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

```asm
<mc_murmur32>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x40,%rsp
  mov    %rdi,-0x38(%rbp)
  mov    %esi,-0x3c(%rbp)
  mov    %edx,-0x40(%rbp)
  mov    -0x38(%rbp),%rax
  mov    %rax,-0x18(%rbp)
  mov    -0x3c(%rbp),%eax
  lea    0x3(%rax),%edx
  test   %eax,%eax
  cmovs  %edx,%eax
  sar    $0x2,%eax
  mov    %eax,-0x24(%rbp)
  mov    -0x40(%rbp),%eax
  mov    %eax,-0x2c(%rbp)
  movl   $0xcc9e2d51,-0x20(%rbp)
  movl   $0x1b873593,-0x1c(%rbp)
  mov    -0x24(%rbp),%eax
  shl    $0x2,%eax
  movslq %eax,%rdx
  mov    -0x18(%rbp),%rax
  add    %rdx,%rax
  mov    %rax,-0x10(%rbp)
  mov    -0x24(%rbp),%eax
  neg    %eax
  mov    %eax,-0x30(%rbp)
  jmp    L65
L56:
  mov    -0x30(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x10(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%eax
  mov    %eax,-0x28(%rbp)
  mov    -0x28(%rbp),%eax
  imul   -0x20(%rbp),%eax
  mov    %eax,-0x28(%rbp)
  roll   $0xf,-0x28(%rbp)
  mov    -0x28(%rbp),%eax
  imul   -0x1c(%rbp),%eax
  mov    %eax,-0x28(%rbp)
  mov    -0x28(%rbp),%eax
  xor    %eax,-0x2c(%rbp)
  roll   $0xd,-0x2c(%rbp)
  mov    -0x2c(%rbp),%edx
  mov    %edx,%eax
  shl    $0x2,%eax
  add    %edx,%eax
  sub    $0x19ab949c,%eax
  mov    %eax,-0x2c(%rbp)
  addl   $0x1,-0x30(%rbp)
L65:
  cmpl   $0x0,-0x30(%rbp)
  jne    L56
  mov    -0x24(%rbp),%eax
  shl    $0x2,%eax
  movslq %eax,%rdx
  mov    -0x18(%rbp),%rax
  add    %rdx,%rax
  mov    %rax,-0x8(%rbp)
  movl   $0x0,-0x28(%rbp)
  mov    -0x3c(%rbp),%eax
  and    $0x3,%eax
  cmp    $0x3,%eax
  je     L37
  cmp    $0x3,%eax
  jg     L29
  cmp    $0x1,%eax
  je     L28
  cmp    $0x2,%eax
  je     L10
  jmp    L29
L37:
  mov    -0x8(%rbp),%rax
  add    $0x2,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  shl    $0x10,%eax
  xor    %eax,-0x28(%rbp)
L10:
  mov    -0x8(%rbp),%rax
  add    $0x1,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  shl    $0x8,%eax
  xor    %eax,-0x28(%rbp)
L28:
  mov    -0x8(%rbp),%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  xor    %eax,-0x28(%rbp)
  mov    -0x28(%rbp),%eax
  imul   -0x20(%rbp),%eax
  mov    %eax,-0x28(%rbp)
  roll   $0xf,-0x28(%rbp)
  mov    -0x28(%rbp),%eax
  imul   -0x1c(%rbp),%eax
  mov    %eax,-0x28(%rbp)
  mov    -0x28(%rbp),%eax
  xor    %eax,-0x2c(%rbp)
L29:
  mov    -0x3c(%rbp),%eax
  xor    %eax,-0x2c(%rbp)
  mov    -0x2c(%rbp),%eax
  mov    %eax,%edi
  call   <_fmix32@plt>
  mov    %eax,-0x2c(%rbp)
  mov    -0x2c(%rbp),%eax
  leave
  ret
```

assistant: ```c
unsigned int mc_murmur32(const void *key, int len, unsigned int seed) {
  const unsigned char *data = (const unsigned char *)key;
  const int nblocks = len / 4;
  int i;
  unsigned int h1 = seed;
  unsigned int k1;
  const unsigned int c1 = 0xcc9e2d51;
  const unsigned int c2 = 0x1b873593;
  const unsigned int *blocks = (const unsigned int *)(data + nblocks * 4);
  const unsigned char *tail;
  for (i = -nblocks; i; ++i) {
    k1 = blocks[i];
    k1 *= c1;
    k1 = (k1 << 15) | (k1 >> (32 - 15));
    k1 *= c2;
    h1 ^= k1;
    h1 = (h1 << 13) | (h1 >> (32 - 13));
    h1 = h1 * 5 + 0xe6546b64;
  }
  tail = (const unsigned char *)(data + nblocks * 4);
  k1 = 0;
  switch (len & 3) {
  case 3:
    k1 ^= tail[2] << 16;
  case 2:
    k1 ^= tail[1] << 8;
  case 1:
    k1 ^= tail[0];
    k1 *= c1;
    k1 = (k1 << 15) | (k1 >> (32 - 15));
    k1 *= c2;
    h1 ^= k1;
  }
  h1 ^= len;
  h1 = _fmix32(h1);
  return h1;
}
```