user: What would the C source look like for the assembly code provided here:

```asm
<bn_mul_high>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x38,%rsp
  mov    %rdi,%r12
  mov    %rsi,%rdi
  mov    %rsi,0x28(%rsp)
  mov    %rdx,0x10(%rsp)
  mov    %rcx,0x8(%rsp)
  mov    %r8d,%r13d
  mov    %r9,%r14
  mov    %r8d,%ebp
  shr    $0x1f,%ebp
  add    %r8d,%ebp
  sar    %ebp
  movslq %ebp,%rbx
  shl    $0x3,%rbx
  lea    (%rsi,%rbx,1),%rax
  mov    %rax,0x18(%rsp)
  mov    %ebp,%edx
  mov    %rax,%rsi
  call   <bn_cmp_words@plt>
  mov    %eax,%r15d
  mov    0x10(%rsp),%rsi
  lea    (%rsi,%rbx,1),%rax
  mov    %rax,0x20(%rsp)
  mov    %ebp,%edx
  mov    %rax,%rdi
  call   <bn_cmp_words@plt>
  mov    %eax,%edx
  lea    (%r15,%r15,2),%eax
  add    %edx,%eax
  cmp    $0x2,%eax
  je     L200
  jg     L340
  cmp    $0xfffffffc,%eax
  je     L39
  cmp    $0xfffffffe,%eax
  jne    L173
  mov    %ebp,%ecx
  mov    0x28(%rsp),%rdx
  mov    0x18(%rsp),%rsi
  mov    %r12,%rdi
  call   <bn_sub_words@plt>
  lea    (%r12,%rbx,1),%rdi
  mov    %ebp,%ecx
  mov    0x10(%rsp),%rdx
  mov    0x20(%rsp),%rsi
  call   <bn_sub_words@plt>
  movl   $0x1,0x10(%rsp)
  jmp    L329
L173:
  movl   $0x0,0x10(%rsp)
  jmp    L329
L340:
  cmp    $0x4,%eax
  jne    L118
  mov    %ebp,%ecx
  mov    0x18(%rsp),%rdx
  mov    0x28(%rsp),%rsi
  mov    %r12,%rdi
  call   <bn_sub_words@plt>
  lea    (%r12,%rbx,1),%rdi
  mov    %ebp,%ecx
  mov    0x10(%rsp),%rdx
  mov    0x20(%rsp),%rsi
  call   <bn_sub_words@plt>
  movl   $0x0,0x10(%rsp)
  jmp    L329
L118:
  movl   $0x0,0x10(%rsp)
L329:
  cmp    $0x8,%ebp
  je     L113
  movslq %r13d,%rax
  lea    (%r14,%rax,8),%r15
  lea    (%r12,%rbx,1),%rdx
  mov    %r15,%r8
  mov    %ebp,%ecx
  mov    %r12,%rsi
  mov    %r14,%rdi
  call   <bn_mul_recursive@plt>
  mov    %r15,%r8
  mov    %ebp,%ecx
  mov    0x20(%rsp),%rdx
  mov    0x18(%rsp),%rsi
  mov    %r12,%rdi
  call   <bn_mul_recursive@plt>
L243:
  mov    %r12,%r15
  mov    0x8(%rsp),%rdx
  test   %rdx,%rdx
  je     L27
  lea    0x0(%r13,%rbp,1),%eax
  cltq
  lea    (%r14,%rax,8),%r15
  mov    %ebp,%ecx
  mov    %r12,%rsi
  mov    %r15,%rdi
  call   <bn_add_words@plt>
L27:
  cmpl   $0x0,0x10(%rsp)
  je     L283
  movslq %r13d,%rax
  lea    (%r14,%rax,8),%rdi
  mov    %ebp,%ecx
  mov    %r14,%rdx
  mov    %r15,%rsi
  call   <bn_sub_words@plt>
L249:
  mov    0x8(%rsp),%rdi
  test   %rdi,%rdi
  je     L347
  movslq %r13d,%rax
  lea    (%r14,%rax,8),%r10
  lea    0x0(%r13,%rbp,1),%eax
  cltq
  lea    (%r14,%rax,8),%r15
  lea    (%rdi,%rbx,1),%rsi
  mov    %ebp,%ecx
  mov    %r10,0x18(%rsp)
  mov    %r10,%rdx
  mov    %r15,%rdi
  call   <bn_sub_words@plt>
  mov    %ebp,%ecx
  mov    0x8(%rsp),%rdx
  mov    %r15,%rsi
  mov    0x18(%rsp),%rdi
  call   <bn_add_words@plt>
  mov    %eax,0x8(%rsp)
L6:
  movslq %r13d,%rax
  lea    (%r14,%rax,8),%r15
  mov    %ebp,%ecx
  mov    %r12,%rdx
  mov    0x18(%rsp),%rsi
  mov    %r15,%rdi
  call   <bn_add_words@plt>
  add    0x8(%rsp),%eax
  mov    %eax,0x8(%rsp)
  cmpl   $0x0,0x10(%rsp)
  je     L22
  mov    %ebp,%ecx
  mov    %r14,%rdx
  mov    %r15,%rsi
  mov    %r15,%rdi
  call   <bn_sub_words@plt>
  mov    0x8(%rsp),%r15d
  sub    %eax,%r15d
  add    %ebp,%r13d
  movslq %r13d,%r13
  lea    (%r14,%r13,8),%rdx
  mov    %ebp,%ecx
  mov    %r12,%rsi
  mov    %r12,%rdi
  call   <bn_add_words@plt>
  mov    %rax,%r13
  lea    (%r12,%rbx,1),%rdx
  mov    %ebp,%ecx
  mov    %r12,%rsi
  mov    %r12,%rdi
  call   <bn_add_words@plt>
  add    %eax,%r13d
  lea    (%r14,%rbx,1),%rdx
  mov    %ebp,%ecx
  mov    %r12,%rsi
  mov    %r12,%rdi
  call   <bn_sub_words@plt>
  mov    %rax,%rdx
  mov    %r13d,%eax
  sub    %edx,%eax
L226:
  test   %r15d,%r15d
  je     L75
  jle    L264
  movslq %r15d,%r15
  mov    %r12,%rdx
  mov    $0x1,%esi
  jmp    L99
L39:
  mov    %ebp,%ecx
  mov    0x28(%rsp),%rdx
  mov    0x18(%rsp),%rsi
  mov    %r12,%rdi
  call   <bn_sub_words@plt>
  lea    (%r12,%rbx,1),%rdi
  mov    %ebp,%ecx
  mov    0x20(%rsp),%rdx
  mov    0x10(%rsp),%rsi
  call   <bn_sub_words@plt>
  movl   $0x0,0x10(%rsp)
  jmp    L329
L200:
  mov    %ebp,%ecx
  mov    0x18(%rsp),%rdx
  mov    0x28(%rsp),%rsi
  mov    %r12,%rdi
  call   <bn_sub_words@plt>
  lea    (%r12,%rbx,1),%rdi
  mov    %ebp,%ecx
  mov    0x20(%rsp),%rdx
  mov    0x10(%rsp),%rsi
  call   <bn_sub_words@plt>
  movl   $0x1,0x10(%rsp)
  jmp    L329
L113:
  lea    (%r12,%rbx,1),%rdx
  mov    %r12,%rsi
  mov    %r14,%rdi
  call   <bn_mul_comba8@plt>
  mov    0x20(%rsp),%rdx
  mov    0x18(%rsp),%rsi
  mov    %r12,%rdi
  call   <bn_mul_comba8@plt>
  jmp    L243
L283:
  movslq %r13d,%rax
  lea    (%r14,%rax,8),%rdi
  mov    %ebp,%ecx
  mov    %r14,%rdx
  mov    %r15,%rsi
  call   <bn_add_words@plt>
  jmp    L249
L347:
  lea    0x0(%r13,%rbp,1),%edi
  movslq %edi,%rdi
  movslq %r13d,%rax
  cmp    $0x1,%r13d
  jle    L263
  lea    (%r14,%rax,8),%rsi
  lea    (%r14,%rdi,8),%rcx
  mov    $0x0,%eax
L343:
  mov    (%rsi,%rax,8),%rdx
  neg    %rdx
  mov    %rdx,(%rcx,%rax,8)
  add    $0x1,%rax
  cmp    %eax,%ebp
  jg     L343
L263:
  lea    (%r14,%rdi,8),%rax
  mov    %rax,0x18(%rsp)
  movl   $0x0,0x8(%rsp)
  jmp    L6
L22:
  mov    %ebp,%ecx
  mov    %r14,%rdx
  mov    %r15,%rsi
  mov    %r15,%rdi
  call   <bn_add_words@plt>
  mov    0x8(%rsp),%r15d
  add    %eax,%r15d
  add    %ebp,%r13d
  movslq %r13d,%r13
  lea    (%r14,%r13,8),%rdx
  mov    %ebp,%ecx
  mov    %r12,%rsi
  mov    %r12,%rdi
  call   <bn_add_words@plt>
  mov    %rax,%r13
  lea    (%r12,%rbx,1),%rdx
  mov    %ebp,%ecx
  mov    %r12,%rsi
  mov    %r12,%rdi
  call   <bn_add_words@plt>
  add    %eax,%r13d
  lea    (%r14,%rbx,1),%rdx
  mov    %ebp,%ecx
  mov    %r12,%rsi
  mov    %r12,%rdi
  call   <bn_add_words@plt>
  add    %r13d,%eax
  jmp    L226
L57:
  mov    %rsi,%r15
L99:
  mov    %r15,%rcx
  add    (%rdx),%rcx
  mov    %rcx,(%rdx)
  add    $0x8,%rdx
  cmp    %rcx,%r15
  ja     L57
L75:
  test   %eax,%eax
  je     L52
  jle    L315
  cltq
  add    %r12,%rbx
  mov    $0x1,%ecx
  jmp    L106
L264:
  neg    %r15d
  movslq %r15d,%r15
  mov    %r12,%rdx
  mov    $0x1,%edi
  jmp    L180
L332:
  mov    %rdi,%r15
L180:
  mov    (%rdx),%rcx
  mov    %rcx,%rsi
  sub    %r15,%rsi
  mov    %rsi,(%rdx)
  add    $0x8,%rdx
  cmp    %rcx,%r15
  ja     L332
  jmp    L75
L45:
  mov    %rcx,%rax
L106:
  mov    %rax,%rdx
  add    (%rbx),%rdx
  mov    %rdx,(%rbx)
  add    $0x8,%rbx
  cmp    %rdx,%rax
  ja     L45
L52:
  add    $0x38,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L315:
  neg    %eax
  cltq
  add    %r12,%rbx
  mov    $0x1,%esi
  jmp    L111
L335:
  mov    %rsi,%rax
L111:
  mov    (%rbx),%rdx
  mov    %rdx,%rcx
  sub    %rax,%rcx
  mov    %rcx,(%rbx)
  add    $0x8,%rbx
  cmp    %rdx,%rax
  ja     L335
  jmp    L52
```

assistant: ```c
void bn_mul_high(unsigned long long *r, unsigned long long *a, unsigned long long *b, unsigned long long *l, int n2, unsigned long long *t) {
  int i, n;
  int c1, c2;
  int neg, oneg, zero;
  unsigned long long ll, lc, *lp, *mp;
  n = n2 / 2;
  neg = zero = 0;
  c1 = bn_cmp_words(&(a[0]), &(a[n]), n);
  c2 = bn_cmp_words(&(b[n]), &(b[0]), n);
  switch (c1 * 3 + c2) {
  case -4:
    bn_sub_words(&(r[0]), &(a[n]), &(a[0]), n);
    bn_sub_words(&(r[n]), &(b[0]), &(b[n]), n);
    break;
  case -3:
    zero = 1;
    break;
  case -2:
    bn_sub_words(&(r[0]), &(a[n]), &(a[0]), n);
    bn_sub_words(&(r[n]), &(b[n]), &(b[0]), n);
    neg = 1;
    break;
  case -1:
  case 0:
  case 1:
    zero = 1;
    break;
  case 2:
    bn_sub_words(&(r[0]), &(a[0]), &(a[n]), n);
    bn_sub_words(&(r[n]), &(b[0]), &(b[n]), n);
    neg = 1;
    break;
  case 3:
    zero = 1;
    break;
  case 4:
    bn_sub_words(&(r[0]), &(a[0]), &(a[n]), n);
    bn_sub_words(&(r[n]), &(b[n]), &(b[0]), n);
    break;
  }
  oneg = neg;
  if (n == 8) {
    bn_mul_comba8(&(t[0]), &(r[0]), &(r[n]));
    bn_mul_comba8(r, &(a[n]), &(b[n]));
  } else {
    bn_mul_recursive(&(t[0]), &(r[0]), &(r[n]), n, &(t[n2]));
    bn_mul_recursive(r, &(a[n]), &(b[n]), n, &(t[n2]));
  }
  if (l != NULL) {
    lp = &(t[n2 + n]);
    c1 = (int)(bn_add_words(lp, &(r[0]), &(l[0]), n));
  } else {
    c1 = 0;
    lp = &(r[0]);
  }
  if (neg)
    neg = (int)(bn_sub_words(&(t[n2]), lp, &(t[0]), n));
  else {
    bn_add_words(&(t[n2]), lp, &(t[0]), n);
    neg = 0;
  }
  if (l != NULL) {
    bn_sub_words(&(t[n2 + n]), &(l[n]), &(t[n2]), n);
  } else {
    lp = &(t[n2 + n]);
    mp = &(t[n2]);
    for (i = 0; i < n; i++)
      lp[i] = ((~mp[i]) + 1) & (0xffffffffffffffffLL);
  }
  if (l != NULL) {
    lp = &(t[n2]);
    c1 = (int)(bn_add_words(lp, &(t[n2 + n]), &(l[0]), n));
  } else {
    lp = &(t[n2 + n]);
    c1 = 0;
  }
  c1 += (int)(bn_add_words(&(t[n2]), lp, &(r[0]), n));
  if (oneg)
    c1 -= (int)(bn_sub_words(&(t[n2]), &(t[n2]), &(t[0]), n));
  else
    c1 += (int)(bn_add_words(&(t[n2]), &(t[n2]), &(t[0]), n));
  c2 = (int)(bn_add_words(&(r[0]), &(r[0]), &(t[n2 + n]), n));
  c2 += (int)(bn_add_words(&(r[0]), &(r[0]), &(r[n]), n));
  if (oneg)
    c2 -= (int)(bn_sub_words(&(r[0]), &(r[0]), &(t[n]), n));
  else
    c2 += (int)(bn_add_words(&(r[0]), &(r[0]), &(t[n]), n));
  if (c1 != 0) {
    i = 0;
    if (c1 > 0) {
      lc = c1;
      do {
        ll = (r[i] + lc) & (0xffffffffffffffffLL);
        r[i++] = ll;
        lc = (lc > ll);
      } while (lc);
    } else {
      lc = -c1;
      do {
        ll = r[i];
        r[i++] = (ll - lc) & (0xffffffffffffffffLL);
        lc = (lc > ll);
      } while (lc);
    }
  }
  if (c2 != 0) {
    i = n;
    if (c2 > 0) {
      lc = c2;
      do {
        ll = (r[i] + lc) & (0xffffffffffffffffLL);
        r[i++] = ll;
        lc = (lc > ll);
      } while (lc);
    } else {
      lc = -c2;
      do {
        ll = r[i];
        r[i++] = (ll - lc) & (0xffffffffffffffffLL);
        lc = (lc > ll);
      } while (lc);
    }
  }
}
```