user: What is the c source code of the assembly code below:

```asm
<jhash2>:
  endbr64
  cmp    $0x2,%esi
  jle    L20
  mov    %esi,%r8d
  mov    $0x9e3779b9,%eax
  mov    $0x9e3779b9,%ecx
L37:
  add    (%rdi),%ecx
  add    0x4(%rdi),%eax
  add    0x8(%rdi),%edx
  sub    %eax,%ecx
  sub    %edx,%ecx
  mov    %edx,%r9d
  sar    $0xd,%r9d
  xor    %ecx,%r9d
  sub    %edx,%eax
  sub    %r9d,%eax
  mov    %eax,%ecx
  mov    %r9d,%eax
  shl    $0x8,%eax
  xor    %ecx,%eax
  sub    %r9d,%edx
  sub    %eax,%edx
  mov    %eax,%ecx
  sar    $0xd,%ecx
  xor    %ecx,%edx
  sub    %eax,%r9d
  sub    %edx,%r9d
  mov    %edx,%ecx
  sar    $0xc,%ecx
  xor    %r9d,%ecx
  sub    %edx,%eax
  sub    %ecx,%eax
  mov    %eax,%r9d
  mov    %ecx,%eax
  shl    $0x10,%eax
  xor    %r9d,%eax
  sub    %ecx,%edx
  sub    %eax,%edx
  mov    %edx,%r9d
  mov    %eax,%edx
  sar    $0x5,%edx
  xor    %r9d,%edx
  sub    %eax,%ecx
  sub    %edx,%ecx
  mov    %ecx,%r9d
  mov    %edx,%ecx
  sar    $0x3,%ecx
  xor    %r9d,%ecx
  sub    %edx,%eax
  sub    %ecx,%eax
  mov    %eax,%r9d
  mov    %ecx,%eax
  shl    $0xa,%eax
  xor    %r9d,%eax
  sub    %ecx,%edx
  sub    %eax,%edx
  mov    %edx,%r9d
  mov    %eax,%edx
  sar    $0xf,%edx
  xor    %r9d,%edx
  add    $0xc,%rdi
  sub    $0x3,%r8d
  cmp    $0x2,%r8d
  jg     L37
L36:
  lea    (%rdx,%rsi,4),%esi
  cmp    $0x1,%r8d
  je     L28
  cmp    $0x2,%r8d
  jne    L40
  add    0x4(%rdi),%eax
L28:
  add    (%rdi),%ecx
L40:
  sub    %eax,%ecx
  sub    %esi,%ecx
  mov    %esi,%edx
  sar    $0xd,%edx
  xor    %edx,%ecx
  sub    %esi,%eax
  sub    %ecx,%eax
  mov    %ecx,%edx
  shl    $0x8,%edx
  xor    %edx,%eax
  sub    %ecx,%esi
  sub    %eax,%esi
  mov    %eax,%edx
  sar    $0xd,%edx
  xor    %esi,%edx
  sub    %eax,%ecx
  mov    %ecx,%esi
  sub    %edx,%esi
  mov    %edx,%ecx
  sar    $0xc,%ecx
  xor    %esi,%ecx
  sub    %edx,%eax
  sub    %ecx,%eax
  mov    %eax,%esi
  mov    %ecx,%eax
  shl    $0x10,%eax
  xor    %esi,%eax
  sub    %ecx,%edx
  mov    %edx,%esi
  sub    %eax,%esi
  mov    %eax,%edx
  sar    $0x5,%edx
  xor    %esi,%edx
  sub    %eax,%ecx
  sub    %edx,%ecx
  mov    %edx,%esi
  sar    $0x3,%esi
  xor    %ecx,%esi
  sub    %edx,%eax
  sub    %esi,%eax
  mov    %esi,%ecx
  shl    $0xa,%ecx
  xor    %ecx,%eax
  sub    %esi,%edx
  sub    %eax,%edx
  sar    $0xf,%eax
  xor    %edx,%eax
  ret
L20:
  mov    %esi,%r8d
  mov    $0x9e3779b9,%eax
  mov    $0x9e3779b9,%ecx
  jmp    L36
```

assistant: ```c
__u32 jhash2(__u32 *k, __u32 length, __u32 initval) {
  __u32 a, b, c, len;
  a = b = 0x9e3779b9;
  c = initval;
  len = length;
  while (len >= 3) {
    a += k[0];
    b += k[1];
    c += k[2];
    {
      a -= b;
      a -= c;
      a ^= (c >> 13);
      b -= c;
      b -= a;
      b ^= (a << 8);
      c -= a;
      c -= b;
      c ^= (b >> 13);
      a -= b;
      a -= c;
      a ^= (c >> 12);
      b -= c;
      b -= a;
      b ^= (a << 16);
      c -= a;
      c -= b;
      c ^= (b >> 5);
      a -= b;
      a -= c;
      a ^= (c >> 3);
      b -= c;
      b -= a;
      b ^= (a << 10);
      c -= a;
      c -= b;
      c ^= (b >> 15);
    };
    k += 3;
    len -= 3;
  }
  c += length * 4;
  switch (len) {
  case 2:
    b += k[1];
  case 1:
    a += k[0];
  };
  {
    a -= b;
    a -= c;
    a ^= (c >> 13);
    b -= c;
    b -= a;
    b ^= (a << 8);
    c -= a;
    c -= b;
    c ^= (b >> 13);
    a -= b;
    a -= c;
    a ^= (c >> 12);
    b -= c;
    b -= a;
    b ^= (a << 16);
    c -= a;
    c -= b;
    c ^= (b >> 5);
    a -= b;
    a -= c;
    a ^= (c >> 3);
    b -= c;
    b -= a;
    b ^= (a << 10);
    c -= a;
    c -= b;
    c ^= (b >> 15);
  };
  return c;
}
```