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

```asm
<twiddleFFT_4>:
  endbr64
  push   %r15
  mov    %edi,%eax
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  mov    0x40(%rsp),%r10
  mov    %edi,-0xc(%rsp)
  mov    0x38(%rsp),%rdi
  mov    %edx,-0x14(%rsp)
  test   %edx,%edx
  jle    L53
  mov    %esi,%ebx
  mov    %eax,%esi
  movl   $0x0,-0x24(%rsp)
  mov    %ecx,%r11d
  imul   %ebx,%esi
  movl   $0x0,-0x20(%rsp)
  lea    (%rcx,%rax,2),%ebp
  movl   $0x0,-0x18(%rsp)
  movl   $0x0,-0x1c(%rsp)
  mov    %esi,-0x10(%rsp)
  movl   $0x0,-0x28(%rsp)
  jmp    L35
  nopl   0x0(%rax,%rax,1)
L56:
  cmp    $0x2,%ebx
  je     L32
  add    %ebp,%eax
  cmp    $0x3,%ebx
  cmove  -0x24(%rsp),%eax
  mov    %edx,-0x1c(%rsp)
  mov    %ebp,-0x18(%rsp)
  mov    %r11d,-0x20(%rsp)
  mov    %eax,-0x24(%rsp)
L43:
  movslq -0x18(%rsp),%rdx
  movsd  0x10(%r8),%xmm6
  movsd  0x10(%r9),%xmm5
  movslq -0x20(%rsp),%rsi
  shl    $0x3,%rdx
  movslq -0x1c(%rsp),%rcx
  movslq -0x24(%rsp),%rax
  lea    (%rdi,%rdx,1),%r13
  add    %r10,%rdx
  shl    $0x3,%rsi
  movsd  0x8(%r8),%xmm8
  movsd  (%rdx),%xmm0
  lea    (%rdi,%rsi,1),%r15
  add    %r10,%rsi
  shl    $0x3,%rcx
  movsd  0x0(%r13),%xmm2
  movsd  (%rsi),%xmm3
  lea    (%rdi,%rcx,1),%r14
  add    %r10,%rcx
  movapd %xmm0,%xmm7
  movsd  (%r15),%xmm4
  shl    $0x3,%rax
  movsd  0x18(%r8),%xmm10
  mulsd  %xmm6,%xmm0
  movapd %xmm2,%xmm1
  lea    (%rdi,%rax,1),%r12
  add    %r10,%rax
  mulsd  %xmm5,%xmm2
  addl   $0x1,-0x28(%rsp)
  mulsd  %xmm5,%xmm7
  movapd %xmm4,%xmm5
  mulsd  %xmm6,%xmm1
  movapd %xmm3,%xmm6
  addsd  %xmm2,%xmm0
  movsd  (%rcx),%xmm2
  subsd  %xmm7,%xmm1
  movapd %xmm2,%xmm9
  addsd  %xmm0,%xmm6
  subsd  %xmm0,%xmm3
  movsd  (%r14),%xmm0
  mulsd  %xmm8,%xmm2
  addsd  %xmm1,%xmm5
  subsd  %xmm1,%xmm4
  movsd  0x8(%r9),%xmm1
  movapd %xmm0,%xmm7
  mulsd  %xmm8,%xmm7
  movsd  (%r12),%xmm8
  mulsd  %xmm1,%xmm9
  mulsd  %xmm1,%xmm0
  movsd  (%rax),%xmm1
  movapd %xmm1,%xmm11
  mulsd  %xmm10,%xmm1
  subsd  %xmm9,%xmm7
  movsd  0x18(%r9),%xmm9
  addsd  %xmm0,%xmm2
  movapd %xmm8,%xmm0
  mulsd  %xmm10,%xmm0
  mulsd  %xmm9,%xmm11
  mulsd  %xmm9,%xmm8
  subsd  %xmm11,%xmm0
  addsd  %xmm8,%xmm1
  movapd %xmm7,%xmm8
  addsd  %xmm0,%xmm8
  subsd  %xmm7,%xmm0
  movapd %xmm2,%xmm7
  addsd  %xmm1,%xmm7
  subsd  %xmm1,%xmm2
  movapd %xmm5,%xmm1
  addsd  %xmm8,%xmm1
  subsd  %xmm8,%xmm5
  movsd  %xmm1,(%r15)
  movapd %xmm4,%xmm1
  subsd  %xmm2,%xmm4
  addsd  %xmm2,%xmm1
  movsd  %xmm1,(%r14)
  movapd %xmm6,%xmm1
  subsd  %xmm7,%xmm6
  addsd  %xmm7,%xmm1
  movsd  %xmm5,0x0(%r13)
  movsd  %xmm4,(%r12)
  movsd  %xmm1,(%rsi)
  movapd %xmm3,%xmm1
  subsd  %xmm0,%xmm3
  addsd  %xmm0,%xmm1
  movsd  %xmm1,(%rcx)
  mov    -0x10(%rsp),%ecx
  movsd  %xmm6,(%rdx)
  add    %ecx,%r11d
  movsd  %xmm3,(%rax)
  add    %ecx,%ebp
  mov    -0x28(%rsp),%eax
  cmp    %eax,-0x14(%rsp)
  je     L53
L35:
  test   %ebx,%ebx
  jle    L43
  mov    -0xc(%rsp),%eax
  lea    (%r11,%rax,1),%edx
  cmp    $0x1,%ebx
  jne    L56
  mov    %r11d,-0x20(%rsp)
  jmp    L43
L32:
  mov    %edx,-0x1c(%rsp)
  mov    %r11d,-0x20(%rsp)
  jmp    L43
  xchg   %ax,%ax
L53:
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void twiddleFFT_4(int sofarRadix, int radix, int remainRadix, int groupOffset, double twiddleRe[], double twiddleIm[], double yRe[], double yIm[]) {
  int yIndx[4];
  int groupNo, blockNo, adr;
  double t1_re, t1_im, t2_re, t2_im;
  double m2_re, m2_im, m3_re, m3_im;
  double yr, yi, twr, twi;
  double ar0, ar1, ar2, ar3;
  double ai0, ai1, ai2, ai3;
  adr = groupOffset;
  for (groupNo = 0; groupNo < remainRadix; groupNo++) {
    for (blockNo = 0; blockNo < radix; blockNo++) {
      yIndx[blockNo] = adr;
      adr = adr + sofarRadix;
    }
    ar0 = yRe[yIndx[0]];
    ai0 = yIm[yIndx[0]];
    yr = yRe[yIndx[2]];
    yi = yIm[yIndx[2]];
    twr = twiddleRe[2];
    twi = twiddleIm[2];
    ar2 = twr * yr - twi * yi;
    ai2 = twr * yi + twi * yr;
    t1_re = ar0 + ar2;
    m2_re = ar0 - ar2;
    t1_im = ai0 + ai2;
    m2_im = ai0 - ai2;
    yr = yRe[yIndx[1]];
    yi = yIm[yIndx[1]];
    twr = twiddleRe[1];
    twi = twiddleIm[1];
    ar1 = twr * yr - twi * yi;
    ai1 = twr * yi + twi * yr;
    yr = yRe[yIndx[3]];
    yi = yIm[yIndx[3]];
    twr = twiddleRe[3];
    twi = twiddleIm[3];
    ar3 = twr * yr - twi * yi;
    ai3 = twr * yi + twi * yr;
    t2_re = ar1 + ar3;
    m3_im = ar3 - ar1;
    t2_im = ai1 + ai3;
    m3_re = ai1 - ai3;
    yRe[yIndx[0]] = t1_re + t2_re;
    yRe[yIndx[1]] = m2_re + m3_re;
    yRe[yIndx[2]] = t1_re - t2_re;
    yRe[yIndx[3]] = m2_re - m3_re;
    yIm[yIndx[0]] = t1_im + t2_im;
    yIm[yIndx[1]] = m2_im + m3_im;
    yIm[yIndx[2]] = t1_im - t2_im;
    yIm[yIndx[3]] = m2_im - m3_im;
    groupOffset = groupOffset + sofarRadix * radix;
    adr = groupOffset;
  }
}
```