user: 请将这段汇编代码片段转换成等效的C代码：

```asm
<ff_dm_quad>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x98,%rsp
  mov    %rdi,0x60(%rsp)
  mov    %esi,0x2c(%rsp)
  mov    %rdx,0x40(%rsp)
  movsd  %xmm0,0x30(%rsp)
  mov    0xd0(%rsp),%rax
  mov    %rax,0x48(%rsp)
  mov    0xd8(%rsp),%rax
  mov    %rax,0x50(%rsp)
  mov    %fs:0x28,%rax
  mov    %rax,0x88(%rsp)
  xor    %eax,%eax
  test   %rdi,%rdi
  je     L103
  mov    %r9,%r14
  lea    0x18(%rdx),%rax
  mov    %rax,0x58(%rsp)
  lea    0x0(,%rdi,8),%rax
  mov    %rax,0x68(%rsp)
  lea    (%r8,%rax,1),%r12
  lea    (%rcx,%rax,1),%r15
  mov    $0x0,%r13d
  pxor   %xmm7,%xmm7
  movsd  %xmm7,0x10(%rsp)
  mov    %r12,%rbp
  jmp    L88
L65:
  lea    0x70(%rsp),%rdx
  mov    %r12,%rsi
  mov    0x20(%rsp),%rdi
  call   <distance_delta@plt>
  movapd %xmm0,%xmm1
L93:
  movapd %xmm1,%xmm2
  subsd  0x8(%rsp),%xmm2
  movsd  0x18(%rsp),%xmm5
  movapd %xmm5,%xmm0
  movsd  0x30(%rsp),%xmm4
  mulsd  %xmm4,%xmm0
  mulsd  %xmm2,%xmm0
  mulsd  %xmm2,%xmm0
  addsd  0x10(%rsp),%xmm0
  movsd  %xmm0,0x10(%rsp)
  test   %r14,%r14
  je     L86
  movapd %xmm4,%xmm0
  addsd  %xmm4,%xmm0
  mulsd  %xmm5,%xmm0
  mulsd  %xmm2,%xmm0
  lea    0x70(%rsp),%rcx
  divsd  %xmm1,%xmm0
  mov    %r14,%r8
  mov    0x40(%rsp),%rdx
  mov    %rbx,%rsi
  mov    0x38(%rsp),%rdi
  call   <add_grad@plt>
L86:
  lea    0x1(%rbx),%rax
  add    $0x18,%r12
  cmp    %rbx,%r13
  je     L42
  mov    %rax,%rbx
L34:
  movsd  (%r15,%rbx,8),%xmm3
  movsd  %xmm3,0x8(%rsp)
  comisd D3(%rip),%xmm3
  jbe    L86
  movsd  0x0(%rbp,%rbx,8),%xmm6
  movsd  %xmm6,0x18(%rsp)
  cmpl   $0x0,0x2c(%rsp)
  je     L65
  lea    0x70(%rsp),%rdx
  mov    0x50(%rsp),%r8
  mov    0x48(%rsp),%rcx
  mov    %r12,%rsi
  mov    0x20(%rsp),%rdi
  call   <distance_delta_periodic@plt>
  movapd %xmm0,%xmm1
  jmp    L93
L42:
  addq   $0x18,0x58(%rsp)
  mov    0x68(%rsp),%rax
  add    %rax,%rbp
  add    %rax,%r15
  mov    0x38(%rsp),%r13
L88:
  lea    0x1(%r13),%rax
  mov    %rax,0x38(%rsp)
  cmp    %rax,0x60(%rsp)
  je     L107
  test   %rax,%rax
  je     L42
  mov    0x58(%rsp),%rax
  mov    %rax,0x20(%rsp)
  mov    0x40(%rsp),%r12
  mov    $0x0,%ebx
  jmp    L34
L103:
  pxor   %xmm7,%xmm7
  movsd  %xmm7,0x10(%rsp)
L107:
  mov    0x88(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L1
  movsd  0x10(%rsp),%xmm0
  add    $0x98,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L1:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: disassemble_data
arguments: data_tag: D3
datatype: f64

tool: D3: 0

assistant: ```c
double ff_dm_quad(size_t natom, int periodic, double *cor, double *dm0, double *dmk, double amp, double *gradient, double *matrix, double *reciprocal) {
  size_t i, j;
  double delta[3], d, d0, k, tmp, result;
  result = 0.0;
  for (i = 0; i < natom; i++) {
    for (j = 0; j < i; j++) {
      d0 = dm0[i * natom + j];
      k = dmk[i * natom + j];
      if (d0 > 0) {
        if (periodic) {
          d = distance_delta_periodic(cor + 3 * i, cor + 3 * j, delta, matrix, reciprocal);
        } else {
          d = distance_delta(cor + 3 * i, cor + 3 * j, delta);
        }
        tmp = (d - d0);
        result += amp * k * tmp * tmp;
        if (gradient != NULL) {
          tmp = 2 * amp * k * tmp / d;
          add_grad(i, j, tmp, cor, delta, gradient);
        }
      }
    }
  }
  return result;
}
```