user: 请从给定的汇编指令推导出C源代码：

```asm
<ifrstage>:
  endbr64
  push   %r12
  push   %rbp
  push   %rbx
  mov    %rdi,%r9
  mov    %esi,%r10d
  mov    %rdx,%rax
  lea    -0x1(%rsi),%ecx
  mov    $0x1,%edx
  mov    %edx,%edi
  shl    %cl,%edi
  mov    %edi,%ecx
  shr    %ecx
  mov    %ecx,%ecx
  lea    (%r9,%rcx,4),%r8
  lea    -0x3(%rsi),%ecx
  mov    %edx,%r11d
  shl    %cl,%r11d
  movslq %r11d,%rcx
  movss  (%rax,%rcx,4),%xmm4
  movss  (%r9),%xmm6
  movss  0x4(%r9),%xmm7
  mov    %edi,%esi
  shl    $0x2,%rsi
  lea    (%r9,%rsi,1),%r12
  lea    0x1(%rdi),%edi
  shl    $0x2,%rdi
  lea    (%r9,%rdi,1),%rbp
  movss  0x0(%rbp),%xmm8
  movss  (%r8),%xmm0
  movss  0x4(%r8),%xmm2
  lea    (%r8,%rsi,1),%rbx
  movss  (%rbx),%xmm10
  lea    (%r8,%rdi,1),%rcx
  movss  (%rcx),%xmm9
  movss  (%r12),%xmm5
  addss  %xmm5,%xmm5
  movaps %xmm0,%xmm1
  addss  %xmm10,%xmm1
  movaps %xmm2,%xmm3
  subss  %xmm9,%xmm3
  subss  %xmm10,%xmm0
  mulss  %xmm4,%xmm0
  addss  %xmm9,%xmm2
  mulss  %xmm4,%xmm2
  movaps %xmm1,%xmm4
  subss  %xmm0,%xmm4
  subss  %xmm2,%xmm4
  addss  %xmm3,%xmm0
  subss  %xmm2,%xmm0
  movaps %xmm6,%xmm2
  addss  %xmm7,%xmm2
  movss  %xmm2,(%r9)
  subss  %xmm7,%xmm6
  movss  %xmm6,0x4(%r9)
  movss  %xmm5,(%r12)
  movaps %xmm8,%xmm2
  xorps  D8(%rip),%xmm2
  subss  %xmm8,%xmm2
  movss  %xmm2,0x0(%rbp)
  movss  %xmm4,(%r8)
  movss  %xmm0,0x4(%r8)
  addss  %xmm1,%xmm1
  subss  %xmm4,%xmm1
  movss  %xmm1,(%rbx)
  addss  %xmm3,%xmm3
  subss  %xmm3,%xmm0
  movss  %xmm0,(%rcx)
  lea    -0x2(%r10),%ecx
  shl    %cl,%edx
  movslq %edx,%rcx
  lea    -0x4(%rax,%rcx,4),%rcx
  movss  0x4(%rax),%xmm11
  movss  (%rcx),%xmm0
  lea    -0x2(%rdx,%rdx,1),%edx
  movslq %edx,%rdx
  lea    (%r9,%rdx,4),%rdx
  cmp    $0x3,%r10d
  je     L19
  lea    0x4(%rax),%r8
  lea    0x8(%r9),%rax
  lea    -0x2(%r11),%r10d
  lea    0x10(%r9,%r10,8),%r9
L14:
  movss  (%rax),%xmm2
  movss  0x4(%rax),%xmm4
  movss  (%rdx,%rsi,1),%xmm8
  movss  (%rdx,%rdi,1),%xmm3
  movss  (%rdx),%xmm1
  movss  0x4(%rdx),%xmm7
  movss  (%rax,%rsi,1),%xmm10
  movss  (%rax,%rdi,1),%xmm9
  movaps %xmm2,%xmm6
  addss  %xmm8,%xmm6
  movaps %xmm4,%xmm5
  subss  %xmm3,%xmm5
  subss  %xmm8,%xmm2
  addss  %xmm3,%xmm4
  movaps %xmm2,%xmm3
  mulss  %xmm0,%xmm3
  movaps %xmm6,%xmm12
  subss  %xmm3,%xmm12
  movaps %xmm4,%xmm3
  mulss  %xmm11,%xmm3
  subss  %xmm3,%xmm12
  mulss  %xmm11,%xmm2
  addss  %xmm5,%xmm2
  mulss  %xmm0,%xmm4
  subss  %xmm4,%xmm2
  movaps %xmm1,%xmm8
  addss  %xmm10,%xmm8
  movaps %xmm7,%xmm4
  subss  %xmm9,%xmm4
  subss  %xmm10,%xmm1
  addss  %xmm9,%xmm7
  movaps %xmm7,%xmm3
  movaps %xmm1,%xmm9
  mulss  %xmm11,%xmm9
  movaps %xmm8,%xmm10
  subss  %xmm9,%xmm10
  movaps %xmm7,%xmm9
  mulss  %xmm0,%xmm9
  subss  %xmm9,%xmm10
  mulss  %xmm0,%xmm1
  movaps %xmm1,%xmm7
  addss  %xmm4,%xmm7
  mulss  %xmm11,%xmm3
  subss  %xmm3,%xmm7
  movss  %xmm12,(%rax)
  movss  %xmm2,0x4(%rax)
  addss  %xmm6,%xmm6
  subss  %xmm12,%xmm6
  movss  %xmm6,(%rdx,%rsi,1)
  addss  %xmm5,%xmm5
  subss  %xmm5,%xmm2
  movss  %xmm2,(%rdx,%rdi,1)
  add    $0x4,%r8
  movss  (%r8),%xmm11
  sub    $0x4,%rcx
  movss  (%rcx),%xmm0
  movss  %xmm10,(%rdx)
  movss  %xmm7,0x4(%rdx)
  addss  %xmm8,%xmm8
  subss  %xmm10,%xmm8
  movss  %xmm8,(%rax,%rsi,1)
  addss  %xmm4,%xmm4
  subss  %xmm4,%xmm7
  movss  %xmm7,(%rax,%rdi,1)
  add    $0x8,%rax
  sub    $0x8,%rdx
  cmp    %rax,%r9
  jne    L14
L19:
  pop    %rbx
  pop    %rbp
  pop    %r12
  ret
```

tool_calls: name: parse_data
arguments: tag: D8
type: byte[16]

tool: {"D8": [0x00,0x00,0x00,0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00]}

assistant: ```c
void ifrstage(float *ioptr, int M, float *Utbl) {
  unsigned int pos;
  unsigned int posi;
  unsigned int diffUcnt;
  float *p0r, *p1r;
  float *u0r, *u0i;
  float w0r, w0i;
  float f0r, f0i, f1r, f1i, f4r, f4i, f5r, f5i;
  float t0r, t0i, t1r, t1i;
  const float Two = 2.0;
  pos = ((uint32_t)1 << (M - 1));
  posi = pos + 1;
  p0r = ioptr;
  p1r = ioptr + pos / 2;
  u0r = Utbl + ((uint32_t)1 << (M - 3));
  w0r = *u0r;
  f0r = *(p0r);
  f0i = *(p0r + 1);
  f4r = *(p0r + pos);
  f4i = *(p0r + posi);
  f1r = *(p1r);
  f1i = *(p1r + 1);
  f5r = *(p1r + pos);
  f5i = *(p1r + posi);
  t0r = f0r + f0i;
  t0i = f0r - f0i;
  t1r = f4r + f4r;
  t1i = -f4i - f4i;
  f0r = f1r + f5r;
  f0i = f1i - f5i;
  f4r = f1r - f5r;
  f4i = f1i + f5i;
  f1r = f0r - w0r * f4r - w0r * f4i;
  f1i = f0i + w0r * f4r - w0r * f4i;
  f5r = Two * f0r - f1r;
  f5i = f1i - Two * f0i;
  *(p0r) = t0r;
  *(p0r + 1) = t0i;
  *(p0r + pos) = t1r;
  *(p0r + posi) = t1i;
  *(p1r) = f1r;
  *(p1r + 1) = f1i;
  *(p1r + pos) = f5r;
  *(p1r + posi) = f5i;
  u0r = Utbl + 1;
  u0i = Utbl + (((uint32_t)1 << (M - 2)) - 1);
  w0r = *u0r;
  w0i = *u0i;
  p0r = (ioptr + 2);
  p1r = (ioptr + (((uint32_t)1 << (M - 2)) - 1) * 2);
  for (diffUcnt = ((uint32_t)1 << (M - 3)) - 1; diffUcnt > 0; diffUcnt--) {
    f0r = *(p0r);
    f0i = *(p0r + 1);
    f5r = *(p1r + pos);
    f5i = *(p1r + posi);
    f1r = *(p1r);
    f1i = *(p1r + 1);
    f4r = *(p0r + pos);
    f4i = *(p0r + posi);
    t0r = f0r + f5r;
    t0i = f0i - f5i;
    t1r = f0r - f5r;
    t1i = f0i + f5i;
    f0r = t0r - w0i * t1r - w0r * t1i;
    f0i = t0i + w0r * t1r - w0i * t1i;
    f5r = Two * t0r - f0r;
    f5i = f0i - Two * t0i;
    t0r = f1r + f4r;
    t0i = f1i - f4i;
    t1r = f1r - f4r;
    t1i = f1i + f4i;
    f1r = t0r - w0r * t1r - w0i * t1i;
    f1i = t0i + w0i * t1r - w0r * t1i;
    f4r = Two * t0r - f1r;
    f4i = f1i - Two * t0i;
    *(p0r) = f0r;
    *(p0r + 1) = f0i;
    *(p1r + pos) = f5r;
    *(p1r + posi) = f5i;
    w0r = *++u0r;
    w0i = *--u0i;
    *(p1r) = f1r;
    *(p1r + 1) = f1i;
    *(p0r + pos) = f4r;
    *(p0r + posi) = f4i;
    p0r += 2;
    p1r -= 2;
  }
}
```