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

```asm
<pc1_256>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  mov    %edx,-0xc(%rsp)
  mov    %ecx,-0x10(%rsp)
  test   %edx,%edx
  jle    L1
  mov    %edx,%eax
  mov    %rsi,-0x50(%rsp)
  mov    %rdi,%rbx
  xor    %r15d,%r15d
  sub    $0x1,%eax
  xor    %r9d,%r9d
  lea    0x1(%rsi,%rax,1),%rax
  mov    %rax,-0x18(%rsp)
  jmp    L27
  nopl   (%rax)
L44:
  xor    %eax,%edx
  xor    -0x34(%rsp),%dx
  movdqu (%rbx),%xmm1
  movd   %edx,%xmm0
  movdqu 0x10(%rbx),%xmm2
  punpcklbw %xmm0,%xmm0
  punpcklwd %xmm0,%xmm0
  pshufd $0x0,%xmm0,%xmm0
  pxor   %xmm0,%xmm1
  pxor   %xmm2,%xmm0
  movups %xmm1,(%rbx)
  movups %xmm0,0x10(%rbx)
L31:
  mov    -0x50(%rsp),%rax
  mov    %dl,(%rax)
  add    $0x1,%rax
  mov    %rax,-0x50(%rsp)
  cmp    -0x18(%rsp),%rax
  je     L1
L27:
  mov    -0x50(%rsp),%rax
  movzbl 0x1(%rbx),%edx
  imul   $0x4e35,%r15w,%r15w
  movzbl 0x3(%rbx),%ecx
  movzbl (%rax),%edi
  movzbl (%rbx),%eax
  shl    $0x8,%eax
  mov    %dil,-0x1c(%rsp)
  add    %edx,%eax
  mov    %di,-0x34(%rsp)
  imul   $0x15a,%ax,%dx
  imul   $0x4e35,%ax,%ax
  add    %edx,%r15d
  lea    0x1(%rax),%esi
  movzbl 0x2(%rbx),%eax
  lea    (%r15,%r9,1),%edi
  mov    %si,-0x36(%rsp)
  shl    $0x8,%eax
  mov    %di,-0x1e(%rsp)
  add    %ecx,%eax
  xor    %esi,%eax
  lea    0x1(%rdi),%esi
  imul   $0x15a,%ax,%cx
  imul   $0x4e35,%ax,%ax
  imul   $0x4e35,%si,%si
  add    %ecx,%edx
  lea    0x1(%rax),%edi
  movzbl 0x4(%rbx),%eax
  lea    (%rsi,%rdx,1),%r14d
  movzbl 0x5(%rbx),%edx
  mov    %di,-0x38(%rsp)
  shl    $0x8,%eax
  lea    0x2(%r14),%esi
  mov    %r14w,-0x20(%rsp)
  add    %edx,%eax
  imul   $0x4e35,%si,%si
  xor    %edi,%eax
  imul   $0x15a,%ax,%dx
  imul   $0x4e35,%ax,%ax
  add    %edx,%ecx
  lea    0x1(%rax),%r15d
  movzbl 0x6(%rbx),%eax
  lea    (%rsi,%rcx,1),%r9d
  movzbl 0x7(%rbx),%ecx
  lea    0x3(%r9),%esi
  mov    %r15w,-0x3a(%rsp)
  shl    $0x8,%eax
  imul   $0x4e35,%si,%si
  mov    %r9w,-0x22(%rsp)
  add    %ecx,%eax
  xor    %r15d,%eax
  imul   $0x15a,%ax,%cx
  imul   $0x4e35,%ax,%ax
  add    %ecx,%edx
  lea    0x1(%rax),%r8d
  movzbl 0x8(%rbx),%eax
  lea    (%rsi,%rdx,1),%r11d
  movzbl 0x9(%rbx),%edx
  lea    0x4(%r11),%esi
  mov    %r8w,-0x3c(%rsp)
  shl    $0x8,%eax
  imul   $0x4e35,%si,%si
  mov    %r11w,-0x24(%rsp)
  add    %edx,%eax
  xor    %r8d,%eax
  imul   $0x15a,%ax,%dx
  add    %edx,%ecx
  imul   $0x4e35,%ax,%ax
  lea    (%rsi,%rcx,1),%r10d
  movzbl 0xb(%rbx),%ecx
  lea    0x5(%r10),%esi
  mov    %r10w,-0x26(%rsp)
  imul   $0x4e35,%si,%si
  lea    0x1(%rax),%ebp
  movzbl 0xa(%rbx),%eax
  mov    %bp,-0x3e(%rsp)
  shl    $0x8,%eax
  add    %ecx,%eax
  xor    %ebp,%eax
  imul   $0x15a,%ax,%cx
  imul   $0x4e35,%ax,%ax
  add    %ecx,%edx
  lea    0x1(%rax),%r13d
  movzbl 0xc(%rbx),%eax
  lea    (%rsi,%rdx,1),%r12d
  movzbl 0xd(%rbx),%edx
  lea    0x6(%r12),%esi
  mov    %r13w,-0x40(%rsp)
  shl    $0x8,%eax
  imul   $0x4e35,%si,%si
  mov    %r12w,-0x28(%rsp)
  add    %edx,%eax
  xor    %r13d,%eax
  imul   $0x15a,%ax,%dx
  imul   $0x4e35,%ax,%ax
  add    %edx,%ecx
  add    %esi,%ecx
  mov    %ecx,%esi
  lea    0x1(%rax),%ecx
  movzbl 0xe(%rbx),%eax
  mov    %ecx,%r15d
  movzbl 0xf(%rbx),%ecx
  shl    $0x8,%eax
  mov    %r15w,-0x42(%rsp)
  movzbl 0x12(%rbx),%r10d
  add    %ecx,%eax
  movzbl 0x16(%rbx),%edi
  movzbl 0x1e(%rbx),%r11d
  mov    %si,-0x2a(%rsp)
  xor    %r15d,%eax
  add    $0x7,%esi
  imul   $0x15a,%ax,%cx
  imul   $0x4e35,%si,%si
  imul   $0x4e35,%ax,%ax
  add    %ecx,%edx
  add    %esi,%edx
  mov    %edx,%r8d
  lea    0x1(%rax),%edx
  movzbl 0x11(%rbx),%eax
  mov    %edx,%ebp
  movzbl 0x10(%rbx),%edx
  lea    0x8(%r8),%esi
  mov    %r8w,-0x2c(%rsp)
  imul   $0x4e35,%si,%si
  movzbl 0x14(%rbx),%r8d
  mov    %bp,-0x44(%rsp)
  shl    $0x8,%edx
  add    %eax,%edx
  xor    %ebp,%edx
  imul   $0x15a,%dx,%ax
  add    %eax,%ecx
  add    %esi,%ecx
  imul   $0x4e35,%dx,%dx
  shl    $0x8,%r10d
  movzbl 0x18(%rbx),%esi
  mov    %cx,-0x2e(%rsp)
  shl    $0x8,%r8d
  add    $0x9,%ecx
  shl    $0x8,%edi
  imul   $0x4e35,%cx,%cx
  add    $0x1,%edx
  mov    %edx,%r13d
  movzbl 0x13(%rbx),%edx
  mov    %r13w,-0x46(%rsp)
  add    %edx,%r10d
  xor    %r13d,%r10d
  imul   $0x15a,%r10w,%dx
  imul   $0x4e35,%r10w,%r10w
  add    %edx,%eax
  add    %eax,%ecx
  movzbl 0x15(%rbx),%eax
  add    $0x1,%r10d
  mov    %cx,-0x30(%rsp)
  add    $0xa,%ecx
  add    %eax,%r8d
  imul   $0x4e35,%cx,%cx
  xor    %r10d,%r8d
  imul   $0x15a,%r8w,%ax
  imul   $0x4e35,%r8w,%r8w
  add    %eax,%edx
  add    %ecx,%edx
  add    $0x1,%r8d
  movzbl 0x1a(%rbx),%ecx
  mov    %edx,%r14d
  movzbl 0x17(%rbx),%edx
  mov    %r14w,-0x32(%rsp)
  add    $0xb,%r14d
  add    %edx,%edi
  imul   $0x4e35,%r14w,%r14w
  xor    %r8d,%edi
  imul   $0x15a,%di,%dx
  imul   $0x4e35,%di,%di
  add    %edx,%eax
  add    %eax,%r14d
  movzbl 0x19(%rbx),%eax
  add    $0x1,%edi
  shl    $0x8,%esi
  lea    0xc(%r14),%r13d
  shl    $0x8,%ecx
  shl    $0x8,%r11d
  add    %eax,%esi
  imul   $0x4e35,%r13w,%r13w
  xor    %edi,%esi
  imul   $0x15a,%si,%ax
  imul   $0x4e35,%si,%si
  add    %eax,%edx
  add    %edx,%r13d
  movzbl 0x1b(%rbx),%edx
  add    $0x1,%esi
  lea    0xd(%r13),%r12d
  add    %edx,%ecx
  imul   $0x4e35,%r12w,%r12w
  movzbl 0x1c(%rbx),%edx
  xor    %esi,%ecx
  imul   $0x15a,%cx,%r9w
  shl    $0x8,%edx
  imul   $0x4e35,%cx,%cx
  add    %r9d,%eax
  add    %eax,%r12d
  movzbl 0x1d(%rbx),%eax
  add    $0x1,%ecx
  lea    0xe(%r12),%ebp
  add    %eax,%edx
  imul   $0x4e35,%bp,%bp
  xor    %ecx,%edx
  imul   $0x15a,%dx,%ax
  imul   $0x4e35,%dx,%dx
  add    %eax,%r9d
  add    %r9d,%ebp
  movzbl 0x1f(%rbx),%r9d
  add    $0x1,%edx
  lea    0xf(%rbp),%r15d
  add    %r9d,%r11d
  xor    %edx,%r11d
  imul   $0x15a,%r11w,%r9w
  imul   $0x4e35,%r15w,%r15w
  imul   $0x4e35,%r11w,%r11w
  add    %r9d,%eax
  add    %eax,%r15d
  movzwl -0x38(%rsp),%eax
  xor    -0x36(%rsp),%ax
  xor    -0x3a(%rsp),%ax
  xor    -0x3c(%rsp),%ax
  add    $0x1,%r11d
  xor    -0x3e(%rsp),%ax
  xor    -0x40(%rsp),%ax
  xor    -0x42(%rsp),%ax
  xor    -0x44(%rsp),%ax
  xor    -0x46(%rsp),%ax
  xor    %r10d,%eax
  xor    %r8d,%eax
  xor    %edi,%eax
  xor    %esi,%eax
  xor    %ecx,%eax
  xor    %edx,%eax
  xor    %r11d,%eax
  xor    -0x1e(%rsp),%ax
  xor    -0x20(%rsp),%ax
  xor    -0x22(%rsp),%ax
  xor    -0x24(%rsp),%ax
  xor    -0x26(%rsp),%ax
  xor    -0x28(%rsp),%ax
  xor    -0x2a(%rsp),%ax
  xor    -0x2c(%rsp),%ax
  xor    -0x2e(%rsp),%ax
  xor    -0x30(%rsp),%ax
  xor    -0x32(%rsp),%ax
  mov    -0x10(%rsp),%ecx
  xor    %r14d,%eax
  xor    %r13d,%eax
  xor    %r12d,%eax
  xor    %ebp,%eax
  xor    %r15d,%eax
  mov    %eax,%edx
  movzbl %al,%eax
  shr    $0x8,%dx
  test   %ecx,%ecx
  je     L44
  movd   -0x1c(%rsp),%xmm0
  movdqu (%rbx),%xmm1
  movdqu 0x10(%rbx),%xmm3
  xor    %eax,%edx
  punpcklbw %xmm0,%xmm0
  xor    -0x34(%rsp),%dx
  punpcklwd %xmm0,%xmm0
  pshufd $0x0,%xmm0,%xmm0
  pxor   %xmm0,%xmm1
  pxor   %xmm3,%xmm0
  movups %xmm1,(%rbx)
  movups %xmm0,0x10(%rbx)
  jmp    L31
L1:
  mov    -0xc(%rsp),%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
int pc1_256(unsigned char *cle, unsigned char *data, int size, int decenc) {
  unsigned short ax, bx, cx, dx, si, tmp, x1a2, x1a0[16], res, i, inter, cfc, cfd, compte;
  short c;
  inline void pc1_256_code(void) {
    dx = x1a2 + i;
    ax = x1a0[i];
    cx = 0x015a;
    bx = 0x4e35;
    tmp = ax;
    ax = si;
    si = tmp;
    tmp = ax;
    ax = dx;
    dx = tmp;
    if (ax != 0) {
      ax = ax * bx;
    }
    tmp = ax;
    ax = cx;
    cx = tmp;
    if (ax != 0) {
      ax = ax * si;
      cx = ax + cx;
    }
    tmp = ax;
    ax = si;
    si = tmp;
    ax = ax * bx;
    dx = cx + dx;
    ax = ax + 1;
    x1a2 = dx;
    x1a0[i] = ax;
    res = ax ^ dx;
    i = i + 1;
  }
  inline void pc1_256_assemble(void) {
    x1a0[0] = (cle[0] * 256) + cle[1];
    pc1_256_code();
    inter = res;
    x1a0[1] = x1a0[0] ^ ((cle[2] * 256) + cle[3]);
    pc1_256_code();
    inter = inter ^ res;
    x1a0[2] = x1a0[1] ^ ((cle[4] * 256) + cle[5]);
    pc1_256_code();
    inter = inter ^ res;
    x1a0[3] = x1a0[2] ^ ((cle[6] * 256) + cle[7]);
    pc1_256_code();
    inter = inter ^ res;
    x1a0[4] = x1a0[3] ^ ((cle[8] * 256) + cle[9]);
    pc1_256_code();
    inter = inter ^ res;
    x1a0[5] = x1a0[4] ^ ((cle[10] * 256) + cle[11]);
    pc1_256_code();
    inter = inter ^ res;
    x1a0[6] = x1a0[5] ^ ((cle[12] * 256) + cle[13]);
    pc1_256_code();
    inter = inter ^ res;
    x1a0[7] = x1a0[6] ^ ((cle[14] * 256) + cle[15]);
    pc1_256_code();
    inter = inter ^ res;
    x1a0[8] = x1a0[7] ^ ((cle[16] * 256) + cle[17]);
    pc1_256_code();
    inter = inter ^ res;
    x1a0[9] = x1a0[8] ^ ((cle[18] * 256) + cle[19]);
    pc1_256_code();
    inter = inter ^ res;
    x1a0[10] = x1a0[9] ^ ((cle[20] * 256) + cle[21]);
    pc1_256_code();
    inter = inter ^ res;
    x1a0[11] = x1a0[10] ^ ((cle[22] * 256) + cle[23]);
    pc1_256_code();
    inter = inter ^ res;
    x1a0[12] = x1a0[11] ^ ((cle[24] * 256) + cle[25]);
    pc1_256_code();
    inter = inter ^ res;
    x1a0[13] = x1a0[12] ^ ((cle[26] * 256) + cle[27]);
    pc1_256_code();
    inter = inter ^ res;
    x1a0[14] = x1a0[13] ^ ((cle[28] * 256) + cle[29]);
    pc1_256_code();
    inter = inter ^ res;
    x1a0[15] = x1a0[14] ^ ((cle[30] * 256) + cle[31]);
    pc1_256_code();
    inter = inter ^ res;
    i = 0;
  }
  si = 0;
  x1a2 = 0;
  i = 0;
  int cnt;
  for (cnt = 0; cnt < size; cnt++) {
    c = data[cnt];
    pc1_256_assemble();
    cfc = inter >> 8;
    cfd = inter & 255;
    if (!decenc)
      c = c ^ (cfc ^ cfd);
    for (compte = 0; compte <= 31; compte++) {
      cle[compte] = cle[compte] ^ c;
    }
    if (decenc)
      c = c ^ (cfc ^ cfd);
    data[cnt] = c;
  }
  return (size);
}
```