0r + 2) = f5r;
        *(p0r + (2 + 1)) = f5i;
        *(p0r + posA) = f2r;
        *(p0r + posAi) = f2i;
        *(p0r + posB) = f7r;
        *(p0r + posBi) = f7i;
        p0r -= Nrems2;
        f0r = *(p0r);
        f0i = *(p0r + 1);
        f1r = *(p0r + posA);
        f1i = *(p0r + posAi);
        iCol -= 1;
        p1r = IOP + BRLow[iCol] * 4;
      };
      f2r = *(p0r + 2);
      f2i = *(p0r + (2 + 1));
      f3r = *(p0r + posB);
      f3i = *(p0r + posBi);
      t0r = f0r + f1r;
      t0i = f0i + f1i;
      f1r = f0r - f1r;
      f1i = f0i - f1i;
      t1r = f2r + f3r;
      t1i = f2i + f3i;
      f3r = f2r - f3r;
      f3i = f2i - f3i;
      *(p0r) = t0r;
      *(p0r + 1) = t0i;
      *(p0r + 2) = f1r;
      *(p0r + (2 + 1)) = f1i;
      *(p0r + posA) = t1r;
      *(p0r + posAi) = t1i;
      *(p0r + posB) = f3r;
      *(p0r + posBi) = f3i;
    };
  };
}
```