user: Demonstrate the C code that generates the assembly output below:

```asm
<byteprocess>:
  endbr64
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  mov    %rdi,%r9
  mov    %rsi,%rdi
  mov    %rdx,%rbp
  mov    %ecx,%ebx
  cmp    $0x1,%r8d
  je     L63
  movslq %r8d,%rax
  imul   $0x2aaaaaab,%rax,%rax
  shr    $0x20,%rax
  mov    %r8d,%edx
  sar    $0x1f,%edx
  sub    %edx,%eax
  lea    (%rax,%rax,2),%eax
  add    %eax,%eax
  cmp    %eax,%r8d
  jne    L90
  mov    (%rsi),%eax
  lea    0x1(%rax),%edx
  mov    %edx,(%rsi)
  cltq
  movl   $0x39c,(%r9,%rax,4)
L102:
  test   %r8d,%r8d
  jle    L113
  movslq %ebx,%rax
  lea    0x0(%rbp,%rax,8),%r12
  mov    $0x0,%r10d
  movabs $0x48d159e26af37c05,%r11
  jmp    L33
L63:
  mov    (%rsi),%eax
  lea    0x1(%rax),%edx
  mov    %edx,(%rsi)
  cltq
  movl   $0x391,(%r9,%rax,4)
  movslq %ecx,%rbx
  mov    0x0(%rbp,%rbx,8),%rdx
  mov    (%rsi),%eax
  lea    0x1(%rax),%ecx
  mov    %ecx,(%rsi)
  cltq
  mov    %edx,(%r9,%rax,4)
  jmp    L113
L90:
  mov    (%rsi),%eax
  lea    0x1(%rax),%edx
  mov    %edx,(%rsi)
  cltq
  movl   $0x385,(%r9,%rax,4)
  jmp    L102
L118:
  add    $0x6,%r10d
  mov    %r12,%rdx
  mov    $0x28,%ecx
  mov    $0x0,%esi
L26:
  mov    (%rdx),%rax
  shl    %cl,%rax
  or     %rax,%rsi
  add    $0x8,%rdx
  sub    $0x8,%ecx
  cmp    $0xfffffff8,%ecx
  jne    L26
  mov    $0x4,%ecx
L75:
  mov    %ecx,%r13d
  add    (%rdi),%r13d
  mov    %rsi,%rdx
  shr    $0x2,%rdx
  mov    %rdx,%rax
  mul    %r11
  shr    $0x6,%rdx
  imul   $0x384,%rdx,%rax
  sub    %rax,%rsi
  mov    %esi,(%r9,%r13,4)
  mov    %rdx,%rsi
  sub    $0x1,%ecx
  cmp    $0xffffffff,%ecx
  jne    L75
  addl   $0x5,(%rdi)
  add    $0x30,%r12
  cmp    %r10d,%r8d
  jle    L113
L33:
  lea    (%rbx,%r10,1),%edx
  mov    %r8d,%eax
  sub    %r10d,%eax
  cmp    $0x5,%eax
  ja     L118
  lea    -0x1(%rax),%ecx
  test   %eax,%eax
  je     L113
  movslq %edx,%rax
  lea    0x0(%rbp,%rax,8),%rdx
  mov    %ecx,%ecx
  add    %rax,%rcx
  lea    0x8(%rbp,%rcx,8),%r8
L70:
  mov    (%rdx),%rcx
  mov    (%rdi),%eax
  lea    0x1(%rax),%esi
  mov    %esi,(%rdi)
  cltq
  mov    %ecx,(%r9,%rax,4)
  add    $0x8,%rdx
  cmp    %r8,%rdx
  jne    L70
L113:
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
```

assistant: ```c
void byteprocess(int *chainemc, int *mclength, uint8_t chaine[], int start, int length, int block) {
  int debug = 0;
  int len = 0;
  unsigned int chunkLen = 0;
  uint64_t mantisa = 0ULL;
  uint64_t total = 0ULL;
  if (debug)
    printf("\nEntering byte mode at position %d\n", start);
  if (length == 1) {
    chainemc[(*mclength)++] = 913;
    chainemc[(*mclength)++] = chaine[start];
    if (debug) {
      printf("913 %d\n", chainemc[*mclength - 1]);
    }
  } else {
    if (length % 6 == 0) {
      chainemc[(*mclength)++] = 924;
      if (debug)
        printf("924 ");
    } else {
      chainemc[(*mclength)++] = 901;
      if (debug)
        printf("901 ");
    }
    while (len < length) {
      chunkLen = length - len;
      if (6 <= chunkLen) {
        chunkLen = 6;
        len += chunkLen;
        total = 0ULL;
        while (chunkLen--) {
          mantisa = chaine[start++];
          total |= mantisa << (uint64_t)(chunkLen * 8ULL);
        }
        chunkLen = 5;
        while (chunkLen--) {
          chainemc[*mclength + chunkLen] = (int)(total % 900ULL);
          total /= 900ULL;
        }
        *mclength += 5;
      } else {
        len += chunkLen;
        while (chunkLen--) {
          chainemc[(*mclength)++] = chaine[start++];
        }
      }
    }
  }
}
```