user: 提供的汇编代码用C语言表示会是什么样子：

```asm
<linreg>:
  endbr64
  sub    $0x28,%rsp
  mov    %edx,%r10d
  movsd  (%rsi),%xmm6
  movq   $0x0,(%r8)
  test   %edx,%edx
  jle    L46
  mov    %edx,%edx
  mov    $0x0,%eax
  pxor   %xmm5,%xmm5
  movapd %xmm5,%xmm1
  movapd %xmm5,%xmm2
L59:
  addsd  (%rdi,%rax,8),%xmm2
  movsd  (%rsi,%rax,8),%xmm0
  addsd  %xmm0,%xmm1
  movapd %xmm0,%xmm7
  minsd  %xmm6,%xmm7
  movapd %xmm7,%xmm6
  maxsd  %xmm5,%xmm0
  movapd %xmm0,%xmm5
  add    $0x1,%rax
  cmp    %rdx,%rax
  jne    L59
  pxor   %xmm7,%xmm7
  cvtsi2sd %r10d,%xmm7
  movapd %xmm2,%xmm3
  divsd  %xmm7,%xmm3
  movapd %xmm1,%xmm4
  divsd  %xmm7,%xmm4
  mov    0x38(%rsp),%rax
  movsd  %xmm4,(%rax)
  movsd  %xmm6,(%r9)
  mov    0x30(%rsp),%rax
  movsd  %xmm0,(%rax)
  mov    $0x0,%eax
  pxor   %xmm5,%xmm5
L71:
  movsd  (%rdi,%rax,8),%xmm0
  subsd  %xmm3,%xmm0
  movapd %xmm0,%xmm6
  mulsd  %xmm0,%xmm6
  addsd  %xmm6,%xmm5
  mulsd  (%rsi,%rax,8),%xmm0
  addsd  (%r8),%xmm0
  movsd  %xmm0,(%r8)
  add    $0x1,%rax
  cmp    %rdx,%rax
  jne    L71
  divsd  %xmm5,%xmm0
  movsd  %xmm0,(%r8)
  mulsd  %xmm0,%xmm2
  subsd  %xmm2,%xmm1
  divsd  %xmm7,%xmm1
  movsd  %xmm1,(%rcx)
  mov    $0x0,%eax
  pxor   %xmm2,%xmm2
  movsd  %xmm2,0x8(%rsp)
  movsd  %xmm2,0x10(%rsp)
L44:
  movsd  (%rdi,%rax,8),%xmm1
  subsd  %xmm3,%xmm1
  movsd  (%rsi,%rax,8),%xmm0
  subsd  %xmm4,%xmm0
  movapd %xmm1,%xmm5
  mulsd  %xmm0,%xmm5
  addsd  0x10(%rsp),%xmm5
  movsd  %xmm5,0x10(%rsp)
  mulsd  %xmm1,%xmm1
  addsd  %xmm1,%xmm2
  mulsd  %xmm0,%xmm0
  addsd  0x8(%rsp),%xmm0
  movsd  %xmm0,0x8(%rsp)
  add    $0x1,%rax
  cmp    %rdx,%rax
  jne    L44
  pxor   %xmm0,%xmm0
  ucomisd %xmm2,%xmm0
  ja     L84
L52:
  sqrtsd %xmm2,%xmm2
  movsd  %xmm2,0x18(%rsp)
L28:
  pxor   %xmm0,%xmm0
  movsd  0x8(%rsp),%xmm4
  ucomisd %xmm4,%xmm0
  ja     L75
  sqrtsd %xmm4,%xmm4
  movapd %xmm4,%xmm0
L86:
  mulsd  0x18(%rsp),%xmm0
  movsd  0x10(%rsp),%xmm1
  divsd  %xmm0,%xmm1
  mov    0x40(%rsp),%rax
  movsd  %xmm1,(%rax)
  add    $0x28,%rsp
  ret
L84:
  movapd %xmm2,%xmm0
  call   <sqrt@plt>
  movsd  %xmm0,0x18(%rsp)
  jmp    L28
L75:
  movsd  0x8(%rsp),%xmm0
  call   <sqrt@plt>
  jmp    L86
L46:
  pxor   %xmm3,%xmm3
  cvtsi2sd %edx,%xmm3
  pxor   %xmm0,%xmm0
  movapd %xmm0,%xmm1
  divsd  %xmm3,%xmm1
  mov    0x38(%rsp),%rax
  movsd  %xmm1,(%rax)
  movsd  %xmm6,(%r9)
  mov    0x30(%rsp),%rax
  movq   $0x0,(%rax)
  movsd  (%r8),%xmm1
  divsd  %xmm0,%xmm1
  movsd  %xmm1,(%r8)
  mulsd  %xmm0,%xmm1
  movapd %xmm0,%xmm2
  subsd  %xmm1,%xmm2
  divsd  %xmm3,%xmm2
  movsd  %xmm2,(%rcx)
  movsd  %xmm0,0x8(%rsp)
  movapd %xmm0,%xmm2
  movsd  %xmm0,0x10(%rsp)
  jmp    L52
```

assistant: ```c
void linreg(double *x, double *y, int nitems, double *a, double *b, double *minp, double *maxp, double *meanp, double *r) {
  double sx = 0.0;
  double sy = 0.0;
  double st2 = 0.0;
  double min = y[0];
  double max = 0.0;
  double ss, meanx, meany, t;
  double errx, erry, prodsum, sqerrx, sqerry;
  int i;
  *b = 0.0;
  for (i = 0; i < nitems; i++) {
    sx += x[i];
    sy += y[i];
    if (y[i] < min)
      min = y[i];
    if (y[i] > max)
      max = y[i];
  }
  ss = nitems;
  meanx = sx / ss;
  meany = *meanp = sy / ss;
  *minp = min;
  *maxp = max;
  for (i = 0; i < nitems; i++) {
    t = x[i] - meanx;
    st2 += t * t;
    *b += t * y[i];
  }
  *b /= st2;
  *a = (sy - sx * (*b)) / ss;
  prodsum = 0.0;
  sqerrx = 0.0;
  sqerry = 0.0;
  for (i = 0; i < nitems; i++) {
    errx = x[i] - meanx;
    erry = y[i] - meany;
    prodsum += errx * erry;
    sqerrx += errx * errx;
    sqerry += erry * erry;
  }
  *r = prodsum / (sqrt(sqerrx) * sqrt(sqerry));
}
```