user: 下面的汇编指令对应的C源代码是什么:

```asm
<bn_mul_words>:
  endbr64
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x8,%rsp
  mov    %rdi,%rbp
  mov    %rsi,%r12
  mov    %edx,%ebx
  mov    %rcx,%r13
  mov    %edx,%edi
  not    %edi
  shr    $0x1f,%edi
  call   <assert@plt>
  mov    $0x0,%eax
  test   %ebx,%ebx
  jle    L47
  mov    %r13d,%edi
  mov    %r13,%rsi
  shr    $0x20,%rsi
  mov    $0x0,%edx
  movabs $0x100000000,%r8
  jmp    L31
L84:
  mov    %r9,%r10
  shr    $0x20,%r10
  shl    $0x20,%r9
  add    %r9,%rcx
  adc    %r10,%rdx
  add    %rax,%rcx
  adc    $0x0,%rdx
  mov    %rcx,0x18(%rbp)
  sub    $0x4,%ebx
  je     L78
  add    $0x20,%r12
  add    $0x20,%rbp
L31:
  mov    (%r12),%rax
  mov    %eax,%ecx
  shr    $0x20,%rax
  mov    %rsi,%r9
  imul   %rcx,%r9
  imul   %rdi,%rcx
  mov    %rdi,%r10
  imul   %rax,%r10
  imul   %rsi,%rax
  add    %r10,%r9
  jae    L76
  add    %r8,%rax
L76:
  mov    %r9,%r10
  shr    $0x20,%r10
  shl    $0x20,%r9
  add    %r9,%rcx
  adc    %r10,%rax
  add    %rdx,%rcx
  adc    $0x0,%rax
  mov    %rcx,0x0(%rbp)
  cmp    $0x1,%ebx
  je     L47
  mov    0x8(%r12),%rdx
  mov    %edx,%ecx
  shr    $0x20,%rdx
  mov    %rsi,%r9
  imul   %rcx,%r9
  imul   %rdi,%rcx
  mov    %rdi,%r10
  imul   %rdx,%r10
  imul   %rsi,%rdx
  add    %r10,%r9
  jae    L95
  add    %r8,%rdx
L95:
  mov    %r9,%r10
  shr    $0x20,%r10
  shl    $0x20,%r9
  add    %r9,%rcx
  adc    %r10,%rdx
  add    %rax,%rcx
  adc    $0x0,%rdx
  mov    %rcx,0x8(%rbp)
  cmp    $0x2,%ebx
  je     L29
  mov    0x10(%r12),%rax
  mov    %eax,%ecx
  shr    $0x20,%rax
  mov    %rsi,%r9
  imul   %rcx,%r9
  imul   %rdi,%rcx
  mov    %rdi,%r10
  imul   %rax,%r10
  imul   %rsi,%rax
  add    %r10,%r9
  jae    L42
  add    %r8,%rax
L42:
  mov    %r9,%r10
  shr    $0x20,%r10
  shl    $0x20,%r9
  add    %r9,%rcx
  adc    %r10,%rax
  add    %rdx,%rcx
  adc    $0x0,%rax
  mov    %rcx,0x10(%rbp)
  cmp    $0x3,%ebx
  je     L47
  mov    0x18(%r12),%rdx
  mov    %edx,%ecx
  shr    $0x20,%rdx
  mov    %rsi,%r9
  imul   %rcx,%r9
  imul   %rdi,%rcx
  mov    %rdi,%r10
  imul   %rdx,%r10
  imul   %rsi,%rdx
  add    %r10,%r9
  jae    L84
  add    %r8,%rdx
  jmp    L84
L29:
  mov    %rdx,%rax
L47:
  add    $0x8,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
L78:
  mov    %rdx,%rax
  jmp    L47
```

assistant: ```c
unsigned long long bn_mul_words(unsigned long long *rp, unsigned long long *ap, int num, unsigned long long w) {
  unsigned long long carry = 0;
  unsigned long long bl, bh;
  assert(num >= 0);
  if (num <= 0)
    return ((unsigned long long)0);
  bl = ((w) & (0xffffffffL));
  bh = (((w) >> 32) & (0xffffffffL));
  for (;;) {
    {
      unsigned long long l, h;
      h = (ap[0]);
      l = ((h) & (0xffffffffL));
      h = (((h) >> 32) & (0xffffffffL));
      {
        unsigned long long m, m1, lt, ht;
        lt = l;
        ht = h;
        m = ((bh)) * (lt);
        lt = ((bl)) * (lt);
        m1 = ((bl)) * (ht);
        ht = ((bh)) * (ht);
        m = (m + m1) & (0xffffffffffffffffLL);
        if (m < m1)
          ht += ((unsigned long long)((1L) & (0xffffffffL)) << 32);
        ht += (((m) >> 32) & (0xffffffffL));
        m1 = ((unsigned long long)((m) & (0xffffffffL)) << 32);
        lt = (lt + m1) & (0xffffffffffffffffLL);
        if (lt < m1)
          ht++;
        (l) = lt;
        (h) = ht;
      };
      l += (carry);
      if ((l & (0xffffffffffffffffLL)) < (carry))
        h++;
      (carry) = h & (0xffffffffffffffffLL);
      (rp[0]) = l & (0xffffffffffffffffLL);
    };
    if (--num == 0)
      break;
    {
      unsigned long long l, h;
      h = (ap[1]);
      l = ((h) & (0xffffffffL));
      h = (((h) >> 32) & (0xffffffffL));
      {
        unsigned long long m, m1, lt, ht;
        lt = l;
        ht = h;
        m = ((bh)) * (lt);
        lt = ((bl)) * (lt);
        m1 = ((bl)) * (ht);
        ht = ((bh)) * (ht);
        m = (m + m1) & (0xffffffffffffffffLL);
        if (m < m1)
          ht += ((unsigned long long)((1L) & (0xffffffffL)) << 32);
        ht += (((m) >> 32) & (0xffffffffL));
        m1 = ((unsigned long long)((m) & (0xffffffffL)) << 32);
        lt = (lt + m1) & (0xffffffffffffffffLL);
        if (lt < m1)
          ht++;
        (l) = lt;
        (h) = ht;
      };
      l += (carry);
      if ((l & (0xffffffffffffffffLL)) < (carry))
        h++;
      (carry) = h & (0xffffffffffffffffLL);
      (rp[1]) = l & (0xffffffffffffffffLL);
    };
    if (--num == 0)
      break;
    {
      unsigned long long l, h;
      h = (ap[2]);
      l = ((h) & (0xffffffffL));
      h = (((h) >> 32) & (0xffffffffL));
      {
        unsigned long long m, m1, lt, ht;
        lt = l;
        ht = h;
        m = ((bh)) * (lt);
        lt = ((bl)) * (lt);
        m1 = ((bl)) * (ht);
        ht = ((bh)) * (ht);
        m = (m + m1) & (0xffffffffffffffffLL);
        if (m < m1)
          ht += ((unsigned long long)((1L) & (0xffffffffL)) << 32);
        ht += (((m) >> 32) & (0xffffffffL));
        m1 = ((unsigned long long)((m) & (0xffffffffL)) << 32);
        lt = (lt + m1) & (0xffffffffffffffffLL);
        if (lt < m1)
          ht++;
        (l) = lt;
        (h) = ht;
      };
      l += (carry);
      if ((l & (0xffffffffffffffffLL)) < (carry))
        h++;
      (carry) = h & (0xffffffffffffffffLL);
      (rp[2]) = l & (0xffffffffffffffffLL);
    };
    if (--num == 0)
      break;
    {
      unsigned long long l, h;
      h = (ap[3]);
      l = ((h) & (0xffffffffL));
      h = (((h) >> 32) & (0xffffffffL));
      {
        unsigned long long m, m1, lt, ht;
        lt = l;
        ht = h;
        m = ((bh)) * (lt);
        lt = ((bl)) * (lt);
        m1 = ((bl)) * (ht);
        ht = ((bh)) * (ht);
        m = (m + m1) & (0xffffffffffffffffLL);
        if (m < m1)
          ht += ((unsigned long long)((1L) & (0xffffffffL)) << 32);
        ht += (((m) >> 32) & (0xffffffffL));
        m1 = ((unsigned long long)((m) & (0xffffffffL)) << 32);
        lt = (lt + m1) & (0xffffffffffffffffLL);
        if (lt < m1)
          ht++;
        (l) = lt;
        (h) = ht;
      };
      l += (carry);
      if ((l & (0xffffffffffffffffLL)) < (carry))
        h++;
      (carry) = h & (0xffffffffffffffffLL);
      (rp[3]) = l & (0xffffffffffffffffLL);
    };
    if (--num == 0)
      break;
    ap += 4;
    rp += 4;
  }
  return (carry);
}
```