user: 请显示与下面列出的汇编代码相匹配的C语言实现：

```asm
<rtrend>:
  endbr64
  mov    %rdi,%rdx
  mov    %esi,%ecx
  test   %esi,%esi
  jle    L6
  pxor   %xmm2,%xmm2
  movslq %esi,%rsi
  xor    %eax,%eax
  movapd %xmm2,%xmm6
  xchg   %ax,%ax
L82:
  pxor   %xmm0,%xmm0
  movss  (%rdx,%rax,4),%xmm1
  cvtsi2ss %eax,%xmm0
  add    $0x1,%rax
  mulss  %xmm1,%xmm0
  cvtss2sd %xmm1,%xmm1
  addsd  %xmm1,%xmm2
  cvtss2sd %xmm0,%xmm0
  addsd  %xmm0,%xmm6
  cmp    %rsi,%rax
  jne    L82
L84:
  pxor   %xmm5,%xmm5
  movsd  D17(%rip),%xmm1
  lea    -0x1(%rcx),%eax
  pxor   %xmm0,%xmm0
  cvtsi2sd %ecx,%xmm5
  lea    -0x1(%rcx,%rcx,1),%esi
  pxor   %xmm4,%xmm4
  cvtsi2sd %eax,%xmm0
  cvtsi2sd %esi,%xmm4
  mulsd  %xmm5,%xmm1
  mulsd  %xmm1,%xmm0
  movapd %xmm5,%xmm1
  mulsd  %xmm6,%xmm5
  mulsd  %xmm0,%xmm4
  movapd %xmm0,%xmm7
  mulsd  %xmm0,%xmm7
  divsd  D29(%rip),%xmm4
  mulsd  %xmm4,%xmm1
  mulsd  %xmm2,%xmm4
  subsd  %xmm7,%xmm1
  movapd %xmm0,%xmm7
  mulsd  %xmm2,%xmm7
  mulsd  %xmm6,%xmm0
  subsd  %xmm7,%xmm5
  subsd  %xmm0,%xmm4
  divsd  %xmm1,%xmm5
  divsd  %xmm1,%xmm4
  test   %ecx,%ecx
  jle    L21
  cmp    $0x2,%eax
  jbe    L35
  mov    %ecx,%esi
  movapd %xmm5,%xmm7
  movapd %xmm4,%xmm6
  mov    %rdx,%rax
  shr    $0x2,%esi
  movdqa D16(%rip),%xmm2
  unpcklpd %xmm7,%xmm7
  unpcklpd %xmm6,%xmm6
  movdqa D10(%rip),%xmm8
  sub    $0x1,%esi
  shl    $0x4,%rsi
  lea    0x10(%rdx,%rsi,1),%rsi
  nopl   0x0(%rax,%rax,1)
L75:
  movdqa %xmm2,%xmm1
  movlps 0x8(%rax),%xmm3
  cvtps2pd (%rax),%xmm0
  add    $0x10,%rax
  cvtdq2pd %xmm1,%xmm9
  pshufd $0xee,%xmm1,%xmm1
  paddd  %xmm8,%xmm2
  mulpd  %xmm7,%xmm9
  cvtdq2pd %xmm1,%xmm1
  mulpd  %xmm7,%xmm1
  subpd  %xmm9,%xmm0
  cvtps2pd %xmm3,%xmm9
  subpd  %xmm1,%xmm9
  subpd  %xmm6,%xmm0
  movapd %xmm9,%xmm1
  subpd  %xmm6,%xmm1
  cvtpd2ps %xmm0,%xmm0
  cvtpd2ps %xmm1,%xmm1
  movlhps %xmm1,%xmm0
  movups %xmm0,-0x10(%rax)
  cmp    %rax,%rsi
  jne    L75
  mov    %ecx,%eax
  and    $0xfffffffc,%eax
  test   $0x3,%cl
  je     L99
L3:
  pxor   %xmm1,%xmm1
  movslq %eax,%rsi
  pxor   %xmm0,%xmm0
  cvtsi2sd %eax,%xmm1
  shl    $0x2,%rsi
  lea    (%rdx,%rsi,1),%rdi
  cvtss2sd (%rdi),%xmm0
  mulsd  %xmm5,%xmm1
  subsd  %xmm1,%xmm0
  subsd  %xmm4,%xmm0
  cvtsd2ss %xmm0,%xmm0
  movss  %xmm0,(%rdi)
  lea    0x1(%rax),%edi
  cmp    %edi,%ecx
  jle    L21
  pxor   %xmm1,%xmm1
  lea    0x4(%rdx,%rsi,1),%r8
  pxor   %xmm0,%xmm0
  add    $0x2,%eax
  cvtsi2sd %edi,%xmm1
  cvtss2sd (%r8),%xmm0
  mulsd  %xmm5,%xmm1
  subsd  %xmm1,%xmm0
  subsd  %xmm4,%xmm0
  cvtsd2ss %xmm0,%xmm0
  movss  %xmm0,(%r8)
  cmp    %eax,%ecx
  jle    L21
  pxor   %xmm1,%xmm1
  lea    0x8(%rdx,%rsi,1),%rdx
  pxor   %xmm0,%xmm0
  cvtsi2sd %eax,%xmm1
  cvtss2sd (%rdx),%xmm0
  mulsd  %xmm5,%xmm1
  subsd  %xmm1,%xmm0
  subsd  %xmm4,%xmm0
  cvtsd2ss %xmm0,%xmm0
  movss  %xmm0,(%rdx)
L21:
  ret
  nopw   0x0(%rax,%rax,1)
L99:
  ret
  nopl   0x0(%rax)
L6:
  pxor   %xmm2,%xmm2
  movapd %xmm2,%xmm6
  jmp    L84
L35:
  xor    %eax,%eax
  jmp    L3
```

tool_calls: name: unpack_data
arguments: data_label: D17
datatype: f64
name: unpack_data
arguments: data_label: D29
datatype: f64
name: unpack_data
arguments: data_label: D16
datatype: f32[4]
name: unpack_data
arguments: data_label: D10
datatype: byte[16]

tool: D17: 0.5

tool: D29: 3

tool: {"D16": [0.0,1.401298464324817e-45,2.802596928649634e-45,4.203895392974451e-45]}

tool: {"D10": [0x04,0x00,0x00,0x00,0x04,0x00,0x00,0x00,0x04,0x00,0x00,0x00,0x04,0x00,0x00,0x00]}

assistant: ```c
void rtrend(float *y, int n) {
  int i;
  double a, b, a11, a12, a22, y1, y2;
  y1 = y2 = 0.;
  for (i = 0; i < n; i++) {
    y1 += i * y[i];
    y2 += y[i];
  }
  a12 = 0.5 * n * (n - 1);
  a11 = a12 * (2 * n - 1) / 3.;
  a22 = n;
  b = a11 * a22 - a12 * a12;
  a = (a22 * y1 - a12 * y2) / b;
  b = (a11 * y2 - a12 * y1) / b;
  for (i = 0; i < n; i++) {
    y[i] = y[i] - a * i - b;
  }
}
```