user: 请显示与下面列出的汇编代码相匹配的C语言实现：

```asm
<scbitrevR2>:
  endbr64
  push   %r15
  mov    %esi,%eax
  movaps %xmm0,%xmm6
  push   %r14
  mov    %eax,%r10d
  mov    %rdi,%r14
  shufps $0x0,%xmm6,%xmm6
  push   %r13
  shr    $0x1f,%r10d
  push   %r12
  mov    %rdx,%r12
  lea    0x3(%rsi),%edx
  add    %eax,%r10d
  mov    %edx,%ecx
  sar    %r10d
  push   %rbp
  shr    $0x1f,%ecx
  push   %rbx
  add    %edx,%ecx
  mov    $0x1,%edx
  sar    %ecx
  mov    %rdx,%r9
  mov    %rdx,%rsi
  shl    %cl,%r9
  mov    %eax,%ecx
  add    $0x1,%eax
  sub    $0x10,%rsp
  shl    %cl,%rsi
  lea    -0x1(%r10),%ecx
  mov    %rdi,-0x48(%rsp)
  shl    %cl,%rdx
  mov    %eax,%ecx
  mov    %esi,%edi
  movaps %xmm6,-0x68(%rsp)
  shr    $0x1f,%ecx
  sub    %r9d,%edi
  lea    -0x1(%rdx),%ebx
  mov    %r9d,%r9d
  add    %ecx,%eax
  mov    %ebx,-0x4(%rsp)
  sar    %eax
  add    $0x1,%eax
  mov    %eax,-0x8(%rsp)
  lea    0x0(,%r9,4),%rax
  lea    (%r14,%rax,1),%r9
  mov    %r9,(%rsp)
  cmp    %r9,%r14
  jae    L12
  lea    0x2(%rsi),%r11d
  lea    0x3(%rsi),%ecx
  movslq %ebx,%r14
  lea    0x1(%rsi),%r8d
  mov    %esi,%esi
  mov    %r14,-0x40(%rsp)
  lea    (%r12,%r14,2),%r9
  lea    0x0(,%r11,4),%r13
  lea    0x0(,%rcx,4),%r15
  shl    $0x2,%rsi
  shl    $0x2,%r8
  lea    0x1(%r10),%ecx
  mov    $0x4,%r11d
  shl    %cl,%r11
  mov    %r11,-0x10(%rsp)
  test   %ebx,%ebx
  js     L12
  movswl (%r9),%ecx
  mov    %rax,%r14
  mov    %r12,%rbp
  neg    %r14
  shl    $0x2,%ecx
  movslq %ecx,%rcx
  lea    0x0(,%rcx,4),%rbx
  mov    %rbx,-0x28(%rsp)
  mov    %edi,%ebx
  mov    %rbx,-0x38(%rsp)
  lea    -0x2(%rdx),%ebx
  mov    %ebx,-0x2c(%rsp)
  mov    %rsi,%rbx
  sub    %rax,%rbx
  mov    %rbx,-0x20(%rsp)
  mov    %r8,%rbx
  sub    %rax,%rbx
  mov    %rbx,-0x18(%rsp)
  nopl   0x0(%rax,%rax,1)
L62:
  mov    -0x40(%rsp),%rdx
  mov    -0x4(%rsp),%ecx
  mov    -0x48(%rsp),%rdi
  mov    -0x38(%rsp),%r9
  nopl   0x0(%rax,%rax,1)
L42:
  movswl 0x0(%rbp,%rdx,2),%eax
  shl    $0x2,%eax
  cltq
  add    %r9,%rax
  lea    (%rdi,%rax,4),%rax
  lea    (%rax,%r8,1),%rbx
  movss  (%rax,%rsi,1),%xmm5
  movups (%rax),%xmm1
  lea    (%rax,%r13,1),%r11
  movss  (%rbx),%xmm2
  movss  0x8(%rax),%xmm3
  lea    (%rax,%r15,1),%r10
  movlhps %xmm1,%xmm1
  movss  (%r11),%xmm7
  movss  (%r10),%xmm6
  unpcklps %xmm2,%xmm5
  movss  0xc(%rax),%xmm2
  movlhps %xmm5,%xmm5
  movaps %xmm5,%xmm4
  addps  %xmm1,%xmm4
  subps  %xmm5,%xmm1
  shufps $0xe4,%xmm1,%xmm4
  mulps  -0x68(%rsp),%xmm4
  movaps %xmm3,%xmm1
  subss  %xmm7,%xmm3
  addss  %xmm7,%xmm1
  mulss  %xmm0,%xmm3
  mulss  %xmm0,%xmm1
  movups %xmm4,(%rax)
  movss  %xmm1,(%rax,%rsi,1)
  movaps %xmm2,%xmm1
  subss  %xmm6,%xmm2
  lea    -0x1(%rdx),%eax
  addss  %xmm6,%xmm1
  sub    $0x1,%rdx
  mulss  %xmm0,%xmm2
  mulss  %xmm0,%xmm1
  movss  %xmm1,(%rbx)
  movss  %xmm3,(%r11)
  movss  %xmm2,(%r10)
  cmp    %edx,%ecx
  jle    L42
  mov    -0x2c(%rsp),%ebx
  movslq %eax,%r11
  sub    %eax,%ebx
  mov    %ebx,-0x4c(%rsp)
  test   %eax,%eax
  js     L56
L15:
  movswl 0x0(%rbp,%r11,2),%eax
  mov    -0x48(%rsp),%rbx
  mov    %r11d,-0x30(%rsp)
  movzbl -0x8(%rsp),%ecx
  shl    $0x2,%eax
  cltq
  add    -0x38(%rsp),%rax
  lea    (%rbx,%rax,4),%r12
  mov    %r11d,%eax
  shl    %cl,%eax
  movss  (%r12),%xmm2
  movss  0x4(%r12),%xmm8
  cltq
  movss  (%r12,%rsi,1),%xmm10
  movss  (%r12,%r8,1),%xmm9
  lea    (%rbx,%rax,4),%rbx
  mov    -0x28(%rsp),%rax
  mov    -0x40(%rsp),%rcx
  lea    (%rbx,%rax,1),%rdx
  mov    %r12,%rax
  nopl   0x0(%rax,%rax,1)
L2:
  movups (%rdx),%xmm1
  movaps %xmm10,%xmm15
  lea    (%rdx,%r8,1),%r10
  movss  (%rdx,%rsi,1),%xmm7
  addss  %xmm2,%xmm15
  subss  %xmm10,%xmm2
  movss  (%rax,%r13,1),%xmm14
  movss  (%r10),%xmm3
  movlhps %xmm1,%xmm1
  movss  0x8(%rax),%xmm6
  lea    (%rdx,%r13,1),%r9
  lea    (%rdx,%r15,1),%rdi
  movaps %xmm1,-0x78(%rsp)
  movaps %xmm9,%xmm1
  movss  0xc(%rax),%xmm5
  movss  (%rax,%r15,1),%xmm13
  addss  %xmm8,%xmm1
  subss  %xmm9,%xmm8
  movaps -0x68(%rsp),%xmm9
  movss  0x8(%rdx),%xmm4
  movss  (%r9),%xmm12
  movss  (%rdi),%xmm11
  unpcklps %xmm3,%xmm7
  movss  0xc(%rdx),%xmm3
  movlhps %xmm7,%xmm7
  unpcklps %xmm8,%xmm2
  movaps %xmm15,%xmm8
  unpcklps %xmm1,%xmm8
  movlhps %xmm2,%xmm8
  movaps %xmm8,%xmm2
  mulps  %xmm9,%xmm2
  movups %xmm2,(%rdx)
  movaps %xmm14,%xmm2
  addss  %xmm6,%xmm2
  subss  %xmm14,%xmm6
  mulss  %xmm0,%xmm2
  mulss  %xmm0,%xmm6
  movss  %xmm2,(%rdx,%rsi,1)
  movaps %xmm13,%xmm2
  movswl -0x2(%rbp,%rcx,2),%edx
  sub    $0x1,%rcx
  addss  %xmm5,%xmm2
  subss  %xmm13,%xmm5
  shl    $0x2,%edx
  movslq %edx,%rdx
  mulss  %xmm0,%xmm2
  lea    (%rbx,%rdx,4),%rdx
  mulss  %xmm0,%xmm5
  movss  %xmm2,(%r10)
  movaps %xmm7,%xmm2
  movss  %xmm6,(%r9)
  movaps -0x78(%rsp),%xmm6
  movss  %xmm5,(%rdi)
  addps  %xmm6,%xmm2
  movaps %xmm6,%xmm5
  subps  %xmm7,%xmm5
  movaps %xmm2,%xmm1
  shufps $0xe4,%xmm5,%xmm1
  mulps  %xmm9,%xmm1
  movups %xmm1,(%rax)
  movaps %xmm12,%xmm1
  addss  %xmm4,%xmm1
  subss  %xmm12,%xmm4
  mulss  %xmm0,%xmm1
  mulss  %xmm0,%xmm4
  movss  %xmm1,(%rax,%rsi,1)
  movaps %xmm11,%xmm1
  addss  %xmm3,%xmm1
  subss  %xmm11,%xmm3
  mulss  %xmm0,%xmm1
  mulss  %xmm0,%xmm3
  movss  %xmm1,(%rax,%r8,1)
  movss  %xmm4,(%rax,%r13,1)
  movss  %xmm3,(%rax,%r15,1)
  add    %r14,%rax
  movss  (%rax),%xmm2
  movss  0x4(%rax),%xmm8
  movss  (%rax,%rsi,1),%xmm10
  movss  (%rax,%r8,1),%xmm9
  cmp    %ecx,%r11d
  jl     L2
  mov    -0x2c(%rsp),%edi
  mov    -0x30(%rsp),%ecx
  xor    %edx,%edx
  movaps %xmm10,%xmm1
  mov    -0x4c(%rsp),%eax
  movaps %xmm9,%xmm7
  addss  %xmm2,%xmm1
  subss  %xmm10,%xmm2
  cmp    %ecx,%edi
  addss  %xmm8,%xmm7
  subss  %xmm9,%xmm8
  cmovge %rax,%rdx
  mov    %rax,%rbx
  add    $0x1,%rax
  imul   %r14,%rdx
  unpcklps %xmm8,%xmm2
  unpcklps %xmm7,%xmm1
  cmp    %ecx,%edi
  mov    $0x1,%edi
  movlhps %xmm2,%xmm1
  mulps  -0x68(%rsp),%xmm1
  cmovl  %rdi,%rax
  add    $0x1,%ebx
  sub    $0x1,%r11
  mov    %ebx,-0x4c(%rsp)
  imul   %r14,%rax
  add    %r12,%rax
  lea    (%rax,%r13,1),%rdi
  movss  0x8(%rax),%xmm4
  lea    (%rax,%r15,1),%rcx
  movss  0xc(%rax),%xmm3
  movss  (%rdi),%xmm6
  movss  (%rcx),%xmm5
  movups %xmm1,(%rax)
  lea    (%r12,%rdx,1),%rax
  mov    -0x20(%rsp),%rdx
  movaps %xmm6,%xmm1
  addss  %xmm4,%xmm1
  subss  %xmm6,%xmm4
  mulss  %xmm0,%xmm1
  mulss  %xmm0,%xmm4
  movss  %xmm1,(%rax,%rdx,1)
  movaps %xmm3,%xmm1
  subss  %xmm5,%xmm3
  mov    -0x18(%rsp),%rdx
  addss  %xmm5,%xmm1
  mulss  %xmm0,%xmm3
  mulss  %xmm0,%xmm1
  movss  %xmm1,(%rax,%rdx,1)
  movss  %xmm4,(%rdi)
  movss  %xmm3,(%rcx)
  test   %r11d,%r11d
  jns    L15
L56:
  mov    -0x10(%rsp),%rbx
  add    %rbx,-0x48(%rsp)
  mov    -0x48(%rsp),%rax
  cmp    %rax,(%rsp)
  ja     L62
L12:
  add    $0x10,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void scbitrevR2(float *ioptr, int M, short *BRLow, float scale) {
  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) = scale * t0r;
        *(p1r + 1) = scale * t0i;
        *(p1r + 2) = scale * f1r;
        *(p1r + (2 + 1)) = scale * f1i;
        *(p1r + posA) = scale * t1r;
        *(p1r + posAi) = scale * t1i;
        *(p1r + posB) = scale * f3r;
        *(p1r + posBi) = scale * f3i;
        *(p0r) = scale * f0r;
        *(p0r + 1) = scale * f0i;
        *(p0r + 2) = scale * f5r;
        *(p0r + (2 + 1)) = scale * f5i;
        *(p0r + posA) = scale * f2r;
        *(p0r + posAi) = scale * f2i;
        *(p0r + posB) = scale * f7r;
        *(p0r + posBi) = scale * 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) = scale * t0r;
      *(p0r + 1) = scale * t0i;
      *(p0r + 2) = scale * f1r;
      *(p0r + (2 + 1)) = scale * f1i;
      *(p0r + posA) = scale * t1r;
      *(p0r + posAi) = scale * t1i;
      *(p0r + posB) = scale * f3r;
      *(p0r + posBi) = scale * f3i;
    };
  };
}
```