user: 下面的汇编指令对应的C源代码是什么：

```asm
<relax>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x68,%rsp
  mov    %rsi,0x8(%rsp)
  mov    0xb0(%rsp),%esi
  mov    0xa0(%rsp),%r10
  test   %esi,%esi
  jle    L79
  mov    %rdx,%rsi
  mov    %rdi,%r12
  mov    %rcx,%rdx
  xor    %r11d,%r11d
  pxor   %xmm3,%xmm3
  xchg   %ax,%ax
L53:
  mov    0xa8(%rsp),%eax
  mov    0x8(%rsp),%rbp
  xor    %ebx,%ebx
  movslq 0xa8(%rsp),%rdi
  test   %eax,%eax
  jg     L48
  jmp    L11
  nop
L19:
  comisd %xmm0,%xmm4
  jbe    L47
  movapd %xmm4,%xmm0
L51:
  subsd  %xmm0,%xmm4
  add    $0x10,%rbp
  divsd  %xmm0,%xmm4
  movsd  (%rdx,%rbx,8),%xmm0
  mulsd  %xmm4,%xmm2
  mulsd  %xmm4,%xmm1
  mulsd  %xmm2,%xmm0
  subsd  %xmm0,%xmm5
  movsd  %xmm5,(%rax)
  movsd  (%rdx,%rbx,8),%xmm4
  movsd  (%r15),%xmm0
  mulsd  %xmm1,%xmm4
  subsd  %xmm4,%xmm0
  movsd  %xmm0,(%r15)
  mulsd  (%rsi,%rbx,8),%xmm2
  addsd  (%r14),%xmm2
  movsd  %xmm2,(%r14)
  mulsd  (%rsi,%rbx,8),%xmm1
  add    $0x1,%rbx
  addsd  0x0(%r13),%xmm1
  movsd  %xmm1,0x0(%r13)
  cmp    %rdi,%rbx
  je     L11
L48:
  mov    0x0(%rbp),%eax
  lea    (%rax,%rax,1),%ecx
  movslq %ecx,%rcx
  shl    $0x3,%rcx
  lea    (%r12,%rcx,1),%rax
  lea    0x8(%r12,%rcx,1),%r15
  mov    0x8(%rbp),%ecx
  movsd  (%rax),%xmm5
  add    %ecx,%ecx
  movslq %ecx,%rcx
  shl    $0x3,%rcx
  lea    (%r12,%rcx,1),%r14
  lea    0x8(%r12,%rcx,1),%r13
  movsd  (%r14),%xmm2
  movsd  0x0(%r13),%xmm1
  subsd  (%r15),%xmm1
  subsd  %xmm5,%xmm2
  movapd %xmm1,%xmm4
  mulsd  %xmm1,%xmm4
  movapd %xmm2,%xmm0
  mulsd  %xmm2,%xmm0
  addsd  %xmm4,%xmm0
  ucomisd %xmm0,%xmm3
  ja     L21
  sqrtsd %xmm0,%xmm0
L67:
  cmpb   $0x0,(%r9,%rbx,1)
  movsd  (%r8,%rbx,8),%xmm4
  movzbl (%r10,%rbx,1),%ecx
  je     L19
L47:
  test   %cl,%cl
  jne    L51
  movapd %xmm4,%xmm6
  minsd  %xmm0,%xmm6
  movapd %xmm6,%xmm0
  jmp    L51
  nopw   0x0(%rax,%rax,1)
L11:
  add    $0x1,%r11d
  cmp    %r11d,0xb0(%rsp)
  jne    L53
L79:
  add    $0x68,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L21:
  mov    %r10,0xa0(%rsp)
  mov    %r9,0x58(%rsp)
  mov    %r8,0x50(%rsp)
  mov    %rdx,0x48(%rsp)
  mov    %rsi,0x40(%rsp)
  mov    %rdi,0x38(%rsp)
  mov    %r11d,0x34(%rsp)
  mov    %rax,0x10(%rsp)
  movsd  %xmm1,0x28(%rsp)
  movsd  %xmm2,0x20(%rsp)
  movsd  %xmm5,0x18(%rsp)
  call   <sqrt@plt>
  mov    0x58(%rsp),%r9
  mov    0x50(%rsp),%r8
  pxor   %xmm3,%xmm3
  mov    0xa0(%rsp),%r10
  mov    0x48(%rsp),%rdx
  mov    0x40(%rsp),%rsi
  mov    0x38(%rsp),%rdi
  mov    0x34(%rsp),%r11d
  movsd  0x28(%rsp),%xmm1
  movsd  0x20(%rsp),%xmm2
  movsd  0x18(%rsp),%xmm5
  mov    0x10(%rsp),%rax
  jmp    L67
```

assistant: ```c
void relax(double *pos, long *links, double *mrel1, double *mrel2, double *lengths, char *push, char *pull, int nlinks, int iters) {
  int i, l, p1, p2;
  double x1, x2, y1, y2, dx, dy, dist, change;
  for (i = 0; i < iters; i++) {
    for (l = 0; l < nlinks; l++) {
      p1 = 2 * links[l * 2];
      p2 = 2 * links[l * 2 + 1];
      x1 = pos[p1];
      y1 = pos[p1 + 1];
      x2 = pos[p2];
      y2 = pos[p2 + 1];
      dx = x2 - x1;
      dy = y2 - y1;
      dist = sqrt(dx * dx + dy * dy);
      if (push[l] == 0 && dist < lengths[l])
        dist = lengths[l];
      if (pull[l] == 0 && dist > lengths[l])
        dist = lengths[l];
      change = (lengths[l] - dist) / dist;
      dx *= change;
      dy *= change;
      pos[p1] -= mrel2[l] * dx;
      pos[p1 + 1] -= mrel2[l] * dy;
      pos[p2] += mrel1[l] * dx;
      pos[p2 + 1] += mrel1[l] * dy;
    }
  }
}
```