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

```asm
<qd_sqr>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  mov    %rdi,%rbx
  sub    $0x88,%rsp
  movsd  (%rbx),%xmm0
  mov    %rsi,0x8(%rsp)
  lea    0x48(%rsp),%r14
  lea    0x50(%rsp),%r12
  mov    %r14,%rdi
  lea    0x60(%rsp),%r15
  lea    0x68(%rsp),%rbp
  lea    0x70(%rsp),%r13
  mov    %fs:0x28,%rax
  mov    %rax,0x78(%rsp)
  xor    %eax,%eax
  call   <dd_two_sqr@plt>
  movsd  0x8(%rbx),%xmm1
  mov    %r12,%rdi
  movsd  %xmm0,0x18(%rsp)
  movsd  (%rbx),%xmm0
  addsd  %xmm0,%xmm0
  call   <dd_two_prod@plt>
  movsd  0x10(%rbx),%xmm1
  lea    0x58(%rsp),%rdi
  movsd  %xmm0,0x20(%rsp)
  movsd  (%rbx),%xmm0
  addsd  %xmm0,%xmm0
  call   <dd_two_prod@plt>
  mov    %r15,%rdi
  movsd  %xmm0,0x28(%rsp)
  movsd  0x8(%rbx),%xmm0
  call   <dd_two_sqr@plt>
  movsd  0x20(%rsp),%xmm1
  mov    %r14,%rdi
  movsd  %xmm0,0x30(%rsp)
  movsd  0x48(%rsp),%xmm0
  call   <dd_two_sum@plt>
  movsd  0x50(%rsp),%xmm1
  mov    %r12,%rdi
  lea    0x30(%rsp),%r12
  movsd  %xmm0,0x20(%rsp)
  movsd  0x48(%rsp),%xmm0
  call   <dd_two_sum@plt>
  movsd  0x30(%rsp),%xmm1
  mov    %r12,%rdi
  movsd  %xmm0,0x48(%rsp)
  movsd  0x28(%rsp),%xmm0
  call   <dd_two_sum@plt>
  mov    %rbp,%rdi
  movapd %xmm0,%xmm1
  movsd  %xmm0,0x28(%rsp)
  movsd  0x48(%rsp),%xmm0
  call   <dd_two_sum@plt>
  movsd  0x30(%rsp),%xmm1
  mov    %r13,%rdi
  movsd  %xmm0,(%rsp)
  movsd  0x50(%rsp),%xmm0
  call   <dd_two_sum@plt>
  movsd  0x68(%rsp),%xmm1
  mov    %rbp,%rdi
  call   <dd_two_sum@plt>
  movsd  0x68(%rsp),%xmm1
  mov    %rbp,%rdi
  addsd  0x70(%rsp),%xmm1
  movsd  %xmm1,0x68(%rsp)
  call   <dd_quick_two_sum@plt>
  movsd  (%rsp),%xmm2
  mov    %r13,%rdi
  movapd %xmm0,%xmm1
  movapd %xmm2,%xmm0
  call   <dd_quick_two_sum@plt>
  movsd  0x68(%rsp),%xmm1
  mov    %r14,%rdi
  movsd  %xmm0,0x28(%rsp)
  movsd  0x70(%rsp),%xmm0
  call   <dd_quick_two_sum@plt>
  movsd  0x8(%rbx),%xmm1
  lea    0x40(%rsp),%rdi
  movsd  %xmm0,0x30(%rsp)
  movsd  (%rbx),%xmm0
  addsd  %xmm1,%xmm1
  mulsd  0x10(%rbx),%xmm1
  addsd  %xmm0,%xmm0
  mulsd  0x18(%rbx),%xmm0
  lea    0x38(%rsp),%rbx
  movsd  %xmm1,0x40(%rsp)
  movsd  %xmm0,0x38(%rsp)
  call   <dd_two_sum@plt>
  movsd  0x60(%rsp),%xmm1
  mov    %r15,%rdi
  movsd  %xmm0,0x38(%rsp)
  movsd  0x58(%rsp),%xmm0
  call   <dd_two_sum@plt>
  mov    %r13,%rdi
  movapd %xmm0,%xmm1
  movsd  %xmm0,0x58(%rsp)
  movsd  0x38(%rsp),%xmm0
  call   <dd_two_sum@plt>
  movsd  0x70(%rsp),%xmm2
  mov    %rbx,%rdi
  addsd  0x40(%rsp),%xmm2
  addsd  0x60(%rsp),%xmm2
  movapd %xmm0,%xmm1
  movsd  %xmm0,0x68(%rsp)
  movsd  0x30(%rsp),%xmm0
  movsd  %xmm2,0x70(%rsp)
  call   <dd_two_sum@plt>
  lea    0x28(%rsp),%rdx
  mov    %rbx,%r8
  mov    %r12,%rcx
  movsd  %xmm0,0x30(%rsp)
  lea    0x20(%rsp),%rsi
  lea    0x18(%rsp),%rdi
  movsd  0x38(%rsp),%xmm0
  addsd  0x48(%rsp),%xmm0
  addsd  0x70(%rsp),%xmm0
  movsd  %xmm0,0x38(%rsp)
  call   <qd_renorm5@plt>
  movupd 0x28(%rsp),%xmm0
  movupd 0x18(%rsp),%xmm1
  mov    0x8(%rsp),%r9
  movups %xmm1,(%r9)
  movups %xmm0,0x10(%r9)
  mov    0x78(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L0
  add    $0x88,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L0:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
void qd_sqr(const double *a, double *b) {
  double p0, p1, p2, p3, p4, p5;
  double q0, q1, q2, q3;
  double s0, s1, t0, t1;
  p0 = dd_two_sqr(a[0], &q0);
  p1 = dd_two_prod(2.0 * a[0], a[1], &q1);
  p2 = dd_two_prod(2.0 * a[0], a[2], &q2);
  p3 = dd_two_sqr(a[1], &q3);
  p1 = dd_two_sum(q0, p1, &q0);
  q0 = dd_two_sum(q0, q1, &q1);
  p2 = dd_two_sum(p2, p3, &p3);
  s0 = dd_two_sum(q0, p2, &t0);
  s1 = dd_two_sum(q1, p3, &t1);
  s1 = dd_two_sum(s1, t0, &t0);
  t0 += t1;
  s1 = dd_quick_two_sum(s1, t0, &t0);
  p2 = dd_quick_two_sum(s0, s1, &t1);
  p3 = dd_quick_two_sum(t1, t0, &q0);
  p4 = 2.0 * a[0] * a[3];
  p5 = 2.0 * a[1] * a[2];
  p4 = dd_two_sum(p4, p5, &p5);
  q2 = dd_two_sum(q2, q3, &q3);
  t0 = dd_two_sum(p4, q2, &t1);
  t1 = t1 + p5 + q3;
  p3 = dd_two_sum(p3, t0, &p4);
  p4 = p4 + q0 + t1;
  qd_renorm5(&p0, &p1, &p2, &p3, &p4);
  b[0] = p0;
  b[1] = p1;
  b[2] = p2;
  b[3] = p3;
}
```