user: Please show me the C implementation that matches the assembly code listed below:

```asm
<ifrstage>:
  endbr64
  mov    %rdi,%r10
  mov    %rsi,%rax
  lea    -0x1(%rsi),%edi
  mov    $0x1,%esi
  mov    %edi,%ecx
  mov    %rsi,%r8
  push   %r13
  lea    -0x3(%rax),%r11d
  shl    %cl,%r8
  push   %r12
  mov    %r8,%rcx
  push   %rbp
  lea    0x4(,%r8,4),%r8
  push   %rbx
  shr    %rcx
  mov    $0x4,%ebx
  movss  (%r10),%xmm6
  lea    (%r10,%rcx,4),%r9
  mov    %rbx,%rbp
  mov    %r11d,%ecx
  movss  0x4(%r10),%xmm8
  shl    %cl,%rbp
  mov    %edi,%ecx
  movss  (%r9),%xmm0
  lea    (%r10,%r8,1),%r12
  movss  (%rdx,%rbp,1),%xmm4
  mov    %rbx,%rbp
  movss  0x4(%r9),%xmm2
  shl    %cl,%rbp
  movaps %xmm0,%xmm1
  lea    (%r9,%r8,1),%rcx
  movss  (%r12),%xmm7
  lea    (%r10,%rbp,1),%r13
  mov    %rbp,%rdi
  add    %r9,%rbp
  movss  (%rcx),%xmm9
  movss  0x0(%rbp),%xmm10
  movaps %xmm2,%xmm3
  movss  0x0(%r13),%xmm5
  addss  %xmm9,%xmm2
  subss  %xmm9,%xmm3
  subss  %xmm10,%xmm0
  addss  %xmm10,%xmm1
  addss  %xmm5,%xmm5
  mulss  %xmm4,%xmm2
  mulss  %xmm4,%xmm0
  movaps %xmm1,%xmm4
  addss  %xmm1,%xmm1
  subss  %xmm0,%xmm4
  addss  %xmm3,%xmm0
  addss  %xmm3,%xmm3
  subss  %xmm2,%xmm4
  subss  %xmm2,%xmm0
  movaps %xmm6,%xmm2
  addss  %xmm8,%xmm2
  subss  %xmm8,%xmm6
  subss  %xmm4,%xmm1
  movss  %xmm2,(%r10)
  movaps %xmm7,%xmm2
  xorps  D7(%rip),%xmm2
  movss  %xmm6,0x4(%r10)
  subss  %xmm7,%xmm2
  movss  %xmm5,0x0(%r13)
  movss  %xmm2,(%r12)
  movss  %xmm0,0x4(%r9)
  subss  %xmm3,%xmm0
  movss  %xmm4,(%r9)
  lea    0x4(%rdx),%r9
  movss  %xmm1,0x0(%rbp)
  movss  %xmm0,(%rcx)
  lea    -0x2(%rax),%ecx
  movss  0x4(%rdx),%xmm3
  shl    %cl,%rbx
  lea    -0x4(%rdx,%rbx,1),%rbx
  mov    %rsi,%rdx
  shl    %cl,%rdx
  mov    %r11d,%ecx
  movss  (%rbx),%xmm0
  shl    %cl,%rsi
  lea    -0x8(%r10,%rdx,8),%rdx
  sub    $0x1,%rsi
  je     L16
  lea    0x8(%r10),%rax
  mov    $0xfffffffffffffffc,%r10
  shl    %cl,%r10
  lea    (%rbx,%r10,1),%rcx
  nopl   0x0(%rax)
L0:
  movss  (%rdx,%rdi,1),%xmm8
  movss  (%rax),%xmm2
  add    $0x4,%r9
  add    $0x8,%rax
  movss  -0x4(%rax),%xmm4
  movss  (%rdx,%r8,1),%xmm6
  sub    $0x8,%rdx
  movaps %xmm2,%xmm5
  subss  %xmm8,%xmm2
  movss  -0x8(%rax,%rdi,1),%xmm11
  movss  0x8(%rdx),%xmm1
  movaps %xmm4,%xmm7
  addss  %xmm6,%xmm4
  addss  %xmm8,%xmm5
  movss  -0x8(%rax,%r8,1),%xmm9
  subss  %xmm6,%xmm7
  movss  0xc(%rdx),%xmm10
  movaps %xmm2,%xmm6
  mulss  %xmm0,%xmm6
  movaps %xmm5,%xmm8
  addss  %xmm5,%xmm5
  mulss  %xmm3,%xmm2
  subss  %xmm6,%xmm8
  movaps %xmm4,%xmm6
  mulss  %xmm0,%xmm4
  addss  %xmm7,%xmm2
  addss  %xmm7,%xmm7
  mulss  %xmm3,%xmm6
  subss  %xmm4,%xmm2
  movaps %xmm1,%xmm4
  subss  %xmm11,%xmm1
  addss  %xmm11,%xmm4
  subss  %xmm6,%xmm8
  movaps %xmm10,%xmm6
  addss  %xmm9,%xmm10
  subss  %xmm9,%xmm6
  movaps %xmm1,%xmm11
  movss  %xmm2,-0x4(%rax)
  subss  %xmm7,%xmm2
  mulss  %xmm3,%xmm11
  movaps %xmm4,%xmm9
  subss  %xmm8,%xmm5
  movss  %xmm8,-0x8(%rax)
  mulss  %xmm0,%xmm1
  addss  %xmm4,%xmm4
  mulss  %xmm10,%xmm3
  movss  %xmm5,0x8(%rdx,%rdi,1)
  movss  %xmm2,0x8(%rdx,%r8,1)
  subss  %xmm11,%xmm9
  movaps %xmm10,%xmm11
  mulss  %xmm0,%xmm11
  addss  %xmm6,%xmm1
  addss  %xmm6,%xmm6
  movss  (%rcx,%rsi,4),%xmm0
  subss  %xmm3,%xmm1
  movss  (%r9),%xmm3
  subss  %xmm11,%xmm9
  movss  %xmm1,0xc(%rdx)
  subss  %xmm6,%xmm1
  subss  %xmm9,%xmm4
  movss  %xmm9,0x8(%rdx)
  movss  %xmm4,-0x8(%rax,%rdi,1)
  movss  %xmm1,-0x8(%rax,%r8,1)
  sub    $0x1,%rsi
  jne    L0
L16:
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
```

tool_calls: name: parse_data
arguments: data_tag: D7
type_guessed: byte[16]

tool: {"D7": [0x00,0x00,0x00,0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00]}

assistant: ```c
void ifrstage(float *ioptr, long M, float *Utbl) {
  unsigned long pos;
  unsigned long posi;
  unsigned long 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 = ((unsigned long)1 << (M - 1));
  posi = pos + 1;
  p0r = ioptr;
  p1r = ioptr + pos / 2;
  u0r = Utbl + ((unsigned long)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 + (((unsigned long)1 << (M - 2)) - 1);
  w0r = *u0r, w0i = *u0i;
  p0r = (ioptr + 2);
  p1r = (ioptr + (((unsigned long)1 << (M - 2)) - 1) * 2);
  for (diffUcnt = ((unsigned long)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;
  };
}
```