user: 这段汇编代码用C语言表示是什么样的:

```asm
<stdlib_strided_dnannsumkbn2>:
  endbr64
  movq   $0x0,(%rcx)
  test   %rdi,%rdi
  jle    L21
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x38,%rsp
  mov    %rdi,%r13
  mov    %rsi,%rbx
  mov    %rcx,%r14
  cmp    $0x1,%rdi
  je     L80
  test   %rdx,%rdx
  je     L80
  mov    $0x0,%eax
  js     L35
L47:
  lea    0x0(,%rdx,8),%rcx
  mov    %rcx,0x18(%rsp)
  lea    (%rbx,%rax,8),%r12
  pxor   %xmm5,%xmm5
  movsd  %xmm5,0x10(%rsp)
  mov    $0x0,%ebp
  movsd  %xmm5,0x28(%rsp)
  movsd  %xmm5,0x8(%rsp)
  jmp    L115
L80:
  movsd  (%rbx),%xmm0
  call   <stdlib_base_is_nan@plt>
  pxor   %xmm0,%xmm0
  test   %rax,%rax
  jne    L26
  addq   $0x1,(%r14)
  movsd  (%rbx),%xmm0
  jmp    L26
L35:
  mov    $0x1,%eax
  sub    %rdi,%rax
  imul   %rdx,%rax
  jmp    L47
L73:
  movq   %rbx,%xmm0
  subsd  0x20(%rsp),%xmm0
  addsd  0x8(%rsp),%xmm0
  movsd  %xmm0,0x8(%rsp)
  jmp    L48
L70:
  movsd  0x8(%rsp),%xmm0
  movq   %r15,%xmm4
  subsd  %xmm4,%xmm0
  addsd  0x10(%rsp),%xmm0
L101:
  addsd  0x28(%rsp),%xmm0
  movsd  %xmm0,0x28(%rsp)
  addq   $0x1,(%r14)
  mov    %r15,0x10(%rsp)
  movsd  0x20(%rsp),%xmm4
  movsd  %xmm4,0x8(%rsp)
L15:
  add    $0x1,%rbp
  add    0x18(%rsp),%r12
  cmp    %rbp,%r13
  je     L66
L115:
  mov    (%r12),%rbx
  movq   %rbx,%xmm0
  call   <stdlib_base_is_nan@plt>
  test   %rax,%rax
  jne    L15
  movq   %rbx,%xmm2
  movsd  0x8(%rsp),%xmm0
  addsd  %xmm0,%xmm2
  movsd  %xmm2,0x20(%rsp)
  call   <fabs@plt>
  mov    %rax,%r15
  movq   %rbx,%xmm0
  call   <fabs@plt>
  cmp    %rax,%r15
  jl     L73
  movsd  0x8(%rsp),%xmm0
  subsd  0x20(%rsp),%xmm0
  movq   %rbx,%xmm6
  addsd  %xmm0,%xmm6
  movsd  %xmm6,0x8(%rsp)
L48:
  movsd  0x8(%rsp),%xmm1
  movsd  0x10(%rsp),%xmm0
  addsd  %xmm0,%xmm1
  movq   %xmm1,%r15
  call   <fabs@plt>
  mov    %rax,%rbx
  movsd  0x8(%rsp),%xmm0
  call   <fabs@plt>
  cmp    %rax,%rbx
  jl     L70
  movsd  0x10(%rsp),%xmm7
  movq   %r15,%xmm3
  subsd  %xmm3,%xmm7
  movapd %xmm7,%xmm0
  addsd  0x8(%rsp),%xmm0
  jmp    L101
L66:
  movsd  0x8(%rsp),%xmm0
  addsd  0x10(%rsp),%xmm0
  addsd  0x28(%rsp),%xmm0
L26:
  add    $0x38,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L21:
  pxor   %xmm0,%xmm0
  ret
```

assistant: ```c
double stdlib_strided_dnannsumkbn2(const int64_t N, const double *X, const int64_t stride, int64_t *n) {
  double sum;
  double ccs;
  int64_t ix;
  int64_t i;
  double cs;
  double cc;
  double v;
  double t;
  double c;
  sum = 0.0;
  *n = 0;
  if (N <= 0) {
    return sum;
  }
  if (N == 1 || stride == 0) {
    if (stdlib_base_is_nan(X[0])) {
      return sum;
    }
    *n += 1;
    return X[0];
  }
  if (stride < 0) {
    ix = (1 - N) * stride;
  } else {
    ix = 0;
  }
  ccs = 0.0;
  cs = 0.0;
  for (i = 0; i < N; i++) {
    v = X[ix];
    if (!stdlib_base_is_nan(v)) {
      t = sum + v;
      if (fabs(sum) >= fabs(v)) {
        c = (sum - t) + v;
      } else {
        c = (v - t) + sum;
      }
      sum = t;
      t = cs + c;
      if (fabs(cs) >= fabs(c)) {
        cc = (cs - t) + c;
      } else {
        cc = (c - t) + cs;
      }
      cs = t;
      ccs += cc;
      *n += 1;
    }
    ix += stride;
  }
  return sum + cs + ccs;
}
```