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

```asm
<cascade_form_iir_up_kernel>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  mov    %rdi,-0x38(%rbp)
  mov    %rsi,-0x40(%rbp)
  mov    %rdx,-0x48(%rbp)
  mov    %rcx,-0x50(%rbp)
  mov    %r8,-0x58(%rbp)
  movsd  %xmm0,-0x60(%rbp)
  mov    %r9,-0x68(%rbp)
  movq   $0x0,-0x28(%rbp)
  movq   $0x0,-0x20(%rbp)
  jmp    L32
L23:
  mov    -0x20(%rbp),%rax
  cqto
  idivq  -0x50(%rbp)
  mov    %rdx,%rax
  test   %rax,%rax
  jne    L6
  mov    -0x28(%rbp),%rax
  lea    0x0(,%rax,4),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  movss  (%rax),%xmm0
  cvtss2sd %xmm0,%xmm0
  movsd  %xmm0,-0x10(%rbp)
  jmp    L19
L6:
  pxor   %xmm0,%xmm0
  movsd  %xmm0,-0x10(%rbp)
L19:
  movq   $0x0,-0x18(%rbp)
  jmp    L66
L29:
  mov    -0x18(%rbp),%rax
  lea    0x0(,%rax,8),%rdx
  mov    -0x68(%rbp),%rax
  add    %rdx,%rax
  movss  (%rax),%xmm1
  mov    -0x18(%rbp),%rax
  shl    $0x4,%rax
  mov    %rax,%rdx
  mov    0x18(%rbp),%rax
  add    %rdx,%rax
  movss  (%rax),%xmm0
  mulss  %xmm1,%xmm0
  cvtss2sd %xmm0,%xmm0
  movapd %xmm0,%xmm1
  addsd  -0x10(%rbp),%xmm1
  mov    -0x18(%rbp),%rax
  lea    0x0(,%rax,8),%rdx
  mov    -0x68(%rbp),%rax
  add    %rdx,%rax
  movss  0x4(%rax),%xmm2
  mov    -0x18(%rbp),%rax
  shl    $0x4,%rax
  mov    %rax,%rdx
  mov    0x18(%rbp),%rax
  add    %rdx,%rax
  movss  0x4(%rax),%xmm0
  mulss  %xmm2,%xmm0
  cvtss2sd %xmm0,%xmm0
  addsd  %xmm1,%xmm0
  movsd  %xmm0,-0x8(%rbp)
  mov    -0x18(%rbp),%rax
  lea    0x0(,%rax,8),%rdx
  mov    0x10(%rbp),%rax
  add    %rdx,%rax
  movss  (%rax),%xmm1
  mov    -0x18(%rbp),%rax
  shl    $0x4,%rax
  mov    %rax,%rdx
  mov    0x18(%rbp),%rax
  add    %rdx,%rax
  movss  0x8(%rax),%xmm0
  mulss  %xmm0,%xmm1
  mov    -0x18(%rbp),%rax
  lea    0x0(,%rax,8),%rdx
  mov    0x10(%rbp),%rax
  add    %rdx,%rax
  movss  0x4(%rax),%xmm2
  mov    -0x18(%rbp),%rax
  shl    $0x4,%rax
  mov    %rax,%rdx
  mov    0x18(%rbp),%rax
  add    %rdx,%rax
  movss  0xc(%rax),%xmm0
  mulss  %xmm2,%xmm0
  addss  %xmm1,%xmm0
  pxor   %xmm1,%xmm1
  cvtss2sd %xmm0,%xmm1
  movsd  -0x8(%rbp),%xmm0
  subsd  %xmm1,%xmm0
  movsd  %xmm0,-0x8(%rbp)
  mov    -0x18(%rbp),%rax
  shl    $0x4,%rax
  mov    %rax,%rdx
  mov    0x18(%rbp),%rax
  add    %rax,%rdx
  mov    -0x18(%rbp),%rax
  shl    $0x4,%rax
  mov    %rax,%rcx
  mov    0x18(%rbp),%rax
  add    %rcx,%rax
  movss  (%rdx),%xmm0
  movss  %xmm0,0x4(%rax)
  mov    -0x18(%rbp),%rax
  shl    $0x4,%rax
  mov    %rax,%rdx
  mov    0x18(%rbp),%rax
  add    %rdx,%rax
  pxor   %xmm0,%xmm0
  cvtsd2ss -0x10(%rbp),%xmm0
  movss  %xmm0,(%rax)
  mov    -0x18(%rbp),%rax
  shl    $0x4,%rax
  mov    %rax,%rdx
  mov    0x18(%rbp),%rax
  add    %rax,%rdx
  mov    -0x18(%rbp),%rax
  shl    $0x4,%rax
  mov    %rax,%rcx
  mov    0x18(%rbp),%rax
  add    %rcx,%rax
  movss  0x8(%rdx),%xmm0
  movss  %xmm0,0xc(%rax)
  mov    -0x18(%rbp),%rax
  shl    $0x4,%rax
  mov    %rax,%rdx
  mov    0x18(%rbp),%rax
  add    %rdx,%rax
  pxor   %xmm0,%xmm0
  cvtsd2ss -0x8(%rbp),%xmm0
  movss  %xmm0,0x8(%rax)
  movsd  -0x8(%rbp),%xmm0
  movsd  %xmm0,-0x10(%rbp)
  addq   $0x1,-0x18(%rbp)
L66:
  mov    -0x18(%rbp),%rax
  cmp    -0x58(%rbp),%rax
  jl     L29
  movsd  -0x8(%rbp),%xmm0
  mulsd  -0x60(%rbp),%xmm0
  mov    -0x20(%rbp),%rax
  lea    0x0(,%rax,4),%rdx
  mov    -0x48(%rbp),%rax
  add    %rdx,%rax
  cvtsd2ss %xmm0,%xmm0
  movss  %xmm0,(%rax)
  mov    -0x20(%rbp),%rax
  cqto
  idivq  -0x50(%rbp)
  mov    %rdx,%rax
  test   %rax,%rax
  jne    L50
  addq   $0x1,-0x28(%rbp)
L50:
  addq   $0x1,-0x20(%rbp)
L32:
  mov    -0x50(%rbp),%rax
  imul   -0x38(%rbp),%rax
  cmp    %rax,-0x20(%rbp)
  jl     L23
  mov    -0x20(%rbp),%rax
  pop    %rbp
  ret
```

assistant: ```c
long cascade_form_iir_up_kernel(lenx, x, y, iup, nblocks, gain, a, b, T)
long lenx;
float *x, *y;
long iup, nblocks;
double gain;
float (*a)[2], (*b)[2], (*T)[4];
{
  long kx, ky, n;
  double xj, yj;
  kx = 0;
  for (ky = 0; ky < iup * lenx; ky++) {
    if (ky % iup == 0)
      xj = x[kx];
    else
      xj = 0.;
    for (n = 0; n < nblocks; n++) {
      yj = xj + a[n][0] * T[n][0] + a[n][1] * T[n][1];
      yj -= (b[n][0] * T[n][2] + b[n][1] * T[n][3]);
      T[n][1] = T[n][0];
      T[n][0] = xj;
      T[n][3] = T[n][2];
      T[n][2] = yj;
      xj = yj;
    }
    y[ky] = yj * gain;
    if (ky % iup == 0)
      kx++;
  }
  return ky;
}
```